Mills, F. (Paper No. 363)
Some factors affecting locomotive design in Western Australia. 2-23. Disc.:
23-33; 458-9.
3ft 6in gauge; 4538 route miles mainly of very light track, nearly
half of which was 45lb/yard and the remainder 60lb/yard.
Clarke, C.W. and Bhote, M.D. (Paper No.
364)
Reflections on the detail design of Indian Railway Standard Locomotives.
34-53. Disc.: 53-68.
Advocated Baker valve gear as there are no sliding pairs; all joints
are pin joints and the valve rod has no fixed relationship to the design
of gear and is particularly adaptable for standardization on different classes
of locomotive; also considered material for piston valve liners; ashpans
and spring compensating gear.
Campbell, J. (Paper No. 365)
Rail cars — notes on their introduction, design and operation (with
special reference to Argentine condition). 70-135. Discussion. 135-84.
Page 131: notes that the GWR diesel railcars were based on the AEC
Q type of bus.engine. Notes local operating costs.
Hancock, J.S. (Paper No. 366)
Locomotive feed-water treatment. 198-221. Disc.: 221-49.
A substantial part of the paper was devoted to the automatic continuous
blow-down system adopted by the LMS to decrease boiler repair costs. Fig.
20 showed the valve and Fig. 21 its application to a locomotive showing some
similarity with a class 5 4-6-0. Discussion: Verecker (Vereker?) (254) asked
whether the LMS used feed water trays and was informed that it did not: Verecker
stated that their use prevented corrosion. Selby (254-5) noted the cost of
boiler repairs in Scotland was far lower and that washing out could be at
monthly intervals. Selby and the author noted that on the Tilbury section
trays had to be cleaned every 7000 to 10,000 miles. In Scotland tubes lasted
for five years and corrosion was almost unknown.
T.H. Turner (222-) noted the Institution has had very few papers upon feed
water: two in 1912 and one in 1924, and.in view of the developments which
have taken place in water treatment, it was time for another. He agreed with
the main findings of the Author: namely, soften completely and the need for
automatic blow down. That was his private opinion, and not necessarily that
of his chief [Gresley], who has, up to the present, kept a very wary eye
on all blow-down devices; but, has fitted his line with more hot water washing
out and filling up plants than have other railways, he need not turn to blow
down on the track so rapidly as others.Why had the LMS Railway treated its
prophets, Archbutt and Deeley, with so little honour: because at the time
of the amalgamation, the London and North Eastern Railway had very many more
softening plants than the London, Midland and Scottish. Next, I should like
to ask the Author why he takes a rather pessimistic tone–and our President,
Mr. Stanier, was rather halting in his attitude in his Presidential
Address–in regard to water treatment, when we see the way in which it
has gone ahead in the USA, in the Argentine and elsewhere, and the strides
that it has made in the last half-dozen years in Britain.. Considered that
emphasis on priming and corrosion was excessive: they are important and must
be considel'ed, but more than half this Paper dealt with priming and corrosion.
It is incorrect to state that the success of water-softening depends on the
elimination of priming. We have priming, and we always have had it. As a
matter of fact, during this last summer it dropped very considerably, although
we were softening more than ever before, and at the present time the figures
show that it is less than at the corresponding time last year. Priming is
so much talked about that there is a tendency to book time to priming, and
therefore I am not sure how reliable the figures are, but the running
superintendents say that the engines are steaming more easily, and the firemen
like the water treatment and the total delays are less than before. Perhaps
it is only a matter of booking time, but of course the management and the
running superintendents will always try to avoid any delays, and delays by
priming will have to be avoided too.On the question of definitions, it is
a pity that we confuse priming and foaming, and are not quite definite about
it. We, the L.N.E.R., are trying to use "priming" for that violent, sudden
train-stopping ebullition, and "foaming" for the steady, wet-water condition,
the carry-over, which is hardly noticeable but which is nevertheless from
the economy point of view, equally undesirable. I think tlult is a fair
distinction between the two, but other people do not always make it, and
I suggest that we should try to keep to it.
