Journal Institution Locomotive Engineers Volumes
32 (including some key Discussion recorded in Volume 33)
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Watney, N.C. (Paper 421)
Application of Gantt Charts to running shed management. 9-36. Disc.: 36-42.
Twelfth Annual General Meeting of the Indian and Eastern Centre held at the Hotel Imperial, New Delhi, on Friday, 9 February 1940, at 6.15 p.m.,: chair taken by Mr. L. N. Flatt.
Gantt charts were perfected by H. L. Gantt in 1918 and enabled the recording of facts, etc., to be carried out in a clear and definite manner. Furthermore they presented them in their relation to time. By this unique combination in one chart they became of notable assistance to a management. The complete methods of drawing charts were described by Wallace Clark, but briefly the principle was that a division of space represented both an amount of time and an amount of work to be done in that time. Lines drawn horizontally through that space showed the relation of the amount of work actually done in that time to the amount scheduled, which feature distinguished it from all other charts.
Woodbridge, E. (Paper 422)
Industrial standardisation with particular reference to the Argentine Republic. 44-76. Disc.: 76-89.
First Quarterly Meeting, 1940 Session, of South American Centre held in Buenos Aires at Centre of British Engineering and Transport Institutions, on Friday, 12 April 1940: chair taken by Mr. J. Mailer, Acting Chairman and Vice-Chairman of the Centre.
Notably the activities of Instituto Argentino de Racionalizacih de Materiales (IRAM) and its relationships with other national standardising organizations, such as British Standards Institution and the International Standards Association.
Journal No. 160
Renwick, H.P. (Paper No. 423)
Some practical reflections on locomotive axlebox design. 99-137. Disc.: 138-46.
Paper read on 9 December 1939, at Dohad, India, also on 4 January 1940, at Calcutta.
Engine failure data on the GIP Railway for ten years showed failures caused by hot axleboxes as percentage of total failures:
The heated bearing problem in India has been with us for so long and has hitherto proved so intractable that it ceased to be a subject of active concern, and had come to be regarded by many as an inevitable concomitant of railway operation.
Journal No. 161
Fairburn, C.E. (Paper No. 424)
Diesel shunting locomotives. 175-202. Disc. 202-25.
Second Ordinary General Meeting of Session 1940-41 and the 29th Annual General Meeting of the Institution was held at the Institution of Mechanical Engineers, Storey's Gate, Westminster, on Wednesday, April goth, 1941, at 5 p.m., the President, Mr. O.V.S. Bulleid, occupying the chair.
To end this Paper it is proposed to sum up the main conclusions reached regarding the application of Diesel traction to shunting on the L.M.S. Railway, and to consider briefly possible future developments. A locomotive weighing about 50 tons and having an engine of certainly not less than 350 h.p. with electric transmission and capable of a maximum speed of about 20 m.p.h. appears to meet all requirements. Such a locomotive is able to show economies when compared with steam when it can be worked a sufficient number of hours per year. This economy arises mainly from reduced fuel costs, due largely to the reduction of standby losses, the quicker handling of traffic and reduced labour costs as there is no fireman.
It had been decided to build a further 20 locomotives similar to those designed in 1937, but this programme has been hindered by the war. The only alterations decided upon were in matters of detail. The use of several.small high speed engines of a standard design instead of a single engine has been considered. Designs, using three or four engines, were worked out and there would be no difficulty of accommodation. The first cost lvould not be substantially cliffereut and the main advantage claimed would be increased availability, due partly to the ability of the locomotive to continue in service with one engine out of commission, and partly to the facility with which ,a defective engine generator unit could be replaced by a stand-by set. Euel costs would probably be about the same, and by using standard engine generator sets maintenance costs might be no greater. Weighing all the circumstances, however, there was no gain in changing, and at this juncture a standard engine is an asset from the maintenance aspect.
Having decided on a single engine, the layout of the locomotive is settled to a large extent. For example, the drivers cab is most conveniently situated at one end of the frame, and this appears to be the best position from the operating point of view. It has already been explained that the traction motor or motors should be force ventilated and should drive through double reduction gears. With a single motor mounted on the frame, the most convenient drive is by means of a jackshaft and coupling rods. This entails some heavy and expensive mechanical construction and also necessitates the use of side rods, which require accurate maintenance to ensure satisfactory working. The difficulty, however, is not so serious in low speed shunting units as it is in high speed locomotives, and in actual fact the maintenance of this form of drive has not given rise to any trouble.
