Journal of the Institution Locomotive Engineers

Volume 34 (1944)
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Journal No. 177

Alcock, G.W. (Paper No. 444)
Development of the locomotive poppet valve gear in America. 5-25. Disc.: 25-61. 19 figures (illus. and diagrs.)
Third Ordinary General Meeting of the Session 1942-43 held at the Institution of Mechanical Engineers, London, on Thursday, 10 June 1943, at 5.30 p.m., O.V.S. Bulleid, President, occupying the chair.
The Franklin System of Steam Distribution marks a step forward in the scientific development of the steam locomotive. This system stems from two important developments: the use of horizontal poppet valves of a design very similar to that applied to a great many British built locomotives ; and an entirely new design of valve gear developed by the late William E. Wood[w]ard, for many years Vice-president in Charge of Design of the Lima Locomotive Works.
The Franklin Railway Supply Company undertook a major research programme to develop .an entirely new system of steam distribution, which would bring to the American locomotive the full potential advantages possible with poppet valves. The objectives of this research programme were 'as follows :-
Increase mean effcctive pressure to be obtained by a separation of the valve events so that the admission and cut-off, release and compression would be controlled independently, at the same time providing large passage areas for both inlet and exhaust and improved steam flow.
Increase cylinder economy to be obtained by reduced clearance volume, the independent control of the valve events, and by a substantial decrease in back pressure.
Increased mechanical efficiency to be obtained by reduced weight of moving masses, reduced friction and elimination of carbonization.
Reduced maintenance to be obtained by the use of light-weight parts, the entire mechanism to be fitted with anti-friction bearings, running in an oil bath. Absolutely fixed valve events at all speeds and all cut-offs.