We differ from the Author in thinking that we have proof that suspended solids do play a part in the priming of locomotives. The senior chemist in our water-treatment section is here to-night, and he may be able to give actual cases of that, but so far as I have seen, we have evidence, that in our engines, suspended solids do help priming. Of course, we know that the dissolved solids must be taken into consideration, and that if we soften and increase the dissolved solids we must expect more water changes. We shall have very many fewer proper wash-outs, but we must have more water changes. That water change may be done, as it is done on the London and North Eastern Railway, with hot washing-out plants and quickly, because nearly always the engine must go in for some mechanical work; but, if that is unnecessary, by all means use automatic blow down. The Author refers to " continuous blowing down" in the Paper, but I prefer the word "automatic" because we should not call a thing continuous which is not in fact continuous, and which works only when the regulator is opened.
I think is is quite wrong to say that partial softening is the cure for priming-. I regnrd partial softening as a confession of defeat; it means taking a wrong attitude in regard to the whole subject. We should have complete softening, with increased water changes, and, if necessary, automatic blowing down on the track. As a matter of fact, priming is not always increased when you soften fully; we have had instances on our line, where, when we introduced full softening, the priming decreased. It did not increase. Even the increased amount of watcr change need not necessarily be uneconomical. At Doncaster, for instance, the number of tubes saved in the sheds alone i.e., just the materia1 cost of the tubes and not the labour-pay for the increased water changes. '"
Turning to corrosion–If I go rapidly through these points, you will understand that, having been interested in this subject from the railway point of view for a number of years, the Author and I could go on chatting together for a very long time, but I must try to be as brief as possibleunder the heading- of corrosion, we are horrified by a set of tubes which the Author has exhibited, and it is rather suggested that a necessary result of softening is corrosion. In my viow, that is entirely wrong. In the very worst shed that we had for corrosion seven years ago, we were softening down to 8° or 10°; we cou]d not go beyond 8° because the priming was too bad. Several gentlemen who are here this evening will know that I am referring to Mexboro. Taking the years 1928 to 1930, and comparing them with the years from 1933 to the present time, during which latter period we have been softening right down by the addition of sodium aluminate to the lime and soda, and we find that corrosion has been very much decreased. The engines are lasting out in the sheds an average of ten months longer than before, which represents a 35 per cent gain in availability at the sheds before they must go to the shops. As a matter of fact, our water treatment section receive very few complaints with regard to corrosion, and when they trace them down they can nearly always be found to be due to the use of mixed waters or other waters' which are not softened at all. Where we have waters that are fully softened, the cases are so few that they may be regarded as freak cases, and are not worth mentioning.
The Author makes no special reference, in the section of his Paper headed "Corrosion," to Ph value and to the influence of magnesium chloride, both of which we regard as most important from the point of view of corrosion. Many of our waters contain magnesium-there is a region in the centre of the line where they are all high in magnesium and we find the addition of sodium aluminate to be of very definite benefit. We are rather surprised at the little use that the London, Midland and Scottish Railways have madc of it, despite the praise that the Author gives it in his Paper in the section headed' , Water Softening."
With regard to our practice, we base our practice on this conception, that the function of water treatment is to keep the sludge and scale out of the boilers, and therefore we cannot have any half measure's with it. If we have the conception of a balance sheet, we are spending the Company's money and we want something back for it. If we stop the softener for week-ends, and if we allow breakdowns-and electrical breakdowns and mechanical breakdowns keep cropping up with these plants-to stop the proper functioning of a good plant, then the balance sheet will rapidly be ruined. As a matter of fact, taking the present figures, our 31 plants are removing 950 tons of sludge and' 500 tons of hard scale per annum. That is what we may call temporary and permanent hardness, using the terms which, from the railway point of view, we shall understand better. These figures are based on the assumption that of the 9,000,000 tons of water that we treat in the plants, half is wasted; in taking these figures, I am assuming advisedly, from knowledge of a considerable number of plants, that half the water is never evaporated. If we assume that half the water that we soften is actually evaporated in the boilers, then on the sludge we are saving £14,000 and on the scale we are saving £44,000. Adding those two figures together, they come to well over twice the total cost of softening, including supervision by chemists and running' department staff as well.