However, a design of locomotive with nose suspended motors and double reduction gears has certain advantages. If the design of the jackshaft locomotive is analysed it will be seen that there is little latitude in the position of the motor in relation to the wheel base. The position of the drivers cab being fixed, the position of the Diesel engine and generator must follow, with the result that the balance of the locomotive is bad, and unless the body is long as compared with the nose suspended motor type, the machines in the body are cramped. Further, the frame of the locomotive has to take the reaction of the drive and has consequently to be stiffened ; the wheel base, too, must be long enough to permit the accommodation of the jackshaft and the springing arrangements are not too good. The gear case for the second gears is a difficult and expensive piece of work and the load on the final gears is high. The jackshaft locomotive at the time it was introduced had certain merits however. A forced ventilated motor with double reduction drive must be used, this limits the maximum speed at which the locomotive can be moved, and when a jackshaft locomotive has to be hauled dead the connecting rods can be removed and the locomotive attached to an ordinary freight train. The development of similar facilities with double reduction nose suspended motors has now been achieved the motor is forced ventilated, and the intermediate shaft carrying the first gear wheel and the second pinion can be drawn out of mesh, incidentally, in much shorter time than is required for dismantling the connecting rods of the jackshaft type.
With the nose suspended motor the position of the engine generator unit is not limited and it can be placed to give good balance and accessibility. The body can be shorter, the wheel base is shorter, and the springing arrangement is simple. The large gear and gear case of the jackshaft type is avoided, and as two motors are used the loading on the gears is lower.
A locomotive has been fitted up for trial to try out the arrangement fully. The locomotive chosen is one of the type listed under 1 2 in the Appendix, the only change being the substitution of force ventilated double reduction motors for those existing. Trials have shown that the limitations of this type in comparison with the jackshaft locomotive have been overcome. The first cost of a new locomotive would not be greatly altered by the change in design, and the total weight would be somewhat less, which would be an advantage.
Having settled the main features of a design it is necessary to concentrate on the details in order to secure simplicity and reliability, so that capital and maintenance costs can be reduced and the avajlability increased. It is on this that the extent of future development mainly depends.
One point to which considerable thought has been given is the method of starting the engine. The method adopted on all the units with electric transmission of motoring the generator from the battery is technically satisfactory, provided the battery is maintained in good condition and is kept sufficiently charged. A few cases have arisen where, due to a faulty or incompletely charged battery, coupled possibly with some mistake on the part of a driver, an engine has failed to start. But the good results from battery starting have been obtained only by making the rather severe stipulation regarding starting, mentioned earlier in the Paper ; this necessitates a heavy battery which has often to deal with only one heavy call per week, i . e . , when starting after standing over the weekend. Starts during the week are not only small in number, but also require only a short discharge. To meet this duty a lead battery costing about £200 or an alkaline battery costing about £300 is needed. The former has a life of, say, four years and the latter should last appreciably longer; but in either case an annual cost of about per locomotive is incurred, which makes the battery the most expensive single item on the locomotive.
Various alternatives have been considered. A separate starting motor or motors, driving through Bendix or other high ratio gear systems, would reduce the size of battery needed owing to the higher electrical efficiency so obtainable, or the battery might be still further reduced by using it to start an auxiliary Diesel engine which would in turn start the main engine. A petrol engine would be cheaper for such a purpose, but it is not desii-able to carry petrol on the locomotives, quite apart from the added complication of having separate tanks to keep filled. An air motor might be used, but even with a large reservoir a separate enginedriven compressor would be desirable. Direct air starting is not favoured.
Experiments are being made with different materials for cylinder liners, valves, bearings, etc., but it has not jet been found possible to come to definite conclusions. The problem of wear is also being tackled by improving the cleanliness of the lubricating oil and of the engine generally. By-pass filtration circuits have been added to the lubrication system of some engines, and various proprietary filters, including tnagnetic filters, are being tried. Again, it is difficult to come to any quantitative conclusions, although it can be said that filtration is very desirable. For new locomotives it is intended to adopt a modified ventilating system in which the air passing through the engine radiator is isolated from the engine compartment. This compartment will then have a common ventilating system with the electrical equipment, taking in air through a filter. Filters on the engine inlets will, of course, be retained.
Certain points of engine design are still under consideration. One of these is the use of valve seats integral with with the cylinder head, instead of the caged valves, i . e . , valve and seating withdrawable from the cylinder head as a unit, used on the majority of the engines now in service. The integral seat obviously lends itself to better port design and is cheaper in first cost, but unless the valves can be left without attention between major overhauls, the caged valve must be employed owing to the delay and cost of removing the cylinder heads to attend to non-caged valves.
As the periods between overhaul are lengthened the caged valve becomes more advantageous and the solution will probably be to use the caged type with the stellite or chromium treated valves which are being tried at present. Another matter to which thought is being given is the use of over-size pistons. Although at first sight it would seem an .obvious economy to bore out worn liners and to have a system of purchasing over-size pistons which would be turned down through a series of standard sizes as they became worn. In the Authors opinion, the complication of maintenance procedure and store keeping and the change in engine conditions makes them undesirable, especially with the rate of liner wear it seems will be obtained. It will be seen from this brief resume that the Diesel electric locomotive for shunting duty has come to stay, but there are still many points where improvements can be hiatle to cheapen maintenance costs and to lessen capital charges, and wider experience will give the data to deal with these adequately. The L.M.S. Railway expect to get this expericnce rapidly as the number of locomotives in service is to be substantially increased.
