Journal of the Institution of Locomotive Engineers
Volume 57-59 (1967-9)
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Volume 57 (1967)
Journal No 315
Keller, Rolf (Paper No. 687)
High power diesel hydraulics. 19-48. Disc.: 48-68.
General Meeting of the Institution held at the Institution of Mechanical Engineers, London, S.W.l, on 13th March 1967 at 5.30 p.m. Mr. M. A. Crane, Presdent, was in the Chair.
The Chairman, in introducing the Author, Dipl. Ing. R. Keller, said that Mr. Keller was a Member of the Institution from Germany. Many present would know that, in view of the position he held with his Company, which manufactured hydraulic transmissions, he might be considered as one who could give members the benefit of considerable experience in that kind of medium. There might be some controversy among those present as between diesel electrics and diesel hydraulics, and that was a very good thing. That was how one got at the truth. Those present had an opportunity of hearing a Paper from someone who had information on the performance of diesel hydraulics in other countries, and although Mr. Keller had knowledge of locomotive performance in this country, he would bring news from elsewhere which would be of great interest to all concerned.
Author was Head of the Turbo Transmission Department of Voith Getriebe KG, Heidenheim, Germany. The inherent problems of the hydraulic transmission including cardan shafts and axle drives were well known. Start up through the transmission is an unnecessary complication which can be avoided, thus preventing any engine problems such as water in the cylinders damaging the transmission. If the specified cooling requirements are not also continuously met trouble arises, but this is so with any piece of equipment. Between 1952 and 1962 the engineers concerned found one solution after the other beginning with :
1.Primary vibrations between engine and transmission.
2. Axle drive suspension and suitable torque arm links.
3. Cooling of transmission oil.
4. Secondary vibrations including coupled bogies and gear
5. Roller bearings.
6. Overspeed and wheelslip protection.
A diesel hydraulic locomotive where these problems are solved and the solutions have been proved by prototype tests, will have a high availability and low maintenance costs
Low, R.C.S. (Paper No. 688)
The reorganisation of British railways workshops. 91-146.
Ordinary General Meeting of the Institution held following the 56th Annual General Meeting, at 5.50 p.m., the Chair being taken by . M. A. Crane, (President).
The Reorganisation of the British Railways Workshops covered the rationalisation and development undertaken between 1963 and 1967. It is of particular interest on account of the scale of the operation and the complexity of the problem in the light of the changing pattern of the Railway requirements
Journal No. 316
Address by the President. How they run. 155-96.
Biographical material used to start biography. Mainly about modern traction: he had started his career in the hope of being involved in electrification from York to Newcastle, but had moved to Gateshead Works to meet the requirements for a Whitworth Scholarship. After a spell in the Drawing Office he moved to the running department where he was involved with the operation of Sentinel steam railcars, with No. 10,000 and the ACFI feed water heaters and poppet valves on the NER Atlantics had made him sceptical of gadgets ever since. He likened the relationship between man and the steam locomotive as that between horse and rider.. He then moved on to his experience of the changeover from steam to diesel hydraulic traction on the Western Region and the centralisation of maintenance in a few excellently equipped depots. He noted the reliability of the D1000 type with the exception of the train heating boilers. He also spoke at length about track improvements with realignments for higher speed at Twyford station and at the Junctioins at Wootton Bassett and Patchway and looked forward to the gas turbine tiltiing trains. He ended by comparing the Paddington to Plymouth running time with Castle, King, D833 and D1000 types and over the Exeter to Plymouth section with two type 833 vesrsus D1000..
Radley, R. (Paper No. 689)
The application of rail stress to locomotive design. 196-205. Disc.: 205-8.
The interaction between diseel or electric bogie locomotives, with various bogie configurations, with track, both straight and curved, but without the consideration of super elevation. The Heumann wheel profile is considered in the discussion.
Mathur, R.B. (Paper No. 690)
The setting up of a broad gauge diesel locomotive shed at Ratlam, India. 208-20.
Journal No. 317
Urban railway rolling stock. (Report of the Stanley Herbert Whitelegg Memorial Travel Scholarship Award). 228-49.
Rapid transit systems in Rotterdam (a Metro underground railway including tunnel under the River Maas), Hamburg (an electrified suburban system, plus an underground railway), Gothenburg (a highly developed tramway system) and Stockholm (underground railway) were visited. In Gothenburg the rolling stock consisted of tram cars (which could operate in multiple). Elsewhere multiple units were the norm..