Journal No. 178

Poultney, E.C. (Paper No. 445).
Locomotive power. 66-103. Disc.: 103-45. 23 diagrs., tables. Bibliog.
The object of this Paper is to put before members a method which the author has evolved for determining the probable power output of simple expansion steam locomotives as measured by the power available at the coupling between the locomotive and the train. During the last few years much attention has been given to this subject, which is, of course, of great interest and importance. A perusal of the technical journals, and more especially those devoted to railway matters, will establish the truth of this statement, and a list of some of the more important contributions dealing with the evaluation of steam locomotive power which have appeared during recent years will be found at the end of the present Paper. No attempt will be made to discuss the various means which have been suggested at various times and by numerous authorities to establish means whereby the power of a steam locomotive may be estimated. This has been very well dealt with comparatively recently in a series of articles by E. L. Diamond, contributed to The Railway Gazette, and to which attention may usefully be drawn. As Iresult of tha study the author has been able to give to the problem the conclusion has been reached that it is best and most convenient to separate entirely the boiler and the engine performance and estimate locomotive resistance by some formulac which includes engine friction and the rolling and air resistances. The means proposed for estimating pulling power throughout the usual operating speeds obtaining in either passenger or freight service is therefore as follows. Four distinct processes are involved. These are the determination of :-
I. The Tractive Force.
2. Boiler Steaming Capacity.
3. The mean effective pressure in the cylinders from which
4. Resistance of the Locomotive.
is calculated the Indicated Tractive Force.
I. The Tractive Force depends entirely on the dimensions and the number of the cylinders, the diameter of the driving wheels, and the steam pressure, the mean pressure (maximum) being dependent upon the initial pressure and the full gear cut off.
Boiler capacity is taken to be proportional to the grate area, and is determined by the firing rate and the heat value of the coal fired.
The available mean pressure in the cylinders depends upon the steam supplied to the engines per unit of time. This is governed by the boiler capacity in relation to that of the cylinders.
Locomotive Resistance is a function of the total weight, the size of driving wheels, the number of coupled axles, and the head-on air resistance.
Without going into a lot of detail the above shortly sets out the factors governing locomotive power. They are accepted by the author as being fundamental, and form the basis of the proposed method for arriving at the performance of any given steam locomotive of normal type and design, a delineation of which followed:
Discussion:. Mr. E. S. Cox (104-6) remarked that the author, particularly in his conclusions, rather disarmed any criticism of his Paper by pointing out the tentative nature of some of the information on which his calculations were based, and by emphasising his desire to avoid complication. It was possible, howcver, to over-simplify so difficult a subject as locomotive performance, and personally he would like to draw attention to two places wherr he thought that the conclusions given in the Paper might be a little misleading. The author gave a diagram (Sheet 2) illustrating the evaporation of a boiler as it was affected by changes in the calorific value of the coal. That, of course, was something which it was very necessary to study in the design of a locomotive, and especially in the design of a freight locomotive, which had to do its booked work with any kind of coal which might be available. But it was not only calorific value which affected the evaporation ; the quantity of ash and the amount of clinker formed by a coal might also, by artificially restricting the effective grate area as it accumulated, affect the evaporation to a greater extent than a consideration of the calorific value alone might lead one to imagine.
To illustrate that, some time before WW2 some tests were carried out on the L.M.S. Railway with a modern freight engine with modern valve events and a good steaming boiler (presumably 8F 2-8-0), in which trains of some 1,000 tons were taken between Toton and London day in and day out under very uniform conditions of running. The steaming was good, time was kept, and the only factor which was changed was the coal; a succession of different kinds of coal were tried, ranging all the way from the best supplied to locomotives to the worst with which they had to put up. The calorific value of the best was 14,500 B.Th.U. per-lb., and in passing it might be mentioned that all engine testing on the L.M.S., where quality of coal did not enter into it, was carried out with -coal from one colliery alone having the B.Th.U. value. The worst coal had a calorific value of 11,150 B.Th.U. The water consumption-the demand on the boiler made by the engine was very uniform throughout the whole series of tests, but the coal consumption varied from 2.73 lb. per d.b.h.p. hour to 4.12 lb. per d.b.h.p. hour, whereas pro ratu to the drop in calorific value alone the lowest consumption should have been only in the region of 3.j lb. per d.b.1i.p. hour. The difference between that figure and the actual heaviest of 4.12 was accounted for by the factor of the restriction of effective grate area which he had already mentioned. The highest and lowest average evaporations were 8.75 and 5.8; lb. of water per lb. of coal, and the average combustion rates throughout the runs were 39.5 and 67.9 lb. per square foot of grate area per hour respectively.
There was another point which came out of those tests, and which confirmed the author’s method of dealing with the subject by separating the cylinder portion of the engine from the boiler. It was quite clear in those particular tests that the cylinders on the engines concerned had no idea ot what was going on in the firegrate, and they continued to demand steam at a rate which required from 23 to 24 lb. of tender water per d.b.h.p. hour throughout the whole series. The boiler was able to supply that quantity irrespective of the quality of the fuel. It was true that at the tail end of the trips with one or two of the worst coals some falling off in steaming was apparent, but otherwise steam production was fully adequate and working pressure was maintained.