Discussion: W.A. Stanier (202-4) said that while from the Authors concluding remarks in presenting his Paper, one might wonder whether there was any hope at all for the steam engine; in the Paper itself it was made perfectly clear that it was no use considering Diesel traction unless the locomotive could be used for six days a week and for a big proportion of the twenty-four hours in each day. The L.M.S. Kailway had learnt that on a three-shift shunting job they could employ a Diesel locomotive costing a certain amount, and with only two shifts it would pay to do so, but with a single shift it did not pay, even though two men had to be employed on a steam locomotive instead of one.
Reference was made in the Paper to the use of the jackshaft drive and to the reasons for its adoption in the case of twenty locomotives. Since then, developments had taken place, and it had been found that the great virtue of the jackshaft drive was that it was driven with a double gear reduction and the motor was artificially cooled, so that it stood up to hard shunting, whereas the ten locomotives with nose-suspendcd motors, with single gear reduction and cooling with a fan on the armature, were not nearly good enough. As a result of further developments, however, there was now running on the L.M.S. Railway a locomotive with double gear reduction on the nose-suspended motor. The motors were artificially cooled, and, if it was desired to take the engine from one depot to another, it was possible to rack the gear out of engagement. That arrangement was quite as satisfactory as and made a much simpler assembly than the jackshaft drive.
In designing a unit of the kind in question, it would be appreciated that if in addition to the generator and Diesel engine it was necessary to find room for motordriven gearing and jackshaft it took up a good deal of space in the engine compartment, whereas if the driving motors could be suspended on the axle it lessened the demand for space in the engine compartment and gave more room for the auxiliaries, which was an important consideration. What they had perhaps not realised at the start was that, as the Author pointed out, creeping a load over a hump meant using a good deal of current and heated up the motors very considerably, so that it was essential to have artificial cooling. One of the great advantages to be looked for with the Diesel locomotive was availability, and that was its high fuel capacity, the oil capacity, the water capacity, and so on, were arranged so that the unit could stop out in the yard for a long time; he believed that the latest engine could be left out for a fortnight without any servicing. That gave considerably greater user from it. A problem which had still to be studied mas the eimplest and best means for filtering the air, the oil and the fuel.
A study of the photograph of the locomotive with jackshaft drive (Fig. 2 ) would reveal another small detail which had been of some advantage to the operating department, namely, the use of thin brake blocks. That gave a much better braking surface, and the brake block surface settled down on the wheel very much more easily.
J.S. Tritton (204-6); J.E. Calverley (206-8); E.P. Paxman (208-9); A. Gordon Wilson (209-10); J. Pelham Maitland (210-11); E.S. Cox (211-12) who was somewhat carping;
K.R. Cameron (212-13); was glad to note that Mr. Stanier favoured the nose-suspended motor rather than the jackshaft drive, and said that before the war he had had something to do with the latter, and he remembered the difficulties that there were with oil leakage from the gcm-case sealing ring, which was about 10 feet in length and ahnost impossible to make oiltight. Grease was tried instead of oil, but other difficulties arose and thc results were not satisfactory.
He had at present ?? Iliesel locomotives, of which one had nose-suspended motors and 'the other jackshaft drive; and he found that the teeth on the jackshaft gear wore unevenly. He thought that that was due to occasional high speeds 15 to 20 m.p.h. when running light, and to the fact that thc balance of the jackshaft was not exactly right. In fact, he did not think that the balance of such an arrangement could be right ; the large counterbalance weight caused a hunting motion in the jackshaft and uneven wear on the teeth when running fast at very light load.
It would be of interest if the Author could give any indication of the quality of metal which had been found satisfactory for big-ends. In his own early experience there had been perpetual trouble with big-ends, no matter what metal was used, and unfortunately he was finding the same difficulty at the present time. Personally, he was of the opinion that much of the trouble was due to the bearing surfaces being inadequate in area for the very heavy shock loading produced by running for long periods at widely varying speeds. The Maintenance Schedule set out in Appendix I1 provided for taking the big-end bearings down for examination every 800 miles, which meant about every four or five weeks in the case ol full availability, three-shift working. It meant, in fact, that the engine had to undergo what was almost a major overhaul at very frequent intervals. If big-end bearings could be made more reliable, the mile examination could then become one of more moderate proportions taking very niuc-h less time to carry out.
For hump shunting, his own preference would be for nose-suspended motors rather than jackshaft drive.
R.J. Welsh (213-14); H.G. McClean (215-16);
O.V.S. Bulleid (216-17); commented on the almost contemptuous way in which the Author dismissed anything in the nature of mechanical drive. Personally, he thought that the Author should be called upon to give in detail his reasons for not liking mechanical drives, instead of making the bland assumption that mechanical engineers would appreciate the drawbacks of mechanical drive, whereas they really appreciated the drawbacks of the electric drive, which in conjunction with the Diesel engine involved the use of batteries costing £200 to £300, filters, double gearing and much else beside, simply to give a little extra availability. If equal attention had been devoted to the combustion of liquid fuel in a container containing distilled water and using the resulting gas as the form of transmission, any lack of availability might be overcome in a simpler, cheaper and more convenient manner. Personally, he had expected an old friend of his whom he was delighted to see present would have succumbed to the temptation of saying that the proper way of designing a shunting engine was to have a small steam engine driving each individual axle separately.
