Journal Institution of Locomotive Engineers
Volume 41 (1951)
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Journal No. 219
Warder, S.B. (Paper No.498).
Electric traction prospects for British Railways. 3-28. Disc.: 28-75 + 2 folding plates. 2 illus., 6 diagrs., 10 tables, 2 maps.
Note: appears to be duplicate Paper number: see also paper by Shields in previous Volume. Includes a map dated 1947 of lines which Southern Railway intended to electrify..
Fourth Ordinary General Meeting of the Session 1950-51 was held at the Institution of Mechanical Engineers, Storeys Gate, London, on Wednesday 13 December 1950 at 5.30 p.m., Mr. R. A. Riddles, C.B.E., President, occupying the chair. The President in introducing the Author of the Paper, said that Mr. Warder who was now Chief Officer, Electrical Engineering, Railway Executive, had had a unique opportunity of studying both electrical and mechanical engineering on British Railways, having been Electrical Engineer for the Southern Region and afterwards becoming Mechanical and Electrical Engineer for the Southern Region. In that way he had had the innermost secrets of mechanical engineering at his disposal, and from the Paper it would be found that he had made great use of them. No one was more fitted to write a Paper on this subject at the present time
Refers to then relatively small proportion of electrified railway track, as compared with steam, in Britain, when considered with corresponding proportions of steam and electric mileage in neighbouring continental temtories. The Southern Region of British Railways has, however, comparable mileages of steam and electrically operated train services, and having regard lo the information disclosed by the Report on Railway Electrification (1950), affords some useful comparisons in assessing some of the problem to be anticipated, if, and when, large scale electrification is embarked upon in other Regions. Details are given of the reduced operating cost of electrified services and some improvements are mentioned which will enable further reductions in annual operating costs to be obtained in the future.
The history of electric traction in this country would certainly support the rigid belief of historians that ,history always repeats itself. Following the WW1 there came in 1923 the amalgamation of the many separate railway companies into the four great groups. There was much agitation about the correct electrical system for traction in this country, and finally the Railway Electrification Committee of 1927 known as the Pringle Committee confirmed an earlier recommendation which led to regulations prescribed by the Railways (Standardisation of Electrification) Order 1932, whereby two standard voltages were permitted: namely, 1,500 Volts DC with overhead collection and 750 Volts DC with third rail collection. The creation of the Central Electricitv Board and the National Grid led to the appearance in 1931 of the Report on Main Line Electrification known as the Weir Report, which showed that extensive main line and suburban electrification would yield substantial returns on the invested capital. This Report, which was well received, caused the prospects of electric traction to soar, but apart from what was undertaken by the Southern Railway little was done. Meanwhile economic conditions in the country were worsening, and the railways, particularly in industrial areas, while feeling the full effect of dwindling traffic, now felt the increasing competition of road transport services. Under a Government scheme for assisting distressed areas and trade generally, the London and North Eastern Railway embarked in 1937 on two electrification schemes viz: Liverpool Street to Shenfield, Manchester-Sheffield and Wath; but within two years war had broken out again, causing these schemes to be suspended. Since the end of the war in 1945 the Railways have undergone another amalgamation as a consequence of the Nationalisation Act of 1948, and another Railway Electrification Committee was appointed to review the recommendations of the Pringle Report in the light of present day advances in the art of electric traction. Meanwhile traffic receipts continue to fall, and road transport still wins traffic from the railways.
In March, British electric traction engineers, together with a number of engineers from neighbouring countries in Europe, attended a three day convention at the Institution of Electrical Engineers; when some 30 papers were read designed to illustrate the achievements of this country in the electric traction field, but the time proved to be too short to do full justice to the formidable capabilities of British engineers and the British electrical industry, which were revealed. It was of course natural for an electrical audience to be ' electrified ' by its own achievements, but it has to be remarked that this country has a very efficient steam operated railway system, of which it has much reason to be very proud. It is therefore not without interest to shift the point of vantage and obtain a different perspective by drawing a comparison with the steam power already so strongly established and fiercely resisting further encroachment on its hitherto exclusive preserves.
The war left the railways with the urgent work of deferred maintenance of track and motive power, and consequently little else has been possible other than to review future traction policies. Countless reports, have, therefore, been made on the relative advantages and disadvantages of the various forms of traction. The technical characteristics, and also $he operating and economic factors, have been closely scrutinised, and finally weight has been given to national considerations. The year 1950 still finds British Railways mainly steam operated, and any enquiry as to our knowledge of electric traction must be directed almost exclusively to the lines radiating from London south of the Thames. The total combined route mileage of the former Great Western, London Midland and Scottish and London & North Eastern Railways amounts to some 17,357 miles of which to date only 165 route miles have been electrified; only a further 75 (Manchester- Sheffield and Wath) are in immediate process of electrification. The Southern Railway, of some 2,277 route miles, has electrified 720 route miles or 32 per cent., as compared with the achievement of 0.94 per cent. by the remaining former railway companies. If, in order to obtain some yardstick to measure this rate of progress, we look to the Continent, we find that electrification has proceeded in many places at about the same rate as on the Southern. In a number of cases, however, traction policy has been determined more by non-railway considerations such as the relative availability of coal, oil and water power, or by international economic policy. Thus we find that France had by 1948 already electrified 2,195 of her 25,225 route miles, and 21 per cent. of the total traffic is electrically operated. Another 1,288 route miles are proposed for electrification by 1955, Which will enable 40 per cent. of the total traffic to be electrically operated.
Brief comparison of the respective repair and maintenance arrangements for steam and electric motive power on the Southern was made to indicate the magnitude of the problem if and when electric traction becomes a reality on the lines north of the Thames. There was sufficient evidence to show that on technical and economic grounds the prospects for electric traction were excellent. On political grounds, that is, those conditions over which the Railway Executive had little control, the prospects were not so favourable, merely because the times were not propitious. Considerable sums of money were required for replacing electrical equipment now life expired and obsolescent; our engineers will be fully employed in renewal programmes of this nature for some years. Nevertheless money and time should be found to carry out some schemes in order to reduce operating costs and assist the railways to pay their way.
Therefore while most of the Author's contemporary engineers seem fated to spend their active railway life as planners there is some hope that in due course they may see some result of their efforts. Certainly there are great opportunities for the generation of young engineers now embarking on their railway career. They hold a unique position in being the first of the truly dual purpose engineers, and should thus be able to ensure, with complete impartiality, that both forms of motive power are given a fair chance of pulling the British Railways into relative solvency. KPJ: normally, the tenses are changed when original texts are used: but Warder's comments are as valid in 2009 as in 1951 and the future indications are still apt in the "environmentally conscious twenty first century.
Includes map which shows Southern to be electrified routes as per 1947: Thanet was implemented; Hastings was delayed, but East Grinstead to Horsted Keynes and Christ's Hospital to Shoreham were closed!
Sir William Stanier, F.R.S., (34) said that the Institution was to be congratulated on the paper, which carried a very important stage further the records in its possession. He wondered however if the Author had been adventurous enough in his prognostications. Personally, he had seen schemes which enabled a gas turbine power unit to be designed which would give 40 per cent. thermal efficiency, while the Author talked about 16 per cent. It might be, therefore, that by the time the Author could get his electric power the gas turbine would have shown him the way to run trains. Mr. Hopkins suggested that Diesel-electric power might be the solution, but there it was necessary to use oil, which was not indigenous to this country. It might be said that gas turbines were using oil. They were doing so at present, but schemes were in hand to enable an attempt, at any rate, to be made to use coal, either by producer or pulverised, and there was no knowing what would happen in the next few years. Reference had been made to the density of traffic and to the great savings which there would be if the main lines to the north of this country were electrified. What about the freight trains? The density of traffic on the main lines was very largely due to the large freight service. A freight train could be run only as fast as the engine would stop it, which meant that one might have a freight train toddling along at 25 m.p.h., with a fast passenger train behind it wanting to run at 80 m.p.h., but the section was not clear, and it would not be clear for the electric train either if freight trains were still designed and run as at present. He was sure that the President had seriously in mind what he was to do with regard to freight traffic. Automatic couplers and power brakes were essential. Sir William said that he was glad to see the suggestion in the paper that if there were an automatic coupler it should include the brake pipe, the electric gear and so on, so that there would be no need for a man to get underneath to connect the brake pipes, etc. It was to be hoped that the Author would find a coupler which would do that. There was one for trams, but he had never seen one yet for railways.
Col. W. L. Topham (35) wrote that compared with rallways in the world generally, the Southern Region could be considered as a local service, and in order to eliminate two distinct methods ,of operation, it might be advantageous to electrify the rest of the Region, including the longer main lines.
Electrification is the obvious answer for main lines in very hilly country, on account of the incredible difficulties of steam operation. Moreover in hilly countries water power is often abundantly available.
Regarding the main lines north of London, one wondered however if electrification were the economic answer. Without denying the economies which would accrue once the project were completed, a vast sum of money would be required to bring it to fruition and the principal object, greater availability, depended as much on timetable-ability as anything else. He thought that if a much smaller sum were invested in first class servicing and Running Shed equipment for steam power and the replacement of all obsolete steam power by up to date machines, the electric availability figures given could be very closely approached. He compared what had been achieved by the Norfolk and Western R.R. in the U.S.A. He also pointed out that the Author had inferred that steel fireboxes were a complication. This was far from being the case; they were lighter and cheaper and easier to repair than copper fireboxes. With Great Britain and one or two other European countries as the exceptions, most railways to-day preferred steel fireboxes.
H.H.C. Barton (36), referring to what Colonel Topham had said about the Norfolk and Western Railway, said that he was told by one of this railways officers that the new route would open up new coal seams; it was more or less a level route so the existing steam locomotives could be worked further westwards from Roanoke, thereby providing a better engine link. These steam locomotives were ideal for the traffic; they were more modern than the electncs and probably as powerful as any in the world. He was glad that Sir William Stanier had mentioned the braking of freight trains. He felt that until far more freight vehicles in this country were equipped with the continuous brake, it would be impossible to get the best from the electric locomotive. Because the electric locomotive could draw large amounts of power from the line at a moments notice, it could put up a much better performance than the stem engine on ascending grades, but until more vehicles were brake fitted, freight trains would have to be reduced in weight on descending grades, although perhaps some form of rheostatic or regenerating electric brake would be more reliable than a steam one. He felt that Table VI did not quite do what the Author intended. He did not see why the cost of wagon maintenance should be lumped entirely into the steam column, unless of course it referred to the cost of maintenance of those wagons which were being used ta distribute locomotive coal to the various locomotive depots.
He did not think that it was clear from this Table where the cost of electric equipment maintenance (other than wages) was included. He asked the Author to what exactly the two maintenance figures for coaching stock of 21,008,000 and 21,037,000 referred? If the latter figure included the cost of maintenance of electrical equipment as well as that of the bodies and bogies it seemed low, because there were about the same number of vehicles in each case and the electric coaches ran about double the annual mileage. It can be shown that there is quite a large saving after electrification in the wages of guards, particularly goods guards. Table V indicates that this saving (as represented by trip-time) averages some 14 per cent. on the Southern Region electric freight services.
Finally, he felt that the saving of half a million tons of coal a year was a major consideration at the present time. On a rough calculation, if all the railways of Britain were electrified that figure might well reach 8,000,000 tons per annum. Also, complete electrification would release a further 6,000,000 tons oi good quality coal, because power houses can use a more inferior quality than that required by the steam locomotive
T. Henry Turner (38) pointed out that the Author had dealt with electric traction without any mention of the track. He himself could not help feeling, he said, that there must be a very big difference between the maintenance of electric track and ordinary steam track. He also referred to the serious corrosion of underground pipes caused by stray currents. He thought that the maintenance of the electric signals and track was a figure which had to be brought in, and was not brought in at the moment, The maintenance of the Southern Region track must be something which the future electrical engineer would require to improve. It must be disappointing that, although the nuisance of dirt had been overcome, it had been done at the cost of abnormal noise and abnormal vibration. Whatever electrical engineers might feel about it, it was true that the centre of a steam passenger coach provided a more level platform in, which to work, and one could write in it in a way which was not possible when going from London to Brighton.
