Ernest Leontine Diamond

Born on 22 February 1902 and, after receiving his education at Rydal School, Colwyn Bay, entered King’s College, London, where he graduated with Honours in mechanical engineering in 1922. He served as a pupil in the Derby Works of the Midland Railway from 1922 to 1924, and from 1924 to 1926 was engaged on the inspection of materials and on special locomotive testing and experimental work.
Later in 1926 he was appointed to the Institution of Mechanical Engineers editorial staff, and within a short time was placed in charge of all the major publications of the Institution, including the Proceedings. When the Specialised Groups were formed, from 1934 onwards, he also took charge of the secretarial work involved. He continued to take a great interest in locomotive performance and in his spare time in the 1920’s and 1930’s he published a number of technical papers giving the results of his observations. In this connection, he was awarded the degree of M.Sc. (Eng.) by the University of London in 1936. For his papers to the Institution of Mechanical Engineers he received the rare distinction of two Graduates’ Prizes, and he also received a George Stephenson Prize.
British engineers, at that time in particular, were following, with keen interest, various engineering developments in Germany; and to help them in their studies the Engineers’ German Circle was formed, with the support of the Institution of Mechanical Engineers, and Mr. Diamond acted as Hon. Secretary of the Circle from 1935 till 1939. In 1940 he was appointed to the Mechanisation Inspection Department (Armoured Fighting Vehicles) at the Ministry of Supply. Later he was transferred to the Components Branch on inspection duties. In 1945 he returned to the Institution of Mechanical Engineers, and became technical assistant to the Secretary and head of the Publications Department. In 1946 he became mechanical engineer to the British Iron and Steel Research Association, and took charge of the Mechanical Engineering Section of the Plant Engineering Division. His operational researches were published in five papers, which included a notable one, written jointly with Mr. Frankau, on overhead travelling cranes, for the Institution of Mechanical Engineers. In 1950 the degree of Ph.D. was awarded to him by London University for his thesis on the handling of steel scrap (based on his work at the Association). For the last twelve years of his life, he occupied senior positions at the headquarters of the British Standards Institution. which he joined as assistant technical diIector in 1949. Later he became head of the Mechanical Engineering Division, and travelled and lectured widely in that Institution’s interests.
He was a great upholder of the British point of view at meetings of the International Standards Organisation, with which he was naturally in frequent contact. He had just returned home after attending an I.S.O. meeting at Turin, when his death occurred, on 22 May 1961. He had been an ILocoE Member since 1945.


Recent improvements in the efficiency of the steam-locomotive. Proc. Instn mech. Engrs,  1925, 108, 53-68.
Author awarded a prize of £5 for this paper, which was read in Manchester on 8th November 1923, and in London on 21st January 1924.
Compound locomotives : their practical economy and disadvantages. Rly Engr, 1931, 52, 430-2. 8 diagrs.
An investigation into the cylinder losses on a compound locomotive. Proc. Instn mech. Engrs, 1927, 112, 465-79. Disc.: 480.517. 10 diagrs., 5 tables.
Development of locomotive power at speed. Proc. Instn mech. Engrs., 1947, 156, 404-43.
Cox lists in Speaking of steam

