Journal of the Institution of Locomotive Engineers
Volume 12 (1922)
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Journal No. 52 (January 1922)
Great Northern Railway: new three-cylinder 4-6-2 express passenger
engine. 4-6. illus., table
Table compares the leading dimensions of the A1 Pacific with the large Atlantics.
New "Baltic" tank locomotives, Glasgow and South Western Railway. 6-8.
Grassick, J.P. (Paper 114)
The locomotive from a footplate point of view. 51-67. Disc. 67-104; 311-28.
Presented in Glasgow on 25 November 1921: chaired R.H. Whitelegg.
Experience on NBR: spark arresters had to be removed. Problems with steel fireboxes. Notes on boiler fittings and the risk of developing leaks whilst in service. The fitment of injectors was considered to be a particular source of difficulty. Criticism of tail rods. Notes on problem of carbonisation in cylinders of superheated locomotives. Noted that comfortable cabs had been introduced by Adams on the LSWR and these had been followed by comfortable cabs on the NER and GER. Results from tests on GWR 28XX, T3 NER 3-cylinder 0-8-0 and NBR 0-6-0 on Glenfarg Bank in which the NER 0-8-0 put up a superb performance. Northumberland coal appeared to be superior to Scotch coal as former led to consumption of 0.099 lb/mile as against 0.118 lb/ ton mile. The water evapouration achieved also favoured Northumberlanbd coal (7.88) as against 6.49. On page 65 Grassick quoted lubricant consumption for NBR classes ranging from the Atlantics to the 0-4-0Ts and where fitted with superheaters the extra oil for cylinder lubrication..
Discussion: R.H. Whitelegg (67-71) noted Grassick's comments on spark arresters and agreed; furthermore he considered that it was vital to maintain a vacuum within the firebox and ensure that the door was tight-fitting.M. Blacklock (Beardmore 71-2) suggested propietory jointing materials such as Walkerite and copper joints to ease the problem of boiler mountings.Like Author queried the resaon tail rods. Cited the advantages of three and four cylinder designs: more even torque and better balancing. Questioned the most suitable location for snifting valves: in Glasgow the steam chest appeared to be the favoured location; critical of Grassick's calculation of tractive effort on the basis of 85% boiler pressure, suggested 80% or even 75% as being more realistic. Advocated smaller diameter driving wheels for 0-6-0. J.W. Tyler (GSWR 72-3) considered that locomotive trials should be conducted in winter under severe conditions.
R. Guest (NBL 73-9) contrasted American practice where steel fireboxes were the norm and where locomotives were worked to the absolute limit of their capacity aided by such devices as automatic firedoors. He considered spark arrestors and stated that Drummond's fireboxes as fitted on the LSWR with cross tubes acted as spark arrestors. He claimed that tail rods were useless. Noted that he had served as a fireman on the LSWR "many years ago", but that fuel consumption did not appear to have increased. On page 81 Grassick responded: spark arrestors: "I don't want them and don't believe in them at all" Considered that there was little to choose mechanical and sight feed lubricators. Very damning about steel fireboxes: at one NBR shed where there had been 19 firebox failures, 17 of these had been steel ones. Tail rods were no use.
"Surely if there is one item more than another which calls for revision of design it is the driving and coupled axleboxes of most of the locomotives of the United Kingdom. How is it that it is almost universal practice to use solid gunmetal boxes for this purpose, weighing, in some instances, not less than 5cwt. each? The London and North-Western and the North-Eastern are striking examples of a step in the right direction, both these companies using cast-steel boxes, the horn faces of the boxes in the case of the former being lined with white metal, and in the case of the latter with gunmetal liners pinned in; the horns of the North-Western engines are not fitted with adjustable wedges, and should a box he found to be knocking in the horns the engine is merely placed on the drop pit, the offending box or boxes removed, relined with white metal and replaced, simplicity itself, and an operation which can be carried through in the very shortest possible time, American practice is to use cast-steel axle boxes entirely, not even lined on the horn faces with either white or gun metal and with gun metal bearings forced in. by hydraulic pressure to save the expense of fitting; there may be some hidden virtue in a gunmetal box, but I would ,venture to say that to use such expensive luxuries, for luxuries they are, is more to the final advantage of the scrap metal. merchant than to the pockets of the railway shareholders, The same could be said regarding the use of gunmetal eccentric straps; what is the matter with cast-iron or caststeel straps? If it be thought by some that gun metal must be introduced in some shape or form at all costs, why not then line the cast steel or wrought iron strap with gunmetal, which gives all the advantages, if any, of the solid gunmetal strap without needlessly throwing away shareholders' money, Mr. Grassick says, and I am quite in agreemcnt with him, that too little encouragement is given to drivers and firemcn in Great Britain to take an intelligent interest in their work; while in the United States some years since I found, almost without exception, that every railway company there had its classes for locomotive employees, which had, perforce, to be regularly attended, and men only became engineers and firemen by attending these dasses and passing the examinatibns set for this purpose. I believe I am ,correct in saying that the late Mr. Dugald Drummond, while Chief Mechanical Engineer of the London and South Western Railway, introduced such classes and examinations with the very best results, and so great has been the success attending them that they are still continued by the present engineer.