Roaring rails had become a very objectionable by-product of electrification which was not to be solved by using rubber-sprung wheel centres. There was another approach needed in the type of wheel as well as the type of track.
Reference was made to the use of steel fireboxes and the water treatment of boilers on the T.I.A. principle. The French had introduced throughout the whole of France the use of T.I.A., and yet they were going ahead strongly with electrification. That was kcause they based everything on the cost of steel and coal-they had not a great deal of coal-and the consideration of how much steel, concrete and copper were required for electrification. If the balance came out in favour of electrification they decided to do it, but the decision was based on the shortage of coal first of all, and then on the cost of those three things.
He asked whether in any of the reports which had been made a third system of arranging the wires had been really considered. Everyone was familiar with the single overhead wire and return from the rail, and the steel rail conductor, but had anyone really gone into the question of using two copper wires, but placed low and in a safe manner? It should be possible to have at a low platform level two copper wires. The heavy overhead structures used, for example, on the Shenfield line represented a colossal amount of capital and of maintenance; and a very considerable expenditure on painting the structures, particularly while steam was used as well as electricity. That made him think that a two-wire system would be possible, and would avoid the stray current nuisance and the unkown losses to other peoples property at present being caused by electrified systems.
E. OBrien (39) wrote that in 1924 he read a paper on this subject; of which, he believed extensive use was made in compiling the Weir report of 1931. He was particularly interested in 1920-24 in the possibility of electrifying the Lancashire and Yorkshire Railway. The investigations made showed that whereas the density of traffic (the L. & Y. probably had the densest traffic in the world, 1,600 locomotives working on a route mileage of under 600 miles) on the main lines would have amply justified electrification, the difficulty and expense of electrifying the many branch lines with low density of traffic and the very large mileage of sidings went so far as to make the scheme impracticable. Conditions have since changed. Automatic and rectifier substations, Diesel locomotives and improvements in the material and design of motors, control apparatus, rails and overhead gear may now make a practicable proposition of what was then impossible. The operation of the Liverpool and Southport electrification of which the writer had charge from 1903-1909 impressed him with the disadvantages of the weight and low centre of gravity of the motor bogies of multiple-unit trains: the wear on the rails was excessive particularly on curves. After examination of many types of main line locomotives with high c. of gs. the types used on the Swiss Railways and later on the G. I. P. and elsewhere seemed to offer great advantages both as regards ease of inspection and damage to track. The Swiss Railways very kindly let the writer examine exhaustively the wear on one of these locomotives after 100,000 miles leading to the same conclusion reached by the Author of this paper, viz., that tyre wear would be the controlling factor in overhauls and that given a D.C. motor with armature and field coils so secured as to reduce movement to a minimum, maintenance would be very low. The fate in wartime of electrically operated railways with overhead collection was not a question that could be answered in 1924 and it would be of great interest to know what happened in this last war. The Author is to be heartily congratulated on his paper, particularly on his indication of the lines on which progress should be made in future. It is suggested that after reading his paper members might find it of interest to read the writers paper of 1924 Journal of I.E.E. Vol. 62, No. 333, September 1924 and also his paper on the Management of a Locomotive Repair Shop, Inst. Loco. Engrs., Paper No. 86, October 1920.
Mr. C. B. Unwin (M) suggested that electrification should be undertaken to make the railways pay, and that if passengers were charged privilege ticket rates the railways would have more traffic than they could handle. However absurd this may seem it can be contrasted with being forced by increased costs of operation to raise charges and lose traffic.
F. W. Roberts (40) wrote that the Southern Railway maintenance periods quoted in Section 5.2 of the Paper are calculated by calendar dates. He asked what the average mileage per year for the suburban and for his express electric multiple-unit stock would be so as to compare the periods on different types of service. An average figure would be useful for forecasting the probable frequency of servicing needed on other systems. The Author said that gear wheels have a long life; this is not unexpected, but corresponding information concerning the pinions would be valued. Would 500,000 miles be a reasonable life for them? He thought that weekly ,oiling of traction motor armature bearings to be very frequent; are they plain or roller bearings? From the writers knowledge many railway motors running today in the U.K. are greased only once a year. Would the Author also state the corresponding periods for lubricating motor suspension bearings (roller or plain) and also for replenishing gear cases. He suggested that a simple method of achieving a high speed traction motor, springing its weight, making the transmission (Journal No. 45.-Ed.) flexible, and yet retaining robust simplicity, is to mount the motor longitudinally and to drive through a universally jointed cardan shaft to a right angle gear drive on the motored axle. .
Smith, S.G. (Paper No. 499)
Standardisation of coaching stock. 77-130. Disc.: 131-52.
Fifth Ordinary General Meeting held at the Institution of Mechanical Engineers, Storey's Gate, London, on Wednesday, 17 January 1951 at 5.30 p.m., Mr. R.A. Riddles, President, occupying the chair.
Author was Technical Assistant to the Carriage and Wagon Engineer, British Railways, Southern Region. An early decision was also taken to adopt welded steel body framing as definite policy, partly to obtain greater strength and partly because of increasing difficulties in obtaining suitable timber. Preliminary experience was available from recent vehicles constructed in this manner on the London Midland and Southern Regions for main line corridor and electric stock respectively.
The 1951 building programme for main line corridor coaches covered the first stage of standardisation. Much remainedto be done and design work had already commenced on non-corridor stock for both steam and electric services, and some special adaptations of the already designed corridor stock would be called for in connection with the longer distance electric services using multiple unit stock. Designs were also in hand for first and third class sleeping cars which will use the standard underframes and bogies, and a considerable variety of non-passenger carrying coaching stock had yet to be undertaken.
It was clear that the majority of standard sections and components already used in the comdor stock would be adaptable to these further vehicle types, so that the benefits of this extensive scheme of standardisation would be increasingly felt as it is extended over the whole range of new coaching stock requirements.
While there had been continuous contact with the shop production side in the preparation of the designs, it was anticipated that when the vehicles went into production many suggestions will come from the shop floor for more economical production, or for better use of existing equipment. It was intended to keep the designs sufficiently fluid so that all such worth while suggestions can be incorporated into the drawings as agreed alternatives.
This Paper has been mainly concerned with design, and workshop practice and manufacturing procedure had only been dealt with incidentally, aspects which might well form the subject for another paper,
W. S. Graff-Baker (131-) was surprised that the stressed body vehicle was not favoured by the Committee; but, even if it had been, he thought that there was no doubt that in the situation which existed, and with the constructional facilities available, the underframe-supported light body must be regarded as the proper solution at the present juncture. With a stressed structure the underframe required props under it until the body was put on, and it could not very well be moved from one works to another. The small weight saving that might be anticipated from the stressed body could perhaps be attributed to the requirements for door and window openings, which in London Transport practice could be readily got round, because they did not have so many doors. They had big ones, but by putting them in the right place they got over part of that dficulty. He would be disappointed if he had to go back to a non-stressed body construction. Even the original wooden electric rolling stock on the District Railway had been to a certain extent a stressed structure.
A good deal was said about making rolling stock lighter. Looking at it from the single point of view of the mechanical and electrical engineer dealing with a stopping service, with very short sections, weight reduction to economise in current was most important, since the train had to be stopped and started so frequently. With long-distance trains at any rate, that did not occur, and it seemed to him that the only important reason for lightening rolling stock was to enable a longer train to be pulled up a given incline at a desired speed with the same locomotive, or the same train with a smaller locomotive.
It was well known that in the USA the use of stainless steel was now practised on a very large scale. That first arose, he thought, when the Zephyr trains were first constructed, and it was desired to limit as much as possible the size and weight, and therefore the cost, of the diesel engines which were installed in the end cars. In the same way, for economical running the diesel locomotive should also be limited in size by reducing as much as possible the rolling stock weight. Moreover, United States passenger rolling stock had been extraordinarily heavy in the past, compared with anything which had ever been thought of in this country.
O.V.S. Bulleid (135) said that he had come specially to this country to congratulate Mr. Smith on his paper. He has suffered from me frequently and often.Bulleid added. I have watched him at work, and he is a first-rate fellow. He has produced the sort of paper that both your President and I expected him to produce. Less than justice, however, had been done to the President. What had been described was a wonderful example of standardisation, and the author of it was sitting in the Chair. He could give the assurance that it required someone with a good deal of drive to get carriage draughtsmen to agree on anything.
Mr. Wade had criticised the lavatory doors, but it was something to have a standard door which could- be easily repaired, even if it did not represent perfection. Mr. Wade might care to help the work of standardisation by suggesting to the Committee concerned the best type of door lock, the best type of lettering and the best arrangements generally.
As he had already said, it was the President whom they had to compliment for having initiated the work which had been described and for carrying it through to its present state in such an extraordinarily short time. How he had done it Mr. Bulleid did not know; " I am," he said, " an old-fashioned individualist and do not believe in standardisation, not one little tiny bit," but he believed that in the circumstances standardisation had been essential, and he thought that they would all wish to say how much they admired what had been done and holw astounded they were at the amount of work which had been done in such a short time.
Journal No. 220
Harvey, R.F. (Paper No. 500)
Modernisation of a large motive power depot, Polmadie, Scottish Region. 191-226. Disc.: 226-61.
Sixth Ordinaxy General Meeting of the 1950-51 Session was held at the Institution of Mechanical Engineers, Storeys Gate, London, on Wednesday 21st February 1951 at 5.30 p.m., Mr. R. A. Riddles, C.B.E., President, occupying the chair. The President said it was his pleasant duty to introduce Mr. R. F. Harvey, who was to read the Paper. Mr. Harvey was a Vice- President of the Institution, and members would wish to congratulate him on his recent appointment as 'Chief Officer (Motive Power) for British Railways. (Applause.) A former President* of the Institution had held that position before, and Mr. Harvey had a very high ideal td follow. Since Mr. Harvey had received most of his training under the late Chief of Motive Power, he could be expected to follow the high standard which had 'been set for him. The Paper would indicate the lines on which in future he proposed to provide the best locomotive depots for the best locomotives which could be built. Mr. R. F. Harvey, M.B.E., Vice-president, then read his Paper entitled " Modernisation of a Large Motive Power Depot: Polmadie, Scottish Region," which was afterwards discussed, and for which, on the motion of the President, he was accopded a cordial vote of thanks. * Col. Harold Rudgard, O.B.E., President 1948
Participants in the discussion included H. Rudgard (226) noted that could offer the Traffic Department a freight locomotive for twenty hours a day and a passenger locomotive for sixteen hours a day, and the locomotive could be in traffic the whole time, apart from the necessary fire-cleaning and taking of water. R.C. Bond (226-8).
J. Blundell (229) congratulated the Author on the layout of the shed at Polmadie, because it brought into prolminence one very important feature, namely that the facilities were in parallel rather than in tandem. The provision of facilities in tandem was one of the great failures of many of the running sheds in this country, because it was not possible to get one engine past another; they got into a queue and had to stay there. The layout of the ashpit and coaling at Polmadie had solved that problem. It was also very important that the ashpit bad been split into two portions, so that one could be repaired while the other was in use. Many wet ashpits, if they went wrong, could not be used at all, and the effect of that was felt not only during the three or four weeks while repairs were being carried out for months afterwards.
Major troubles could arise when something went wrong with the coaling plant, or the electrical engineer cut the power off, as often happened. When the plant had to be shut down there was no alternative but hand coaling, and it was not possible to get men in these days for hand coaling, so that some duplication was desirable which would enable part of the plant to continue to be used while repairs were carried out.