Do not think that those figures are purely imaginary; they are not. We took ro8 engines of six different kinds in three different areas in order to build up the data upon which that estimate was made. I think we should bear in mind that that estimate. showed clearly that if we leave 5 grains of hardness in our waters we lose £24,000 of our possible saving. I think that is worth knowing. You may say, " Oh, but these are just figures, and we do not generally believe an accountant's figures and will not believe a chemist's figures." In view of that, I took the precaution yesterday of asking the local running superintendent and the local mechanical engineer whether it was safe to say that water treatment was doing any good. The reply was that the length of time in service had increased, the boilers were incomparably cleaner, less labour was now needed, the boilers were going into the shops in better condition, and three types of engines which normally had some of their tubes changed once or twice between shops now went from shop to shop without tube changes, and there were corresponding improvements in the copper stays.
I should like to take this opportunity of saying that any success which has been obtained-and I believe that we have obtained very considerable success-has been due to the gentleman whom I have mentioned, and his colleagues co-operating in such an intelligent and willing manner with the members of the water treatment section. That teamplay has helped enormously, and I feel that if i\he Author enjoys similar team-work on the L.M.S. they will very soon be setting us a high mark at which to aim.
To check up the views of the shed and the shops, I went to Mr. Thom and put the same question to him, and his reply was that the water treatment definitely was helping, and that I could say to anyone that he would defy them to say whether some of the Pacifics now coming off the Southern area, where we used to have the worst waters, had been running there or on the Scottish waters. That means a great deal, and anyone belonging to our Company will appreciate what it means, because Mr. Thom knows what a boiler is and has been in Scotland for many years, and the Scottish waters are regarded as perfect, whereas the Great Northern main line waters used to be definitely bad. ,
Mr. F. 1. Bassett remarked that he himself had presented a Paper on this subject nearly twenty-five years ago-one of the earliest Papers read before the Institution.
It was, therefore, interesting to compare the position of knowledge and practice to-day with what it was at that date.
Water treatment was now much more widely applied, although as regards the actual technique of the lime-soda process, there had not been much advance. The improvement had been mainly in the higher rate at which modern plants could be worked and the increased efficiency of fi1ters and re-agent, mixing. The base-exchange or " Permutit " process had been greatly extended in application since the introduction of reliable synthetic material. The introduction of sodium aluminate in the soda-ash treatment was a distinct advance.
The problem of feed-water control on the Iraq railways was very much more difficult than in this country, and the omission to provide for it when the 350 miles of route was first opened between Basrah and Baghdad in 1920, resulted in such frequent engine failures, that the service was greatly disorganised. Softeners were then put in, but owing to the fluctuations in the character of the water, it was necessary to work them under a system of daily sampling and control from the Government Laboratory. After two or three years the routine of softening had settJed down and failures on the road became very infrequent, but the question of corrosion then emerged, and in fact appeared to become more accentuated with the softened water. He had given considerable study to this question since about 1926, both in regard to boilers and to corrosion of pipelines buried in soil. Before discussing it, however, he would venture a few remarks on the subject of prining.
Priming, as the Author remarks, has never been strictly defined, and the term "foaming" is used indiscriminately. In chemical engineering practice it was recognised that steady or quiescent foaming would commonly occur in any type of evaporator worked at as great a rate as a locomotive boiler, and provision was therefore made to deal with the consequent" entrainment" before the vapour passed to the condenser. He confirmed the Author's observation that the tendency to foam, as measured by the" lift" of the foaming surface, was mainly dependent on the proportion of soluble salts-up to a certain point. Blow down-intermittent or continuous-was the means of keeping down the concentration.
However, he did not think this general explanation could altogether account for the sudden intense bursts of priming which occur without any apparent reason. This was observed in some cases when the engine came on a different water supply. There was reason to think that aggravated" priming" of this kind, when the boiler conrlitions otherwise had not changed, was due to introduction in the feed water of certain organic matter in small traces, which were not usually looked for in analysis. Traces of soil humus, for example, would cause priming. Most oils and fats brought about priming, though it was remarkable that some three or four of them had a strong effect in repressinK it, and the use of castor oil for this purpose was well-known. ,,It had been shown that certain scale containing traces of oily matter tended to promote priming, and that this effect ceased when the oily matter was removed. He thought there was need for further investigation on the generation of steam bubbles from scaled heating surfaces of this kind.
