Sir Nigel Gresley - The L.N.E.R.’s First C.M.E.

S.A.C. Martin · Jan 19, 2023

huochemi said: ↑

The paper is essentially about counter pressure brake testing of a B17 using an old NER 4-6-0, partly dealing with the details and benefits of that testing procedure and partly some comments about the B17's performance and leading on to some generic comments about the need for larger valves and the possible advantage of two cylinders (v. three) (perhaps he had the B2 with two cylinders and 10" valves in mind?), and one or two acerbic observations. Robson obviously upset the president, Bulleid, who made the rather gnomic comment "Another of the author's great merits was that he had no hesitation in saying exactly what he thought." Tester incidentally uses some of Robson's findings in his book on large lap valves and provides some useful commentary on what they reveal e.g. the difficulty of getting steam into the cylinders at short cut-offs.
Click to expand...

That's quite a reading of the paper. I read it very differently, rather than acerbic from the author it was perhaps pointed in the use of larger valves, but it wasn't aimed at anyone specifically. Bulleid seems to write quite defensively. See below:

The counter pressure method of testing locomotives. 171-98. Discussion:198-217+ folding plate. 5 illustrations., 12 diagrams. (including 2 side elevations.)

In order to save expense the Author attempted to use one locomotive only, although it was appreciated that the extra power absorbed per cylinder might cause difficulties. An old 4-6-0 locomotive with outside cylinders and piston valves, built in 1906, was put at his disposal and the necessary alterations made, the French practice being followed. When about 600 horse-power mas being absorbed, the metallic packing was melted out of the piston and tail rod glands, so the water injection was led to the centres of the cylinders instead of into the steam chests, the supply was much increased and the glands were lubricated mechanically. These alterations were an improvement, but when attempting to absorb 900 horse-power, the driving axleboxes heated badly. These were steel with an inserted bronze bearing in the crown, and the side faces were too small to withstand the heavy side thrusts. Solid bronze axleboxes, without any white metal, were fitted to the driving axle having large bearing surfaces on the inside of the wheel boss, and three oil feeds were supplied to each box, one syphon feed to the wheel boss and one syphon and one mechanical feed at the rear.

Includes details of the tests performed on the B17 class locomotive No. 2811 Raynham Hall. Whilst the data are presented in graphic form, the precise location and dates are not given

The Author wishes to thank Dr. F. Aughtie and Mr. F. M. Colebrook , of the National Physical Laboratory, for helpful criticisms during the design of the circuits used, and Mr. C. Jarvis, Mr. P. Dobson and Mr. D. Carling, members of his staff now engaged on more important work, for the help received in the development of the apparatus mentioned, and also Mr. E. Thompson, the Chief Mechanical Engineer of the London and North Eastern Railway, for permission to publish the results given in this Paper.
Pp. 206-7 : Comment on the Vitry tests with P2 class 2001 Cock o' the North, Contributors to the discussion included E.S. Cox, O.V.S. Bulleid, H. Holcroft and E.C Poultney.

E. C. Poultney (198-9) , who opened the discussion, prefaced his remarks by thanking the author for contributing such a very interesting and valuable Paper to the proceedings. He hardly knew which part of the Paper to admire more—the graphic description of the testing or the very pointed remarks on locomotive design, and particularly with regard to valves. He felt that he could not usefully make any observations on the question of testing, except that probably the method which had been outlined, while very ingenious, must require an enormous amount of rehearsal before the results desired could be obtained. Inasmuch as each point plotted on the diagrams represented a separate test, the results were obviously extremely good; the points were very close together, and there was not much discrepancy between one test and another when the same specific object had been in view.

So far as the results obtained at various cut-offs were concerned, he could not but think that the Author had perhaps been a little unfortunate, because while personally he would be the last to criticize the performance of the locomotives of the London and North Eastern Railway, in view of the excellent work that they had done and were doing, he thought that on the whole the valves employed on them were very much too small for the cylinders, judged by modern standards. On the other hand, the cylinder design adopted for the B.17 type locomotive used in the tests did not lend itself very well to the adoption of what might be called a full-sized valve. The arrangement was, he thought, well-known, and was shown in the accompanying sketch. The three valves were all in line, and the position of the frames prevented the fitting of a valve of proper size for the centre cylinder. When the Gresley Pacifies were first built they had cylinders of 20-in. bore, and an 8-in. valve, while modern practice would be to employ an 11-in , or 12-in. valve with a 20-in. cylinder. That made an enormous difference to the power which could be obtained at an earlv cut-off.