He asked how the sand was brought to the engines at Polmadie. There seemed to be a very long carry. Young firemen of sixteen or seventeen could not handle sand in the same way as some of the older and bigger men could, but there did not seem to be any arrangement in the layout for dealing with the sand. The same remark applied to the carrying of oil and fire-irons. Personally, he would like to see the stores which wers immediately required kept in the middle of the layout. There should also be some arrangement to avoid putting an engine in a dead-end road in the main repair shop in order to do some small job which required a pair of wheels to be lowered for a short time.
T. Henry Turner (231-2) criticised lack of reference to lighting up: fire droppers and savings obtained in that respect were mentioned, but, it was more important to save time in lighting up by direct steaming which the Americans had used for twenty years. No British shed used direct steaming which was very much kinder to the metal. It gave an opportunity of filling up with less total dissolved solids than when the ordinary method was used, because there was a considerable amount of condensed steam coming in, so that it was kinder to the metal, kinder to the water and kinder to the men; there was obviously much less smoke, and it was quicker. He suggested that all those advantages deserved consideration from the availability point of view. He asked if triangle reversing would not be possible for a layout over relatively flat country. The new French depots to which he referred all had turntables, but at Doncaster they used a simple length of track, and it seemed to be foolproof and not quite so vulnerable as a turntable.
which did not arise with electric traction or with Diesel locomotives.
Mayne, J.D. (Paper No. 501)
The thermal insulation of the steam locomotive. 262-71.
Fourth Ordinary General Meeting of the North Eastern Centre was held at the Danum Hotel, Doncaster, on 24th January 1951 at 6.45 p.m., the Chair being taken by J.C. Spark. The Minutes of the Meeting held on 22nd November 1950 were read, approved, and signed as correct. The Chairman introduced Mr. J. D. Mayne (Graduate)
The Thermal was an envelope of woven asbestos fibre filled with loose asbestos. The whole is tailored like a coat to fit the boiler with cut-outs as required. The loose filling is weighed out to give the density required per sq. ft.-L.N.E.R. 1-13 Ib. sq. ft.-and is prevented from settling by zig-zag buttoning of the envelope, at an approximate pitch of 3 in. The individual mattresses are laced together and thus provide the maximum coverage of the area to be protected. An asbestos mattress, therefore, fulfills adequately the requirements for an insulator as shown by the following summary :
1. Cost :-reasonable initial cost when anticipated life is considered at least 15 years. An asbestos mattress recently removed from a L.M.R. Royal Scot had been in service for 23 years and had outlived the boiler.
2. Fire resistant qualities, good. The word asbestos is derived from a Greek word meaning unquenched.
3. Physical stability, good, does not settle.
4. Chemical stability, good.
5. Lightness, this is obviously controlled by individual requirements and can be adjusted to suit.
6. Availability, once the cloth is cut, awkward fittings present no further problem. Modifications to the boiler are adjusted by cutting out and sewing up or inserting a patch in the mattress.
7. Handleability, good, easily fitted by two men and can be rolled up out of the way when not in use.
8. Railproof, good, not easily damaged.
These are manufactured in all shapes and sizes to provide a tight fitting form of insulator. A standard rectangular block is used wherever possible. The outer covering consists of asbestos paper and the filling is chrysotile. Summary :
1. Cost:-reasonable, depends on number of rebates and nonstandard sections required. Their life is not so long due to their semirigid form. Once the outer cover is damaged the contehts soon fall out.
2. Fire resistant qualities :-good.
3. Physical stability :-good. It is impossible for the Mocks to settle as they are all wired together to form a solid unit.
4. Chemical stability :-good.
6. Availability :-limited. Blocks are not very satisfactory on the firebox where the stay heads prevent a close fit. If one block is damaged it may not be possible to replace it immediately if it is not a standard section.
7. Handleabi1ity:-very good. Small light sections give a rapid erection and individual sections are soon removed for inspection.
8. Railproof:-fair. Blocks do not stand up very well to rough usage.
Plastic Asbestos may be applied in a similar manner
Journal No. 221
Cox, E.S. (Paper No. 502)
British standard locomotives. 287-335. Disc.: 336-403 + 5 folding plates. 22 illus., 20 diagrs., 7 tables. .
Fortieth Annual General Meeting of the Institution was held at the Institution of Mechanical Engineers, Storeys Gate, London, S.W.I., on Wednesday 21st March 1951 at 5.30 p.m., followed by the Seventh Ordinary General Meeting of the Session 1950-31, Mr. R. -4. Riddles, C.B.E., President, occupying the Chair.
Key paper: Ian Allan book with similar title is more widely available, but both covers a greater ground and was intended for a different readership. The response to the paper is especially important.
The new designs incorporated the following criteria:
Utmost steam producing capacity permitted by weight and dimensions; in other words, capacity to boil waterH.A. Ivatts old dictum.
Simplicity with the least number of working parts all readily visible and accessible.
Each type proportioned to give widest range of mixed traffic working.
High level of bearing performance by adoption of roller bearings throughout for road wheels where financially justified and otherwise by use of manganese steel liners on generously proportioned plain bearings.
Simplified shed preparation by estended use of mechanical lubricators and grease lubrication.
Reduction in work of disposal by means of self-cleaning smoke- box, rocking grate, and self-emptying ashpan.
Engines to be made as sure footed as possible by high factors of adhesion, sensitive regulator and efficient sanding gear.
Within the above requirements, thermal efficiency is sought by large grate areas promoting low rates of combustion under average working conditions, by high degree superheat and by long lap valve gear.
Bar frames were originally proposed, but in detailed working out, available machine capacity and handling space in railway shops was found to be insufficient, not only to deal with slabs, but with box castings tentatively developed in conjunction with the British Steel Founders' Association, to reduce the amount of machining. Further, bar frames would, have increased cost and weight and had to be abandoned. Except in the case of the largest 4-6-2 not yet in contemplation, use of two cylinders only was decided upon for the following reasons:-
The split inside big end was a source of trouble at high speeds and powers unless exceptional integrity of maintenance could be guaranteed.
Theoretically, multi-cylinder engines should be better at starting than two-cylinder engines, but this was not observable in practice.
Four exhausts per revolution in general promote better steaming than do six or eight, other things being equal.
Sir William Stanier (337-8) congratulated the President and his team for the extraordinarily fine results they had obtained in their first effort. There were certain things that might be open to criticism, of course, but they had done a very fine job. "What a lot we all owe to George Jackson Churchward. He could assure them that a little accident like water in the cylinders was not new, and he had seen broken pistons on many occasions. It seemed to him that the smoke box door was rather too flat. In his experience it was desirable to make the smoke box doors as stiff as possible so that they would stand being tightened regularly without distortion and he would have liked to see the smoke box door of this engine about 2 in. deeper. Since he had left the L.M.S., they seemed to have gone in for very expensive coupling rods. He had yet to learn the reason why. He did not know why it was necessary to flute the rods on a mixed traffic engine. With regard to the area of the steam passages; in most cases the area through the superheater was rather less than the area through the steam pipe. In his opinion this was a weakness of the King class of the old Great Western. He noticed, too, that the superheater units had 13/8 in. diameter tubes. In his experience, he found that if superheater tubes were much more than 1 in. outside diameter, the temperature of the flue gas did not get to the centre of the column of steam passing through the superheater tube, so that full benefit from the heat passing through the flue was not obtained. It was possible that one would get better superheat by using 1 in. tubes. He was glad to see that the engine wheels had triangular section wheel rims. He had introduced these on the L.M.S. after seeing them on the German State Railways engines in about 1933 and they made an excellent wheel. The engine had a first-class boiler and a good design of cylinders and valve gear, and he thought they could be very proud of the first engine produced under the new regime and felt sure it would give excellent service.
Dr. W. A. Tuplin (338)
See Tuplin page for his Tuplinesque response to this paper.
E.V.M. Powell (340-1) remarked that in the list of Standard Classes there are three classes of engines, the 4-6-2 Class 6, the 4-6-0 Class 5, and the 4-6-0 Class 4, which cover a difference in T.E. of only 2,400 lb. Could not these have been telescoped into 2 classts ? Further down the list there are two classes of 2-6-0 with the same size cylinders and wheels, differing by only ¾ ton in axle load and 2,680 lb. in tractive effort. There may be good reason for this, but to the uninformed it does seem that one class might fulfil the purpose of these two, especially as there is still another lighter 2-6-0 further down the list. He asked what is the reason for placing the multiple-valve regulator on the saturated side. In some engines with which the speaker was intimately connected they placed the multi-valve regulator on the superheated side, with a separate shut-off valve in the dome, so that, when putting an engine away, the valve in the dome may be shut, and the pilot valve of the regulator opened to cxhaust any steam left in the elements, and so prevent corrosion. There is no more deterioration of superheater element joints, as they are more likely to stand up under continuous than intermittent pressure. He noted that on the smaller engines the old-fashioned sliding regulator is retained. It is no friend of enginemen, as the wear on the square of regulator rods bears witness, since most drivers slack off the regulator handle so as to get a bit of a heave on the regulator. He would recommend a trial of the JOCO regulator of which he had had intimate personal experience. The pilot valve gives just the right amount of steam for starting without slip, and for moving the engine light about the yard, and no extra force is required to lift the second and main valves. It is a delight to handle. Another point is regarding the number of oil feeds to the cylinders. How are the individual feeds from the mechanical lubricator cut down so fine that the total amount of oil delivered from the four feeds will not cause excessive carbonization ? He had not met the mechanical lubricator which, from four feeds, would supply no greater quantity of oil than the 3 drops a minute, which is perfectly adequate from each feed of a hydrostatic lubricator with single feed to each cylinder. From the cab diagram it would appear that there is a separate handle for operating the big ejector, and that the brake handle does not do this which must be most inconvenient for a driver, especially when backing on to a train, and may lead to jerky stops in the ordinary handling of the brake. The design as a whole he considered entirely admirable, and one who started his training in the L. & N.W. Rly. tradition of putting everything out of sight (and reach), can well appreciate the increased availability of the new engines due to accessibility. We are most unlikely ever to get the best steam coal again and he considered the wide firebox a necessity for the future: indeed, after seeing the Austerity 2-10-0s, he hoped to see boilers with wide fireboxes provided when the L.M.S. 2-8-0s need new boilers. It would make for economy, and avoid the necessity for a more expensive 2-8-2 engine for heavy freight.
H.M. Dannatt (343) said regarding
hammer-blow, that he had had considerable experience of troop and passenger
train working by W.D. 2-8-0 Austerity Locomotives. The reciprocating masses
on these engines are only balanced to a small extent. The fore and aft movement
anticipated at 40-60 m.p.h. on these engines was actually very small, provided
the engine and tender were tight. With tender and stock
buck eye coupled, could not the whole of the disturbing force arising
from a low ratio of balanced reciprocating masses, be absorbed by the train
as a whole ? Incidentally, the drag box on the W.D. Austerity tender would
not stand up to these unbalanced conditions when working passenger trains,
and in a case when working General Eisenhowers train for about 200
miles at maximum speeds of 60-70 m.p.h. in East Belgium and southern Holland,
the distance between the intermediate buffing blocks increased from
3/16 in. to ¾ in. due to partial collapse of the tender
With regard to grease lubrication, could more details be given as this was comparatively new to British practice? No drawing of the baffle plate appeared; he hoped it was a big one, as this was essential on free steaming engines. Enginemen were more inclined than ever to leave the door open to keep her quiet. With open ashpan, this of course was the only way and no doubt contributed to some of the troubles with S. Region Pacific firebox maintenance. He was sorry the Author had criticised the S. Region steel fireboxes. The cooling down methods were too vigorous in the early days and the first Merchant Navy class engines suffered very badly as a result. Was this a factor in the short life of their fireboxes? What was the recent performance like ?
Well fitted and with a decent feather to prevent fretting, these fittings would give a good performance. He had seen badly fitted pins with small pin feathers fail due to fretted corrosion on the inner face, whilst the outer face was still blue from thc heat treatment, and gave no indication of pending failure.