Pp. 84 et seq: Manchester Meeting on 8 December 1921: J.W. Smith (Chairman) spoke about lubricants; W. Sinclair (NSR p. 88) described a staff suggestion scheme (document for which reproduced on pp. 97-8); S. Clayton (LYR, Darwen) pp 88-9 noted the need for simplicity and also commented on lubrication; R. Opie (GCR, Gorton) pp 89-90 considered that six-coupled locomotives were more versatile than eight-coupled as they could also be used for passenger work; D. Corbett Fletcher (GNR, Manchester) pp. 90-1 noted the performance of Foden steam wagons used between Manchester and Southampton and of petrol lorries between Manchester and Leicester; J.N. Gresham (LYR, Horwich) pp. 91-3 commented on injectors; F.W. Attock (LYR) pp 93-5: Leeds Meeting on 5 December 1921 pp 99 et seq: A.C. Stamer chaired Leeds meeting on 5 December 1921: comments 99-102: engine failures were very rare, structure limits were more significant than gauge; advovcated 20 ton capacity wagons; the use of assisting engines on severe gradients was an effective means; considered that the NER T3 had been superior to the Churchward 28XX due to the better turning momemnt provided by three cylinders and the total adheion available on the 0-8-0, also considered that the exhaust steam injector was very useful; G.A. Musgrave (GNR, Doncaster) was against the pooling of locomotives; A. Hird (Hunslet) requested information on carbonization in cylinders on superheated engines, especially where the Detroit displacement lubricator was used.;
Walter Chalmers chaired a second meeting in Glasgow and returned to the topic of the Glenfarg trials; Whitelegg noted the accessability provided by outside cylinders, the need to avoid cranked axles, and the advantages of the traffic control system introduced by the Midland Railway and adopted by the NBR. Kermack (318-19) observed the use of feed water heating on the LBSCR and noted the potential of exhaust steam injectors; McFarlane (319-21) considered that compressed air should be used to power auxiliaries; J. Aitken (NBR) 321-2 advocated improved training for footplate staff and noted that this was far more advanced in Canada; M. Blacklock showed the relationship between coal consumtion and tractive resistance.
Fowler, Sir Henry (Paper 115)
Steels for locomotive purposes. 106-27. Disc.: 127-33; 198-209; 259-64.
Presented in Glasgow on 16 December 1921: chaired R.H. Whitelegg.
The first steel purchase made by the Midland Railway was for spring steel in January 1861. This was followed in 1874 by purchases of steel for tyres and for straight and crank axles. In 1884 steel was adopted for frame plates, boiler plates and wheel centres. There were no specifications for steel until 1887. Sir Henry describes how testing and analysis were introduced. Note running title given as "steels for locomotive fireboxes" which might have led to some false citations. Page 110: mentions machine designed by Deeley for the torsion testing of crank axles. Cited contemporary work on steel and testing: Charpy, Izod, Fremont and the the work of Sir Charles Hadfield. The Midland Railway operated 3000 locomotives and the following table shows how the life of crank axles improved.
|year||av. age crank axles broken up||average mileage|
Discussion: D. Irvine Kempt (CR) (127-8) asked about the mileages achieved by crank axles; Walter Chalmers (NBR) (128) asked about built up crank axles; M. Blacklock (Beardsmore) (129-30); W. Chalmers (130-1) on steel fireboxes; Thos Lunt (NBL) (131) cracked frames; Wm Hain (CR) (131) the Izod impact test; H.A. Treadgold (131-2) the need for closer co-operation with steel manufacturers. In Manchester A.E. Kyffin (Gorton Foundry) (260) discussed steels for connecting rods and J.R. Billington (Horwich) mentioned low carbon steels for cranks. Fowler response on pp. 262-4.
Turner, F. (Paper No. 116)
Management difficulties. 135-50. Disc. 150-70.
Presented in London on 17 December 1921: chaired J.A. Hookham. The difficulties of costing, especially to make allowance for increasing wage rates and the intervention of shop stewards. Discussion: A.E. Howell (Armstrong, Whitworth, 153-4) shared the same problems and introduced time and motion study...
J. Clayton (pp 154-5): shop stewards should be educated men. H.A. Tonkin (SECR 168): "Locomotive engineering is in essence a problem of £ s. d., and of producing things at a price, and the function of costiong is the translation of technical results into monetary terms of measurement."
Journal No. 53 (February 1922)
Allen, C.J. (Paper No.117)
Notes on the influence of design on express locomotive performance. 175-85. Disc. 185-97; 248-58; Meeting at Leeds 516-22 (Journal No. 55)
The Chairman (J.W. Smith) was hostile: "The author seems to have formed the opinion that locomotive engineers do not possess data obtained from actual tests to guide them on matters of design. They have quite a lot of information..."
W. Rowland (G.C. Rly., Gorton 186) : In the early part of the Paper the Author, in commenting on the assumed impossibility of designing a locomotive by other means, says " We therefore have recourse to ratios," and proceeds to set forth various ratios, such as tractive effort to heating surface, heating surface to grate area, and so on, which he quite gratuitously assumes are actually employed by the designer. Although these ratios are apparently of great interest to the readers Q popular literature on the subject, they happen, with perhaps one exception, to be those with which any designer who knows his business is totally unconcerned. In fact, the Author, perhaps not intentionally, accuses the designer of total ignorance of the principles of his business and reduces him to slavish copying of proportions which have been found more or less satisfactory as the result of a course of errors or happy accidents in the past. Let me a5s~11-hei m that the state of the art is hardly as bad as that, whatever it may have been once. Certainly ratios do enter into design, but they are not those quoted by the Author.