Anoop Singh (Paper No. 691)
A method for estimating braking distances. 251-78. Bibliog. 14 diagrs., 2 tables
Based on experience in India.
Davidson, D. (Paper No. 692)
The influence of railway requirements on motive power selection. 279-86. Disc.: 286-89.
Paper presented in Bulawayo to the Rhodesian Section on 24 February 1967.
Jackson, J.A. (Paper No. 693)
Locomotive-hauled Pullman trains. 289-300. 4 illus.
As employed on services on the London Midland Region's electrified services from Euston to Manchester and Liverpool.
Journal No. 318
Wilcock, H. (Paper No. 694)
Container design. 303-35. Disc.: 335-67.
General Meeting held at the Institution of Mechanical Engineers, S.W.l on Monday 23 October 1967 at 5.30 p.m. Mr. T. Matthewson-Dick, C.Eng. (President) was in the Chair.
T. Henry Turner (343-4) asked how the design philosophy of modern containers for rail, road and sea had dealt with demurrage, vibration and condensation.
Beasant, F.H. (Paper No. 695)
Development of the Brush type 4 locomotives of British Railways. 368-92. Disc.: 392-418.
General Meeting of the Institution was held at the Institution of Mechanical Engineers, London, S.W.l, on Monday 20 November 1967, at 5.30 p.m. T. Matthewson-Dick, C.Eng. (President) was in the Chair.
Journal No. 319
Koffman, J.L (Paper No. 696)
Design for comfort. 428-507.
General Meeting held on 18 December 1967, at the Institution of Mechanical Engineers, with the President, Mr. T. Matthewson Dick, in the Chair.
Dunkley, F.G. (Paper No. 697)
Painting of railway rolling stock. 509-35. Disc.: 535-53.
Ordinary General Meeting held at the Institution of Mechanical Engineers on 22 January 1968, with Mr. T. Matthewson-Dick (President) in the Chair.
Journal No 320.
Scott, H.W. (Paper No. 698)
High-speed diesel engines of high power. 582-605. Disc.: 606-24.
General Meeting held at the Institution of Mechanical Engineers, London, S.W.l, on 19 February 1968, at 5.30 p.m.: T. Matthewson-Dick, President, was in the Chair.
Broughton, A.J. (Paper No. 699)
The maintenance of diesel locomotive starting batteries. 625-42. Disc.: 642-55.
Ordinary General Meeting of the North-Eastern Centre held at the Great Northern Hotel, Leeds on 23 January 1968 at 6.45 p.m., the chair being taken by P. Garnett.
Bonavia, P.C. (Paper No. 700)
The computation and analysis of locomotive performance. 645-56. Disc.: 656-7.
Steam age computing on an ICT 199 with data input via punched cards and results transmitted by Telex. Problems being tackled included repetitive failures, notably high water temperatures encountered on the English Electric Type 4 diesel electric locomotives which were traced to corrosion in the cooling system. Another problem was the failure of cylinder liner seals.
Volume 58 (1968)
Journal No. 321
Fish, M.E and T.J. Lowe (Paper No. 701)
Wiring and associated terminations on London transport railways rolling stock. 28-77.
General Meeting held at the Institution of Mechanical Engineers, London, S.W.1, on Monday, 18 March 1968, at 5.30 p.m. The President, Mr. T. Matthewsow-Dick in the Chair.
Wise, S. (Paper No. 702)
Ultrasonic testing of railway components. 77-110.
Ordinary General Meeting of the Midlands Centre held at Midland Hotel, Derby, on 24 April 1968 at 6 p.m., the Chair being taken by Mr. F. H. Beasant.
Jouran No. 322
Cooke, B.W.C. (Paper No. 703)
The technical journalist. 113-22. Disc.: 122-35.
Ordinary General Meeting of the Institution of Locomotive Engineers was held at the Institution of Mechanical Engineers, after the Annual General Meeting had terminated at 5.50 p.m., on 22nd April 1968. The President, Mr. T. Matthewson-Dick, C.Eng., F.I.Mech.E., F.I.E.E., was in the Chair.