High superheat would promote clean front ends, as the oil would remain in suspension in the exhaust steam until discharged into the chimney due to the steam remaining slightly superheated throughout The use of Circlips appeared to have been abandoned. the cycle. In his opinion this was the reason why the Southern Region Pacifics has such clean front ends and showed a pronounced tendency to caxbonise the chimney. He was sorry the multi-valve regulator was on the saturated side and not on the superheated side as the advantage of reducing the volume of steam between the regulator and steam chest was lost. This was a big factor in reducing the violence of slipping, now so noticeable on big engines of modem design with their large superheaters and steam pipes. In his view the pilot valve was too large on present day locomotives. The W.D. 2-8-0 engines could do most of their work on this valve alone. Was it not better to reduce this and enable better control to be obtained When starting ? It was interesting to note the new position of the atomisers. Could not the question of reducing the steam temperature and pressure to which the atomiser was subjected be considered ? If the atomiser was fed from the same supply as the steam chest, pressures could be reduced when the engine was working easily. The wear and tear on atomisers seemed very high on modern locomotives. The lubricator gauge would show ( u ) the lubricator was working. ( h ) whether water was getting in.
He did not like the absence of anti-vacuum valves. Their behaviour when drifting was open to doubt, but to clear steam from a leaking regulator was their real value. The mist round a front end to passengers and staff was a nuisance and dangerous. He felt a hand controlld release valve should bc fitted to the superheater, he believed Mr. Robinson on the Great Central had done so. This could enable steam to be discharged through a vertical exhaust pipe after a driver had I set back to uncouple. The present high pressure oily steam bath one gets from the cylinder cocks is not at all welcome.
H. Holcroft (345): Looking back over
locomotive design during the first half of this century, the most striking
feature is the use of multi-cylinder types for all classes of traffic, both
before and after Grouping. There must have been good and sufficient reasons
for this preference.
With Nationalisation the pendulum swings the other way and we arc back to a plain two-cylinder design, and sound reasons arc advanced by the Author for its choice. It is evident, then, that some considerable change of late in operating conditions in this country has forced this reaction, and everything points to labour legislation and the attitude of labour itself to the job as being the principal underlying cause. Mechanical considerations are set aside and every thing is subordinated towards meeting new conditions, in reduction of preparation time and servicing to a minimum and taking all means possible to keep engines out of the shed and repair shops and to secure the maximum of availability to traffic. A counterbalance equivalent to 10 per cent. of the reciprocating mass on each side is distributed over three wheels. To each wheel is added a dynamic loading of plus and minus 2 tons approximately at 5 r.p.s.; that is to say the rail load varies from about 8 to 12 tons with each revolution of each wheel. While this is taking place in a vertical direction 60 per cent. of the reciprocating 'mass is producing simultaneously on the opposite side of the engine a fore and aft motion with a force half as much again as the total of the vertical. When the driving gear is divided into three or four sets instead of two, all these contortions are cancelled out or considerably reduced in intensity, and vibration is minimised. It would now appear that an engine less desirable from the mechanical aspect must be adopted as a matter of expediency.
Judging by the Author's reasons for adopting two cylinders numbered (1) to (5) on page 293, his experiences with multicylinder engines do not appear to have been very fortunate. One has only to look back through papers and discussion at meetings of this and other Institutions to read expressions of opinion and statements of fact very much in favour of them, in which the writer shares. Some speakers have raised doubts as to the necessity for a 4-6-2 type on British Railways as a general purpose ,machine. While a limited number of the type may be required on the heaviest long distance passenger trains, the more general use is questioned and the suggestion made that a cheaper 4-6-0 with narrow firebox is sufficient for all duties.
It may be very comforting to the operating side to have an engine with a large reserve of power which can cover peak loadings at holiday times without double-heading, but it is an expensive luxury if the engine normally operates much below full power over most of the year on duties which could be easily covered by a 4-6-0, though a pilot might be needed for it to cover the peaks. As to fuel saving by a wide firebox, that only takes place during the period the engine is at work with the regulator well open: at all other times it is at a disadvantage. It takes more coal to raise steam and cover the grate to sufficient depth, and the large grate area consumes more fuel than the narrow during periods of standing, running wisth regulator shut and in light engine running. It is total coal that counts, and this can be expressed as Y = A.+ Bx + C( t-x) , where Y = total coal used in a day's work, A is a constant for steam raising and B is a constant expressing coal consumed per hour with regulator well open, and x the total hours of this working. C is a constant for fuel consumed per hour at all other times and t the total hours from the time the engine leaves the shed to the time it amves back and the fire is thrown out. Thus with the wide grate constants A and C are larger and B is less than the corresponding constants for the narrow grate, and overall saving only occurs when x approaches it in magnitude. In how many turns of duty can such favourable conditions be found for general purpose machines?
Outer chimney and liner in one casting makes it more difficult to set chimney true with blast pipe axially. Why has the jumper top not been adopted: has it been sacrificed to accommodate new type of blower?
Southern practice of fastening by dogs spaced round the circumference is preferable to central fastening for ensuring airtightness and prevention of warping. Main Steam Pipe in Boiler
Why has the Western practice of collecting stearn from top corners of firebox not been adopted? The writer's experience with two different types of steam driers in the dome is that they neither bring about any reduction in water consumption nor any increase in superheat.
The small tubes in horizontal rows as set out in Fig. 9 seen1 to be much too crowded for good circulation. The spacing of tubes in vertical rows in Fig. 10 looks much better.
Monel metal stays, while being free from fracture, are very expensive. Nickel-plated steel stays as an alternative are much cheaper, and Ashford Works has had good results in service by the technique adopted there.
Why not the Swindon taper thread fastening, enabling flat front covers to be used and eliminating nuts which add to the reciprocating weight?
A hard carbon shoe to carry the weight would be preferable to gunmetal as it is self-lubricating in event of dryness.
Why perpetuate the old type of fastening? Cotters are difficult to get at to drive out and are liable to be joggled in place by water trapped in cylinders. Tackle has to be used 'to separate crosshead and piston rod. The American type of split crosshead clamped on to shallow recesses turned on the piston rod end is more up-to-date. Crosshead arms should be solid with crossheads, as they are liable to work loose otherwise.
No mention is made in Appendix A that the fastening of the slide bars at point of maximum thrust and independently of the back cylinder covers is taken from Southern practice.
The difficulty in withdrawing solid heads has necessitated differential sizes of front and back heads, thereby duplicating stocks of heads, rings and liners. In the writers experience the semi-plug valve is much to be preferred. Port bars are simpler and it gives cleaner admission, cut-off and release of steam at the edges.
Very little wear occurs in oil-lubricated bronze bushed gear, even if covered in dirt and grit due to neglected cleaning. Grease lubrication would improve matters further by forcing any dirt outwards and so preventing its entry.
By adopting steam brakes on both engine and tender much steam will be saved in non-fibted freight train working by shutting off the small ejector. The branch pipe to tender should be fitted with a cut-out cock within reach of the driver in case the flexible connection between engine and tender fails or becomes uncoupled, or in the rare event of the drawbar breaking; otherwise all brake power will be lost unless the tender can be isolated.
In the writers opinion the general adoption of the type shown is premature: sufficient experience has yet to be gained. In the event of double fracture there is nothing to prevent a large section of the tyre being thrown off and causimng a serious accident. It may be argued that a single fracture would be detected and the engine taken out of traffic before this could occur. The writer investigated a case where a large portion of a tyre was flung off the wheel centre. Here a second fracture had very rapidly developed after the first had occurred.
Large wheel centres carrying crank pin bosses and balance weights are liable to get I out of round and to warp slightly after the first or second re-tyring. Owing to the fine .limits of working this would raise difficulty with the fastening shown and necessitate skimming up perimeter and sides, making the wheel centre nonstandard.
As situated the blower valve is inaccessible to the fireman if flames issue from an open fire door. In any case the type of valve is out of date on a modern locomative: it should be replaced by a specially designed fitting which would indicate whether it was open or closed and be operated like the whistle, from either side of the footplate.
In case of a burst gauge glass the verticle handle to Item 16, Fig. 26, is in a favourable position if everything goes according to plan, but on occasions, as the writer has experienced, the ball valve in thc bottom cock fails to rise or seats imperfectly, with the result that a fountain of boiling water spurts in an upward direction from twhind the gauge protector, releasing clouds of steam which obscure everything in the cab. In a case of this sort a shut-off handle attached to the bottom cock and located as far as practicable to one side of it would help matters.
Why the expense of two water gauges when the Western have always managed with one and a set of try cocks? Southern (Ashford) practice is to carry the fire doors on a set of rollers : the doors slide more easily than with the plain groove shown.
Window wipers are unsuited to steam locomotives but great benefit can be derived from a hot water spray above the cab window fed under pressure from the working injector. This will remove smuts, dirt, mud from tunnel roofs, snow and ice.
The steam heating relief valve should be placed horizontally at footboard level in the cab, as in Southern practice. If it starts to blow the fireman immediately reduces excess pressure in the camage warming train pipe. Situated outside the cab, this valve can go on blowing indefinitely and wasting steam unobserved.
The projectian of the cab floor over the tender to avoid use of a fall plate results in a large throw-over of the back end on sharp curves with a 4-6-2 type. An insidious and quite appreciable loss of coal on to the four-foot occurs through spillage at the shovelling plate dropping through the gap.
J.O.P. Hughes (355-7 observed that the shortages
of furl and labour have evidently been the dominating factors in the design
of the Class 6 and 7 locomotives, and it will be interesting to see whether
the Railway Executive is justified by the continuance of the former in pursuing
a policy of introducing 140-ton locomotives on duties where 126-ton locomotives
are used now. The building progmmme appears to conflict with the Railway
Executives own policy of lighter trains and with the national steel
shortage. Is it not likely that the Class 6 and 7 Pacifics will never be
built in the numbers which are at present contemplated? Unification of the
railway companies leads naturally to the preparation of standard designs
and it therefore follows that some of the locomotives under discussion may
be built in greater numbers than any of their predecessors and that a good
opportunity for intensive development of the prototypes prior to building
in quantity has been missed. Misadventures such as described by the President
can still occur in my new design, however long the experience behind it,
and perhaps the purely engineering considerations have taken a back place
in face of the apparent desire to present the locomotives at an early date
as achievements of nationalisatisn. In view of the long life of the steam
locomotive, the building of standard types could surely have been determined
by proof of their ability to do the job, provided by development running
of prototypes. Could not new construction be centred on one or two works
only? The present practice of mixing building and repairing often in the
same assembly bay seems to be a bad one. The time seems right for thc formation
of a development running section, on the lines used by the motor industry
the type of work done being quite different from research for which
an organisation already exists.
In the paper mention is made that in thc original proposals for a Class 5 Pacific the carrying wheels were to be the same diameter throughout and with outside axleboxcs, whch are obviously dcsirablc with roller bearings; it states further that outside bearings could not be used on the bogie due to rolling stock gauge, but this is not clear unless it is due to the limitation imposed on the bogie wheel diameter by the outside cylindcrs. Although two designs of axle became necessary, could not the carrying wheels have been standardised throughout? Cannon boxes always seem a cumbrous method of supplying roller bearings to a locomotive axle, and although in this case the horizontal split of the casing is not present, about 1½ tons could be saved in the weight of each locomotive by the use of roller bearings of the self aligning type, and all the advantages of enclosure can be achieved vcry readily by a light tube resiliently connected to the inside faces of the axleboxcs. Would there not be less maintenance if more attention were paid to the protection of lubricated working surfaces, and although the Railway Executive are apparcntly discouraged by some of the results of the total enclosure of the Southern Pacifics (page 305) it is not necessary to go to total enclosure and flood lubrication which has brought troubles of its own. Power operated grease pumps may lead to the wastage of grease, and there is opportunity here for local sealing of the bearings so that they can be greased packed and untouched between shoppings, the motion for instance with many of its pins only having a small angular motion might be sealed by synthetic rubber elements. The reversing screw in particuIar could benefit from a study of modern commcrcial vehicle stcering gear practice and it is possible that such a box would out-last the locomotive. No doubt many will comment on the complexity of the reverse wheel layout which seems to have so much to do so little, and which is coupled to its screw through universal joints which appear to be of a well known proprietary type. It would be intertsting to know if in fact they include needle rollers, whose use is necessary on a 4,000 r.p.m. propellor shaft, but likely to bc troublesome on a shaft making a few revolutions a few times a day and spending the majority of its time vibrating in one position. It would seem that a slight realignment of the screw and wheel, in view of the length of shaft would avoid the use of misalignment couplings altogether.