For example, the ratio of firebox surface to volume, u hich is really a measure of the water-cooling effect of the fii -box sides, has a very important bearing on the completeness of combustion possible at high rate of firing, particularly when bituminous coal or oil is used as fuel. The ratio of firebox volume to fuel consumed per unit of time is also important. Then again, the ratio of hydraulic mean depth of a tube, or set of tubes, to its length is of importance as a measure of the heat-absorbing capacity of the tube or set. The ratio of the total resistance to gas flow of a set of tubes, which is deduced from the last quoted ratio, hydraulic mean depth to length, in conjunction with the number, is a measure of the power required from the blast, and is therefore of senice in conjunction with other considerations in designing a boiler to give the required power and efficiency. For high speed work, in particular, the ratio of mean port opening, on both steam and exhaust edges, to cylinder volume is likewise important; so is the ratio of the internal surface of cylinder ports and piston head to their voIume, as this ratio is largely concerned in determining the cylinder losses, and therefore the engine, as distinct from the boiler, efficiency of the locomotive. The ratio of tractive effort to adhesive weight is about the only one of the .4uthors ratios that is of real importance, but even this ratio is by no means a constant for all engines, since it is by no means necessary to base it on the normal or full gear tractive effort for all classes of locomotive. In fact, a single driving wheel engine, designed with a nominal tractive effort to adhesion ratio suitable for a slow-running mineral engine, would be badly under-cylindered and most vneconomical at the express speeds for which such engines were designed, and to some extent the same holds good for four wheels and even six wheels coupled engines. May I assure the Author that modern locomotive design had progressed far beyond the rule-of-thumb methods which one would infer from his remarks to he still in vogue. The Author, further on, refers to the four-cylinder Great Western engines having a lap of 15/8. Perhaps he can also tell us the full gear valve travel which must be very much greater than is usual in British practice to prevent these engines constantly refusing to start. Is it a fact that these engines have a full gear valve travel of 7in. or so? If not, they must have a starting notch in the steam lap as is sometimes done in American engines designed to give an early cut-off in full gear. I have not so far heard of this expedient having been adopted in this country. It would have been of far greater interest to members of the Institution had the Author given records of long sustained high speed upgrade work with heavy loads, as this is the true measure of locomotive efficiency
E.W. Seilby (L. & N.W. Rly., Horwich: 188) : The Author refers to the ordinary every-day performance of a locomotive as opposed to special test runs. I think he is quite right, as there is extremely little published information about this subject. Some railways haVe test runs with a dynamometer car, but as a rule the engine is specially tuned up and picked coal is used. The results obtained are doubtless valuable for comparison with other similar test runs, but they do not give much idea of what those locomotives as a class may be expected to do day in, day out, in all v eathers, throughout the year.
As regards tractive effort, the two chief factors limiting the power of a locomotive are :-
1 . Adhesion (when starting and running slowly).
2. Steam producing capacity of boiler (when running fast).
As the tractive effort formula does not take either of these factors into account, it seems rather futile and is often misleading.
Some reference has already been made to Great Western locomotives. These engines have quite exceptionally large steam and exhaust ports, and this point, coupled with their high boiler pressure, and with the fact that they have more lag on their valves than most locomotives, is largely responsible for the extraordinary turn of speed which these engines undoubtedly possess. The long lap enables the engines to be notched up to a very considerable degree without undue compr'ession, thus, whilst cutting off early, the exhaust port remains open until quite late in the stroke.
( J. Parry (G.C. Rly., Gorton 190) : The Author expressed the opinion that piston valves allowed a freer escape for exhaust steam than did slide valves. This is not necessarily so. With piston valves the steam leaving the cylinder has to break up into a number of streams in order to pass to the inside of the liner, where these streams converge and then suddenly have their direction changed through an angle of go degrees. Sudden changes of direction and velocity are as bad as throttling. Probably a balanced slide valve with the exhaust passage through the back offers the least resistance.
Parry did not think that the quoted opinion that harder rails and tyres reduced the undulatory motion of the road can be maintained. The coefficient of elasticity, Youngs modulus, of the harder steel is very little different to that of the softer, and therefore the rails, unless at the same time deeper, will not be stiffer. The rolling friction of hard materials is less than with soft; but, within the range of hardness permissible in railway practice, the difference is too small to be considered. The object of using harder steel is, of course, durability. The One of the comparisons of engines made in the Paper is between P. Stirlings 8ft. single driver and Ivatts Atlantic, as regards their relative heating surface. In Stirlings time coal was comparatively cheap, therefore fuel economy was not so much in the forefront as in later times. To get an engine low in first cost and maintenance, simple and reliable, it is quite permissible to sacrifice something in the way of fuel economy. Later, as in Ivatts time, large heating surfaces were in vogue, this being then considered the way to fuel economy. History often explains things. The Paper will serve at least one useful purpose, that of emphasising the fact that the design of locomotives, like the design of most other things, requires a knowledge of many matters other than the arithmetical rule of simple proportion.
J. Parry (G.C. Rly., Gorton, 189) : The Author expressed the opinion that piston valves allowed a freer escape for exhaust steam than did slide valves. This is not necessarily so. With piston valves the steam leaving the cylinder has to break up into a number of streams in order to pass to the inside of the liner, where these streams converge and then suddenly have their direction changed through an angle of go degrees. Sudden changes of direction and velocity are as bad as throttling. Probably a balanced slide valve with the exhaust passage through the back offers the least resistance.
I do not think that the quoted opinion that harder rails and tyres reduced the undulatory motion of the road can be maintained. The coefficient of elasticity, Youngs modulus, of the harder steel is very little different to that of the softer, and therefore the rails, unless at the same time deeper, will not be stiffer. The rolling friction of hard materials is less than with soft; but, within the range of hardness permissible in railway practice, the difference is too small to be considered. The object of using harder steel is, of course, durability.
The Author complains that railxvay companies do not publish reports of locomotive performances when apparently unfavourable. It would be very imprudent of them to do so, for these results getting into the hands of non-technical pe+ople might easily be the cause of much mischief. One of the comparisons of engines made in the Paper is beween . P. Stirlings 8ft. single driver and Ivatts Atlantic, as regards their relative heating surface. Irr Stirlings time coal was comparatively cheap, therefore fuel economy was not so much in the forefront as in later times. To get an engine low in first cost and maintenance, simple and reliable, it is quite permissible to sacrifice something in the way of fuel economy. Later, as in Ivatts time, large heating surfaces were in vogue, this being then considered the way to fuel economy. History often explains things.
The Paper will serve at least one useful purpose, that of emphasising the fact that the design of locomotives, like the design of most other things, requires a knowledge of many matters other than the arithmetical rule of simple proportion.
E.M. Gass (L. & N.W. Rly., Horwich 190-): The Author made no comments in respect to the loads hauled by the Stirling singles and the Ivatt Atlantics. There is little doubt that the running performances of the former have hardly ever been surpassed when hauling loads equal to their capacity, but the constantly increasing demands of the running department for heavier trains taxed these engines beyond their limit, the result being that a more pomerful machine became necessary.