That led to the conclusion that a well-designed engine working within its designed capacity and in good working order did not have its performance affected by quality of coal, within very wide limits ; it simply used more of the coal as the quality declined. Bad coal seemed to affect performance only if it was very bad indeed or if the engine was run down or if it was obviously overloaded. Indeed, if that were not so it was difficult to see how the locomotives in this country could grapple with war-time conditions as they were doing to-day. That was just one more example of the extreme flexibility of the steam locomotivo to meet fluctuating conditions.
Another instance of where it was not easy to agree with the author's rather simplified conclusions was where he said that steaniing power was proportional to the size of the fire-grate and was independent of the heating surfaces, within the limits set by normal boiler proportions. That might be true if the word "ideal" were substituted for the word "normal," and it could, of course, be conceded that heating surface simply expressed in square feet was now discarded as a suitable comparative measure of boiler capacity ; but unless each tube was so proportioned that it would give up the maximum amount of heat with the minimum resistance, and unless the total cross-sectional area through all the tubes was sufficient as an index of the capacity of the whole tube bank to boil water, then the steaming power would be restricted, whatever the grate area. It might be said that all modern boilers should have ideal proportions in that respect as a matter of course, but unfortunately such was not the case. Factors such as weight and loading gauge restrictions, the quality of uater used, the individual ideas of designers and the wish to standardise sizes of tubes had their influence in preventing the theoretically best values for those factors being adopted, and the maximum steam production rate had to be discounted accordingly.
Turning to the specific examples of performance curves given in the Paper, he thought that the author had been too much led away by the desire to correlate his characteristic curves with actual details of engine performance, and had also rendered the comparison rather more difficult by drawing his curves to cover a particular running condition, namely, running on level tangent track, whereas variable-speed dynamometer car tests, with which he was trying to make the comparison, were carried out on British railways under every variety of curve and gradient. To be of general use, it would seem that a locomotive characteristic performance curve must be done for the maximum performance of which the engine and boiler was reasonably capable at each speed expressed in terms of performance at the rim of the wheel, so that the data provided could be applied, with suitable allowance for engine and train resistance, to every successive variation in running conditions which the engine \voultl encounter in service. The best way to obtain each point on such a curve was by constant speed tests on the line with the particular locomotive, but in the absence of means to do this—and hitherto means for carrying out constant speed tests had been available only one the L.N.E.R., and there only recently—it was possible to produce the curves, but more tentatively, from theory combined lvith the published results of constant speed tests.
The author’s curves, however, suffered from an artificial restriction in the imaximum steam production capacity of the boiler, because the author had selected rates corresponding to the average throughout a test run in which speed, cut-off, rate of combustion and rate of steam production had varied widely. It was in fact impossible to use the average figures from the variable speed dynamometer car test to fill in the points on a characteristic curve, because such tests were tests of trains rather than engines, and even the maximum recorded power output on such runs might be well below the maximum of which the engine was capable, but it was none the less adequate for the schedules of the trains being tested. The two series of tests on the L.M.S. referred to in the Paper, Sheets 13 antl 14, did, however, involve very nearly the niaximum output of which the engines were reasonably capable for one or two individual parts of the run. Taking Sheet 14, the test of the Pacific engine, first, the three steam-flow rates on which the curves xvere based were far below the sustained capacity of the boiler to produce steam. On the particular runs on which the top curve was based, giving an average steam flow of 29,600 lb. per hour, ;I maximum rate of steam production of p,soo Ib. per hour was atctually attained.
None the less that was a maximum power of which the engine was capable, and corresponded to a rate of comhustion of about 13.5 lb. per square foot of grate per hour. The corresponding recorded d.b.h.p. was 2'510 at 44 m.p.h. No indicator cards were taken, but as a result of careful calculations the i.h.p. was estimated at 3,350. It would be seen, therefore, that the true characteristic curve of that engine’s performance was very much higher than the author indicated; and, while the above figures were on that particular run translated into a load of 600 tons and an average speed of 55 m.p.h. over the very severe road betwccn Crcwe and Glasgow and return, the same high power output was always available if needed to deal with a heavier train or at it higher speed and more level route. In the case of the 4-6-0 cngine, Sheet 13, this was nearer the maximum of which the engine was capable, but there again the recorded sustained maximum, on the particular runs selected by the author, gave 1,232 d.b.h.p. at 57 m.p.h. and 1,208 d.b.h.p. at 69 m.p.h., with calculated i.h.p.’s of 1825 and 1863 respectively. The maximum steam production of that boiler was in the region of 27,000 lb. per hour, at a combustion rate of 150 lb. per square foot of grate per hour.
It was very necessary, of course, not to confuse maximum power output with maximum thermal efficiency. The rates of output just mentioned were not, of course, those at which the highest thermal efficiency was obtained, but they were liable to be attained at any time on short severe sections within the length of a run whose average figures would bc very much less. 'lhey were moreover short of the point at wllich the curve of consyniption per d.b.h.p. hour steepens sharply towards an uneconomic level. They gave high operating efficiency in representing the reserve capacity available to meet maximum conditions oi spcetl, gradient and load on a given run.