The spring hanger seems to have been developed at the expensc of the rubber section the bulge area, having been greatly increased by the use of separate pads, The tender spring suspension points the way to the virtual elimination of hanger and link. A rubber pad, bonded to steel backing plates interposcd betwen spring end and frame, could accommodate the change of leaf spring length by shear movement in the rubber, the main spring-borne load continuing to be carricd in compression in the rubber. This system would have the stability of the tension link, would be lightcr, and because there need be no hole in the rubber element, the life would bc longer. Is it justifiable to mention the neatness of the back plate when this has largely hcen achieved by placing so much pipework outside: Some attempt seems to have been made to arrest the decline in appearance of post war British locomotives but the conception remains transatlantic and it seems sad that in the closing years of the use of the steam locomotive is should work in borrowed clothing. The maximum of accessimbility with the best appearance remains a challenge to the designers; dare we hope to see it successfully met if the Class 8 Pacific is ever built?
(357-8) On page 292, reference is made
to bar frames and the attraction offered by their use, which was, however,
finally turned down as such frames could not be dealt with by the plant installed
in the various railway owned workshops. The writer stated that for many years
the "Contract" shops have produced numerous export locomotives with bar frames
of the slab type, whilst in the mid 1920s, Armstrong Whitworths
built a number of large locomotives for the Southern Australian Railways,
with cast steel frames or chassis, these frames being imported from the [United]
States. More recently, the North British have built a large batch of locomotives
for the South Afxim Railways, again with cast steel chassis. At present,
with the very large world demand for locomotives, every available piece of
building capacity must be maintained, but on a long term policy, very serious
consideration should be given to abandoning new construction in railway owned
workshops, and concentrating all new locomotive construction with Contractors,
as is otherwise the almost Universal practice elsewhere. A cheaper and at
least equally good locomotive would result, the Contract shops would be better
able to compete in export markets, with the assurance of the home market
to build on and very much quicker deliveries could be given. The 12 steam
types proposed, seem excessive, and the same powered locomotive with almost
identical axle loading seems to have been duplicated. Why produce both Nos.
7 and 8? Surely one design would have sufficed. Again, surely an L.M.S. Class
5 or an L. & N.E. BI, could meet Nos. 4 and 5 requirement. Is it envisaged
that all train loading is to go up so necessitating the replacement of 4-4-0s
by larger and more costly 4-6-0s ? Surely an engine of equal power should
suffice, and, at the worst, all 4-4-0 duties could be met by a Class 5 or
BI 4-6-0 standard design.
On page 299, it is stated that for plain bearing axleboxes, it is proposed to use mechanical lubrication. Was consideration given to hard grease lubrication, so widely used in North America, and which gives first class results in South Africa and India, greatly reducing the incidence of hot boxes, and also shed maintenance costs? For carrying and tender boxes consideration might also well be given to the Isothermos design. Hard grease lubrication is also very successful on big ends and coupling rod bushes, whilst the grease being under pressure and forcing its way out of the bearing keeps it dirt free, whilst in m oil lubricated bearing the oil tends to have an entraining action for dust into the bearing.
They are very successful in South Africa, where water conditions are far worse than in this country. The short life of the first 10 Southern boxes is noted, but the troubles experienced can be attributed to lack of knowledge in the sheds, especially when washing out, and probably due to wrong air conditions over and through the fire when running. It seems extraordinary that with the great bulk of the worlds locomotives fitted with steel fireboxes, we, in this country, which produces no copper but excellent firebox steel plates, should have our locomotives almost 100 per cent. fitted with copper boxes, whilst North America, the worlds greatest copper producer, has almost 100 per cent. steel boxes fitted. A steel firebox has just as long, if not longer, life as a copper firebox, is lighter and can very much more easily be repaired by electric welding whilst leaking tubes can be overcome by welding them instead of expanding them into the tubeplate. If so many other countries can make them a success, surely we can and should, and thereby we should show an appreciable saving in cost. With a steel box Thermic Syphons can easily be welded in, thus greatly increasing the firebox heating surface and improving the water circulation.
On page 319, means of effecting economy are detailed. No mention is made of a steam soot blower, which is cheap in first cost, and readily cleans fouled tubes, so ensuring good steaming and economy; most desirable for engines on extended runs and multiple manned, and where another delight of Nationlisation is the supply of pool coal of dubious quality, instead of the special grades readily available twelve years ago. Another fitting the writer strongly advocates is the power operated firedoor. It enables the rate of air over the fire to be carefully controlled, reduces the effort on the fireman and effects economy in fuel. The writer took part in some tests in South Africa during 1939, a Class 15F, 4-8-2 locomotive of some 48,000 lb. tractive effort, and with a grate area of 62.5 sq. ft. hand fired, hauled a 1,200-ton loaded coal train from Whitbank to Germiston, and the empty wagons on the return journey of approximately 140 miles. The tests showed that under identical conditions, except for the steam-operated firedoor being in action, there was a reduction in coal consumption per round trip of some 950 lb. As they are cheap in first cost, made in this country, and easily maintained, there is a strong case for fitting them to the new standard locomotives.
He regrettcd that steel fireboxes have been turned down.
T.T. Lambe (358-60) wrote that the
Class 5 4-6-0 has a grate area only slightly greater than the Class 4 (28.65
sq. ft. compared with 26.7) and one is driven to ask whether the provision
of two different designs basically so close together is really justified,
particularly as the Class 5 has not got so good a route availability as the
Pacific Class 6. One would have thought that the Class 5 4-6-0 might perhaps
have been eliminated. The tyre step sizes of 6 ft. 2 in. diameter to 5 ft.
6 in. are good but it does seem a pity to have standardised both 5 ft. 3
in. and a 5 ft. 0in. when a 5 ft. 2 in. would, one would have thought, made
a nice even single step. Of course, a lot depends on what you are going to
have for the 2-8-2. A 4 ft. 8 in. diameter for this engine would have made
a neat completion to the range of sizes. Although the writer is wholeheartedly
in favour of the simplification the provision of an ashpan drench might have
been an improvement. If the ashpan is truly self emptying (one would be a
little inclined to doubt this on reference to Fig. 5) there would seem to
be a considerable risk of the fireman (being himself out of harms way)
emptying the ashpan without first drenching the ashes, and so covering the
engine with fine ash.
He was surprised at the retention of the costly copper firebox. Once maintenance staff are properly trained in boiler washing practice as has been done without difficulty overseas the steel firebox should give satisfaction. The provision of universal treated water, in the writers opinion, is as important from the aspect of tube renewal as it is from the point of view of firebox renewal. Sir William Stanier has commented on the smokebox door. In view of the box of tricks that has to be encountered in any case before the washout staff can reach the mud plugs; why not follow the Indian practice and provide a standard door small enough to suit the smallest engine and fitted with six dogs to ensure air-tightness. The self cleaning arrangement should be easily and quickly removable when warm has the Author any comments on this? But there must be no risk of it falling and fouling the blast pipe. It seems doubtful in any case whether it will be completely self-cleaning and it is a pity that a bottom hopper door-which will also clear washout water-was not provided.
He asked if the Indian type of inward opening firehole door (which is self closing in the event of mishap in the smokebox or firebox) had been considered.
The straight steampipe through the smokebox side looks nice but one wonders if the additional efficiency is really measurable compared with the Indian right angled elbow arrangement, simplifying as it does manufacture and maintenance. Additional volume on the cylinder side of the superheater elements might, in fact, be an advantage. Now that the initial Britannia trouble has been traced to its source will pistons again be made of cast iron? Incidentally a useful dodge to enable standard water gauge glasses to be used with varying demands for length of view is to provide shrouds on the top or bottom nuts.
One wonders whether the additional load on the valve gear due to the difference in size of valve heads has been given sufficient consideration. This in conjunction with long travel valves must heavily Id the gear and the fact that the die block runs on oil while the rest of the gear is on soft grease would appear to sound a Also foot operation? warning note. How often during the trip does the driver have to oil his die-blocks?
Bringing the reverse gear forward is a good idea and no doubt reduces lost motion, but it would have been better still if theIndian type of split nut with jamb action on the bracket to take the load off the reversing screw nut could have been incorporated.
Mr. T. Lunt (360-.) wrote that many thousands of Walschaert Gear designs
must have been put out since its inception, but it would be a bold man who
would maintain that the ideal gear had been evolved, and particularly when
it is to be applied to various engines. Towards the end of the paper it is
remarked that poppet valve gears would still be considered and as only some
five designs of two types of gear have so far been running on a large scale,
he suggested that the subject should be considered from a new basis.
R.C. Bond writing in Paper No. 231, Fundamental
Considerations in the Design of Locomotives, (1928) demonstrated that
it is not sufficient to take any engine and just fit a superheater to it,
but that the superheater, boiler and cylinders must be correlated and since
this was done the many highly successful machines, the Royal Scots, Jubilees,
King George V [sic], have been household words, and it is suggested that
the same idea should be brought to bear on poppet valve gears. During many
years on locomotive design, the writer had designed a number of Walschaert
gears, and at one firm it was the practice always to run a new gear through
on a full size model. He had spent many hours running over the gears to obtain
various curves, such as by holding the radius rod in the mid gear position
and plotting the lap and lead curve, and again holding the combination lever
and obtaining various cut off curves which could be combined to show why
the lead angle altered as the gear is notched up. In 1933 when working on
a poppet valve gear company he calculated the valve gear events right though,
and turning the reversing shaft from full forward to full back, and again
from full back to full forward in steps of two degrees of angular turn at
a time, the writer worked through the whole range producing a smooth curve
of events and so appreciated why it is necessary with the locomotive type
of Caprotti valve gear to have one turn of the hand wheel. Consequently,
when the Class 5, 4-6-0 engines came out fitted with Caprotti gear and a
multi-turn reversing handwheel the writer came to the conclusion that, although
this gear had been fitted on the L.M.S. and L.N.E.R. for many years, no endeavour
had ever been made to understand it.
Now, there are two types of poppet valve gear in operation, the Caprotti type and the Locomotive Valve Gears type, both of which are capable of development with further practical working in service. But, as with the superheater, the engine should be designed to get the best results. Although some 600 poppet valve gears have been fitted to various classes of 1ocomotivrs, only one engine has been designed to make use of the particular feature of the poppet valve and It is not without significance that, in spite of all the difficulties of trade, the railway which was formerly the Central Argentine should have had 20 more engines of a type originally supplied in 1932.
Although these are three cylinder engines the same ideas and proportions could be incorporated in a two cylinder engine. Besides shielding the working parts from rust and at. and a saving in operating power for the gear, there is only a certain amount to be gained from simply replacing a Walxhaert gear by a poppet valve gear, but it would obviously seem worth while to design some new engines to take advantage of the particular features where the poppet valve improves on the radical types of gear and shows superior steam control.
J.L. Koffman (361-2) wrote that the
dictum that "as a simple, cheap, rugged tractor the steam locomotive can
still have a part to play, a part which it cannot sustain should it leave
its vantage ground and once more descend to the complexities of the compound,
the turbine and the condenser," should be written in red letters over the
desks and drawing boards of all engaged in the design of steam locomotives.