Magazine article & its reprint

The horse-power of locomotives—its calculation and measurement. E.L. Diamond. Railway Gazette. Reviewed in Locomotive Mag., 1936, 42, 131.
The text, which has recently appeared in the pages of our contemporary, "The Railway Gazette," has now been reprinted in the form of a brochure in response to numerous requests. As Mr. Diamond states in his introductory remarks, the problem is to relate the indicated horse-power and drawbar horse-power recorded at any given instant to the dimensions and design of the locomotive and the nature of the resistance it is overcoming.
This problem, which is complicated by the presence of many variables, of design and otherwise, in the cylinders and valve gears, the action of the blast pipe and limitations of the boiler, may be approached by two avenues. In the first instance there is the empirical method, i.e., the determination of formulae, graphs or tables of figures, based on available test data, for universal application, and secondly, the experimental method whereby a standard is established to which the results of tests on individual types of locomotives may be truly compared.
The earlier pages, then, are devoted to a critical essay on the work of recognised investigators, commencing with D.K. Clark, who is pertinently described as the "pioneer in the systematic study of locomotive performance," and one whose work "can still be read with profit." Exhaustive attention is then given in chronological order to other experimentalists, including such well known names as Desdouits, Goss, von Borries, Dalby, Strahl, Cole, Kiesel and Lipetz.
The latter part of the brochure reviews current methods of road testing. Mention is made of the Russian method, developed by Professor Lomonossoff, in which tests are made under constant conditions on selected portions of track with a dynamometer car, the Polish method, in which an auxiliary engine is used, and the German system, an elaboration of the Polish, in which the brake locomotives are capable of finely graduated braking by compression when run in reverse gear.
No one will quarrel with Mr. Diamond's expressed opinion that there is a defined field for each of the two methods of locomotive testing: the road test for the determination of performance characteristics which will ensure the most efficient utilisation of the locomotive in daily traffic; and the stationary testing plant to determine the value, in terms of thermo-dynamic efficiency, of special devices. Where the latter are concerned, we cannot resist the temptation to remark that thermo-dynamic efficiency and operating, or commercial, efficiency are usually two very different quantities. In many instances substantial economies effected in, say, fuel consumption by the adoption of a special fitting have been more than counterbalanced by additional costs of maintenance; in all cases such as these the results obtained from tests over extended periods in ordinary service must remain the only, ultimate criterion.
The subject is very completely covered, but in its treatment a slightly academic bias may be observed. When discussing drawbar horse-power, for instance, it is stated that it is "scientifically almost valueless"; this, although perhaps rather dogmatic, is undeniable, and any reduction effected in the internal, rolling or air resistance of the engine and tender will have an immediate effect on the extent of the power available at the drawbar, but after all, this latter quantity, in the author's own words, "represents the power ultimately available for drawing carriages and wagons." Again, it is generally accepted scientific practice in attacking any problem where more than one variable is present that successive experiments shall be made in each of which all variables except one shall be excluded. But, having thus segregated and finally evaluated the effects of each variable, it must not then be disregarded, as appears to be the author's attitude when comparing the various methods of testing locomotives and discussing the effects of air resistance, oscillation, centrifugal action on curves and the behaviour of the spring suspension gear. These small phenomena which, where testing is concerned, have a nuisance value only, but for which allowances must be made and are made when designing a locomotive to meet normal running conditions.
The practical locomotive man who thinks he will find here some simple formula, which will enable him to calculate with a slide rule the maximum load a given class of engine will haul, will be disappointed; in the first place it is out- side the specified scope of the work, and secondly, "there ain't no such animal." Mr. Diamond has, however, effectively assailed many of the apprehensions which have resulted from muddled thinking on this matter. He is, too, the master of a particularly pleasing, lucid style, somewhat reminiscent of that of the late Professor Ewing, and we recommend this contribution on locomotive performance, which we hope will not be by any means his last, to the consideration of all those who are interested in this fascinating subject.

Discussion on other's papers

Cox, E.S. A modern locomotive history. J. Instn Loco. Engrs, 1946, 36, 100. Paper 457.
Though there have been many locomotive histories of great literary merit and technical accuracy, Mr. Cox's paper is unique in combining these qualities with an intimate knowledge of the policies and personalities behind the actual course of events. It is seldom indeed that an author with so great a gift for writing locomotive history in the grand style has occupied a position affording knowledge of all the facts. If one regrets that his history covers only ten years on one railway, there is- the compensating reflection that the period was the most interesting in all locomotive history since its beginnings, and the railway the one in which the transition from static mediocrity to progressive design the most striking. -

The paper will do much to enhance the reputations of Hughes and Fowler, which have naturally suffered, especially in the case of Fowler, from the complete eclipse of their products by those of Sir William Stanier. Sir Henry Fowler was a man of very keen intellect, not original, - but receptive, and singularly free from prejudices. He appreciated the ideas of others, encouraged scientific study and attainments in those under him, and was about to take full advantage of the fruits of this broadminded policy when the administrative changes following the grouping threw the whole locomotive policy of the company into a state of flux. It is true that under Fowler two influences were in conflict, and he is naturally identified with the Midland tradition because of his position after Deeley's retirement. But in the final conflict he had clearly appreciated the issues and, left to himself, would have followed the line of progress initiated by Hughes, as his four-cylinder compound designs, now revealed for the first time, clearly show.

The paper suggests that the " Royal Scot " design was the embodiment of the Operating Department's requirements as opposed to Fowler's proposals, but I would like to ask if it was not the case that despite the over-ruling of his main proposals, the details of these engines, and particularly of the valve gear, on which their success depended, were largely due to Fowler?

It would be of great interest to know what the Author's own opinion is, in the 'light of his full knowledge of its details, of the probable success of the proposed Compound Pacific. In this connection Fig. 12 shows the compound in a seriously unfavourable light, and it does seem to demand a more detailed explanation than the Author offers. As the years go by and a locomotive type of any kind is relegated from long-distance express work to stopping trains, its coal consumption on a purely mileage basis is bound to rise considerably unless its efficiency at high speed is very low indeed. A policy based on Fig. 12 without a great deal more information as to the average speeds run at the different periods and the nature of the duties (e.g., we are told that the Horwich compound was confined to the difficult route over Shap) might also, in the Author's own words, "go far astray." This is not intended as pleading in favour of the compound, but simply as a warning that broad overall statistics cloaking a multitude of variables can be just as misleading as technical data based on isolated trials. I would readily agree that for mixed duties under present-day conditions a compound locomotive would be unsuitable, but the Author presumably does not advocate that all locomotives should be built for mixed duty.