I t might be that on certain types of surface it was difficult for the bubbles to form, and the water ,became local1y superheated. Such effects were often seen when liquids were boiled in glass flasks; although the rate of heat supply was not altered, ebullition would slow down until it practically ceased, and after a short interval of quiescence, an almost explosive liberation of vapour would occur and continue for perhaps a minute or so in'violent ebullition, notwithstanding the rapid temperature drop accompanying the absorption of so much latent heat. This effect wasl called" bumping," and cpuld be cured by the introduction of suitable angular or porous material on which the bubbles could form regularly.
.
Wilkins, J.H.A. (Paper No. 367)
The development of the locomotive turntable. 257-85. Disc.: 286-8.
Turntables could be turned by manual effort, or by electric motors
(at that time the GWR had several and the LMS a few, or by vacuum (or by
compressed air as in Germany). The first vacuum-driven turntable was at King's
Cross (cited Rly Gaz., 1935 8 February and Engineering for
1936 31 July for experience after one year in service). A similar
installation at Camden on the LMS is also described.
In the American Railway Age for 18 November 1933, an article appeared on locomotive turntables dealing with a report which was presented before the 1933 Convention of the American Railway Engineering Association by Mr. J. M. Metcalf, Assistant Engineer of the Missouri-Kansas-Texas line. The Author listed the conclusions reached by this association at the subsequent discussion, which were later incorporated in their Proceedings. These are as follows:
The above conclusions are interesting and to a large extent are applicable to all types of turntables. Although the balanced type of turntable is to a certain extent losing favour, this type is still in common use, and for many years to come it will no doubt be used in this Country and abroad, particularly where smaller tables are required. The continuous girder type will no doubt gain favour, as well as the articulated type, both of which have many advantages, particularly for the large turntables now being built. Regarding the future, welding may be utilised in place of riveting for certain sections in a similar manner to that now in use in structural steel work. There is no doubt that ball thrust bearings for the centre pivot, and ball or roller journal bearings for the carrying wheels, arc now universal, and very few plain bearing tables arc likely to be built in the future.
Power operation is becoming more and more necessary and all tables over 60 feet in length, which are in frequent use, are likely to be fitted with mechanical or electrical assistance. In view of the possibility of increasing the length of turntables almost indefinitely, there would seem to be a chance of adopting even longer tables enabling two locomotives to be turned at once. This would, of course, only apply at busy sheds or terminals.
Graff-Baker, W.S. (Paper No. 368)
The retardation of trains. 290-305. Disc.: 305-17.
Metadyne control system.
Journal 137
Whitcombe, H.A. (Paper No. 369)
The history of the steam tram. 327-79. Discussion. 380-400.
Shown in error as 367. Holcroft (384-7):
see Holcroft. Paper contains a
great deal of information, both as a general historical survey and for listing
which firms manufactured tramway locomotives and tramcars, and which systems
employed steam motive power. The latter included Accrington Corporation;
the Alford & Sutton Tramway; the Barrow-in-Furness Tramway; the Birmingham
& Aston Tramway co.; the Birmingham Central Tramway Co.; Birmingham &
Midland Tramways Ltd; Blackburn & Over Darwen Tramway Co.; Blackburn
Corporation Tramway Co.; Bradford Tramway and Omnibus Co. Ltd.; Bradford
and Shelf Tramway Co. Ltd; Brighton & District Tramway Co. Ltd., Bristol
Tramway Co. Ltd; Burnley & District Tramway Co.; Castlederg & Victoria
Bridge Tramway Co. Ltd; Cavehill and Whitewell Tramway Co. Ltd; Coventry
and District Tramway Co. Ltd; Dewsbury, Batley and Birstal Tramway Co. Ltd;
Drypool and Marfleet Tramway Co. Ltd. (Hull); Dublin & Blessington Steam
Tramway Co; Dublin Southern District Tramway Co. Ltd.: Dudley & Stourbridge
Tramway Co. Ltd; Dudley & Wolverhampton Tramways Ltd; Dundee & District
Tramway Co. Ltd; Edinburgh Street Tramway Co. Ltd. Mentions Loftus Perkins
and Henry P. Holt..
Poole, A.J. (Paper 352)
Locomotive boiler proportions and design (with particular reference to Indian
practice). 403-9 (Summary). Disc.: 409-
This refers back to original presentation (Vol. 26 Journal 131).