In conclusion, he would like to say a word about the L.M.S. curves for train and engine resistance to which the author referred, and which were published in Sir William Stanier's address. The curves were drawn as the result of many dynamometer car tests over a long period of time, and, though they appeared to be low and were lower than the curves which the present author had given, they none the less seemed to be very close to the true values for modern engines and stock. It was interesting to note that the L.M.S. resistance curve for rolling stock was very close to the curve based on the formula given in the American press at the time that tests were being made in America with very heavy trains at 100 m.p.h.
F.C. Johansen (107-8) deplored the tendency evident in the Paper to perpetuate the idea of air resistance being associated with weight ofe the locomotive.
The President (O.V.S. Bulleid: 116-118) said he always enjoyed a Paper by the author, but whenever he read a Paper he always asked himself, “ What practical use am I going to get out of this? ” A locomotive, after all, was a hauling machine, purely and simply, and the author had described how to arrive at its drawbar capacity. Personally, he had once had the onerous task of re-loading the whole of a railway company’s engine power, and, being young and enthusiastic, he studied every locomotive resistance formula that he could get hold of and, having made one or two simple tests, he took one of Ivatt’s Atlantic engines to find out, by coasting, what sort of resistance a 4-coupled engine would have. Running down from Stoke, they found that if they ran at 49 m.p.h. the engine pulled herself down to 31, and if they ran at 20 m.p.h. she pulled herself up to 31, so that they took 11.2 lb. per ton as representing the resistance of an Atlantic engine, which was just as good as any other figure.
When they worked out the loading, which they did at considerable length, they quickly realised that when loading trains over gradients of 1 in 50 in the West Riding of Yorkshire, 1 in 100 on other routes, and 1 in 200 on the main line, and when they had to add 22 or 44.8 lb. per ton to every ton of the engine and the train, it was really of very little moment whether the resistance of the engine became 12, 15 or even 20; and from that day onwards he had always used a rough and ready calculation, taking the goods train at 6 lb. per ton and the locomotive at 12. He found that as a rough and ready approximation, which did not even call for the use of the slide-rule, he could get a very fair approximation by taking the engine resistance at 12 lb. per ton plus the gradient and deducting that from the tractive effort of the engine, which gave him R very crude but workable figure for the tractive effort available behind the engine; and if he divided into that the figure obtained for the train he got the weight of the train behind the engine, as closely as he wanted it. That had one undesirable consequence ; very often it bought him back to the difficulty he had to face as a young engineer when confronted with the fact that some of the older engines could in fact haul more than some of the more modern ones, which was a very awkward stumbling-block when one was young, to find that the latest was not necessarily always the best. They confirmed their train resistance formula in a very striking manner. They were working the  Cock o’ the North ” (which, it would be recalled, was a poppet-valve engine originally), and she was undoubtedly, as he had said on a previous occasion, an extraordinarily free-running engine. On one occasion they passed Potters Bar with about .500 tons behind the tender at 70 m.p.h., and they then pulled the engine up into mid-gear, so that all the poppet valves were off their seats; and, having begun that 12-mile stretch, mostly downhill at 1 in 200, at 70 m.p.h., they found, when they began to slow down to stop at King’s Cross, that they were doing 72 m.p.h.! He concluded, therefore, that anybody who talkcd about the high friction resistance of a locomotive was confusing the machine friction of the locomotive and its compression resistance. That was a point to notice, because obviously that engine was rolling down the 1in 200 very nearly as freely as the passenger rolling stock. Those were two interesting experiments which they made, which confirmed the figures as to train resistance in a very practical way.
A good deal had been said about coal, and the Institution was very indebted to Mr. Cox for the information he had given about the experiments he had described. Personally, he thought that that information was the most interesting addition which had been made in the course of the discussion to the Paper. To him, however-, bad coal did not mean coal of 11,000 or 12,000 B.Th.U. What most of the Southern drivers called bad coal was coal which preferred to go straight up through the chimney rather than burn at all, and which remained as a solid slab in the bottom of the tender, because it was so fine and so packed that they could hardly handle it. It was not, therefore, altogether a question of B.Th.U., but of the wretched stuff which one had to try to hold 011 the grate, That was why the figures on the Southern, using South Wales coal which had been shattered by putting it through a coaling plant, were a great deal higher than one liked ta see published. The Paper was very interesting, but he did not like the author’s short cuts with grate area. If the author would reflect for a moment on certain recent locomotives which had come into this country, he would perhaps think again and decide that grate area alone was not the measure of a good locomotive boiler. Personally, he had always thought that locomotive firebox volume was the critical factor.
He would like someone to tell him whethcr steam was genetated instantaneously. Did steam just happen in that way because one wanted it, or did it in fact take a time? He had never been sure about that. He thought that the author was quite wrong in taking Kiesel’s formula and saying that it was devised twenty years ago. Locomotive engineers had not been standing still for twenty years, and locomotive proportions, steam-pipe size, volume of steam in the steam-chest and so on had made great progress, and so, too, had the exhaust arrangements. Mr. Kiesel had been very remarkable at the time, but was surely a little antiquated now.
The President added the author was, unfortunately, in indifferent health, and he was sure members would understand if he preferred to reply to the points raised in writing.