It was of interest, in that connection, to study a diagram, Fig. 17, published in The Engineer, 23 May, 1906, which showed the performance of a Great Western Railway locomotive with 18-in. by 30-in cylinders with l0-in. valves. At 18 per cent. cut-off and 63 m.p.h., the drawbar horse-power was 800; at 20 per cent. cut-off and 58 m.p.h. it was 900; and at 23 per cent. cut-off and 60 m.p.h., 1,100 drawbar horse-power was shown by the dynamometer. Those figures were far in advance of those obtained with the B.17 type engine dealt with in the Paper, and he thought that that was clue entirely to the fact that the valves were large in proportion to the cylinders. The figures he had given, moreover, were obtained with a saturated steam locomotive. If he were a chief mechanical engineer, he would have that chart exhibited in his drawing office; it was a wonderful example of what could be done with large-size ports and valves to get the steam into the cylinders and out again.

He thoroughly agreed with the author's remarks with regard to the design of cylinders; he was sure that there was a great deal of room for improvement. He knew that there were strong objections to the use of very large and heavy valves, which threw enormous stress on the valve motion. There were also strong objections to the use of small valves, because it was difficult to get the power reguired. There was probably very good reason, therefore, to do away with them altogether and use poppet valves.

E. S. Cox (199-) said that great credit was due to the author and his colleagues for having done so much useful work and for obtaining so much valuable information by what were relatively simple and inexpensive means. The London and North Eastern Railway, however, enjoyed certain advantages, the absence of which might preclude other railways from following quite so simple a method, the principal one being a stretch of line 44 miles in length of almost unvarying gradient, for the most part dead level. Similar tests made abroad had also been carried out on long lengths of level track, or at any rate track with only a gentle and continuous gradient.

Some reference was made in the Paper to the fact that the L.M.S. Railway, which had been considering the use of the type of testing in question before the war, were proposing to develop it by the use of electrically braked vehicles. That was done not from any desire to make the tests more complicated or more expensive, but because on that railway there was not a sufficient length of level track, comparable with that to be found on the L.N.E.R., and also because it was desired in the L.M.S. tests to bring in the question of coal consumption, for which purpose it was felt that at least an hour's run would be necessary, in order to stabilise conditions in the fire. An hour's test at 70 to 80 m.p.h. meant a continuous run of more than that distance, and on the L.M.S. there was no level or even continuous up-grade track of that length; the best piece of track which could be found would include both up and down gradients, and in those circumstances the problem of the regulation of speed was likely to be very much more difficult than on the L.N.E.R. or in the case of the tests carried out abroad. For that reason the electrical method was decided upon, simply because it gave the assurance of very accurate control under widely differing conditions of running resistance, He regretted that it was not possible to give any comparable results of tests on the L.M.S" for the units had only just been completed when the war broke out, and no data were yet available.

The author had referred to Figs. 5 and 6 of the Paper as containing the most important of the deductions made from the tests, and they did in fact confirm in a nutshell the result of all the investigations made by M. Chapelon, underlining the importance of freedom through steam ports and passages. It would be interesting to hear from the author what practical steps were taken, in view of the information so disclosed, in order to obviate on actual engines the difficulties disclosed by the diagrams. In that respect the omissions from the Paper were rather tantalising, because it was well known that the L.N.E.R. had a number of locomotives with poppet valves, and it: would be very interesting to hear whether those valves, with their separation of inlet and exhaust events, and the possibility of better valve opening at early cut-offs, had shown any signs of bringing- about the improvements which were so much to be desired.

He was sorry also that the author did not show in the Paper what an actual indicator diagram looked like when taken by the cathode-ray and photographic method referred to in the Paper. It would be of particular interest to know whether that method gave a diagram which corresponded exactly in its area and characteristics with a diagram taken by an ordinary Crosby indicator on the same engine under conditions where it was known that it could be fairly accurate, as for example at slow speeds. If that could be shown it would be a step forward, because he felt that while it was necessary to develop and utilise the cathode-ray indicator to a much greater extent in future, some form of comparison with the older type of diagram was desirable in order to give confidence in its use for measuring power output.

A.F. Webber, (201) speaking as one who himself had been engaged for some years on engineering research in industry, remarked that his experience during those years entitled him to say that the work disclosed in the Paper was engineering research work of the highest order. Every credit was due to the author and his colleagues for the work which they had done and for the successful conclusion to which they had brought it.