Discussion is noteworthy in that the President (W.A. Stanier) was present
in Delhi and concluded the discussion. Before that L.N. Flatt noted a few
years back I was fortunate enough to be allowed to ride on one of the fast
trains at home to Doncaster with a heavy load, and I was astounded to see
the ease with which steam was maintained. Almost from tbe start to finish
there was just a whisper of steam at the safety valve at periodic intervals
and the fireman did everything which, according to those advocating mechanicaIJy
operated fire doors, was wrong in practice. From start to finish he never
threw a shovel fuJl of coal. The coal was piled in the fire door which
was never shut, and as Mr. Stanier has said, was allowed to feed itself
both forwards and sideways. The whole trip was a lesson in the extremely
efficient results obtained from the boilers of these locomotives on the London
and North-Eastern Railway.
The President (Stanier) (420-2) could at any rate accept some of the statements made in the Paper with greater confidence than some of the claims made regarding American practice referred to by Mr. Case. Mr. Case also referred to fire grates having an air space of 13.5 per cent. of the grate area. We in England are now experimenting with an air space of 55 per cent. grate area, and we are hoping to get better results than we have had with an air space of about 48 per cent. grate area. I think the quality of coal used is important, and I am rather surprised at the small air space tried out here. Mr. Case also referred to steel fireboxes. They are fitted in the States in wide firebox boilers, and are extraordinarily successful in the Eastern States of America.
Mr. Wrench also referred to the question of copper fireboxes and steel fireboxes. I do not think his experiment justified condemning steel fireboxes. My experience is that if you put steel fireboxes in narrow type fireboxes, trouble is to be expected, but if steel fireboxes are fitted to wide type fireboxes, they give satisfactory service. A particular example that may be of some interest is the case of the standard War Department locomotives used in France during the war, and used after the war on English railways. A good number of these, R.O.D. engines, some 250, designed by the Great Central Railway and used in France during the war were fitted with steel fireboxes. Later, after the war, when used on English railways, their fireboxes had to be replaced by copper fireboxes because of the plates cracking between stays. It seems to me that when steel fireboxes are put in narrow firebox boilers, you get trouble of that kind. Mr. Wrench also referred to the question of steel stays. Well, I have had many years' experience of steel stays. The wide firebox boilers on the L.M. & S. Rly. are fitted with steel stays except in certain areas. We did not use flexible stays, as such stays are commonly called, that have special provision for allowing certain movement, but used flexible steel stays–a stay ¾in. diameter, but flexible in itself.
Mr. Sindhu referred to the question of steam pressures of locomotive boilers, and the fact that stationary boilers have steam pressures of 450lbs. per sq. inch, and 750 degrees of superheat. Locomotive boilers with pressures higher than this have been built, but it must be remembered that they are experimental boilers; no repeat orders have been given for boilers such as the Swiss and German locomotives fitted with high pressure boilers. One is making history slowly with regard to high pressure locomotive boilers. The usual high pressure locomotive boiler pressure is 250lbs. per square inch. Mr. Sindhu also refers to the question of weig'ht in locomotive type boilers.One type of locomotive we are getting out in England keeps the boiler weight down considerably by the extensive use of high tensile steels for the boiler plates. With regard to Mr. Sindhu's remarks on water tube boi1ers, it must be realised that with a water tube boiler on a locomotive, it is very difficu1t to keep the boiler high enough to get circulation a1wavs in the same direction. Sometimes when steaming hard, the direction of circulation is completely reversed in a water tube locomotive boiler. Mr. Sindhu also, refers to the question of water softening, and its effect on the maintenance of the locomotive boiler. It is very little use putting down a few isolated water softening plants if locomotives are also to draw water from stations not provided with water softening plants. On the L. M. & S. Rly. we have installed water softening plants. for the whole of the North-Western Section. I am afraid it is too early for me to give you figures relating to savings effected on maintenance. We have 20 locomotives working on a particular section, where water softening plants are installed, and some of these locomotives have run 10,000 miles between washing outs. Of course, in some parts of Scotland, where the water is remarkably soft, very little boiler trouble is experienced and installing water softening plants in such districts is hardly justified.
Rajangam, Sri (Paper No. 370).