O.S.M. Raw (217-19).
Malhotra, D.R. (Paper No. 425)
Cupola practice. 226-38. Disc.: 238-43.
Ordinary General Meeting of the Western Branch of the Indian and Eastern Centre held at the Conference Room of the Bombay Electric Supply and Tramway Co., Ltd., Bombay, on Friday, 23 February 1940, at 6.15 p.m.: chair taken by Mr. T. Cooper.
Listed some of the special types of cupola, but the last-named, i.e., the Balanced Blast, evolved and developed by the British Cast Iron Association, appears to be much superior to the others. The melting is controlled by a balanced blast arrangement and besides the consistently uniform and good quality of metal turned out by this process, a saving of 20 to 25 per cent. in fuel is claimed by its users.
(1) The Centre Blast cupola tuyers.
(2) The Schurmann Side Blast cupola with reversing generators.
(3) Oil-fired Wust combination furnace and cupola.
(4) The joint Hearth attachment to an ordinary cupola.
(5) The Poumay cupola.
(6) The Balanced Blast cupola.
Spalding, T.A. (Paper 426)
The ideal diesel unit for the Argentine. 244-7.
Puper presented at fourthi Quarterly Meeting of Argentine Section, 1939.
Author indicated the great advantages of the Diesel Electric over the Diesel Mechanical, and it will no doubt be agreed that it would be well to follow the example of the United States who use almost exclusively this method of transportation as having proved itself to be etlicient, rapid and, above all, economical.
Journal No. 162.
Smith, H. (Paper No. 427)
Intensive usage and control of locomotive power. 250-72. Disc.: 273-87.
17th Ordinary General Meeting of the Western Centre held at the European Institute, Rhusawal, on Saturday, the 2 September, 1939, at 5.45 p.m.: chair taken by Mr. H.P. Renwick who made the following introductory remarks:
He was very pleased to see such a large gathering of members and visitors at the meeting, which was the first that the Western India Branch has held outside Bombay; and I have to thank the officers of the Hhusawal Division of the G.I.1. Railway for making this meeting possible and for their kindness in providing facilities this morning for visiting the Locomotive Running Shed.
The Paper, though .not dealing with a technical subject, is of considerable interest at the present moment, as with the rapidly gathering war clouds the subject of intensive locomotive usage is one that will be very much to the fore in the next few months. On the first page of the Paper the Author gives figures showing the increasing trend of steam locomotive miles run by the G.I.P. Kailway over the past seven years, and the very large decrease in the number of locomotives available to run that mileage. Under war conditions the traflic on the G.I.P. Railway is likely to increase very considerably, and it is therefore imperative that every avenue is explored to avoid the wastage of locomotive power in order that the locomotive stock we have can handle the expected increase in traffic
Sindhu, B.S. (Paper No. 428)
Some experiences with locomotive utilization and maintenance in an Indian running shed. 288-317. Disc.: 317-39.
10th Ordinary Meeting of the Northern Centre was held at the Nedous Hotel, Lahore on Monday, 7 August 1939, at 7.0 p.m.: Chair taken by Mr. L.N. Flatt.
Purdom, D.S. (Paper 429)
Argentine railway workshops in War-time. 344-401. Disc.: 401-58.
Paper presented on 25 April 1941, at Remedios de Escaladn. The Escalada workshops were described more extensively than those at Bahia Blanca on the Southern Railway and Liniers on the Western Railway firstly, because they were the largest workshops and scope for innovation had been greater there, and the Members were to visit these Workshops. Nevertheless, practice in all three workshops was similar to a large extent.
Many other minor steps had been taken to help towards economies including substantial economies in the consumption of stationery by:
suppression of forms.
suppression of unnecessary copies of forms in current use
cheaper quality paper and ink in printing forms
use of scrap paper for carbon copies, etc.
elimination of unnecessary inter-sectional correspondence.
Journal No. 164
Holcroft, H. (Paper No. 430).
Smoke deflectors for locomotives. 462-89. Disc.: 490-509 + 3 folding plates. 31 illus., 8 diagrs.
Opening General Meeting of the Session 1941-1942 held at the Institution of Mechanical Engineers, London, on Wednesday, 3 September 1941, at 5 p.m.: Mr. O.V.S. Bulleid, President occupying the chair.