Turning to some points of detail in the Paper, he did not think that the author had fully explained the effect of the port opening. In the first diagiam showing the drawbar pull against speed for different cut-offs (Fig. 4) there was a certain trend going on up to and including the 35 per cent. cut-off, in that the slope of the line was steadily steepening; but at 45 per cent. cut-off there was a reversal of that trend. He understood that that was due to the increasing port opening, but, if that was so, he would have expected that it would become apparent gradually. Instead of that, up to and including 35 per cent. cut-off the port opening did not seem to influence the position, the drawbar pull falling off with increasing steepness, while at q j per cent. cut-off there was a sudden reversal of that trend. Fig. 5, which was used to show the marked increase in drawbar horse-power when the cut-off was increased from 15 per cent. to 25 per cent., was from one point of view a little unfortunate, because it should be noted that the zero was not shown on the diagram, the ordinates starting at zoo db.-1i.p. That had the effect of exaggerating to the eye the difference in drawbar horse-power between 15 per cent. and 25 per cent. cut-off.

On page 182 of the Paper there mas a remark which seemed to require some amplification. The author said: “The pressure drop to the steam chest will be proportional to the amount of steam take:> by the cylinders.” Strictly speaking, the word “proportional,” if it was not qualified, meant directly proportional, whereas, in fact, the pressure drop would be proportional to the square of the steam flow. He thought that a correction should be made there, as otherwise readers might be led astray. Further, one should be very careful about taking a system resistance as equivalent to an orifice. The pressure drop across an orifice arose primarily from the convI:rsion of a certain amount of pressure energy to kinetic energy. The pressure drop across such a system as the regulator, superheater elements and steam pipes was chiefly due to frictional resistance, and the characteristics were not identical with those for the pressure-velocity conversion.

With regard to smokebox temperatures, although the point was, perhaps, not strictly relevant to the main thesis of the Paper it would be interesting to know whether any steps were taken to make traverses with a thermocouple to ensure that the point finally selected for the test was an average temperature in the smokebox, and also whether any tests had been made with a high-velocity suction thermocouple to ascertain the effect on the ordinary sheathed couple which he assumed, in the absence of any statement to the contrary, was used; because such a couple, if of fairly large dimensions (5/8in. or ¾-in. in diameter), would be very seriously affected, so far as the temperature which it attained was concerned, by its surroundings, by which he meant the front tube-plate of the boiler, which was approximately at boiler-water temperature, and the rest of the smokebox shell, which was at some temperature intermediate between the gas temperature inside it and the air temperature outside. He had had some experience of that problem of gas temperature measurement, and he thought that it was not an over-estimate to say that in conditions which were roughly similar to those at present in question the thermocouple reading might be 50°F. to 100°’F. lower than the true gas temperature.

A point which occurred to him as being of great importance if successful steps were to be taken to overcome the difficulty at the inlet ports at early cut-offs was the following. If the drawbar horse-power at 15 per cent. cut-off was increased sufficiently to maintain constant drawbar pull, it would, of course, mean a very great increase in the steam demand on the boiler. As the cut-off would remain at 15 per cent., the exhaust pressure would presumably remain more or less constant, ‘and he would suggest that the repercussion on boiler design would be very serious, because the boiler would have to produce this increased quantity of steam without any help from increased blast-pipe pressure.

A final comment, though a minor one and one even further removed from the main thesis of the Paper, was that according to ordinary financial reasoning a company was not, as the author seemed to suggest, insolvent if it could not pay dividends to its shareholders, but only if it could not pay its debts.

D.R. Carling ((202-) (the only member of the author's dynamometer car staff who was able to be present) said that to the main description of the tests already given he could add very little, except to say that the tests occupied about a fortnight on the line, and, due to the traffic-passing on the line in question, it was usually possible to make only one run in each direction daily. That was often a severe handicap. When Professor Lomonossoff initiated constant speed testing in Russia in 1908, his test trains were given equal priority with the Tsar's train, and all ordinary traffic had to give way to them. It was improbable that such a position would ever exist in this country, but possibly a little more help in that direction might be received from the Traffic Department in future.

The Paper necessarily condensed into a small volume a large amount of work done in the tests, and when one little point was shown on a graph with a small figure against it, it meant that a great deal of work had gone into establishing that figure from genuine data. Unfortunately they were not able to complete their work on the indicators. They had just reached the tantalising stage when they intended to photograph the screen and obtain some final results when Hitler threw his spanner into the works, and any further work had to be postponed. The same thing applied, of course, to any altera- tions in design which might have been based on the results of the tests carried out. There was no doubt that the slide shown by Mr. Poultney did indicate how far in advance of all others the G.W.R. were at the date in question, and the effect on design on the L.N.E.R. of the locomotive exchange between the two railways was too well known to need detailed description. It was quite true that it was extremely difficult to get larger valves of the ordinary type into the space available in the British loading-gauge with three cylinders, especially with the conventional British plate frame, and probably it would become necessary to use entirely independent inlet and exhaust valves at each end of the cylinder-either poppet valves, as Mr. Poultney suggested, or independent piston valves , as used by M. Cossart on the former Northern Railway of France.