Some factors contributing to derailments of railway rolling stock. 427-46.
Discussion. 446-8.
Shown in error as Paper 368
Journal 138
Noble, E.C. (Paper No. 371)
The economics of locomotive engineering. 478- 99. Disc.: 499-514.
MacAulay, D. (Paper No. 372)
Some notes on the mechanical aspect of working steam-operated suburban services
with particular reference to the Eastern Bengal Railway locals around Calcutta.
517-40. Disc.: 540-51.
The Chairman (L.N. Flatt) referred to the opating practices adopted
at Liverpool Street station in London: It will be noted that the Author refers
to the intensive service entering Liverpool Street Station and states that
the fireman uncouples on arrival and then takes water. Having worked into
Liverpool Street when firing, I can assure him that I have suffered quite
good tempercd but, nevertheless, caustic criticism from my driver when doing
these things in the order quoted by the Author. The time allowed at Liverpool
Street is so short that the first essential is to get the water column into
the tank opening and open the cock, after which the engine can be uncoupled.
It is only in this way that the full quantity of water can be, obtained before
having to follow down the outgoing train' to enter the refuge siding. I mention
this point as it emphasises how very important the odd few seconds are, when
working intensified suburban services.
Scott, J.I. (Paper No. 373)
Roller bearings. 552-9. Disc.: 559-61.
Stewart-Fergusson, I.D. (Paper No. 374)
New methods of locomotive cylinder production. 562-70. Disc.: 570-2.
Turner, James (Paper No. 375)
The locomotive boiler. 573-9.
Collins, F.E.
Presidential Address. 586-625.
Richly illustrated: main theme was effects of gauge. Began with WW1
2ft gauge 10 ton capacity bogie wagon. Noted that he could remeber the GWR
broad gauge conversion. Noted the multiplicity of gauges in India and Australia
and implied thatt high capacity could be achieved on the standard gauge.
Illustrated this by a Virginian Railways gondola car which ran on six-wheel
bogies and had an axle load of 24 tons. Coal trains of 10,000 tons could
be operated. The LNER operated 50 ton capacity bogie wagons. Most of the
Address related to freight, but modern passenger stock was also
considered.
Wall, H. (Paper No. 376)
Iron and copper pipe working. 626-40. Disc.: 640-2.
Scott, J.S. (Paper No. 377)
The lining-up of locomotive frames, cylinders and axleboxes. 643-66. Disc.:
666-76.
The opto-mechanical method of aligning frames using a telescope was covered on p. 657 et sqe. H. Chambers (666) was a little disappointed to see, on the form issued to the shops for repairs to axleboxes, with regard to the dimensions of the journal, fillets on the left-hand journal of ¾in. and 1in. and on the same axle, but on the other side, 7/8in. and 1in., and I hope, though the author said that the shops had no need for a drawing, that the foregoing is due to an error in the dimensions on the form.
I was struck, too, by the Author's remark that on axles where collars were provided very great care was taken to give a clearance on the collar side. My expeience was that the inside co11ar was provided to take a share of the lateral thrust of the axlebox and so reduce the pressure on the opposite wheel boss. I agree that with modern locomot!ves, with a large wheel boss, collars are not being provided on the journals of the axles.
The President has already said that the mechanical method of setting out the frames is that used on the London Midland & Scottish Railway, and I have no doubt that a similar method is in general use in this Country. With regard to the alternative optical method, I am inclined to say that it is a complicated system, and I should like to ask the Author what is the time required to set up the Zeiss optical apparatus as compared with the mechanical system? 1 would also point out that this question is affected by the fact that at Crewe and at other large works the belt system is employed; would the Author recommend the optical system, bearing in mind the engine is taken from stand to stand, as the repairs progress?
Webber, A.F. (Paper No. 378).
The proportions of locomotive boilers. 688-725. Disc.: 726-63. 8 diagrs.,
8 tables. Bibliog.