No harm should cme to them as long as they will adhere to the commandment
" Thou shalt no complicate." So fhr as instruments are concerned, in the
case of most vehicles they were mounted on a panel where they could be
conveniently seen and with almost all vehicles they were suitably illuminated
as well. This applied to motor cycles as well as to electric and diesel
locomotives, to ships and to aircraft. Only on steam locomotives the instruments
were also used to decorate the boiler, preseumably to facilitate olbservatim
by fireman, inspectors, etc., but scarcely for the sole convenience of the
driver. The writer did note that the German Federal Railways decided to have
all instruments on their Class 23, 65 and 82 engines including the water
level gaugeconveniently mounted on a panel in front of the driver. He would
like to suggest that this practice might be worth considering with future
designs. With regard to the smoke and steam deflectors a device originated
by Prandtl he noted that starting with Class 23 and 62 engines, smaller,
curved deflector plates are used because they proved to be more effective.
He thought that so far as railways were concerned, they used enormous quantities
of ferrous metals, a large proportion of which could be saved if more attention
were paid to the question of weight, particularly so far as roIling stock
was concerned, thus reducing both first costs and operating expenses. The
steam locomotive was not immune from this "heavy handed" treatment and to
analyse present trends, he looked into the useful load/total weight relationship
of modern tenders. The results are plotted in Fig. 36 which average ratio
emerged as 0.5 to 0.6. The new standard tenders are slightly on the heavy
side, whilst the two very light tenders A and B were those used with the
German Utility Class 52 and the Norwegian 2-8-4 locomotives respechvdy. Both
tenders have self supporting tanks, the design closely resembling that developed
by Kreissig for bogie tank wagons. It is somewhat more difficult to analyse
the weight of steam locomotives on a common basis. He plotted the weight
per square foot of heating surfaces against the total weight of a considerable
number of modern engines, the results being shown in Figs. 34 and 35. The
mean value field is shown as well-although it must be admitted that the
conception of what is meant here might vary with the point of view. However,
whilst the Class 4 to 7 engines were within the given region the tank engines
are below it, i.e. they are heavier than might be expected. As a first
approximation the weight W [tons] of modern engines can bc estimated with
the help of the empirical equation:-
where: A is the total heating surface (including superheater) [sq.ft.] and C a constant which is usually bracketed by limiting values of 0.024 and 0.027. It is interesting to note that for Class 5 and 6, C=0.0256, whilst for Class 7, C=0.0233, i.e. these machines are as indicated above within the mean range, whilst for Class 4, C=0.0302, 1.e. this engine is on the heavy side. It would appear from this that the design of the larger locomotives was more effective and that the smaller one and particularly tank engines had to suffer slightly. He thought that by and large, this was a small price to pay for standardisation on a grand scale, but at the same time, it was a pointer to possible weight reduction with future marks of this remarkable series. The Author's view on the effect of standardisation on weight would be very much appreciated.
S.E. Lord (362.) wrote that many of the details introduced into the Class 7 4-6-2 locomotive are admirable and the emphasis given to availability and maintenance is a wise policy. On page 312 it states that the interchange trials established that a small clearance volume on two cylinder engines can give rise to a marked fore and aft movement at certain speeds. The writer would like to be sure what is implied by this statement. Presumably it means that at certain speeds the compression pressure is too high. Can the Author say what kind of indicator diagram resulted and at about what speeds this occurs? On a point of design it is noted that in the boiler Class 3 (Fig 10) the tubes are banked vertically whereas in the boiler Class 7 (Fig. 9) the tubes are banked horizontally. In recent Indian locomotivcs the vertical banking has been used on the theory that this arrangement allows the steam bubbles to rise more freely.
H.M. LeFleming (362-3) raised the following points- 1. The standard range of locomotives does not include any purely mineral or shunting types such as the 2-8-0 and 0-6-0T. Surely the need for these most useful types is not likely to diminish or disappear. Or are British freight trains to become still smaller? It is doubtful whether the number of types remains limited to 12 for long, or there is any disadvantage in a much larger number of types provided they incorporate standard boilers, cylinders, motion and wheels. 2. In regard to acceleration the Stephenson gear seem superior to the Walschaert. The writer believed that recently one or more L.M.S. Class 5 4-6-0s were so fitted and it would be interesting to know how these performed, particularly as regards acceleration. 3. Purely aesthetic points:- ( a ) Deep valance. At first this seems a pleasing simplification but except on designs with some degree of streamlining the effect wears off and the normal angle depth gives more lasting satisfaction. (b) Emblem: If the present form is to be retained it is suggested that it should be half the present size and in one colour. The present dull and heavy yellow could be replaced by a lighter and more metallic shade. A brass casting could be used on special engines. (c) The Colour. Without altering the tone could not a more pleasing and cheerful shade of green be selected?
R.T. Carr (364-5) wrote that
one of the conclusions of the published report of the interchange trials
was that broad fireboxes were superior to narrow ones, but he had found no
evidence that they were superior to narrow fireboxes of fhe same grate area,
and some outside evidence to the contrary. True, certain Pacific locomotives
excelled in their performance, on similar duties, smaller narrow firebox
engines of much smaller grate area-in some cases both in power and thermal
efficiency. But the 4-6-0s were working much nearer their maximum capacity.
The tests suggested that large grate areas, and therefore, perhaps, broad
fireboxes, were appropriate to centah traffic requirements, but they did
not explain why the broad firebox should ever have been thought appropriate
to a Class 5 design, as indicated on page 292 an increase of 25 per cent.
in grate area improved combustion efficiency by only about 2 per cent. at
the low-power duties envisaged, and this gain was wholly neutralised by the
additional engine resistance and inertia. Even the Class 6 Pacifics of 36
sq. ft. grate area, though they might be justified on grounds of improved
route availability, ease of firing, or better riding, were unlsikely to be
superior in performance to equally well-designed narrow firebox 4-6-0s of
similar grate area and boiler diameter; the Pacifics would be heavier and
more expensive to build. The Kings and Lord Nelsons had 34.3 and 33 sq. ft.
of grate, which, in output, must be well-nigh equivalent to the Pacifics
36 sq. ft., allowing for the Pacifics additional engine resistance and poorer
length of combustion course. Perhaps the capacity of the firemen, on
mixed-traffic duties, to handle 33 sq. ft. of narrow grate was in doubt.
If so, the area could have been reduced a little.
Surely one should, if possible. utilise the weight of the firebox for adhesive purposes up to that maximum length of firebox beyond which it became impracticable to fire a narrow grate, and only then to resort to a broad firebox over an idle pair of carrying wheels. It was, after all, a narrow firebox 4-8-0 rebuilt by Chapelon of the French railways which, in the 1930s, developed over 4,000 indicated h.p. at an engine weight of 107 tons, altogether its boiler barrel was only some 5 ft. 6 in. in diameter and 14 ft. long. Its grate area was 40 sq. ft.
Special nozzles of the bridge, pepperbox, double and other types seemed to have improved upon the performance of plain nozzles (and not only at high power), on the Continent and in the United States, both in full-size and small-scale tests, but great care wrds required in the front-end design. A nozzle that split up the exhaust jet did so at the expense of increased nozzle perimeter, hence resistance and back pressure; it needed therefore to be larger in total area than the equivalent plain nozzle, and its chimney had to suit the unusual angle of divergence of the exhaust jet. He wondered whether special nozzles had been given a full-enough trial by British Railways. He admired the proportions of the Class 7 Pacific, and was glad to see that the neat, familiar three-bar crosshead had been incorporated.
Newcastle-on-Tyne Centre held at Newe House, Newastle-on-Tyne on 28th March 1951, the Chair being taken by C.R. Hinds.
C.R. Hinds (367) asked what provision was going to be made for 8-coupled engines and what was going to take the place of the 6-coupled and 8-coupled engines in the future. He also asked if the only shunting locomotive was to be the diesel. He pointed out that the Western Region injector had been adopted as standard and wanted to know why the monitor injector, which he believed had hen very successful, had not been standardised. He asked if there were any particular reasons for adopting the three-bar crosshead and suggested that if the Maddison type crosshead was studied it would be found to be a better design and so far had produced better results.
R.W. Taylor (368-9) suggested that in connection with the point raised by Mr. Hinds there was a great need for a six or eight coupled goods and mineral engine in the North Eastern Region, and he was surprised to note that there was no such design suggested without the addition of a pony truck, which was not looked upon with favour for working into poorly maintained colliery and works sidings, there being a constant tendency to derail under these circumstances at crossings. It was noted that the side control for the pony trucks were provided with ferobestos pads to give a damping effect, and that these pads should be lubricated. It appeared somewhat inconsistent to provide a surface with a high frictional resistance and then to lubricate it. In connection with grease lubrication of valve gear pins; what arrangements were made to ensure continuity of lubrication? Was any spring loaded form of greaser provided, as if not there would appear to be a tendency on long runs for the grease to dry off the pins and so cause excessive wear ? With regard to the ashpan shown in the photograph for Locomotive No. 70,000; was this entirely self emptying when the front doors were open, or is it necessary to rake out the ashes? So far as could be seen from the photogaph it appeared that the ashpan is not provided with completely self-emptying bottom doors. With regad to the cast iron cored-out piston heads ; was it not considered possible to provide a solid steel forged head as in Mr. Taylors opinion this would give more satisfactory service than a cast iron head which was very liable to damage if water entered the cylinders? From a shed maintenance point of view, in order to keep fireboxes clean, it is found to be an advantage to have inspection doors rather than plugs, not only to give a better view of the crown sheet, but in addition to facilitate the removal of sediment. Would the Author say why doors had been omitted from the design at crown sheet level ? It was noticed that the cab was actually attached to the boiler. What effect had this on the riding of the engine from the drivers point of view? It would appear that in addition to the normal motion of the frames there would be further movement caused by the movement of the boiler on the frames. It was also noted that because the footplate was entirely on the locomotive only a main centre draw bar was fitted, and side chains were not provided. He suggested that if the main draw bar broke there was still a serious risk of injury to the enginemen, in addition to difficulty which may be caused in train operation if such a failure occurred. He therefore suggested side chains should be provided. With regard to the steam opmted cylinder cocks; what provision was made to ensure steam tightness of what may be termed loading steam? Was any form of lubrication provided for the piston, or packing ?
Cox responded (394-5): The stock of 2-8-0 locomotives in this country was so strongly reinforced by the building of L.M. and W.D. locomotives of this type for war purposes, that no further units are likely to be necessary. The 0-6-0 steam tank engine is not included because of the policy now adopted of building only Diesel Shunters in view of their proved economy. There are a very large number of steam engines of this type, some of modern design, and while construction of Diesels will replace a number of steam units annually, there will remain for many years a solid core of this type available for the many duties which they perform so well
Scottish Centre: The Ninth Ordinary General Meeting held at St. Enoch Hotel Glasgow, 11 April 1951 at 19.30, the Chair being taken by C.D. Hanna.
E.D. Trask 370-1) refrrred to the remark about
the cut-offs of Express Passenger engines being in the region of 77 per cent.,
and to the fact that in the past there have been too many engines with very
severely restricted cut-offs making them poor starters. It took some time
to persuade thc appropriate authorities to improve the cut-offs of certain
engines having 77 per cent. cut off. On a two-cylinder engine, as descnbed
by the Author, such an engine should have excellent starting abilities, although
this will not get over the occasional difficulty of dead centre. He asked
about the methads of securing elements in superheater headers, since those
in use today do not give entire satisfaction, and he hoped that mention would
be made of a header and a fixture for the elements which would guarantee
steam tight fitness from shop to shop.
In the photograph of the Downs sanding gear, he wondered whether the side of the sand box had been removed for the purpose of illustration or whether this was another joint to be maintained at the Shed.
He wondered to what extent spark arrestors had been included in the new designs and the Chairman in his remarks had referred to self-cleaning smokcboxes. The existence of a baffle plate plus wire mesh screen has the effect of minimising the emission of live sparks
at the chimney, but if the Author could give a little more information on this point, it would be most interesting.
