This is not a detailed look at the life and times of D1702 - D1706, rather a brief glimpse at the 12LVA24 engines that were installed in these locomotives, and which should have had a bright future, but did not.
Significant dates in the timeline of D1702 - D1706 and the Sulzer LVA24 engine in service on British Railways and elsewhere.
1927 Sulzer discontinue development on 'V' engine design.
The LD series of engines had been introduced in the early 1930's and after almost thirty years of service and development had reached the limit of their design. This was perhaps very obvious in light of the challenges that faced the 12LDA28B & 12LDA28C series of engines operating on British Railways. The other major operators of similar engines had kept the engine rating in the 2000/2100hp range, thus avoiding many of the issues experienced by British Railways.
Sulzer had discontinued development of the 'V' engine design in the late 1920's. The configuration of 'V' engines places high stresses on crankshaft and big end bearings - the technology to produce these had not kept pace with the increased outputs being demanded during the 1920's. Since Sulzer's 'bread & butter' came from its inline marine engines where space and weight were not so critical as for railway purposes it continued development of these vertical inline designs. The inline double bank engine was Sulzer's answer to increased output for locomotives without the need for development of lengthy crankshafts and other components. Just prior to World War Two the railways in France and Rumania took delivery of locomotives equipped with double bank engines, these were the forerunners of the locomotives that would see major orders in the 1950's for the 12LDA28 series.
During the late 1950's the SNCF approached Sulzer with regard to the possibility of obtaining an engine producing greater output than the LDA series. Increased output from the existing range of engines meant compromising axle load limits and the availability of space withing the European loading gauge. This request and subsequent development led to a completely new and more conventional V-engine being designed and built in Switzerland, designated the LVA24 engine which had a higher cylinder output than the LDA28 unit. The Sulzer plant in France then built two eight cylinder 1,750hp 8LVA28's for installation in SNCF locomotives 040 DG class numbered 501 & 502, entering service during 1960.
Following this a substantial number of 12 cylinder engines were constructed and installed in the SNCF 68000 series locomotives. British Railways were watching these developments with interest, in particular JF Harrison, the Chief Officer for Locomotive Construction & Maintenance, who had been heavily involved with the British Transport Commission decision to have Sulzer engines installed in parts of the Modernisation Plan fleet. To evaluate the new engines five 2,650hp 12LVA24's were delivered for installation in Brush Type 4's D1702 - D1706, the last five from an order covering D1682 - D1706. These five locomotives were delayed in entering service as they awaited their engines, the delay was at least eighteen months.
The locomotives were initially allocated to Tinsley, where resident specialist Sulzer Service Engineers (Hans Spaltenstein and others) could monitor them. They were assigned to coal train operations out of Shirebrook. Routine running repairs could be handled at Tinsley, but repairs of a more serious nature were handled at Crewe Works, where other Sulzer specialist staff were available. As the locomotives started to accumulate running hours a number of faults came to the surface, but these were of a minor nature and were quickly diagnosed and modifications made. However it would be the visits to the main workshops that would lead to major problems with the engines.
During a routine big-end bearing examination at Works, the opportunity was taken to change the bearings because they showed signs of wear and would probably not last until the next scheduled major repair. The big-end bearing consisted of an upper and a lower shell which were not interchangeable, and as such the lower shell only had a locating hole on the back which lined up with a dowel on the lower cap, thus ensuring that the bearings could not be interchanged. This dowel formed no other function in the running of the bearings and hence became known as the ‘idiot’ pin! The fitting of the con-rod involved lowering the piston and rod with its upper shell in place, down onto the crankshaft. The fitter then fitted the lower shell into a tool which looked like a bearing cap - complete with dowel pin, attached to a long arm. So we now have the fitter reaching across the crankcase with this heavy tool at arms length and offering it up to the crankshaft to line up with the edges of the upper shell. He then lowers the tool leaving the bearing shell held temporarily in place by an oil film, before finally fitting the big-end cap.
Within a fairly short time, one by one, the locomotives that had been worked on failed in a variety of disastrous ways - crankcase explosions, thrown connecting rods, crankshaft scoring, etc. Quite understandably British Railways became frustrated with all this loss of service, down time and Works expense and demanded that Sulzer find solutions. Oil samples were taken, bearing surfaces and manufacturing tolerances were checked and even Crewe Works cleanliness came under scrutiny. Nothing stood out as being the root of the cause of the on-going failures and the decision was taken to withdraw all the locomotives from service and send them to Crewe Works to have 12LDA28C engines fitted.