Author was Managing Director, Transport and Technical Publications Limited and Editor-in-Chief, Railway Gazette. Claimed that technical journalism probably began when Dr. John Theophilus Desaguliers published the first volume of A Course of Experimental Philosophy in London in 1734. This contained the first detailed description of a railway (the Prior Park Wagon-Way, Bath) and its rolling stock and was contributed by a practical engineer, Charles de Labelye, afterwards Engineer of Westminster Bridge, completed in November 1750. The rolling stock drawings were scaled, keyed with letter references and showed considerable detail. A Collection for Improvement of Husbandry and Trade began in 1692 and was probably the first trade newspaper. The British technical press is a direct descendant of a publication entitled The Mechanics Magazine, founded in 1823, via the activities of Dr. George Birbeck, pioneer of the mechanics institutes. The contents were not exclusively technical, but they did contain a considerable amount of material of interest to engineers. The spread of steam-operated railways led to the development of a special technical press, of which the earliest example was begun in May, 1835, and from which The Railway Gazette traces direct descent. In its early days it was an admirable journal, conducted by John Herapath, but it deteriorated with the first railway financial boom and for a very long period of years became mainly a commercial and financial journal. From 1836 it bore the sub-title Annals of Science but in 1839 the words Commercial Journal were introduced. The Builder, of which No. 1 was published on the last day of 1842, for a time covered a wide range of engineering matters, mainly in the years until on January 4th, 1856, The Engineer was launched. Its famous rival, Engineering, was begun exactly ten years later. Not until February, 1880, however, was there a specialised railway engineering journal, when the Railway Engineer began its long and noteworthy career under the control of Mr. S. Richardson Blundstone. It passed under the control of the Railway Gazette in 1919, but continued as a separate publication until January, 1935. Today the British engineering press has attained world-wide eminence in the practical sphere. The widely-claimed excellence of the pre-war German press was true rather in the scientific and mathematical spheres and tended to be too selective and too continental in its outlook. The American press has many admirable features but, as a matter of policy, devotes its attention mainly to the New World.. The technical press could be divided into horizontal and vertical publications: horizontal journals deal with a subject common to many industries at some point in their manufacturing or productive process, whilst vertical journals deal with an industry as a whole with a readership rangeing from top management down to some pre-determined level in the total labour force.
Maxwell, W.W., J. Richards, J. Shaw, B.R. Dudley, and A.B. Cleary
(Paper No. 704)
Measures to counter fatigue failure in railway axles. 136-71.
Ordinary Meeting of the Institution of Mechanical Engineers, in conjunction with the Railway Engineering Group of the Institution of Mechanical Engineers and the Midlands Centre of the Institution of Locomotive Engineers. held at the British Railways Research Centre, Derby, on Thursday, 30November 1967, at 7 p.m. Mr. D.C. Brown, C.B.E., B.Sc.(Eng.). C.Eng., Chairman of the Railway Engineering Group and Past-President of the Institution of Locomotive Engineers, was in the Chair and he was supported by Mr. E. Sharp,, C.Eng., Vice-chairman of the Midlands Centre of the Institution of Locomotive Engineers.
Redhead, J.J.M. (Paper No. 705)
Some applications of solid-state devices on locomotives. 171-91
Ordinary Meeting following the Annual General Meeting of the Midlands Centre held at the Midland Hotel, Derby, on 19 March 1968, at 6.00 p.m., the Chair being taken by Mr. F. H. Beasant.
Journal No. 323.
Robson, A.E. [Presidential Address]
"All Change". 207-39.
Boocock, C.P. (Paper No. 706)
The application of network analysis to locomotive and carriage overhauls at Eastleigh Carriage Works, British Railways. 239-73.
Ordinary General Meeting of the Institution was held at the Institution of Mechanical Engineers, London, on Monday 21 October 1968 at 5.30 p.m. Mr. A. E. Robson, (President), was in the Chair.
Devitt, W.R. (Paper No. 707).
The metrication of British Railways Workshops. 274-98.
Ordinary General Meeting of the Midlands Centre held at the Midland Hotel, Derby, on 22 October 1968 at 6.00 p.m., the Chair being taken by Mr. E. Sharp, Chairman of the Midlands Centre.
Journal No. 324
Thorley, W.G.F. (Paper No. 708)
Traffic-oriented training for locomotive engineers. 305-42. Disc.: 342-84. 38 illus, (incl. diagrs.)
General Meeting of the Institution was held on Monday 18 November 1968 at the Institution of Mechanical Engineers, The President,. A. E. Robson, M.B.E., was in the Chair.
Determination of trailing loads and point-to-point times, wheel burned rails due to slipping, parts loose or detached, hand brakes, speed indicating gear, fire hazards, warning horns, access arrangements, cab ergonomics, fault lights, windscreen, route indicators, heating and ventilating, driver's safety device, re-railing and training.