I believe the success of the Great Northern singles was due, in a large measure, to the low ratio grate surface to heating surface, being 1 to 58 as compared with 1 to 80 in the case of the Atlantics. This low ratio results in a higher evaporation value; for instance, at a speed of 30 miles per hour the evaporation values are 8.31bs. and 6.25Ibs. respectively per pound of coal with a feed water temperature of 100°F. I have endeavoured to figure out the loads that the two designs are capable of hauling on the assumption that they are running at a speed of 30 miles per hour on,an up-grade of I in 200, this being about the ruling grade over the section of the line of the Great Northern Railway, Leeds to King's Cross and vice versa. The detailed statements A, B, C show how the figures are arrived at. The loads behind the drawbar in the case of the single driver is 283 tons as compared with 393. tons for the Atlantic. I have also estimated the rate of coal consumption. Assuming a speed of 70 miles per hour with a steam cut-off of 15 per cent., and cylinder clearance of 8 per cent., the Stirling engine, on this assumption, would be burning coal at th'c rate of 157 lbs. per square foot of grate surface per hour, whereas Ivatt's Atlantics would be consuming at the rate of 115 lbs. The rate of the former is considerably above economical limit, which is about 130 lbs.
With respect to high speed, I should like to mention a record of 94 miles per hour attained by one of Sir John A. F. Aspinall's Atlantics when hauling a train of four bogie coaches, practically 100 tons behind drawbar, between Rainford Junction and Kirby, on the Manchester and Liverpod line. This section of the road is on falling grades, the ruling being 1 in 235. The time occupied in passing the two points was 3¼ minutes, the distance being five miles 179 yards. This engine was fitted with Geo. Hughes' patent compression ball release balanced slide valves at the time.
The bad starting qualities of the single driver are well known. In the case of the Great Northern engine the weight available for adhesion was 18 tons, and only 25 per cent. of this weight could he utilised, or 10,0801bs. tractive force. This figure gives a mean effective pressure in the cylinders of 108lbs. or 61.7 per cent. of the boiler pressure. The corresponding piston speed at this pressure is 310ft. per minute," which in the case of the Great Northern single is equal to a running speed of nearly 20 miles per hour.
C.J. Allen was not present at the Leeds Meeting: A. Hird (Hunslet) pp. 516-17 considered that fuel economy had been ignored by Allen, and he had failed to address the problems of design for narrow gauge lines; J.J. Laine (NER, York) was critical of Allen's enthusiasm for the performance of the LYR 2-4-2Ts: these were only suitable for short-distance work with light loads. Noted that the NBR "Glenfarg" tests with NER 3-cylinder 0-8-0 had been reported in Rly Gaz.
E.L. Ahrons (pp. 519-22) The Author of this Paper has raised a question of great interest upon which much might be said. Since he quotes my views upon the effect of harder and stronger tyres, and harder rails of heavier section upon the speed of express locomotives, perhaps I may be allowed to explain these more fully. During the periods 1884-1892 and 1898-1904, I made a large number of observations on the speeds of express engines on many of the English main lines. During the period 1898-1902 I frequently noted that the maximum speeds attained by the older engines showed a very marked increase. The same engines which, during the period 1884-1892, had not within my own experience exceeded speeds of 70 to 76 m.p.h., were in 1898-1902 attaining speeds of 80 to 82 m.p.h. with considerably heavier trains. This was very marked in the case of the Midland 2-4-0 and 4-4-0 engines, and also to some extent on the Great Northern with the celebrated 8ft. single engines. Speeds of 75 m.p.h. before 1892 were extremely rare, and on three occasions only did I ever find this maximum to be exceeded. On one run a Great Northern 8ft. single attained 76.6 m.p.h. and on another occasion a Midland 4-4-0 engine with 7ft. wheels reached 76 m.p.h. Both instances occurred on descending gradients of 1 in 200 with trains of 120-140 tons weight.
During 1899-1901 I timed several Midland coupled engines with 6ft. 8in. and 6ft. 9in. driving wheels at speeds of 80 to 82 m.p.h. with trains of 160 to 210 tons. The. engines were the same as those which I had timed at speeds not exceeding 736 m.p.h. during the 1884-1892 period. No alterations had been made in the cylinders, wheels, dimensions of boilers, etc., and the pressure had not been increased above the original 140lbs. per sq. inch, but other changes had taken place. The tensile strength of the new tyres had been increased from about 37 to 40 tons per sq. inch to about 45 tons per sq. inch and over, and the material was harder. The old 85 1b. rails had been replaced by 100 lb. rails and these also were of harder steel. The moment of inertia of the 100 lb. rail section is of course considerably greater than that of the older 851b. section. From these changes in both rails and tyres, it resulted that there was not only much less bending of the rails between the chairs, but also that there was less crushing and flattening of tyres and rails at the line of contact on the tread. These two causes combined would reduce the resistance due to rolling friction. Incidentally, this tends to show that the old formula for train resistance, such as that of D. K. Clarke, are of very little use under modern conditions. Probably the formula derived by Sir John Aspinall as a result of his experiments, published in the Proc. Inst. Civil Engrs., 1902 are the only ones upon which reliance can be placed to suit present day British practice. It appears to me that the success of the modern 4-6-0 locomotive as a fast express engine may be largely ascribed to the same cause. The 4-6-0 express engine did not exist in this country before 1901. It seems likely that had this type been employed in the 1880-1890 period with the softer tyres and softer and lighter rails then in use, it would not have been a success as regards high speeds, for the reason that the softer tyres of the six-coupled wheels would have worn too unevenly, and the resulting different diameters of the coupled wheels would have caused excessive frictional coupling rod resistance after the engines had been in service a comparatively short time. The present day hard D class tyre of 56 to 62 tons per sq. inch tensile strength has made all the difference in favour of the modern six-coupled express engine. Another point of the greatest importance in the design of a high speed express engine is the obtaining of a very free exhaust, in other words the back pressure horse-power should be the least possible. The back pressure horsepower may be defined as the horse-power absorbed in producing the draught and depends not only upon the dimensions, length and straightness of the cylinder ports and passages, but also upon the boiler dimensions and proportions, tube and grate areas, smokebox and blast pipe design and proportions.