A. Hood (371) asked why the cylinders could
not have been designed horizontally. Regarding the boiler; the Author illustrated
a design which conformed more or less with the standard L.M. practice; but
with regard to the inner firebox the speaker felt that by a simple redesign
of the throat plate it might have been possible to remove and replace the
inner firebox without disturbing the rivetted joint of the outer back plate.
The 2-10-0 Austerity and the S.R. Merchant Navy
and West Country classes are good examples in this respect. The
Author has paid tribute to Mr. Bulleid by utilising his frame design; he
might have contributed further by utilishg his firebox. The firebox is designod
to come out from the bottom. Regarding arch tubes and thermic syphons; the
Author referred to these as complexities of design, as these are claimed
to improve the thermal efficiency of the boiler why introduce, at a later
stage, an exhaust steam injector which is also looked on by many as a complexity
but something which will improve the thermal efficiency of the boiler
Regarding the bogies and trucks; the side control on all these items but one is by means of coil springs. Has the Author not considered the constant resistance device which has been used in this Country by the locomotive builders on designs for overseas and also on the Continent? It is gratifying to learn that the Committee have collaborated so well and put all their own experience together. They have not confined themselves to this, however, but have taken advantage of the best features of oversea design.
The cantilever cab is a good feature and one which might have been used many years ago; another good feature is the attachment of the running board to the boiler. Regarding the frame design; the Author found that the plate type of frame should be adhered to. He introduced a joint behind the trailing coupled wheels and a built-up structure with a thicker slab. Could he not have considercd steel castings for the rear portion as this is well within the scope of the steel founders in this country and which, incidentally, lightens the hind end of the locomotive? One other feature-the support at the back of the firebox. He asked if there are also supports at the front as on the latest South African designs. This is an exceptionally good feature which avoids excessive racking at the back end of the frame. Cylinder diameters for Class 7 and Class 6 respectively are 20 in. and 19½ in., the corresponding grate areas being 42 and 36 sq. ft. These functions are closely related. Would the Author explain how he arrived at these figures for grate area? Cylinder lubrication-the Author has stated that he has carried out an alteration to the superheater to provide a further 100°F. of superheat. What degree of superheat is thereby attained? Is it not possible that this high degree of superheat is likely to create trouble with the cylinder lubrication?
He asked if the spring loaded shoes on the under side of the piston function properly and if excessive wear in the hers or cylinder barrel is avoided.
He thought the reversing gear is complicated but appreciated the advantages of having the Screw at the reversing shaft. He asked if power reverse gears had been considered.
Does this conform to the simple type of two pin drawbar with side control springs? The Author might give some idea of the type of buffer and draw springs, if such are incorporated.
A.C. Smith (372) commented on the Sevenoaks
accident on the Southern Railway in 1927 when the engine concerned in the
derailment was a River Class 2-6-4 tank engine; an edict went forth, as a
result of the enquiry that these engines had to be rebuilt as 2-6-0 tender
engines. Thc L.M.S.R. continued to run 2-6-4 tanks, and this is now perpetuated
in the British Standard designs. The Author says that these engines can run
up to 70 m.p.h., but for for the corresponding tender engine a bogie is used.
Could not the 2-6-0 type be used instead of the 4-6-0? Reply (394):
question the suitability of 2-6-4 Tanks and reference is made to the Sevenoaks
accident following which some S.R. engines of this type were rebuilt into
tender engines. It is necessary here to distinguish clearly between the wheel
arrangement itself and the mechanical features of a particular design. It
is now well established that the design of the River class was defective,
but long years of experience with many hundreds of other 2-6-4 Tanks has
established that they are amongst the most stable and good riding of any
With regard to the table of types; not much difference is apparent between Nos. 7 and 8. Perhaps with a little more information the reason for the two classes would be clear. He asked if consideration was given to the provision of an ashpan drench, water being taken from the injectors. He asked with regard to coupling and connecting rods if consideration was given to grease lubrication instead of oil and the use of floating bushes, also the provision of bronze axleboxes with grease lubrication thus eliminating whitemetal which could be troublesome. It was noticed that there are sets in the coupling rods, presumably this, though undesirable, was unavoidable. He also had to agrce with Mr. Hood with regard to brick arch tubes, which are not complexities, but give arch support and act as circulators. In connection with the reversing gear it would appear that with the bevel gears, etc., there might be more backlash, especially after some wear had taken place, than with thc conventional type of reverser, so that the former gear might upset the valve events more than the latter. At first sight it would also appear that the driver would have to stand at right angles to his usual position-facing the direction in which he is travelling-to operate the gear. A mockup had been made and presumably the drivers liked it but it seemed awkward. Thc old central dart is apparently preferred to circumferential dogs for the smokebox door. It is 4 ft. 9 in. in diameter. He liked the Authors remark about the appearance of the chimney and thought that this was a good point. He thought that it was necessary that an engine should look pleasing and this one did! There has been no mention of intermediate buffing gear. Does the door remain tight?
Midlands Centre: Eighth Ordinary General Meeting held at the Midland Hotel, Derby, on 18 April 1951 at 19.00, the Chair being taken by E.R. Durnford.
J.W. Caldwell (375-7.)said
in regard to locomotive policy, it would appear that the Railway Executive
had to choose between the following four alternatives:-
1. To let each region carry on individually and design its own locomotives.
2. To choose from all regions a selection of locomotives and standardise them.
3. To standardise a suitable selection of designs from one region.
4. To design a completely new series of locomotives as the standard range.
There were people who considered that the first was the correct policy and would be content to rely on competition to produce improvement in locomotive design. The speaker did not think that this course could be sustained as it would mean the retention of four design staffs instead of one, and a unified locomotive stock would never be achieved.
The second course, that is choosing the best locomotive in each traffic category irrespective of region and standardising such locomotives, sounded fair and sensible, but it would have led to a wide variety of locomotives with no parts in common and no practice in common. He thought the Executive were right in rejecting that course.
The third course seemed to be the most sensible, that is to decide on one regions range of locomotives as standard. The whole of the stock of that region would then form a large stud of standard engines for which tools, patterns, spare part stocks, and operating experience would be available.
Such a course however would perhaps have led to such pratestations from the regions not selected as to make its adoption politically unthinkable.
Such a course, however, had the advantage of a precedent in that the late L.M.S. Railway, somewhat belatedly, adopted the more modern Midland locomotives as the basis for standardisation. It may perhaps also be said that the Great Western Railway did the same at the grouping, as one did not recollect that any Taff Vale or Cambrian Railway engines survived to become standards on the greater Great Western.
The fourth course was to design 12 completely new locomotives. The Railway Executive apparently boggled at producing 12 complete new designs and had compromised between alternatives 3 and 4. That is, they were to design nine new types and adopt three types with minor modifications from one of the regions.
If it were granted that to adopt one regions engines was politically impossible, and that the conventional type of steam locomotive was to be retained, the Railway Executives policy seemed unassailable except that the design and building of many new types of locomotives had been decided upon when inflationary tendencies were dominant.
The Author implied that, it was no use trying to design a non-conventional steam locomotive because the two avenues, of higher initial pressure, and lower terminal pressure (by condensing), had been tried and found wanting. Was there not, however, a possibility of getting a more convenient and economical steam tractor, without going outside the present range of temperatures and pressures, bearing in mind that the present conventional tender locomotive weighed 1½ to 2½ times the adhesive weight necessary to draw its load? Its coupled axle-load plus hammer blow far exceeded the axle-load of the other vehicles on the railway and thus set an unnecessarily expensive standard for the track and other permanent way works. Also the ordinary steam tender locomotive required a turntable, a disability from which no other type of locomotive suffered.
The Author had told them that in the first conception of the British Railways Standard range of locomotives, the Class 5 engine was to have been a Pacific and that this decision was rescinded and the engine built as a 4-6-0.
In view of the reputed success of powerful 4-6-0s such as the Castles and Rebuilt-Scots, the question arose as to whether the line dividing the 4-6-0s from 4-6-2s had been drawn at the correct place. To what extent had it been proved that the increased coal economy of the 4-6-2 sufficiently off-set the increased initial and maintenance costs incidental to the provision of a trailing pony truck not to mention the additional 10 to 12 tons weight.
The Author had pointed out that the three largest classes only were provided with roller bearing axleboxcs. It would be interesting to know the reason for this. One might have thought it worth while to fit roller bearings on engines used for stopping trains because an additional advantage of reduced starting resistance might be obtained. The Author claimed that the hammer blow figures on these engines were very moderate. It must be remembered however that they were based on five revolutions per second, which although based on the recommendation of the Bridge Stress Committee, was rather a low rate of revolution for engines such as the Class 6s and 7s which were presumably intended to attain fairly high speeds in spite of their moderate wheel diameter.
Taking the Class 7 the axle-load being 20.25 tons and the hammer blow per axle 2.55 tons. That gave a combined figure of 22.8 tons which, he suggested, was quite high compared with most existing engines, because, of course, practically all existing powerful engines had more than two cylinders. In this connection it seemed to him that greater efforts could perhaps have been made to reduce the weight of the reciprocating parts still further. He did not think everything had been done in this direction when mild steel castings were used for crossheads and iron castings for pistons, neither of which could be considered first class materials for those duties. Again in the matter of lubrication, it would appear that a good policy had not been followed out to its logical conclusion. The lubrication points on the motion of a locomotive may be divided into (1) those where both elements move relative to the frame when the locomotive was in motion and (2) those where one element was stationary relative to the frame. The latter category can of course be conveniently lubricated from the mechanical lubricator, and as Table 3 in the paper showed this was done in all cases with the solitary exception of the expansion link trunnion bearings. Since minimum preparation time was aimed at, it seemed illogical to treat those bearings differently from the others in the same category. Early in the paper the Author made the disclaimer that only well known and tested features were incorporated and indeed no other policy was sensible where a new design was expected to go into traffic as initially turned out. Such being the case, and taking into account the longevity of the steam locomotive, the impact of the new types on the existing stock could not be impressive. The speaker therefore, whilst appraising this range of locomotives as impeccably competent but highly conservative, felt a little disappointed that the railway mechanical engineer could not apparently do more to assist British Railways in the fight for higher efficiency which was so
Journal No. 222
Gudgin, D.S.E. and Birkinhead, G.H. (Paper 503)
Some impression of the American diesel locomotive industry. 408-21. Disc.: 421-55.
Fifth Ordinary General Meeting of the Manchester Centre was held at the College of Technology, on the 14th of March 1951, the chair being taken by Mr. J. J. Finlayson
When the Sales Department has discovered the range of requirements of the field in which it intends to campete it is the job of the Designers to cover that range with the fewest possible models. All American Railways share a common gauge, permissible axleloads of well over twenty tons and a generous loading gauge, so that three of the variables that make standardisation difficult in British markets do not exist for the American manufacturer producing for his large Home Market. Two or at most three Diesel engines designed to be de-rated or supercharged, with one size of traction motor and one or two sizes of generator cover the whole range of horse-power required. Three or four standard bogies with a choice of gear ratios cover the whole range of tractive efforts, and speeds. Three or four types of nose and superstructure house all the combinations of power units. Several types of underframes are required but they have common features. These basic units are combined in various ways to cover the whole field with about a dozen basic types of locomotive.
Jendrassik, G. (Paper 504)
Practice and trend in development of diesel engines with particular reference to traction. 426-51. Discussion: 452-66. 6 diagrs..