A point of considerable difficulty in dealing with the test equipment was that the locomotive under test was housed in the ordinary engine sheds, and all the apparatus hac! to be designed with that fact in mind, because one never knew when one's carefully made indicator was going to receive a clout from the shovel of ~ passing fireman, or when some similar mishap would occur to other apparatus. All delicate equipment had to be dismantled every night. When he had the honour of accompanying the author to France they had been greatly impressed by the fact that for certain tests which were being done there a large electric express locomotive was placed permanently at the service of the experimental section, which was provided with adequate accommodation for it, and only at times of great traffic activity was it returned to the Traffic Department, as a favour. There could no doubt that an improvement in the conditions under which tests were carried out would greatly simplify the apparatus used, and probably the value of the results obtained would far outweigh the cost of providing the equipment.

As a result of tests on a single locomotive class in Russia before the last war, Professor Lornonossoff succeeded in saving annually about ten times the total cost of his experimental department. The difficulties in developing the new indicators had often been very discouraging and it was due to Mr. Robsons persistence that so large a measure of success had been attained. H. Holcroft (203-)said the author had done the Institution a great service by describing the latest form of locomotive testing, which is comparatively new to this country, although it has been used on the Continent for some time past. It would be of interest if the Author would give some indicator diagrams showing the action taking place in the cylinders of the counter-pressure engine. If information of that kind was available, it would be a valuable addition to the Paper.

While it simplifies the procedure and facilitated research by enabling constant conditions to be maintained and unwanted variables eliminated the system described in the Paper should not be regarded as seperseding all other tests. there being at least five methods of testing locomotives. There was first of all direct observation from the footplate in actual service, with or without a measured coal and water over-all lest.

That method was of value in assessing the fitness of the design to carry out the intended duties, and it was purely an operational test. Then there was testing by means of the dynamometer car with a train attached, which recorded the actual work done: by the engine over a particular route with a given load and speed. It was very difficult to evaluate the dynamometer record accurately in this case because the inertia effects of the locomotive on the -drawbar with varying speed added plus and minus quantities to it which had to be allowed for, and it was not at all easy to assess the correct amount of acceleration or deceleration taking place at any moment. Then there were indicator trials, and these were run, with or without coal consumption tests, when no dynamometer car was available. The author had described the latest form of testing with the dynamometer car and a braked load, and the advantage of that method, of course, was that it was possible to get steady conditions of speed and so plot the results more accurately and thereby determine what the engine would do under any given circumstances. Finally, there was testing with stationary plant; and that had some advantages where development was concerned, and some disadvantages.

For instance, the drawbar pull recorded was not the true reading which would be obtained on the line, because the atmospheric and track resistance were not present, and only the machine resistance was deducted from the indicated horse-power, and, of course, there was the absence of the cooling effect due to the passage of air over the hot surfaces of the engine. All five methods have their particular merit in one direction or another, and they should be regarded as being complementary rather than competitive.

He was very interested in what was said in the Paper with regard to the low efficiency at 15 per cent. port opening, and would like to suggest to the author the use of a piston valve of half the normal diameter and twice the travel, which he thought should give greater port efficiency. The greater inertia forces set up by the acceleration of the valve would be largely balanced by the lighter weight of the valve, so that the valve gear itself would not be subjected to any more loading.

It had to be remembered that the 15 per cent. cut-off was only a nominal figure, and the clearance volume in the cylinder modified its value very considerably; ordinarily, 15 per cent. nominal cut-off represented an expansion rate of about 20 per cent. ; but here again at fast engine speed the diminishing aperture in the closing phase of the valve while the piston was moving at high velocity resulted in very little steam getting through approaching cut-off point, and, as speed increased, this amount decreased, the cut-off really becoming limited by the time factor rather than by the precise action of the valve, so that a 15 per cent. cut-off became virtually 12 per cent. or less with increasing speed.

The author also suggested the lengthening of the cut-off to 85 per cent. to give greater starting effort, but' the difference in mean effective pressure between 75 per cent. and 85 per cent. was scarcely appreciable, and one would be using 10 per cent. more steam to little purpose. On the other hand, an improved starting effort, i.e. the avoidance of dead centres, would be the chief advantage; but, while that might be desirable in the U.S.A., where there were long close-coupled trains with automatic couplers, and setting-back at starting was to be avoided, it was scarcely needed in this country, where there was usually sufficient elasticity in the draw-gear for the engine with a 75 per cent. maximum cut-off to be able to make enough angular movement to open the second cylinder to steam.