Discussion: K. Cantlie (347-8) said that the purport of the Author's able and interesting Paper appeared to be the training of mechanical engineers to build trains that were best suited to operating conditions, altering them as soon as experience showed it to be necessary. This seemed admirable. One such condition, already touched on, was the obvious one of preventing drivers from going to sleep while driving. When he became a Crewe man, many years ago, drivers wel1e provided with a small board hooked onto the panel plate and wide enough for one buttock only. If the driver dozed off, he fell off. Later Bowen Cooke introduced a wider seat but, oddly enough, it was not favoured by the top-link drivers who preferred to stand while driving and sit only while standing. They had been trained to stand, and stand they would.
On steam locomotives a driver could either sit or stand, getting up to stretch his legs whenever he wanted to'. But, on diesels, standing while driving was often impossible. Drivers had to sit, and enforced sitting could become agonising. Furthermore if a driver became sleepy the best cure was to get on his legs. Mr. Cantlie, therefore, thought it very desirable so to design locomotives of all kinds and m.u. trains as to permit the driver to stand as well as sit while driving.
Another point mentioned was that of passage-ways through diesel locomotives. These were often very cramped for big men, and Mr. Cantlie suggested that all projections on which heads or bodies could be banged should either be padded or at least painted in bright colour's.
In his opinion external passage-ways were preferable in the cramped loading gauge of the U.K., and in those of narrow-gauge railways overseas. Many of the latest and largest American locomotives were of this type, as were B.R. shunting engines.
As to horns on locomotives, experience had shown that the higher the note the further it carried. One disadvantage of the present two-note horn was that it sounded too much like horns on road vehicles and thus tended to be disregarded by motorists on level-crossings. 1t was noticeable that motorists were increasingly flashing their headlights for warning purposes, even by day, and he thought that the same arrangement on trains might give some reduction of risk on level crossings. In this country, however, headlights on trains were not used, and drivers had to sit in depressing darkness in order to see the signals. With headlights like those on cars, they could travel in a lighted cab and still have perfect external vision. The argument against headlights in this country was that they would have to be dimmed whenever another train passed, but this was already the case on roads, where headlights were dimmed far more frequently than would ever be necessary on railways, and yet there was little trouble. He suggested therefore that traffic-oriented designers, should provide trains with headlights set near the buffers, or on the bogie frames to provide traverse on curves; one light being a thin pencil up the track and the other being diffused. He believed that safety and the comfort of drivers would both be improved at very low cost.
Wade, C.C.H. (Paper No. 709)
Some aspects of electric and diesel traction in railway modernisation. 387-98. Disc.: 398-407.
General Meeting of the Institution was held on 20 January, 1969, at the Institution of Mechanical Engineers, at 5.30 p.m. The President, A. E. Robson, was in the Chair.
Obviously diesel traction is doing many jobs around the world, including the United Kingdom, and not only in territories having no. sufficient basic supply af electricity. It is also clear that only electric tractian can cope satisfactorily with intensive suburban and inter-urban passenger traffic and with intense main line traffic particularly over physically difficult country. National policy can be a factor in the choice af type af traction. If there is plenty af fuel far thermal power stations, or water far hydro-electric stations but no. indigenous oil supply, electrification should be. considered seriously. The main consideratian is the traffic volume to be handled in relatian to. the anticipated financial receipts particularly additional earnings likely to accrue from improved services attracting increased traffic. Providing improved servies frequently involves increased power af motive power for still further improvement. Electrification enables a built-in reserve of power to be provided in the first instance. With diesel traction any future increase in power may more quickly appraach the limiting capacity which can be obtained fram a locomotive of limited dimensions and weight.
Journal No. 325
Sykes, W.J.A. (Paper No. 710)
The Bournemouth electrification. 445-88.
Ordinary General Meeting of the Institution of Locomotive Engineers was held in the Lecture Hall of the Institution of Mechanical Engineers on Monday, 16 December, 1968. A.E. Robson was in the Chair.
Despite the unduly large number of initial defects in both electrical and mechanical equipment the end of 12 months intensive service has seen most of the causes of failure diagnosed and either already reinedied or in course of rectification, and the financial results justify the confidence placed in electrification. The lessons are clear for all to read; electric traction still imposes some of the most arduous tests to which equipment can be subjected, and a reliable public service cannot be created at short notice with new designs and new techniques which have not had an adequate time to prove themselves under the actual operating conditions in which both vehicles and electric traction equipment will be called upon to function. The Southerns first venture into the field of high-speed electric traction had been successful; the lessons learnt will be used to the full in designs of future electric rolling stock which will play their part in raising the standards of service in other parts of the electrified system.