Pp. 473-84 (17 illus.j : Includes an abstract of a National Physical Laboratory report by F.C. Johansen on experiments with models of the U and V classes: mainly the latter. Both the paper and the discussion range far beyond the U and V classes and considerable attention is paid both to the successful smoke-lifting propensities of the streamlined A4 Pacifics and their precursors, as well as to the height of the chimney (possibly why the GWR did not require smoke deflectors) , to the louvres fitted to the Jones locomotives on the Highland Railway, and to the predominant direction of travel (it is argued that strong head winds caused the greatest problem and that is why the London & South Western Section caused greater problems than the Brighton mainline). Holcroft cites both D.K. Clark and Colburn for references to capuchons. Many experimental designs adopted on the SR mainly for the King Arthur class are illustrated. E. Windle (pp. 490-9 described the system adopted for the A4 and for the P2 class, although it was B. Spencer (p. 503 and 504) who showed how smoke deflection on the A4 class was greatly enhanced by modifying the rear of the chimney (earlier a continuous line from the front of the chimney along the boiler casing had been envisaged). Windle also showed some of the many experimental smokebox/chimney arrangements had been evaluated on the non-streamlined Pacifics. and on the P2 2-8-2s. The connection with the Bugatti railcars in the case of the A4 is also mentioned. E.C. Poultney uses the term "blinkers" and considered that there appeared to be no difference in smoke lifting terms between those fitted with smoke deflectors and the taper-boiler locomotives. A.R Ewer (page 499) used the mention of streamlining to condemn it in terms of accessibility. W.A. Willox (500-1) returned to the topic of chimneys on the GWR and noted that "recent" Castle class locomotives had shorter chimneys. He also referred to the French Huet system and to the Pottier system which eliminated head wind from the front of the cab. J. Clayton (501-2) considered that the alignment of the mainlines had some influence on smoke deflection: on the SR the problem was greatest on the West of England mainline, although this contrasted with the GWR where smoke drifting did not appear to be a problem. D.W. Peacock (502-3) smoke of wind tunnel work and noted that smoke deflector plates should be placed "well in front of the smokebox". O.V.S. Bulleid (503-4) considered that long boilers accentuated the problem of drifting smoke and suggested that the problem was "amost insoluble". Replying to the discussion Holcroft (p. 505) considered that ashpan pressure was a significant factor in blowbacks induced by tunnels, and that closing the dampers removed the risk. F.C. Johansen made a written contribution (507-9) which considered Jones' louvred chimneys on the HR and the increase in air resistance induced by deflector plates..
Murphy, P.J. (Paper No. 431)
Notes on railway wagon maintenance. 510-63.
Second meeting (Session 1941) of the South American Centre held Friday, 29 November 1940, in Buenos Aires, Argentina: Mr. F. Campbell was in the chair. By kind permission of the General Manager of the Buenos Aires and Pacific Railway, the meeting was held at the Railway Companys workshops at Alianza.
Volume 32 (1942)
Back to main file
Journal No. 165
Cox, E.S. ( Paper No. 432)
Balancing of locomotive reciprocating parts. 2-37. Disc.:1943, 33, 218-36. 4 illus., 11 diagrs., 3 tables.
Third Ordinary General Meeting of the Session 1941-42 was held in the Lower Hall of the Institution of Mechanical Engineers, Storeys Gate, London, on Friday, 16 December 1941, at 2 p.m., W.A. . Agnew, Past-President, occupying the Chair. This paper was also published in Proc. Instn mech. Engrs, 1941, 146 148-62 and J. Instn civ. Engrs, 1941/42, 17, 221-50.
A class 5 locomotive was deliberately slipped on greased rails at a speed equivalent to 100 mile/h to establish the effect of coupled wheel lifting at speed.
'I'hc following deductions
(1) The bouncing of the wheels is of the nature of a forced vibration, resulting from the unbalanced forces, and is not one of resonance between engine and track.
(2) 'The wheels lift in thesc circumstances at rather lower speeds than indicated by theory, in which upwards centrifugal action of the balance weight and the downwards static load of the wheel on the track are alone considered.
(3) Bouncing and track damage become less as the hammer blow diminishes. No appreciable wheel lift occurred with 30 per cent. balance.
(4) The limiting factomr in reduction in hammer blow so. far as these tests were concerned was the fact that undue oscillations were observed on the engine with 30 per cent. balance.
(5) The condition of the track has little effect on the incidence or extent of wheel lift, which depends primarily on the hammer blow.
After these tests the proportion of balance on this class of engine was standardized at 50 per cent., instead
London, Midland and Scottish two-cylinder 2-6-4 tank engine No. 2408, with zero balance, was carefully measured for wear in its coupled wheel bearings after 58,560 miles, in comparison with No. 2407, a sister engine having 66.6 per cent. balance which had run the same mileage in the same district. The average measurements are set out in Table 3 ; they are based on 50,000 miles running, which is the average mileage above which axleboxes require attention on this class :-
The wear is greater in the case of engine No. 2408, but is by no means excessive for the mileage run, and was not of a value which of itself would cause the engine to be stopped any earlier for repairs. This engine has just been overhauled after 198,000 miles since last general repair, the axleboxes having been overhauled three times intermediately. No abnormal wear has been observed on any occasion.
(b) The Southern Railway School class three-cylinder engine, already referred to, with zero reciprocating balance was reported to show no appreciable difference in wear from other engines of the class with 30 per cent. balance, when specially examined at general repair after 81,219 miles.