The longer travel required for an 85 per cent. maximum cut-off adversely affected the valve gear design and was at the expense of the short cut-offs. The author suggested a reversion to the two-cylinder engine and the lightening of the reciprocating parts; but two-cylinder engines must have at least 40 per cent. to 60 per cent. reciprocating balance if they are to run satisfactorily at speed, whereas the latest multi- cylinder engines were without any reciprocating balance" and there- fore with these engines the bridge stress diagrams recorded were smooth parabolas as compared with the jagged saw-tooth diagrams obtained with two-cylinder engines, and, because the bridge stresses were so much lower, three or four-cylinder engines were allowed a higher static loading on the wheels, and therefore had more adhesion than could be obtained with a two-cylinder engine.

The lightening of the reciprocating parts involved the use of alloy steel, and that again raised difficulties, because the liability to hair-cracks and so to fatigue-fractures was much greater, and also the parts could not be handled by the shed staffs in the way that plain carbon steel parts could be. If parts had to be sent to the works for attention engines were held out of traffic so much longer.

Still on the question of reciprocating parts, he would like to suggest that mass was actually beneficial in the short cut-off's at high speed. With a IS per cent. cut-off there was a large steam load at the beginning of the stroke tailing off to very little at the end, whereas the reciprocating parts by their inertia absorbed some of the steam pressure at the beginning of the stroke and gave it out towards the end, with the result that there was a very much more even turning moment at the crank shaft. It had been proved by test on more than one occasion that the least internal resistance of an engine coincided with evenness in the 'turning moment, and a point which might very well be investigated by the new method of testing described in the Paper was how to get the most beneficial weight of the reciprocating parts in relation to the variation of pressure and cylinder diameter. Owing to less internal friction with even turning moment, it did .not necessarily follow that the maximum indicated horse-power or most economical point of cut-off necessarily coincided with maximum drawbar horse-power or most economical production of power at the drawbar; it might be, for instance, that lengthening the cut-off and easing the regulator would result in a more even turning moment, and therefore an actual increase in drawbar horse-power or decrease in steam consumption per drawbar horse-power hour.

In conclusion, he would like to support the views held by the author in regard to the limited opportunity for engineers in executive positions to enter into technical investigation under present circum- stances. With regard to the remarks of Mr. Poultney on the Great Western Railway dynamometer record illustrated bv him, it should be pointed out that 'that exceptional result was obtained with a well- designed Stephenson valve gear, and in his (the speaker's) experience the Stephenson valve gear could give much better results than the walschaerts , although the mechanical arrangement of the latter made it preferable in modern locomotive design.

The President (O.V.S. Bulleid 206-), in closing the discussion, said he had known the author for many years, and did not think there was a better experimental engineer in the country. Another of the author's great merits was that he had no hesitation in saying exactly what he thought.

Personally, the Paper had made him think a great deal, because he did not like to have it said that locomotive engineers did not know so much about the steam engine as they ought to know, and particularly that they could not get steam into their cylinders. On thinking it over, however, he came to the conclusion that there must be a mistake there, because locomotives had been and were being built which ran very fast and pulled very hard; and so he came to the conclusion that the author had forgotten two things: time, and the inertia effects of steam.

he author did not pay enough regard to the weight of the steam, but almost contemptuously disregarded the necessity for large steam pipes and, above all, for large steam chest volumes immediately adjacent to the valve opening, while concentrating on the peripheral measurements of ports, based on extremely badly-designed ports with unnecessary bridges, so getting a false picture. The author might also be wrong in not taking into account the volume behind the piston and the rate at which that volume was increasing; had he asked himself whether the steam would have anywhere to go if he had a bigger port opening?

M. Chapelon had stated definitely that there was a good deal of illusion about the poppet valve with its separated phases, and that what was of prime importance was the location of the piston at any given moment; it was no use having big port openings to feed a volume which did not require feeding.

Personally, therefore, he thought that the reason for the failure of the B.17 locomotive to develop higher horse-power at 70 m.p.h. should be looked for in other directions than a port opening of the order of that in question. In his own practice, and with the dimensions employed, he found that the steam had more time to fill the volume available at 15 per cent. cut-off than at 25 per cent. cut-off. The point, therefore, seemed to need considerably more explanation than it had so far had.