Journal No. 179

Fairburn, C.E. (Paper No. 446)
Maintenance of diesel electric locomotives on the L.M.S. Railway. 212-58. includes folding diagram (side elevation).
Worked three shifts and either six or seven days per week: weekly mileage 200-250. Outlinesmodifications made to the design.

Journal No. 180

Cox, E.S. (Paper No. 447)
Locomotive axleboxes 1944, 34, 275-317. Discussion: 317-40:1945, 35, 221-38:1946, 36, 171-6+ 3 folding plates. 21 diagrs., 8 tables.
In 1939, the last pre-WW2, there were 87, 914 axleboxes on the 7,508 steam locomotives in stock on the L.M.S. Railway, and 43,476 of these were coupled axleboxes. The design, manufacture, operation and maintenance of this large number of bearings is an important part of the work of the Mechanical Department, especially in the case of the 50% of the total represented by coupled boxes, which are subject to such a variety of fluctuating forces as to render them something quite apart from journal bearings as normally understood in engineering practice. The service given by these axleboxes is one of the major controlling features in locomotive availability.
There are three principal factors which directly affect such a\ ailability so far as axleboxes are concerned :
1. Rate of wear.
2. Number of failures in traffic--almost entirely in the.....
3. Time taken for repairs.
(u) Inherent characteristics such as loading, design, choice of material and lubricating oil, method of Iybrication, repair procedure, etc. ; and
(b) Incidental failure in individual cases due to human element, defective material or accident.
The greater part of this Paper is devoted to group (a) above. Unless otherwise stated the experience and practice referred to is that of the L.M.S. Railway and, in view of the many abnormal features of wartime operation, it is confined with one or two exceptions, to the period before the present war
Bulleid (325-7): lubrication of Merchant Navy class. The 1945 Meeting was held in Birmingham on 28 February 1945 and was chaired by E.J. Larkin (his remarks in Volume 45 pp221-2); D.W. Sanford (222-3)noted that the Stroudley method of arranging the cranks reduced the load on the axlebox, but increased the stresses on the crank axle; R.G. Jarvis (224-5) showed axlebox force curves and noted that outside two-cylinder locomotives tended to develop knock more noticeably on the left-hand side; G.M. Rickards (225) observed that heavy collar work has a greater affect upon bearings than speed; A.H. Edleston (226) requested the size of the axleboxes on the SR Q1 0-6-0 and was refered to Journal 166 (1942) where it is stated that they were 8¾ inches in diameter; N.E. Neale (226-7) observed that the 8F locomotives in Persia did good work when lubricated with castor oil and also observed that the Hennessey lubricator fitted to the USA 2-8-2s worked well. R.G. James (227) noted that the 8F class in Turkey were lubricated with oil distilled from coal (which he called a form of creosote); F.G. Carrier (227) noted that the 4F 0-6-0s were the worst offenders with their steeply inclined cylinders. H.S. Hanson (227) noted that the load varied greatly on idividual axleboxes on the 4F class. C.E. Peake (227-30) submitted a written communication; J.W. Caldwell (230-2) commented on the Cannon type fitted to the LMS turbine locomotive (Turbomotive) and was appreciative of the GWR under pad form of lubrication. C.W. Clarke (236-8) recorded the difficulty of using non-ferrous alloys in India.
****Second Ordinary General Meeting of the Birmingham Centre was held at the Midland Hotel, on Wednesday, 28th February, 1945, at 7.30 p.m., the Chair being taken by Mr. E. J. Larkin. The Minutes of the Meeting held on 31st January, 1945, were read, approved, and signed as correct.