The Midland 4-2-2 single express engines designed by S. W. Johnson were excellent engines in this respect, the indicator diagrams taken on express trains showing an average back pressure during exhaust of 3 to gilbs. per sq. inch only at high speeds, and their capabilities for fast running were well known.
On the other hand there are many saturated steam express engines at work which show an average back pressure during exhaust of more than 10 lbs. per sq. inch at speeds above 45 m.p.h. In the case of superheater engines of good design with piston valves the exhaust appears to get away more freely, with a considerable reduction of back pressure. Apart from the use of piston valves,. the use of superheated steam appears to show a great advantage in this respect. Short straight ports of ample area are essential in a high speed locomotive, but on the other hand the clearance space must not be excessive. Some designers in their anxiety to reduce the clearance spaces appear to have gone somewhat too far in the wrong direction and have throttled the exhaust to such an extent that the back pressure losses exceed the gain obtained from reduced clearance spaces. The amount of power consumed in driving the locomotive itself at high speeds is enormous. The following figures are taken from those given by H.A. Ivatt Proc. Inst. Mech. Engrs., 1904) and relate to one of the Great Northern " Atlantic " engines, No. 251, working on saturated steam.
|Draw-bar H P||
In the discussion on the same paper, some tests made by Mr. D. Drummond
on two different classes of L. and S.W.R. 4-4-0 type express engines, when
running light, were given. At speeds of 62 m.p.h. the power required to run
the engines light, with tenders only, was 600 i.h.p. and the 6ft. 6in. coupled
engine with 18½in. by 26in. cylinders developed 912 i.h.p. when running
light at 70 m.p.h. This is extremely high, and possibly the engine was
accelerating when the diagrams were taken. But at this speed the back pressure
is about 18 1bs. per sq. inch, and if by any means it could have been reduced
to 4lbs. per sq. inch calculation shows that 300 i.h.p. would be saved and
made available at the draw bar.
The Great Northern engine, No. 251, shows to considerably better advantage, and only 115 i.h.p. could be saved by reducing the back pressure from 9½ to 4lbs. per sq. inch. In this engine the exhaust is direct through the back of a balanced slide valve.
In the above cases and in other indicator diagrams taken at various speeds on British locomotives, the back pressure increases with the speed. This might naturally be expected, since the time for exhaust diminishes with increasing speed and there is more tendency to choke the ports and blast orifice. On the other hand, some very different and remarkable results were obtained by H. B. MacFarland, engineer of tests of the Atcheson, Topeka and Santa FC R.R., U.S.A. He made a long and elaborate series of experiments on every class of engine on that railroad, which were recorded very fully in a paper read by him in 1912 before the International Fuel Association at Chicago. In practically all these tests . MacFarland found that the back pressure was nearly constant at all speeds, and did not increase as the speed increased. From these tests he deduced that the back pressure horse-power was equal to a constant multiplied by the speed, the constant differing with the dimensions and design of each engine. For American 4-4-2 and 4-6-2 type heavy passenger engines the constant varies from 6 to 10, according to the design, and this figure multiplied by the speed in miles per hour gives the back pressure horse-power at that speed. The engines tested were considerably larger than British express engines and the mean back pressure in psi was also considerably greater.
An engine may be over-cylindered from two causes. The one usually taken into consideration is that the boiler is too small to supply steam to the large cylinders, but there are also cases of over-cylindering in which the cylinders are too large for the port areas, and the resulting increased back pressure acts upon a much larger piston area, thus impeding the free running of the engine. I can instance the case of some 4-4-0 type (saturated steam) engines with 19½in. by 26in. and 19in. by 26in. cylinders, which in other respects were alike. The 19-inch engines gave excellent results with heavy express trains, and their performances were always much better than those with 19½in. cylinders
Kermack, W.L. (Paper No. 118)
The modern passenger locomotive. 210-22. Disc.: 223-7.
Presented Glasgow 19 January 1922
Notes the CR 3-cylinder design. Considered that the Wootton and Belpaire fireboxes offered similar advantages and that the water tube boiler provided steam quickly and noted the cross tubes used in LSWR fireboxes. Other topics noted included oil fuel, feed water heating, the Vortex blastpipe, superheating and electric locomotives. Quotes results of trials with GCR Directors vs Atlantics; GER 1500 class vs Claud Hamilton 4-4-0s; and GWR Saints vs Stars.
Kermack's general observations on the CR 3-cylinder design are of interest: "In view of the present demand for increased power, three-cylinder and four-cylinder engines are coming into vogue, and their use is likely to extend. The Caledonian Railway was the first Scottish railway to put a three-cylinder engine into service. The principal advantage of these is, that they are able to deal with trains which would otherwise require assistance. Exerting great power and having rapid acceleration, they are, for reasons given above, indirectly economical. There is a mechanical advantage obtained in the threecylinder engine, in that the cranks follow one another with more regular sequence than in the case of the two-cyiinder engine with the cranks at right-angles, thus dividing the work more evenly and giving more regular turning moment, balancing being also assisted."
Blacklock (223-4) mainly considered the paper in terms of its literary merit. J.W. Tyler (225-6) noted the effect of Joy valve gear on boiler pressure, the higher boiler pressures adopted on the GWR and Midland Railway, the coned domeless boilers adopted at Swindon and that the LYR was one of the few railways to employ superheating on slide valve engines. On page 214 Table 1 shows performance gathered from uncited sources
|Max hp||Average of best performance|
The trials recorded above were very exhaustive, and were conducted on a fairly long up grade with a rising approach to eliminate conserved energy. It is seen that the four-cylinder class last mentioned are exceptionally povxrful engines. The working pressure of these is 225lbs. per square inch. Trials of single-wheelers gave figures of 783, 773 and 785 h.p. respectively.