These two cases are special in that the first engine has a high total weight in relation to the reipcrocating weights unbalanced ; and the second, being a three-cylinder engine, does not demonstrate the worst effects of lack of balance. The question therefore, remains open, so far as recorded experience in this country goes; and the cases cited only show that where oscillations are small, increased wear is small. Subject to later verification, it is reasonable to suppose that rate of wear will vary with the amplitude of oscillation ; and where that amplitude exceeds the permissible amount for tolerable riding, an undue degree of wear can be expected to develop, which in turn will intensify the effects of the unbalanced force.
(1) The modern locomotive is capable of speeds up to 8 r.p.s. and the resulting hammer blows with the usual percentages of reciprocating balance can attain much higher values than were visualized in the Bridge Stress Committees report in 1928.
(2) The phenomenon of wheel bouncing at high rotational speeds was first observed in America in 1937, and tests have shown that it can occur in British practice in certain circumstances.
(3) Conclusions (1) and (2) suggest a reconsideration of locomotive design in the direction of reducing hammer blow still further.
(4) As regards the effect on the locomotive, longitudinal and nosing oscillations depend on the weight and length of engine, weight of reciprocating parts unbalanced, and characteristics of the drawbar springs. They are independent of speed.
(5) Theory suggests that three and four-cylinder engines which are already in a state of balance with regard to longitudinal forces, do not require any portion of their reciprocating parts to be individually balanced to deal with the nosing couple, because of the small magnitude of the displacement. Three-cylinder engines with zero reciprocating balance are already running in this country.
(6) In two-cylinder engines, theory-supported by a certain amount of practical evidenceindicates that some degree of reciprocating balance is still required if undue longitudinal oscillations are to be avoided. The percentage required will vary with the engine characteristics, and a method has been suggested for arriving at the amount. Not less than 40%. balance appears to be required on the heavier type of British two-cylinder engine weighing from 65 to 75 tons.
(7) For the highest speeds, therefore, niulticylinder engines arc the most desirable, if they are of the reciprocating type. If it is thought necessary to balance a percentage of the reciprocating parts, the four-cylinder is preferable to the three-cylinder type, from the point of view of hammer blow. If this balance is eliminated, there appears to be little to choose between the two types.
(8) The final criterion as to what percentage of balancing is necessary is the magnitude of the oscillations which can be admitted on the engine, having regard to riding comfort for engine crew and passengers, wear and tear, maintenance costs, and safety.
Practical experience so far recorded tends to support the theoretical conclusions. It is, however, very scanty, and when normal conditions return, scientific investigation will be required, not only to establish the precise effects of the unbalanced parts on the locomotive, but also to define the limiting value of the disturbances which can be admitted. More experimental verification is needed as a prelude to any large-scale reduction in hammer blow.
Discussion: W.A. Stanier (218) noted that for many years locomotive engineers had lacked adequate means for measuring various things they did. He also observed that Churchward had realised the limitation of static balancing due to the variability in the density of steel castings and had introduced dynamic balancing. The mass of the locomotive had a considerable influence upon balancing.
George Ellson (Chief Engineer, Southern Railway, 219-20) commented upon the Merchant Navy class which had been designed without balance weights and to experiments conducted on the a member of the two-cylinder H15 class from which the balance weights had been removed. He observed that the principal factors in the relationship between the locomotive and the track are: the total weight of the locomotive and the disposition and magnitude of the axle loads; the maximum speed of the locomotive; the amount of hammer blow, if any, of the locomotive and the unsprung weight on the axles. F.C. Johansen (220-1) noted that at very high speeds the wheels actually lifted off the track, and that bouncing led to further damage of the track. J.C.L. Train (221-2) commented at length on his concern about the effect of high speed trains, but had accepted Gresley's reassurances. He considered that the steam locomotive was at a disadvantage compared with other forms of motive power due to their reciprocating parts. Mr. Train concluded that balancing of reciprocating parts was an undesirable practice from the civil engineer's point of view and that the mechanical engineer's best way of dispensing with the balancing of reciprocating parts was to employ multi-cylinder engines which were to a great extent naturally balanced. An excellent specification for a locomotive would be that it should have no greater hammer-blow at 8 revolutions per second than at, say, 5 revolutions per second. :
Bulleid (222-3) observed that, so far as reciprocating balance weight abolition was concerned, he seemed to have struck a rather fortunate line in locomotive design, and, as Mr. Ellson had demonstrated, they could see no ill effects from the absence of reciprocating balance if they took reasonable precautions in other directions. The absence of reciprocating balance weights was very interesting from the locomotive point of view, for on the engine which had been mentioned 1,377 lb. of dead weight had been saved, and that, if one was designing locomotives to the maximum weight allowed, was very important. Any ill effects of such lack of balance had been minimized by using a shorter stroke, which, of course, reduced the inertia effect. He thought the ratio was something like 38 to 30 when comparing a 30 in. stroke with a 24 in. Moreover, with a 24 in. stroke and a 6 ft. 2 in. wheel the piston speed was reduced to about 1,090 ft. at 60 miles per hour, in comparison with 1,160 ft, with a 6 ft. 9 in. wheel and a 28 in. stroke. As Professor Inglis had pointed out, springs with no frequency should be used. He had emplojed rubber springs, the rubber having no natural frequency, to damp out any ill effects and so prevent their transmission from the engine to the tender and from the tender to the train. No ill consequences on the engine had been observed owing to this departure from conventional practice. Mr. Ellson had shown some diagrams to illustrate the effect of a two-cylinder engine. The balancing weights had been altered to remove the reciprocating portion, but it was not possible to be quite certain, in view of the results, that the engineers had succeeded in doing what they set out to do, and they would be compelled to re-balance the engine and make a further test. Locomotive engineers looked forward to higher speeds and were particularly anxious to be allowed heavier axle loads. Only by multiple-cylinder engines, however, and with no reciprocating weight balanced, were they likely to induce the engineer to give them what they wanted.