Analysis of boiler design on a comparative basis: includes SR V, N15X
class and LNER P2 class. The President, F.R. Collins, (page 726) opened the
discussion: he had been a Webb pupil: and noticed that the design of the
Greater Britain boiler was received with a certain amount of amusement. His
impression of what had been referred to as a combustion chamber, placed in
the middle of the barrel, was not so much a combustion chamber, but was put
in because Webb was scared of the length of the tubes. The boiler was longer
than any other which had been put on an engine at that date, and he was afraid
that trouble might happen owing to the tubes being too long. Since then,
of course, very much longer tubes have been used. "In what the Author calls
the combustion chamber Mr. Webb placed, if I remember rightly, a soot blower,
so that the tubes could be easily and quickly cleaned. An ash hopper was
also provided."
Mr. W. A. Stanier: (pp726-8) stated that he had enjoyed very much the analysis which the Author has made of our boiler problem; it has been, he thought, more complete than most of the analyses seen. As he has indicated, he has perhaps not given due weight to the firebox volume, but he has gone a long way towards endeavouring to evaluate the various bailer propartions which have been used on the engines of comparatively recent times.
It may be of some interest if I give an indication af the free areas in use on the present L.M.S. engines. As you know, Dr. Wagner indicated the importance of getting in balance the areas through the small tubes and the areas through the large flue tubes. On the Pacific" Coronation" engine the area through the small tubes is 3.23 sq. ft. and through the large tubes 3.66 sq. ft., making a total of 6.89 sq., ft. On the "5X" 3-cylinder engines the figures are 2.22 sq. ft. and 2.52 sq. ft., making a total of 4.74 sq. ft.
You will remember that in his Paper Dr. Wagner gave particulars of a boiler which had a free area through the tubes of something like 8 sq. ft. The comment of a member of my staff was that that engine would burn brickbats!
The difficulty is, of course, to obtain the free areas which you want and to maintain a balance with the grate area and the firebox volume within the load gauge from which we suffer in England.
In connection with the "5X" engines, it may interest yau to know that the L.M.S. have recently carried out some accelerated train trials between Glasgow and Leeds and Leeds and Bristol with "5X" engines. With a train weighing 300 tons, the coal consumption on that engine to do the work varied from 40 lb. per sq. ft. af grate area per hour to 100 lb. per sq. ft. of grate area per hour, which I think indicates what an extraordinarily flexible steamraiser a locomotive boiler is. I do not advocate an engine being used to burn l00 lb. per sq. ft. of grate area per hour; I think that if we did that with some of the bigger engines we should have to put in a mechanical stoker.
The Author has referred to smokebox vacuum. It may be of interest to mention that the vacuum in the smokebox of the L.M.S. turbine locomotive with one nozzle open is just over 1 in. of water, and with two nozzles it is 2 in., so that with the maximum number of nozzles open it is 6 in.
The engine steams quite well on the fast trains between Liverpool and Euston of something like 500 tons weight. It seems to me that that is a comparatively low vacuum in the smokebox for a big boiler, when account is taken of the vacuum which the French engines are obtaining with the Kylchap blast pipe, and one of the investigations which I think that every locomotive superintendent within my memory has carried out is an investigation to endeavour to improve the vacuum in the smakebax withaut increasing, and in fact decreasing, the back pressure in the cylinders.
When I was in the drawing office, there was a drawer full of experiments which had been carried out in connection with blast pipes and smokebox arrangements, and I am sure that in the. drawing office which I now control there are similar quantities af experiments, but I do not think that even yet we have determined what is the most efficient arrangement.
The Author has referred to sinuous tubes. One af the difficulties in a locomotive is to keep the tubes clean, and there are quite enough difficulties at present in keeping a flue tube with a superheater element in it clean af smokebox ash and soot. The old dodge af the driver of putting a little sand on a shovel and putting it in the firehole door to scour the tubes has been developed an the L.M.S. and some other railways by introducing sand guns for this purpose.
K. Cantlie (pp. 738-42) submitted a graph (Figure 9) which compared the boiler performance at speeds from 0 to 70 mile/h of the following locomotives: "his" 4-8-4 for the Chinese National Railways; the Lord Nelson type with new boiler; and same type with original boiler; the enlarged Claughton/Patriot boiler; the original Claughton boiler; George V; Precursor, Teutonic; Greater Britain and Jumbo (comparitive performance was in descending order as listed) .
Critchley, R.P. (Paper No. 379)
Mechanical coaling plants. 780-808. Disc.: 808-13.
Appears to be based on overall British practice, with some emphasis
on LNER installations.