Nelson, Lord of Stafford
Industry's contribution to locomotive development (The Sir Seymour Biscon Tritton Lecture). 489-512.
Ordinary General Meeting of the Institution was held in the Great Hall, The Institution of Civil Engineers, Great George Street, Westminster, London, S.W.l, on Monday, 17 March 1969, at which The Sir Seymour Biscoe Tritton Lecture was delivered by the Rt. Hon. Lord Nelson of Stafford, M.A., Hon. D.Sc., C.Eng., F.I.C.E., F.I.Mech.E., F.I.E.E., F.R.Ae.S. Mr. A. E. Robson, M.B.E., C.Eng., F.T.Mech.E., M.I.Loco.E., President, was in the Chair.
In part he looked far back to the development of locomotive manufacture by Robert Stephenson between 1828 and 1930: the period in which Lancashire Witch and Rocket were manufactured and the Planet type was introduced (all illustrated).
Webster, E. (Paper No. 711)
Design considerations for new rolling stock for the Victoria Line, London Transport railways. 516-51. Disc.: 551-63. 8 illus., 9 diagrs.
General Meeting of the Institution held at the Institution of Mechanical Engineers, London, on Monday 17 February 1969 at 5.30 p.m. Mr. A. E. Robson, M.B.E., C.Eng., F.I.Mech.E., M.I.Loco.E., President, was in .the Chair
Included the special design requirements for one-man operation.
Batchelor, G.H. and Stride, R.C.T. (Paper No. 712)
Hydraulic dampers and damping. 563-628.
Fifth Ordinary General Meeting of the Midlands Centre was held at the Midland Hotel, Derby on 22nd January 1969 at 6.p.m., the Chair being taken by Mr. E. Sharp.
After brief review of the influence of viscous damping on free and forced oscillations of mass-spring systems, and its effect on response to impulses, suitable damping factors are quoted for control of body and bogie oscillations on the suspension. This is followed by discussion of the most suitable forms of force-velocity characteristics for railway applications, and a section dealing with damping calculations. The influence of damper flexible mountings is then examined, with particular reference to impulsive suspension response and response to sinusoidal excitation. The Paper goes on to deal with experimental work relating to vehicle damping requirements and then proceeds to discuss the recently issued B.R. specification with stipulates the requirements for dampers for use on British Railways vehicles. Difficulties in the manufacture of dampers with linear symmetrical force-velocity characteristics are then pointed out, with special reference to the tendency for current damper designs to result in S-shaped characteristics. A section is then devoted to the more common faults and difficulties that have been experienced wiirh hydraulic dampers, and this is followed by a section dealing with the testing of dampers to ascertain forcevelocity characteristics and endurance. Recent damper developments are then mentioned, and this is followed by conclusions covering the principal aspects of hydraulic dampers and damping
Volume 59 (1969)
This was the final Volume and was limited to two Issues: it was replaced
by the Railway Division Journal
Return to main file
Journal No. 327
Stewart, W.A. (Paper No. 713)
Whither motive power? 16-51. Disc.: 51-84; 256-9.
Captain Stewart had come to railways following a career in the Royal Navy, and the observations made in this paper were mainly looking forward: to 125 mile/h running, to the Advanced Passenger Train and to a form of general purpose locomotive capable of handling all sorts of traffic which has since disappeared. A considerable amount of attention is spent on gas turbines and the French Turbo-train is considered at length. His sole comments on steam traction were "NEVER under any circumstances do such a sudden change of motive power again on such a wide front." He also mentioned the very high price of coal. Contributors to the discussion are only noted where they observe upon what went on before, or on the transition. G.W. Carpenter (59-60) observed that there were still over 50,000 steam locomotives in service elsewhere in the world; K Cantlie (60-1) refering to steam locomotives, mainly in India and China, considered thhat standardisation could be taken too far. F.J. Bellwood (68) whilst advocating a policy of continuous up-rating for diesel locomotives questionned whether it was good economics. K.R.M. Cameron (71) noted that the re-engining of the NBL Class 2 locomotives had been achieved at one third of the cost of a new locomotive: Stewart (72) in response noted that the re-engining had been "wished" upon the Scottish Region: it was wongly conceived, executed in a way which should never be repeated, and has proved unreliable in practice
Tompkin, J.B. (Paper No. 714)
Development of the disc brake with particular reference to British Railways application. 84-117. Disc. 117-29.