On the general question of testing locomotives, he had always been entertained by the fact that in France there were two completely hostile schools. There were the engineers in charge at Vitry, who were convinced that Vitry provided the only way in which to carry out tests, and there was M. Chapelon, who was quite certain that the results with the Vitry plant were most misleading and deceptive. When, therefore, the testing plant at Rugby was finished, the best thing would be to have Rugby plus the counter-pressure, and, probably better still, the electric braking agent, complementary one to the other.

The author trod on very delicate ground in his reference to multi- cylinder engines. The" Channel Packet" Pacifies, owing to weight restrictions, could not have been built as two-cylinder engines. The benefit of the absence of reciprocating balance was clearly shown on bridge tests, and he, was sure that no two-cylinder engine had ever been designed which could give such a smooth bridge deflexion curve. Another problem involved was that of the piston load; there, would have to be a load on the piston of 45 tons, or something of that order, and that would present a problem not easy of solution.

The author's indicator was extremely interesting, and it was a pity that the war put a stop to the work, because it was not possible to be happy about indicator diagrams at present, and if the author could produce a real indicator diagram which would, at long last, show where the true point of cut-off was, locomotive engineers would be extremely indebted to him.

Written contribution from Dr. G. V. Lomonossoff.
Click to expand...

Source: https://www.steamindex.com/jile/jile33.htm#pap441

Hermod · Jan 19, 2023

S.A.C. Martin said: ↑

That's quite a reading of the paper. I read it very differently, rather than acerbic from the author it was perhaps pointed in the use of larger valves, but it wasn't aimed at anyone specifically. Bulleid seems to write quite defensively. See below:
Source: https://www.steamindex.com/jile/jile33.htm#pap441
Click to expand...

Where did You get access to the original paper please?

S.A.C. Martin · Jan 19, 2023

Hermod said: ↑

Where did You get access to the original paper please?
Click to expand...

Sorry, I should clarify - I am referring to the responses. I am waiting to get a copy.

Big Al · Jan 20, 2023

Spamcan81 said: ↑

I forget the book but the author wrote that the A1 was a fine loco and was the ideal choice for the heaviest trains but as loads decreased, the 50 sq. ft. grate was less than ideal as the fireman would be shovelling as much to keep the grate covered as to generate steam. A4/A3 being the better choice for these duties as the smaller grate could still produce all the power needed for lighter trains.
Click to expand...

In their twilight years the A4s in Scotland produced some remarkable runs with the lighter trains on the Aberdeen route. I've never thought of the A4 as a load carrier and I have always been under the impression that there were not intended for that type of train.

Spamcan81 · Jan 20, 2023

Big Al said: ↑

In their twilight years the A4s in Scotland produced some remarkable runs with the lighter trains on the Aberdeen route. I've never thought of the A4 as a load carrier and I have always been under the impression that there were not intended for that type of train.
Click to expand...

Whilst the class was introduced for the initial streamliners. Other members of the class were built for general express traffic and there were some heavy long distance trains in the 30s and they performed prodigious feats of haulage during WW2. Think it was 2509 working a train that was so long, she was inside Gasworks tunnel at the head of the train and they needed a special form of "right away" as she was well forward of the starter.

torgormaig · Jan 20, 2023

Spamcan81 said: ↑

Whilst the class was introduced for the initial streamliners. Other members of the class were built for general express traffic and there were some heavy long distance trains in the 30s and they performed prodigious feats of haulage during WW2. Think it was 2509 working a train that was so long, she was inside Gasworks tunnel at the head of the train and they needed a special form of "right away" as she was well forward of the starter.
Click to expand...

I doubt that happened very often. It would have stitched up the whole station in the process. Even in wartime it is not a good idea to operate trains that are longer than the infrastructure can handle.

Peter

30567 · Jan 20, 2023

torgormaig said: ↑

I doubt that happened very often. It would have stitched up the whole station in the process. Even in wartime it is not a good idea to operate trains that are longer than the infrastructure can handle.

Peter
Click to expand...

True. But the A4s were regularly rostered for the Scotch Goods as far as Newcastle, 50 wagons/750 tons. And how heavy were the sleeping car trains?

Spamcan81 · Jan 20, 2023

torgormaig said: ↑

I doubt that happened very often. It would have stitched up the whole station in the process. Even in wartime it is not a good idea to operate trains that are longer than the infrastructure can handle.

Peter
Click to expand...

There were fewer trains running in wartime, that’s why the ones that did were often longer than the norm. There were other instances of very heavy trains on the ECML but not quite so long as the one I mentioned. I doubt it stitched up the whole of KX though as there were other roads and platforms available.