W.K. Wallace (Chief Engineer, L.M.S.R.) said that higher speed was becoming general, and that made balancing more important than in the past. Moreover, the railways were developingJ mixed traffic locomotives with smaller wheels, and those, due to improved valve gear, ran more quickly. Even though a train might not be timed to run at a high speed, if the engine driver wished to make up time high speed might be produced in any case. It was very important to obtain light-weight motion for twocylinder engines. He liked the London and North Eastern Railway reciprocating weights, because the permanent way engineer wanted a small hammer-blew which controlled the design of permanent way. He agreed that engineers were more interested at present in impact on the permanent way in the sense of the track than on bridges, because they were probably nearer the limit of stress in respect of rail and permanent way than in respect of bridge structures.. Johansen had mentioned that it was thought that the engines of Class 5 had an effect upon the road. There was no doubt about it, and that was one reason wby they had conducted the tests which had been filmed.
Wallace was perfectly prepared to grant Stanier additional axle weight if he did away with hammer-blow. On the other hand, it was essential to ensure that no damage should be done by the older class of engines running at the higher speed. If the operating people were given a small class of new engines to speed up specific trains which they were re-timing, a number of other trains for which there was not a specific high-speed engine available would be speeded up also, and some more serious effects might ensue. It was interesting to note in Coxs Paper the remark that nosing need not receive much attention in a locomotive, because he had been rather afraid that it might be said that if reciprocating balance were omitted trouble would arise from nosing. It was quite obvious that the locomotive engineer would not give trouble in that respect. The chief thing from the permanent way engineers point of view was to reduce the hammer-blow as much as possible. He would like to omit reciprocating counter-balance altogether if possible, but if the locomotive engineer found that that led to lateral motion which would also abuse the track (and the track was not so stiff against lateral loads in Great Britain as in countries where flat-bottomed rails were used) that counter-balance would have to be tolerated but the use of lighter motion and anything else that would tend to reduce hammer-blow was all to the good. No doubt a demand for more ultra-high-speed trains would arise after the war, and he did not know that it would be possible to require that such trains, as hitherto, should have a limited seating capacity. Whereas the Coronation Scot was a limited train, after the war similar speeds might be required with a train about the weight of the Royal Scot Of course, those engines were not so serious from the permanent way point of view, because they were always multi-cylinder, as they required such a large tractive effort. But the two-cylinder mixed traffic engine with a modern valve gear, which gave a high rotational speed, was the one which permanent way engineers needed to watch.
Alan Mount (226-7) commented upon his Indian experience. J.J.C. Paterson discussed nosing and hunting. V.A.M. Robertson (LPTB, 229-30) discussed nosing, articulated locomotives, multiple-cylinder designs and turbine locomotives...
Colam, H.N. and Watson, J.D. (Paper No.
Hammer-blow in locomotives: can in not be abolished altogether? 38-45.
Abridged: main paper published J. Instn Civ. Engrs (Paper 5243).
Journal No. 166 (March-April 1942)
SOUTHERN Railway: new 0-6-0 freight locomotive. 59-63. illus., diagr. (s. el.), table.
Costa, G.D.A. (Paper No. 434)
Low grade fuel in Indian locomotive practice. 64-85. Disc.: 85-92.
Ordinary General Meeting of the Western Branch of the Indian and Eastern Centre was held in the Conference Room, B.E.S.T. Co., Bombay, on Thursday 21 August 1941, at 6.30 p.m., the Chair being taken by H.P. Renwick.
The generally accepted theory that a small increase in back pressure may reduce the power of a locomotive considerably is not necessarily sound. At equal cut-offs there is a definite reduction of work per cycle with an increase in back pressure, but, as these notes have shown, there may be conditions under which equal work may be done in two cylinders-one with a back pressure of 1.3 psi gauge, the other 5.3 psi./gauge-for about the same consumption of fuel, the cylinder with the higher back pressure requiring merely to operate at a slightly later cut-off. The power of a locomotive over short periods is limited ultimately by the rate at which coal can be burned on the grate and over long periods by the rate at which it can be fired. If then a small reduction in blast orifice diameter does not affect the fuel consumption seriously, it cannot have a serious effect on the power of a locomotive.