Beesley, F.W. (Paper No. 119)
The modern express passenger locomotive. 228-46.
Read by David Smith at meeting in Glasgow on 19 January 1922. A general examination of locomotive types (at time of paper there were 3457 4-4-0; 293 4-4-2 and 1083 4-6-0 in service in Britain. This is followed by a broad survey of the locomotive on a component and its composition basis. Noted the emergence of Walschaerts valve gear, the Schmidt and Robinson designs of superheaters; Robinson's contribution to piston valves and the large cabs employed on the GER, NBR and NER.
Robson, T. (Paper No. 120)
The inspection and testing of materials used in the construction of locomotives and rolling stock. 265-301. Disc.: 301-10.
At Darlington Works: notes on steel manufacture, crank axles, straight axles, tyres, boiler plates, frame plates, copper platess, boiler tubes, laminated springs, helical and volute springs, castings, drawgear, chains and wire ropes. Test house for NER. Quoted from statistics in Government reports decline in tyre and axle failue. Discussion: J. Weatherburn (303-4); R.J. Robson (304); P. Liddell (304)(all of NER, Darlington), C.N. Goodall (Robert Stephenson, 304-5); Norman J. Lockyer (309-10) noted that Stroudley at Brighton in 1882 had specified arsenic limits for copper.
Journal No. 54 (March-June)
Malcolm, P.L. (Paper No. 121)
Railway lubrication. 335-63. Disc. 364-401.
Chadwick, G.H. (Paper No. 122)
Electric welding in railway shops. 402-6.
Journal No. 55 (July-September 1922)
Howell, A.E. (Paper No. 123)
Modern production and costing methods as applied to locomotive engineering. 416-68. Disc.: 469-72; 532-43; 571-7 (latter in Journal No. 55)
Paper presented 3 March 1922 in Manchester, 23 March in London, and 10 April in Leeds.
E. Colclough (Cambrian Rlys., Oswestry, 470-1) Highly critical: "In the first place it looks to me rather a serious item to take the works manager away and create another one by introducing a production engineer. It appears to me that, in the first place, a works managers duty is absolutely and essentially that he should control the whole business and work of the works which are put into his charge. I should like to know if this production engineer is under the works manager, and does he submit his views and decisions to the works manager for his final consent? Generally speaking, I should say that the principles on which this system have been laid down are based on premium bonus ; the Author would find a little more difficulty on straight piecework when arriving at accurate times and costs".
Also critical of approach in concentrating on manufacturing, rather than manufacturing and repairing at the same time. A difficulty would crop up very soon if the Author had both systems going in the same works. If we could have had some figures which would have helped us in repairs in general, it would have been a very great help to some of us. Chopping and changing, and pulling out of one machine and putting something else in, is a very constant occurrence. The mean speeds and feeds generally adopted is done for mass or quantity production, but generally, in a small shop, I think it is more advisable to take each machine on its own basis, especially in an old works where a few new machines are introduced amongst a lot of old ones. The only real way, and saving way, is to take a machine on its own feed and speed. Then, again, there is another difficulty ; the whole thing is based on the production office working out these basis prices. These prices are submitted to the foreman, and that foreman is an intermediary between the firm and the men. How would he go on if, as I have just lately experienced, the men objected absolutely to an intermediary, and wanted a clear deal between the firm and themselves? The question cropped up in this way. We had taken the feeds and speeds of all tools in the shops. We had worked out the whole of our jobs and given the basis times in which each of these jobs should be done, and generally speaking, they could be worked to ; but great objection was made that the whole thing must be agreed on between the foreman and the men. As soon as ever they got to know that the thing had been worked out on feeds and speeds, the men were up in arms in a minute.
I am glad that our Chairman mentioned the boiler shop, because in some cases on piecework in the boiler shop probably there are eight or nine men on one job, and at the same time, and probably these eight or nine men are on different rates, and it is a very difficult matter to give a real straightforward piecework price for any job under these conditions. It is quite easy, I know, generally speaking, if every man is paid the same rate, and they are working on similar machines as in a machine shop.
I should like to know actually the number of men engaged in this production office work in proportion to the men in the shops.
Clayton, J. (Paper 124)
The lubrication of a modern locomotive. 473-503. Disc.: 504-15. 14 diagrams
Read in London on 4 March 1922. Started with the lubrication of coupled or driving wheel bearings: noted that the SECR employed an oil box adopted by Maunsell on the GS&WR in Ireland: this was of the syphon tube type. It was designed for the ready removal of the pads without lifting the engine. Similar methods had been adopted by Gresley on his 2-6-0 locomotives for the GNR and by Churchward at Swindon. Carrying wheel bearings were then considered. For the Bissel or bogie truck Cartazzi slides were used to provide side control and it was noted that the trailing bogies of the SECR 2-6-4Ts had this form of suspension. Consideration was given to axlebox guides and to the motion: recent big end design on the SECR followed that adopted by Churchward at Swindon: a solid bush bearing made from bronze and lined with white metal. This design had also been adopted for the 2-8-0s built at Derby for the SDJR. The specification for cylinder oil (for cylinders using superheated steam and mechanical lubricators) was noted. Hydrostatic sight feed lubricators were used on the latest SECR locomotives. Ten "recent 4-4-0s" employed mechanical lubricators with anti-carbonizers. The lubrication for the N class 2-6-0s was illustrated with the aid of double-sided folding diagrams. Many diagrams.
The sight feed lubricator fitted to the 4-4-0s shown may be said to fulfil the conditions indispensable to railway locomotive working as follows :-
1.. It is simple, with few parts, and readily understood by the enginemen.
2. The delivery of the several feeds is under the sight and control of the driver without leaving the footplate, and provision is made for seeing the feeds at night.
3. There is no danger to enginemen from broken, glasses.
4. The lubricator-can be replenished on the journey if necessary, and feeding can be stopped readily at any time without readjustment being required.
5. The condenser being separate from the lubricator the oil reservoir is not under direct steam pressure and never becomes hot enough to affect the rate of feed or the consistency of the oil.