The Green Howards · Jan 20, 2023

Spamcan81 said: ↑

Whilst the class was introduced for the initial streamliners. Other members of the class were built for general express traffic and there were some heavy long distance trains in the 30s and they performed prodigious feats of haulage during WW2. Think it was 2509 working a train that was so long, she was inside Gasworks tunnel at the head of the train and they needed a special form of "right away" as she was well forward of the starter.
Click to expand...

I'm trying to remember where I read that, but it wasn't unknown and on numerous occasions. Maybe those wartime volumes of "Railway Magazine" I own could shed some light.

The Green Howards · Jan 20, 2023

Spamcan81 said: ↑

There were fewer trains running in wartime, that’s why the ones that did were often longer than the norm. There were other instances of very heavy trains on the ECML but not quite so long as the one I mentioned. I doubt it stitched up the whole of KX though as there were other roads and platforms available.
Click to expand...

Indeed, worth remembering back then all three bores of Gasworks were open. Then of course there was that legendary V2-hauled occasion with 26? on after Peterborough.

torgormaig · Jan 20, 2023

Spamcan81 said: ↑

There were fewer trains running in wartime, that’s why the ones that did were often longer than the norm. There were other instances of very heavy trains on the ECML but not quite so long as the one I mentioned. I doubt it stitched up the whole of KX though as there were other roads and platforms available.
Click to expand...

Fewer trains running in wartime? Thats not my understanding, but I'm no expert on the subject.

Peter

D6332found · Jan 20, 2023

It was a legend in WW2 V2s in particular A3s in the tunnel with load 20. It was to do with troop movements at night

S.A.C. Martin · Jan 20, 2023

Spamcan81 said: ↑

There were fewer trains running in wartime, that’s why the ones that did were often longer than the norm.
Click to expand...

There might have been fewer passenger trains running in wartime ("is your journey necessary?"), but overall the number of trains running actually increased, in no small part due to the requirement for armaments, coal/fuel and other freight. This is borne out by the LNER's full mileage figures:

Which, as you can see, went up significantly in years matching greater pushes in Europe/Africa and France against the Axis powers.

The King's Cross A4s were initially stored alongside the streamlined trains at the outbreak of war. When it became clear that demand for locomotives was far greater than anticipated, these A4s were brought back into service quite quickly. Those at other sheds never stopped working and went from working the passenger services to anything that required locomotives.

Something that was brought to my attention recently was that during the war, all locomotives effectively became "common user" and regular crews were not allocated to steam locomotives, as the A4s had been pre-war. Haymarket bucked this trend from 1943 by retaining "double-trips" duties with regular crews, which helped to keep their performances up. We can actually evidence this by the Use of Engine Power document: the availability and mileages of the Scottish locomotives went up significantly, to the extent that by 1946, their availability was the highest of all the A4s (73%) but mileages were nearly double everyone else's (at an astonishing 71,888 miles achieved as an average mileage per locomotive for the year).

If Haymarket's were the only A4s on the LNER, they would have been the best locomotive class on the railway. As it was, all of the English based A4s brought the class average down, and for 1946 Thane of Fife and Great Northern did better.

There were other instances of very heavy trains on the ECML but not quite so long as the one I mentioned. I doubt it stitched up the whole of KX though as there were other roads and platforms available.
Click to expand...

Without the drawing plan for Kings Cross in the 1940s I wouldn't like to comment but I suspect there might have been some disruption with the 20+ coach trains that have been recorded.

S.A.C. Martin · Jan 20, 2023

Spamcan81 said: ↑

Think it was 2509 working a train that was so long, she was inside Gasworks tunnel at the head of the train and they needed a special form of "right away" as she was well forward of the starter.
Click to expand...

Spot on. Page 128 of the RCTS 2A Green Book - total train weight was 850 tons gross, 25 vehicles, 5th April 1940.

Spamcan81 · Jan 20, 2023

torgormaig said: ↑

Fewer trains running in wartime? Thats not my understanding, but I'm no expert on the subject.

Peter
Click to expand...

Sorry. Should have said fewer passenger trains running. Much more freight of course.

Jamessquared · Jan 20, 2023

S.A.C. Martin said: ↑

There might have been fewer passenger trains running in wartime ("is your journey necessary?"), but overall the number of trains running actually increased, in no small part due to the requirement for armaments, coal/fuel and other freight. This is borne out by the LNER's full mileage figures:

View attachment 74196

Which, as you can see, went up significantly in years matching greater pushes in Europe/Africa and France against the Axis powers.

The King's Cross A4s were initially stored alongside the streamlined trains at the outbreak of war. When it became clear that demand for locomotives was far greater than anticipated, these A4s were brought back into service quite quickly. Those at other sheds never stopped working and went from working the passenger services to anything that required locomotives.