The reduction of the blast orifice diameter to induce a locomotive to steam freely has never been a popular expedient with locomotive engineers. An endeavour has been made to show, however, that the usual objections of loss of economy and power have been stressed unduly-particularly at cut-offs below 40 per cent.
Journal No. 167 (May-June 1942)
York, R.S. (Paper No. 435)
Locomotive superheating: with special reference to headers and elements in use on modern locomotives and their arrangement. 99-135.
4th Ordinary General Meeting of the members of the Institution in New South \Vales was held at Science House, Gloucester and Esses Streets, Sydney, on 12 June, 1941, at 8 p.m., . H. Young, chaiman of the Local Memhcrs Committee, being in the chair. New South Wales
The paper also includes power station boilers. The. first British Patent covering a locomotive superheater was taken out by R. Trevithick in 1832, and was applied to what in effect was a vertical water tube boiler. The earliest British patent showing a smoke tube superheater was granted to John Henry Johnson in 1855, as a communication from J.P.C. Montety, the: most intetesting feature of this patent being its very strong resemblance to the Schmidt 1890 patent. Between 1832 and 1870 numerous superheating devices were brought out but, owing to troubles with valves, packing and lubrication superheating on steam locomotivcs was more or less abandoned, until the rcsearches of Wilhelm Schmidt resultcd in Robert Garbe carrying- out practical trials on the Prussian State Railvays in 1897. Ahout 1902, Schmidt introduced his V bolt headcr design, this being the first superheater with elements arrangcd in a numher of separate flue tubes in a locomotive boiler. The steam-tight joints betwecn the header and the elements were made by expanding the elements into flange blocks, and inserting copper or other jointing material between the flanges and the header. T his V bolt header was first introduced into England by George Hughes on the Lancashire and Yorkshire Railway in 1906, into Africa in 1910 on five 4-6-2 passenger engines by G.G. Elliott of the Central South African Railways, into India in 1911 on four 2-8-0 goods engines by Brock of the Madras and Southern Mahratta Railways, and into Australia in tlie same year on a 4-6-0 passenger and a 2-8-0 goods engine by Lucy of the New South Wales Government Railways.
Journal No. 168 (July-August)
Bhote, M.D. (Paper No. 436)
Modernisation of a B.E.S.A. 460 locomotive on the G.I.P. Railway. 142-65. Disc.: 165-72.
Fitted with new cylinders and more efficient valve gear.
Journal No. 169 (September-October, 1942: dated 1941 in IMechE electronic database)
Poole, J. (Paper No. 437)
Freight locomotive rating and the statistical control of fuel consumption. 185-204; 239-53.
Mainly experience in Americas, notably Argentina, but some of the topics covered had general significance. J. Campbell (243-4) commented on locomotive and train resistance formulae, noting that Poole had opted to use those formulated by Lawson H. Fry. He recorded, but did not evaluate some of the other resistance formulae which were being or had been used: Wellington's, Baldwin's, Deeley's, Aspinall's and "even those of our very old acquaintance" D.K. Clark. Also makes reference to F.J. Cole's ratios In Poole's response (page 251) to Durnford (page 240-3) and his reference to the back pressure valve as used in the USA he noted that apparently it is hard to find anything new under the sun and it is not generally realised that a hand-operated exhaust bye-pass was a standard fitting on the Fletcher and Tennant engines of the North Eastern Railway from very early days, while the "jumper" blast pipe used on the Great Western Railway falls under the same category.
Bradley, J.N. and O'Neill, Hugh
Railway bearing metals: their control and recovery. 205-29.
Reprinted from Institute of Metals paper: Authors worked for LMS
Journal No. 170 (November-December)
Turner, T. Henry (Paper No. 438)
Corrosion of boiler tubes. 254-85.
Same paper published in Proc. Instn Mech. Engrs, 149, 74- The effects of the compostion of the tubes, and the action of the feed water, especially its chemical composition and treatment, and the combustion products upon them, Necking or grooving is experienced. near to the edge of the firebox plate and to a lesser extent at the smokebox end. Pitting also occurs, especially when tubes have been straightened or bent. Turner recommended the avoidance of known sources of poor quality water and the softening of water to eliminate hardness. Tubes should be scale-free, pickled or shot-blasted and contain 0.5 to 0.5% copper; new ends for second-hand tubes should be affixed by flash-butt welding; tubes should not be stretched; the new ends of such tubes should always be placed adjacent to the firebox; both the inside and outside of the boiler shell and firebox should be shot-blasted, especially where cracking is feared. The boiler feed should be near to the surface of the water in the boiler and blow down should be performed as continuously as possible. A list of British fire and water tube manufacturers is included (the paper also includes marine and stationary boilers). Includes both the effects of water source and the composition of the tubes.