6. The oil reservoir cannot be overfilled and provision is made for expansion of the oil.
7. The lubricator being carried from the firebox back, no relative moment between the pipes and the boiler takes place, and being inside the cab, the action of the lubricator is unaffected by atmospheric variations.
8. The rate of feed (practically constant under all conditions) * is on a time basis (not dependent upon the revolutions of the driving wheels), and adjustments of the feeds can be made en route by the driver as necessary.
9. All wearing parts are easily renewable. 10. The oil is delivered in the form of an emulsion ( L e . , a mixture of oil and steam) and readily ensures the oily atmosphere in which valves and pistons, etc., are bathed, thus ensuring good distribution of the lubricant to the wearing surfaces.
Discussion: C.F. Dendy Marshall (p. 504) wondered how hydrostatic lubrication had evolved from the form of lubrication invented by Ramsbottom and was informed that the form described had been invented at Ashford; F.J. Hookham (pp. 504-5) discussed oil composition; on pp. 505-6 Clayton noted that tail rod lubrication was based on that adopted by Ramsbottom and was almost identical to that employed on Westinghouse brake pumps since 1914; J.L. Crosthwait (B. & C.D. Rly., Belfast: 507): I enjoyed Mr. Clayton's Paper very much and am very interested in the question of compound oil for ordinary engine lubrication. About a year ago we received from Manchester some 4-6-4 type tank engines with Igin. x 26in. outside cylinders and had trouble with the driving crank pins. Great difficulty was experienced in keeping brasses tight, and set screws had to be fitted, etc. The Belfast and County Down Railway are using a very cheap grade of oil at present. As a matter of fact, it is about the same price as paraffin oil, and we are getting perfect satisfaction at the moment, but it has only been in use for about three months. Its viscosity at 140' is 40 seconds, and at 200' works out at about 61 seconds. I am very interested in the lubricator described, as compared with the Detroit in use on our system. I have taken great pains in the matter of trying to make a single-feed Detroit feed four places at the one time. I succeeded fairly well, and fitted an enclosed cone on to which the oil was sprayed, on the cylinder side of the choke, taking leads off, one to each cylinder and one over each valve. The idea of fitting a lead to each cylinder is that the Rowan ring is in use. This is a ring that may be continually kept up to its work by the expansion of an internal spring, but it is found that it requires considerably more lubrication than the ordinary Ramsbottom ring G.M. Wells noted trouble experienced with Roscoe lubricators; Clayton (p. 508) noted the differences between Ashford and Swindon practice; Cleary (p. 509) commented upon carbon deposits ¼in thick in the low pressure cylinders of four-cylinder compounds; W.A. Barnett (South Metropolitan Gas Co.) p. 510 congratulated the author for the get-at-ableness nature of the design. Speaker had encountered problems with hydrostatic head and doubted the value of tail rods; Tayerson (p. 511) asked about single bar crossheads and Clayton considered them to be very successful (cheaper to construct and simpler to maintain). It was noted that the Great Eastern Railway exploited them on inside cylinder locomotives. F. Turner (Chairman of the meeting) pp. 511-12 queried whether the lubricant might congeal in the long pipes; J.A. Hookham (pp. 514-15) noted that straight mineral oil was adequate for freight and light passenger work;
Mellanby, A.L. (Paper No. 125)
Some phenomena associated with the flow of steam through nozzles. 544-50. Disc.: 550-70.
Design of turbines: research at the Royal Technical College, Glasgow.
Hookham, J.A. (Paper No. 126)
Comparison between superheated and non-superheated tank engines. 578-603. Disc. 578-603; 604-33.
Results from trials with an 0-6-2T. Contributors to the discussion included Kyffin (p. 604); W. Rowland (GCR 605-7); H.N. Gresley (613-16) commented on the use of snifting valves, his own experience of superheating on 0-6-2Ts (includes side elevation of N1 0-6-2T No. 1598), and on the superb slide valves used by Hookham; A.J. Hill (616-18 and 631-3) noted that the large number of stops in suburban work led to a high cost in superheater repairs for the 0-6-2Ts; B.K. Field (Works Manager, LBSCR) quoted experience with 4-4-2Ts; J. Clayton (621-2) commented on the Detroit lubricator; A.H. Whitaker (SDJR page 625) on cylinder packing; and A.J. Hill (631-3 including side elevation of 0-6-2T) noted that suburban working provided little opportunity for notching up. .
The Scotswood Locomotive Works of Messrs Sir W.G. Armstrong,
Whitworth & Co. Ltd. 634-9.
Material used in Armstrong Whitworth page
Journal No. 56 (October-November 1922)
Sedgfield, P. (Paper No. 127)
Continuous automatic brakes with special reference to their use on goods trains. 649-76. Disc.: 677-95.
As used in Uruguay.
Simpson, L.S. (Paper No. 128)
Railway operating in France. 697-728. 112 figs. (including plans and illus)
Read in Argentina: Author describes how he returned to Britain to serve during WW1 in the Railway Operating Division. Originally made up in sections of 266 men and no specific number of officers, the R.O.D., in January, 1917, came under the organisation of Sir Eric Geddes, the Director-General of Transport, when the mechanical side was made into a separate department and the remainder expanded into a variety of companies, consisting of three officers and 250 men, whose occupations are well described by their titles:-
Broad Gauge and Light Railways;
Miscellaneous Trades Companies;
Transportation Stores Companies
On pp 699 and 700 he noted his encounters with Colonel Cecil Paget who directed him to repair 35 Belgian locomotives and noted on page 701 that Paget had a precise knowledge of the French language. The repair work was performed in a sugar factory (the source of some wonder to the speaker) at Pont d'Ardres, but work had to be transferred when the beet crop was harvested. Also served at Candas, Amiens and Hazebrouck. At the last named he experienced a major ammunition explosion on 21 July 1917 involving 10-12,000 tons of ammunition. On page 707 he recorded a visit made by R.E.L.Maunsell and by C.J. Bowen Cooke. He visited the shops at Borre with Col. Paget. He worked under Colonel George T. Glover, then of the NER, but later released to become CME of the GNR(I) page 718. He was interviewed by Geddes and paper notes several aspects of his invovement in France. He visited the Gaza Railway in Palestine with Col. McLellan of Merz & McLellan to report on its state and at the end of WW1 he was requested to assess damage to railways in Belgium. Notes on train ferries.