Something that was brought to my attention recently was that during the war, all locomotives effectively became "common user" and regular crews were not allocated to steam locomotives, as the A4s had been pre-war. Haymarket bucked this trend from 1943 by retaining "double-trips" duties with regular crews, which helped to keep their performances up. We can actually evidence this by the Use of Engine Power document: the availability and mileages of the Scottish locomotives went up significantly, to the extent that by 1946, their availability was the highest of all the A4s (73%) but mileages were nearly double everyone else's (at an astonishing 71,888 miles achieved as an average mileage per locomotive for the year).

If Haymarket's were the only A4s on the LNER, they would have been the best locomotive class on the railway. As it was, all of the English based A4s brought the class average down, and for 1946 Thane of Fife and Great Northern did better.

Without the drawing plan for Kings Cross in the 1940s I wouldn't like to comment but I suspect there might have been some disruption with the 20+ coach trains that have been recorded.
Click to expand...

Why did mileage drop in 1944? I suspect the SR figures would have been rather different that year!

BTW, can you format your mileage figures with comma separators - they are very hard to scan without. (i.e. is it 15 million or 150 million or 1.5billion - you can’t easily scan).

Tom

S.A.C. Martin · Jan 20, 2023

Jamessquared said: ↑

Why did mileage drop in 1944? I suspect the SR figures would have been rather different that year!
Click to expand...

I think it's probably around normal for the war years and the 1943/45/46 figures are exceptional where significantly more trains were run. But that's speculative.

BTW, can you format your mileage figures with comma separators - they are very hard to scan without. (i.e. is it 15 million or 150 million or 1.5billion - you can’t easily scan).

Tom
Click to expand...

Hi Tom, I'll have a go at it shortly. I left it in excel without formatting for the purposes of copy/pasting for other stuff I was working on.

Edit:

Jamessquared · Jan 20, 2023

S.A.C. Martin said: ↑

I think it's probably around normal for the war years and the 1943/45/46 figures are exceptional where significantly more trains were run. But that's speculative.

Hi Tom, I'll have a go at it shortly. I left it in excel without formatting for the purposes of copy/pasting for other stuff I was working on.

Edit:

View attachment 74198
Click to expand...

Thanks. You can set a number format in Excel to add the commas while still leaving the data type as a number.

Tom

S.A.C. Martin · Jan 20, 2023

Jamessquared said: ↑

Thanks. You can set a number format in Excel to add the commas while still leaving the data type as a number.

Tom
Click to expand...

Yep, that's what I've done

maddog · Jan 28, 2023

Sorry for going off-topic but as it has been previously mentioned, and vaguely relevant..

The Kitson-still locomotive, what did it sound like? are there any reports of it? was it loud or quiet?

Log in or Sign up

Sir Nigel Gresley - The L.N.E.R.’s First C.M.E.

S.A.C. Martin Part of the furniture

Hermod Member

S.A.C. Martin Part of the furniture

Big Al Nat Pres stalwart Staff Member Moderator

Spamcan81 Nat Pres stalwart

torgormaig Part of the furniture Friend

30567 Part of the furniture Friend

Spamcan81 Nat Pres stalwart

The Green Howards Nat Pres stalwart

The Green Howards Nat Pres stalwart

torgormaig Part of the furniture Friend

D6332found Member

S.A.C. Martin Part of the furniture

S.A.C. Martin Part of the furniture

Spamcan81 Nat Pres stalwart

Jamessquared Nat Pres stalwart

S.A.C. Martin Part of the furniture

Jamessquared Nat Pres stalwart

S.A.C. Martin Part of the furniture

maddog New Member

Share This Page

Log in or Sign up

Sir Nigel Gresley - The L.N.E.R.’s First C.M.E.

S.A.C. Martin Part of the furniture

Hermod Member

S.A.C. Martin Part of the furniture

Big Al Nat Pres stalwart Staff Member Moderator

Spamcan81 Nat Pres stalwart

torgormaig Part of the furniture Friend

30567 Part of the furniture Friend

Spamcan81 Nat Pres stalwart

The Green Howards Nat Pres stalwart

The Green Howards Nat Pres stalwart

torgormaig Part of the furniture Friend

D6332found Member

S.A.C. Martin Part of the furniture

S.A.C. Martin Part of the furniture

Spamcan81 Nat Pres stalwart

Jamessquared Nat Pres stalwart

S.A.C. Martin Part of the furniture

Jamessquared Nat Pres stalwart

S.A.C. Martin Part of the furniture

maddog New Member

Share This Page

Useful Searches