Journal No. 181

Lynes, L. and Simmons, A.W.  (Paper No. 448)
Brake equipment and braking tests of Southern Railway C.C. electric locomotive. 345-95.
Sixth Ordinary General Meeting of the Session 1943-44 held at the Institution of Mechanical Engineers, London, on Wednesday, 31 May 1944, at 5.30 p.m.: Mr. O.V,S. Bulleid, President, occupying the chair.
The brake trials carried out with the S.R. Mixed Traffic Electric Locomotive Type C.C. brought some problems when introduced to traffic were unique. Further, the Authors intend, in order not to prejudice any paper which may yet be read to this Institution, to deal exclusively with the brake on the locomotive, giving a brief description of the essential parts of the brake apparatus necessary to the subject.

Journal No. 182

Graff-Baker, W.S.
Address by the President. Looking forward. 403-13.
The opening Ordinary General Meeting of the Session 1944-45 held at the Institution of Mechanical Engineers, London, on Thursday, 26 October, 1944, at 5.30 pm.,
As the advantages of electrification decrease, the case for diesel electric- or the retention of the steam locomotive improves. In any case, the job cannot all be done at once and first things should come first.
Stage I .-Electrifying suburban services plus such parts of the main line as present clear advantages;
Stage 2.-Gradually replacing main line steam locomotives on unelectrified sections by diesel electric locomotives, using the gradualness of the change to gain technical and operating experience ;
Stage 3.-Gradually electrifying the remainder of the main lines by sections, applying the experience gained under stages I and 2; and
(a) Abandoning branch lines and substituting road
(b) Developing specialised branch line vehicles and motive
(c) Continuing the use of steam locomotives on branch or a combination or selection of any or all of these according to circumstances.
In the development of main line diesel electric locomotives it may well be practicable and certainly desirable for such :ilachines to operate from the electric power supply as electric locomotives when working in urban electrified areas and-in the interests of smoke and noise abatement-to run on the diesels only outside the cities. Such locomotives could be converted to all-electric at a later date when opportune and have a continuing life after the transition from Stage 2 to Stage 3.
What form is the passenger rolling stock of the future to take? The answer is largely independent of the means of traction. There are two kinds of vehicles used generally in the world-saloon cars and compartment coaches. America uses saloon cars exclusively, but in Europe compartment coaches form by far the majority of passenger vehicles. It is to be noted that of late the saloon car has increased in number in this country, while it is also to be noted that many persons like to get into a dining-car and stay there. Incidentally, the Pullman car in its British manifestation, regarded as a luxury train, retained the saloon form. The Blue Trains and the Golden Arrows were saloon car trains. It seems perhaps reasonable to suggest that there will be a further turn over from compartment to saloon type vehicles.

Young, Harold (Paper No. 449)
Some notes on the C.38 class 4–6–2 type locomotive in service on the New South Wales Government Railways. 418-43. Disc.:443-50.. 17 figures (illus. & diagrs.)
Joint meeting of the Institution of Locomotive Engineers and the Institute of Engineers (Australia) held at Science House, Sydney, on Wednesday, 15 March 1944.
The heaviest passenger trains ol 500 tons then operatcd on the N.S.W. Railways with two 4-6-0 type locomotives of the C.36 class. It was considered that a Pacific locomotive (4-6-2 type) could be designed to give better locomotive proportions, greater power with a relatively small increase in weight on the driving wheels, less destructive action upon the track and eliminate double heading on all grades other than the 1-40 or steeper. Therefore, the C.38 class locomotive, of the two-cylinder simple Pacific type, illustrated in Fig. 1 , was designed by the Mechanical Branch, N.S.W. Railways, and constructed by the Clyde Engineering Company, Sydney, to railway working drawings, specifications and inspection and certain important components were completed at Eveleigh and supplied to the company. The first of a series of five was placed in service on 22 January, 1943, and has performed to expectations. Fig. 2 gives outside dimensions and weight distribution.