Journal No. 57 (December 1922)
New four-cylinder tank engine, North Staffordshire Railway. 732-4 + folding plate (general arrangement side elevation). 2 illus.
Rodolfo Jaramillo (Paper No. 129)
Combustibles used in the industries especially in locomotives. 740-78. Disc.: 778-
South American paper which considered the preparation of pulverized fuel for combustion in locomotive fireboxes and in industrial plant: cement kilns, industrial boilers, forges and copper smelting. The Fuller system which used ball mills to pulverize the coal and the feed systems and grates were considered in detail. Locomotives designed or modified to burn pulverized fuel in the USA, Sweden, Italy and Brazil were considered. Discussion: Nixon (Grant & Co.) 781-5 gave details of the results of trials on the GCR with various forms of fuel from Elsecar steam coal as burned on the grate to powdered coal to various forms of colloidal fuel through to straight fuel oil. J.G. Mayne 790-4 gave further information on the Robinson system, and on the Lupulco and Fuller systems for pulerized fuel
Visit to Melon Cement Works, Calera, Chile, 18 February, 1922. S.J. White. 800-2
Visit to electric generating plant of the Compania Chilena de Electricidad Limitada at La Florida, 19 February, 1922. A. G. Noble. 802-4
Florida Hydro-Electric Power Station, Santiago de Chile. C.D. Smith. 804-5.
Visit to San Bernardo Workshops, Chilian State Railways, 20 February, 1922. E.C. Noble. 805-9 + plates. plan
Visit to the Steel Foundry of the Compania Electro-Metalurgica, Santiago. (Chile), 20 February, 1922. G. Mansfteld and H. Matthews. 809-10
Visit to Valparaiso, 21 February, 1922. J.G. Mayne. 811-15
Describes the exciting and scenic journey from Santiago to Valparaiso where the assisting locomotive was detached at La Cumbre at speed and switched into a siding without the main train slowing. At Valparaiso the harbour protection works being constructed by the Pearsons were inspected.
Visit to port works at San Antonio, 22 February, 1922. P.W. Dobson. 815-16.
Inaugural Address. 828-45. Disc.: 845-9. 4 illustrations (photographs), 4 diagrams
Presented at Darlington on 6 October 1922 by Chairman of the Leeds Centre. First part reasons for establishment of another centre. Second on the business of locomotive building. Comments on the appearance of older locomotives and mentions Stroudley 0-4-2 (noting how weight was saved whilst having a boiler as powerful as contemporary 4-4-0s) and Gresley K3 2-6-0 (where weight was saved by avoiding splashers). Fig. 7 (p. 844) shows a Beyer Peacock 2-4-0T designed by J. Beattie in its original condtion and considers as a a pradigm for appearance. Compares British and American design practice: noted the far greater rigidity achieved in American designs through the use of cast cylinders and cast steel bar frames, but was critical of the high heat losses due to radiation of the steel mass. The wagon top boiler used in America was dictated by the vast dimensions of American boilers (8ft diameter and 80ft2 grates). American boilers gave ample room for circulation.
Renwick, H.P. (Paper No. 130)
The district supervision of the locomotive department of an Indian railway. 850-72.
Presented in London on 19 October 1922. In effect an examination of the characteristics of railways in India in terms of geography (mileages, gradients, guages), climate (temperature and rainfall) and social groups including religions
Inaugural address. 876-88. Disc.: 888-90.
Opening of Scottish Centre in Glasgow on 2 November 1922. Noted the limitations of the British loading gauge in comparison with the far more generous loading gauges in North America and Australia (cited agreement between New South Wales and Victoria): such gauges large outside cylinders to be used. Mentions LSWR 4-6-0, GSWR 4-6-4T and electrification and three-cylinder Pacifics and eight-coupled designs on NER and GNR. Considered the booser: following are stated as objections to this form of booster:
(1) Equal to a pilot engine, except for absence of boiler ;
(2) Extra total length (this applies where a special tender is designed having driving wheels larger than the usual tender wheels) ;
and some of the advantages as follows :-
(1) Dispenses with a fully equipped pilot engine; (2) Requires no fuel or water;
(3) Saves boiler construction and repairs ;
(4) Permits using up of old boiler and locomotive stock
when extra power is required; (5) Equally useful on flat high-speed lines as on steep inclines ;
(6) May be made up from scrapped engines able to work at 50lbs. pressure without danger to cylinders ;
Kyffin, A.E. (Paper 131)
Some features of boiler design and construction in relation to upkeep. 891-910. Disc. 910-16.
Presented in Manchester on 3 November 1922. Involved in the discussion were S. Jackson (Gorton Foundry, p. 910), J.N. Greham (911), W.E. Richards (Gorton Foundry, 911); J.W. Glover; D.C. Fletcher (GNR, 913-14); S. Clayton (914-15); T. Hargreaves (GCR, 915) and E.W. Selby (LNWR, Horwich, 915-16) who made reference to GWR and SECR practice.
Presidential Address. 925-65.
Second Ordinary General Meeting (1922/3 Session) of the Leeds Centre was held at the Philosophical Hall, Leeds, on Friday, 1 December 1922, Mr. C. N. Goodall occupying the chair. (13, 134) Includes A.J. Hill's pamphlet Enginemen, do you know? produced to educate footplate crews to reduce fuel consumption wherein it was stated that the GER spent £1.5m on loco coal and the cost had risen from 18s 2d/ton in 1913 to £2. 4. 9/ton. In 1913 62 lb/mile of coal had risen to 72½ lb/mile..