Read by M.F. Ryan before Institution in London on 18 April 1951 with President in the Chair. The Railway Traction Diesel Engine is examined in terms of general design, supercharging, cooling, torsional vibration dampers, connecting rod design for engines with cylinders in V arrangement, eugine bearings, etc. Engine weight per unit of swept volume and piston speed for existing engines are shown in diagrams. Special attention was paid to the heat flow in the boundary walls of the combustion space per unit area and time, for which a formula is derived giving comparable figures for engines of different speed and dimensions- all other things being equal. Similar formulae are derived for the static heat stresses and for the variable heat stresses in the boundary walls and are related to conditions prevailing in the engine of 4 in. bore and 4 in. stroke and 1,000 r.p.m.-chosen as a standard engine, always supposing that all other things are equal. An approximate formula is also derived for the heat developed by friction in the big end bearing per unit area and time and is related to the conditions in the standard engine. The Relative Heat Flow, Relative Static Heat Stress, Relative Variable Heat Stress and the Relative Bearing Number thus obtained are shown for existing engines in diagrammatic form and some conclusions are drawn. J.F. Alcock (456) contributed to the discussion..
The effect of changing economic conditions in Canada on railway operations and equipment [Sir Seymour Biscoe Tritton Lecture]. 467-80.
The diesel-electric locomotive is now almost completely automatic and with 65 m.p.h. gearing has no short-time electrical ratings, as the maximum tractive effort, which can be produced continuously, considerably exceeds the traction possible due to weight limitations. Adhesion is definitely the limiting factor of the modern diesel and experience has shown that wheel slippage, together with tread and flange wear, is probably the most critical feature of this form of transportation tool. No reduction in rating is required for the diesel locomotive for cold weather alone, but experience indicates that up to a 15 per cent. reduction in tonnage is necessary for bad rail conditions producing slippage. Most diesels are equipped with 40 in. wheels and it is our considered opinion that this wheel is not large enough to withstand the abuses of slipping and the concentrated flange wear in territory where curves are prevalent. Considerably larger wheels would be much more desirable and, it is felt, will gradually come into use.
Koffman, J.L. (Paper 505)
Dynamic braking of steam, diesel and gas turbine locomotives. 490-536. Disc.: 537-57.
R.A. Riddles (537) explained Sillcoxs trouble (the paper had opened with an extensive quotation from L.K. Sillcox's Mastering momentum. New York, 1940). It had little to do with the heavy braking found with heavy stock in America; but was primarily due to the the American use of chilled cast iron wheels. When working for the Ministry of Supply he thought that if chilled cast iron wheels could be used successfully with the heavy rolling stock in America Britain could probably take advantage of the rapid production achievable with chilled cast iron wheels, and they were fitted to the tenders of the austerity" locomotives only to find that although he reduced the brake percentage to make sure that they were not applied too hard, the practice was to put the brake on by the steam brake, screw the hand brake down, release the steam brake and run down the gradients with the hand brake not only screwed on but put on with the steam pressure, and they had all the trouble of cracks and galls on the tyres. This to such an extent that they changed all the wheels to steel, after which there had been no further trouble.
The suggestions made in the Paper were, on the authors own confession, not new. He himself was a. great believer in the simplicity of the steam locomotive. While regenerative braking was undoubtedly the right and proper thing for electric traction, where possible, he thought it would complicate the steam locomotive too much.
He congratulated the author on the tremendous amount of research that he must have covered in order to produce a paper of that kind. He agreed with the President that they would be able to study much of what the author had said, and see whether the general suggestions that he had made could be used in particular cases.
D.R. Carling. (538-9) said that in considering the possible use of counter-pressure braking on steam locomotives it would seem essential to use a system of the utmost simplicity simplicity of construction, of maintenance and of operation. The system developed by the Test Department of the former London and North Eastern Railway and described in Paper No. 441, read before the Institution in 1943 by T. Robson which might be added to the Authors most admirable bibliography was of particular interest.
There were no moving parts beyond two stop valves in the cab; one of these valves controlled a supply of steam from the boiler to the blast pipe and the ther a supply of hot water from the boiler direct to the cylinders. With such a locomotive it would be possible to change from full power to full dynamic braking in a matter of seconds as only three operations were needed, to open the steam valve to the blast pipe, to reverse and to open the water valve to the cylinders. There would be no need to touch the regulator at all unless it happened to be closed when the need for braking occurred. Control of the braking was carried out by adjusting the cut-off in back gear. The locomotive actually converted by the LNER (Fig. 41) was capable of absorbing in the cylinders any power that could be transmitted to the wheels by adhesion, the adhesive weight being 47 tons and the two cylinders 20 in x 26 in. with wheels 6 ft. 1 in. diameter, and boiler pressure 160 psi.
Some of the alterations made to permit that obsolete locomotive to absorb up to 1,500 h.p. continuously, including its own running resistance, at speeds up to 70 m.p.h., would not be required for braking to rest, even from very high speeds due to the short duration of the braking and such high powers would hardly be called for when descending long gradients with a locomotive of that size. A more modern machine would have more adequate bearing surfaces and better lubrication. It would be advisable to fit cylinder relief valves of generous size.
The real secret of successful counter-pressure braking lay in an ample supply of water to cool the cylinders and valves, but it was most important not to supply too much water when the power being absorbed was not enough to vaporise it as this would result in damage due to excess of water in the cylinders.
Counter-pressure brakes were still being fitted to locomotives for service in mountainous countries and there was no doubt that a well designed brake of that type could be used to improve operation and to reduce maintenance, provided, of course, that the staff were taught to use it correctly.
On very long gradients one advantage of dynamic braking was that it was no longer necessary to stop heavy freight trains for an hour or more to allow the brake blocks to cool off.
R.S. Hall (552-3) it was essential to differentiate between dynamic braking and regenerative braking; the latter system naturally coming to mind whilst digesting the Authors paper.
In many countries where there were long grades and heavy trains, both dynamic braking and also regenerative braking would be of much use, the latter method being also economical where electric tractian was in use. In this country,there were not so many long grades, and from the illustrations they had seen it would appear to be an expensive way of dissipating energy as compared with the more usual method of braking by means of iron brake blocks on the wheel treads.
Two queries came to mind : did a dynamic form of braking increase emergency braking efforts, and, secondly, assuming the ordinary brake blocks were also in use, did the combined system tend to produce more or less wheel-lock? Perhaps the Author would be good enough to round off his address by giving them a few figures as to costs; the initial cost of a dynamic braking system must be fairly high and would equal that of a very large number of brake blocks.
Tritton, J.S. [Presidential Address].
The inspecting engineer's contribution to railway economy. 559-92. 18 figures
The First Ordinary General Meeting of the Session 1951-52 was held at the Institution of Mechanical Engineers, Storeys Gate, London, on Wednesday 17 October 1951 at 17.30, Mr. J. S. Tritton, President, occupying the Chair. The following is a summary published in Loco. Mag. Rly Carr. Wagon Rev., 1951, 57, 165.
In the introductory remarks it was pointed out that it is usual for the author of a Presidential Address to choose a subject on which he can speak from long personal experience and in selecting Inspection accepted practice was being followed. The President expanded the title to "The Inspecting Engineer's Contribution to Railway Economy"; although inspection in its technical aspect is of interest to all members of the Institution, he showed that it provides a service which is of value to other Railway Departments.
It is a long time since the subject of Inspection figured in the Institution's proceedings and no doubt many of the parties concerned with it have had an imperfect grasp of the matter as a whole. This able exposition showed that the services of the Inspecting Engineer, when rightly used, are a good investment for all parties to an Engineering contract. The President examined the functions of the Inspecting Engineer, the requirements which bring those functions into being, and how they are fulfilled. It was explained "What manner of men these are," what their training and experience gives them and some examples of their work were described. Finally an estimate of the cost and value of their services was given. The procedure built up during over half-a-century's experience was explained and many of the tests, checks: analyses, etc., described. The excellent locomotive inspector's notebook evolved by W.A. Lelean, a past President of the Institution, was outlined. This formed the subject of a paper by Lelean as far back as 1915, but it was commended by Tntton as worthy of careful study. The President suggested that shop and shed inspectors on Railways would find booklets of the form outlined of considerable assistance in settling any points in dispute when engines received in shed after periodic shopping do not come up to expectations.
The final step in the procedure of inspection is the signing or countersigning of the inspection certificate.
This most important document serves several purposes, which were described. The most oft quoted objection to inspection is that it "wastes time." Efficient inspection obviously "takes" time, but should not "waste" it. One of the most frequent difficulties the Inspecting Engineer encounters is that of working to a loose specification. Sir Alexander Rendel, the eminent Consulting Engineer, used to say, "a good specification saves money. What is the use of starting on half-a-sheet of notepaper and ending in the law courts?" In addition to the maintenance of standards the Inspecting Engineer is usually called upon to perform a number of subsidiary duties. The most common of these are:the submission of progress reports, providing forecasts of delivery, advising the client on any unusual rejections and suggestmg Improvements in his specification, and assisting both client and contractor by "chasing" delayed sublet material.
The benefits resulting from Inspection to Client, Contractor and Consulting Engineer were considered under their respective headings. The old argument that a tenderer puts 10 per cent. on to his price if the contract is subject to inspection is usually discredited. If taken seriously it is a compliment to inspection. Naturally it implies that the Contractor will be working to finer limits with a higher percentage of rejects and, consequently, the Purchaser gets better value. In the President's experience good inspection by a competent authority is generally welcomed by Contractors, for reasons which he explained. All Designers should be encouraged to visit the works where their contracts are under inspection. Similarly Inspecting Engineers should pay frequent visits to their Designer's Office so that when they have interpretations to make or borderline cases to deal with they may be fully cognisant of the Designer's intentions. The cost of inspection was considered and the possible methods of charging explained. Theoretically, and from the professional point of view the time basis is the correct method of charging for inspection work. In practice it gives the Inspecting Engineer the free hand he should have in carrying out his duties conscientiously and, in the long run, it is generally cheaper for the client. This excellent survey of a most important branch of mechanical engineering was wittily concluded by the apposite remark that there is more in inspection than meets the eye!
The President stated that looking through the records of our Institution he found that it is a long time since the subject of Inspection was dealt with. It is usual for the author of a Presidential Address to choose a subject on which he can speak from long personal experience and he was, therefore, following accepted practice in selecting Inspection as his subject. He had expanded the title to The Inspecting Engineers Contribution to Railway Economy because, although inspection in its technical aspect is of interest to all members of our Institution, he hoped to show that it provides a service which is of value to other Railway Departments. We, in this Institution, have an important part to play in providing a large proportion of the worlds transport. To that extent we are responsible for seeing that the transport we provide is safe and economical and in this responsibility the Inspecting Engineer has a vital share.
He hoped to show that the services of the Inspecting Engineer, when rightly used, were a good investment for all parties to an Engineering contract.
In doing this we shall examine the functions of the Inspecting Engineer, the requirements which bring those functions into being and how they are fulfilled. We can then go on to see what manner of men these are, what their training and experience gives them, and give examples of their work. Finally, we will attempt to give an estimate of the cost and value of their services.
Journal No. 224
Peacock, D.W. (Paper No. 506)
Railway wind tunnel work. 606-31. Disc.: 631-61.
Fourth Ordinary General Meeting of the Midlands Centre was held at the Midland Hotel, Derby, on 14 December 1950, the Chair being taken by E. R. Durnford.
The wind tunnel installed by LMS at Derby. Describes work on the Stanier streamlined Pacifics, the streamlined articulated railcar, smoke deflection, the Britannia Pacifics, the Fell diesel and on platform awnings.
Discussion: A. H. McNair (634) said in connection with smoke deflection the Author remarked that the L.N.E. type of front end which was used on the A4 class engines was found to be less satisfactory than the L.M.S. type, but he understood that Sir Nigel Gresley, when he designed the front end, did not have streamlining entirely in mind, but had also smoke deflection. A considerable amount of work put into this particular point resulted ultimately in the wedge shaped front end being extended comparatively far back on the boiler barrel. At the same time the chimney casing was kept completely proud of the ultimate top of the casing which allowed a wedge of air, when the wind was at an angle to the train, to be driven in between the point of exhaust and the top of the casing behind the chimney. Consequently, it tended to relieve the down draught on the lee side, to which the Author referred in Mr. Sharps question