Experiments were first made on a Southern Region EMU and this led to the adoption of disc brakes on the AM10 multiple units used on outer-suburban electric serives from Euston. Disc brakes were also applied to high capacity coal wagons and to the bogies of high speed freight vehicles.
Journal No. 328
Dunn, K. (Paper No. 715)
The use made of spectrographic analysis of diesel engine sump oil by the engineer. 138-42.
Watts, P.H. (Paper No. 716)
Weight transfer compensation in four-axle direct current locomotives. 143-53.
Holmes, S.C. (Paper No. 717)
The Sulzer 12LDA28 diesel engine as applied to rail traction: a discussion of some of the structural failures encountered in B.R. service. 153-67
Hudson, C.J. (Paper No. 718)
The use of computers in the production of locomotive repair schedules. 167-81.
Scott, M. (Paper No. 719)
Modern developments in wheelslip control on electric locomotives. 182-90.
Rix, M.M. (Paper No. 720)
Diesel multiple-unit cooling systems. 191-202. Disc.: 202-4. 14 figures (mainly illus.)
Porta, L.D. (Paper No. 721)
Steam locomotive development in Argentinaits contribution to the future of railway technology in the under-developed countries. 205-33. Disc.: 233-56
Abstract based on Rogers' Last steam locomotive engineer p. 162 et seq: modifications to a number of steam locomotives on gauges from 2 feet 6 inches to 5 feet 6 inches following recommendations from Andre Chapelon, J. Vittone, and L.D. Porta, which included the draughting, the steam circuit, and, in the later engines, introducing the gas producer technique to combustion. Included a prototype metre-gauge compound 4-8-0 that had been rebuilt to Porta's designs from a 4-6-2 and which, as a result, had developed an exceptionally high output. In all, locomotives of nine different classes of different gauges had been modified, including three 2-10-2s of the Rio Turbio mineral railway in Patagonia. These latter engines regularly hauled trains of 1700 tons over a line on which the axleload was restricted to 7½ tons; and on trials 3100 tons had been hauled on level track. The metre gauge 4-8-0 hauled loads of up to 2000 tons at 50 mph and 1200 tons at 65mph. The fuel consumption was extremely low. A class of thirty oil-fired 5 feet 6 inches gauge 2-6-2 tank engines on the Roca Railway were also rebuilt in a similar fashion, with the result that their maximum output was nearly doubled and their performance became comparable to that of the PS11 class three-cylinder Pacifics, which had a normal boiler capacity twice that of the tank engines. On express services the tank engines worked trains hitherto hauled by the 12E class Pacifics and burnt 23-25 lbs. of oil per mile as compared with 43-50 lbs. of the latter. The modifications introduced in the rebuilding included the provision of a Kylpor exhaust which increased the evaporation rate and cut the back pressure. Another remarkable rebuilding was that of a three-cylinder 4-8-0 engine of class 11C, which had been supplied to the 5 feet 6 inches Roca Railway in the late 1920s. This was modified under the direction of Chapelon at the extraordinarily low cost of only 15% of a general overhaul. It was so successful that the whole class of 75 engines were similarly modified. The increase in output at the drawbar was from 26 to 40%. The improvements were due to 50% better steam distribution, 30% better draughting, and 16% improved combustion. The rebuilt engines could handle 2000 tons as compared with 1500 before modification, and with a 30% reduction in fuel consumption. They eventually replaced the later 15A and 15B class 4-8-0s, which were more modern and powerful than the 11C in its original form, in the haulage of the 1000 ton fast fruit trains between the Rio Negro Valley and Buenos Aires, a distance of 740 miles. The 2-10-2 locomotives belonged to a batch built for the 2 feet 5½ inches gauge Rio Turbio Railway,in 1956. A second batch was built by Mitsubishi in 1964 incorporating the modifications made to the three in the first batch. These included a new firebox which incorporated Porta's gas producer combustion system in which most of the air is admitted above the fuel bed. With this arrangement secondary air is introduced through the sides of the firebox as well as the firehole and amounted to about 70% of the total. Beneath the bars a small proportion of the exhaust steam is fed in to mix with the primary air and reduce the temperature of the fire bed. The fire bed is always dull red, showing that most of the heat is liberated in the combustion space. The sustained output was increased from 700 drawbar horse power to 1200.