I very much hope that the Author will in the future extend this essay in engineering history to cover a wider field. It is at once the kind of writing that is most readable and the most informative. In reply, Cox brusquely dismissed Diamond's observations, which may tell future historians much about Cox.

Lomonossoff, G.V. and Lomonossoff, G. Condensing locomotives. Proc. Instn Mech Engrs, 1945, 152,  275-88. Disc.: 289-303.
Diamond considered the lack of blast rendered by the exhaust was the defining problem with condensing on locomotives


Cox (Speaking of steam)  noted that Nock in his Midland compounds) refers at some length to a paper accepted by the Institution of Mechanical Engineers for written discussion by E. L. Diamond (above), and this unobtrusive and little known paper marks such an important 'might have been' in British Locomotive development that it merits a little more attention. Diamond, a contemporary of this author (Cox), and well known personally to him, had been a pupil of Fowler's, and, until he left railway service around 1926, had been occupied in relatively lowly positions in the CME department at Derby. However he combined a brilliant analytical brain with a deep love for and understanding of the steam locomotive, and might have gone far in the railway service had it not been for one defeating circumstance. He was one of that rare type one only meets occasionally, if at all, in a lifetime to whom everything was blazing light or total darkness. He was in other words a zealot incapable of pursuing his objectives with subtlety and craft, who unfortunately put everybody's back up with the undeviating zeal with which he championed his beliefs and the undisguised scorn which he heaped upon those who disagreed with him. It takes the keenest human insight to see through the superficial asperity of characters of this kind, and to recognise the gold which lies below the dross. Unfortunately for Diamond, and indeed for British locomotive progress, there were no sufficiently broad gauge characters in charge of affairs at Derby at that time. This preamble seems necessary to explain what followed, or rather did not follow. As Nock has pointed out Diamond took the indicator cards which had been obtained during the often described dynamometer car trials with compound No 1065 between Carlisle and Leeds in February 1925, and subjected them to a searching technical examination. It must be remembered that 1065's efforts had put the Midland compound at the top of the league for efficiency in comparison with its best contemporaries on the LMS, and that Follows, Anderson, Fowler and the whole heirarchy were perfectly delighted with it. In his paper to the Mechanicals, given during Fowler's Presidential year, Diamond poured cold, not to say freezing, water upon its claims to optimum efficiency.

Comparing the areas of work done on the diagrams with the total areas theoretically available between steam chest pressure and exhaust he showed that, to quote [using a longer quotation taken from Nock (Great locomotives of the LMS]:

'Perhaps the most important fact of all those set forth is that in the cylinders of the locomotive under investigation which is known to be of high efficiency, the total losses due to restricted passages given to the steam at admission and exhaust increase from 17.6 per cent at 24 miles an hour to no less than 67.6 per cent at 68 miles an hour, of which probably not more than 15 per cent is necessary for the production of draught; that is to say, an amount of power equal to half the work that is actually being exerted on the train is wasted in throttling losses at this speed. In view of this fact the Author unhesitatingly recommends the universal adoption for compound as well as simple- expansion locomotives of the long-lap valves by means of which the port opening to steam at admission and exhaust can be materially improved.'

The writer of these words had not only discovered a notable fact, but he had a cure. He proposed the adoption of long lap valves, and in the cylinders themselves large direct ports and free exhaust passages. In addition he said: "It must be stated that even with these improvements the conventional valve gear can never approach perfection, and it is suggested that serious experiments be made with various forms of poppet gear.

Now what have we here but the identical specification for locomotive improvement of that great engineer Andre Chapelon, which in the fullness of time so transformed the steam locomotive. And what is the date of Diamond's proposals? 1927, by which year Chapelon had no doubt commenced his independent studies, but the first transformed Paris and Orleans compound Pacific to his designs did not take the rails until 1929. So there was the great opportunity lost. If the central facts of Diamond's work had been properly understood and taken up with force and vigour then to England and not France might have belonged the honour of first eliminating the results of internal congestion, and promoting the new life for the locomotive which emerged from allowing the steam to move freely. It was here that Fowler's understanding of the steam locomotive, only superficial amongst all his other interests, stood him in poor stead. He offered no reply to the written discussion, and only permitted his henchmen Chambers and Sanford to offer some comments which were well below their usual standard. In other words he was not going to be taught his business by any youngster, and although there was some subsequent discussion of Diamond's work back at Derby the whole thing was allowed to lapse, but not according to Nock: see .

On page 141 of Nock's Great locomotives of the GWR it is noted that Diamond had been a pupil of Fowler's and that when he left Derby he joined the technical staff of the Institution of Mechanical Engineers. For a time he travelled between London and his parent's home in South Wales and was an eager recorder of locomotive performance.

On page 156 of Fifty years of Western express running Nock notes that Diamond travelled to school in Colwyn Bay from his home in South Wales during WW1 and in 1917 recorded some outstanding performances by the County class between Hereford and Shrewsbury with heavy trains.