A short while later on the prototype 4,000hp locomotive HS4000 ‘Kestrel’ fitted with a 16LVA24 engine was running on BR and it too suffered a crankshaft failure shortly after having some work done on the big-end bearings at Tinsley, the reputation of this engine was getting worse and worse. By shear coincidence, at about this time, a senior engineer from Sulzer UK paid a courtesy visit to the SNCF workshops and saw some bearings from a 12LVA24 engine on the bench and noticed that the wear pattern was different from those in the UK, and asked the staff why this was so. Their reply was startling! They stated that this wear pattern was normal after a long period of service and they had not experienced any major engine failures and that furthermore as a shop-floor change of practice, they had removed the famous ’idiot pin’ because all the fitters knew the difference between the upper and lower bearing shells! They remarked that this had been mentioned to the Service Manager from Switzerland, but clearly the information was never communicated to other operators. With the engineers and staff in the UK following the Sulzer procedure manual to the letter, the slightly imperfectly manufactured tool doomed the LVA24s operated in the UK.
During the rebuild of the ‘Kestrel’engine this pin was removed, but the Sulzer people at Tinsley and Crewe wanted to get to the bottom of it because their fitting expertise had been brought into question. It was found that the locating pin in the lower bearing fitting tool was about ˝ mm out of position, i.e. the tool had been incorrectly made. The penny then dropped. This was the only tool in the UK and was used at both Tinsley and Crewe; it was realised that with the heavy tool at arm’s length inside the crankcase, the fitter could not feel the pin fouling on the back of the bearing instead of locating cleanly in its hole. Thus the lower shell was not correctly located and a high spot was being pushed up on the surface of the bearing caused by the ill fitting pin. A high spot will quickly heat up, leading to rapid wear and material transfer from the bearing to the crankshaft; complete failure will occur in a short space of time due to break up of the bearing, debris in the oil will contaminate the other bearings, the cylinder liners and pistons.
There is an interesting post-script that has come to mind regarding the reputation of the UK engineers involved with the overhaul of the 16LVA24 Kestrel engine prior to its dispatch to Russia. The Swiss parent company were so concerned about the failure of the crankshaft in this engine, following so closely after the failures on the Class 48 engines, that they sent a supervising engineer (Willi Schoop) from Switzerland to oversee the repair of Kestrel’s engine at the Vickers works at Barrow-in-Furness. (Edwin Wild made all the arrangements between Sulzer and Vickers.) The locomotive was positioned on the dock-side at Vickers so that their massive Goliath crane could be used to lift out the engine as a single unit. Time was of the essence because this dock was normally used for fitting out submarines and in earlier years the crane lifted boats in and out of the water in one piece! As occupation of the dock had to be kept to a strict timetable, the Sulzer staff worked in round-the-clock shifts, something which the Victoria Park Hotel never really got to grips with, and hence the work was done by whoever was on shift at the time. The supreme irony of all this is that when the time came to install the pistons and big-end bearings (without their idiot-pins) the work was supervised by the same UK engineers who had been so heavily criticised previously, because the Swiss engineer was off shift at the time!
It was too late to save the removal of the five 12LVA24 engines, but in a strange twist Kestrel’s engine (without the pin) ran satisfactorily and because BR had no requirement for a single 4000hp locomotive, it was sold to Russia and ran for a considerable time without any major engine problems. Sulzer and Brush lost track of ‘Kestrel’ after a few years, but no doubt the technology was copied and used to advantage by the Soviets!
Meanwhile the reputation of the Sulzer and BR engineers in the UK had been restored and the damaged 12LVA24 engines were purchased by Sulzer France, refurbished and sold to SNCF for their locomotives.
Retrospect is a wonderful thing and if these LVA24 engines had not suffered such catastrophic failures, it is almost certain that they would have been specified for the later Class 50 locomotivess. In this respect the licence for the LVA24 engine was bought by English Electric (later Rustons) who used many of the design features in their CSVT engine and promptly dropped the Sulzer licence, even though at their insistence a 16LVA24 engine with a cast cylinder block had passed a full 840 hour test in Switzerland! The Class 50 went ahead with the Ruston engine, as did the Classes 56 & 58. The Class 60 was fitted with a Mirrlees 8MB275 engine, but that is another different but interesting story. At the time of tendering for the Class 58s, Sulzer, Ruston & Mirlees offered solutions. Mirlees won the contract but ended up losing a lot of money on the limited contract. The decision of Sulzer, Winterthur to withdrawn from the bidding because of costs and cuts to the Class 58 fleet took place on the day that a group of BR technical staff arrived at Zurich airport for meetings in Winterthur! It was left to the manager of Sulzer, London to break the news that night over dinner.
The LVA24 was discontinued for traction after the sale of the licence, but it had a big influence on the very successful Sulzer A25 engine which was used in great numbers as a marine auxiliary engine in many deep-sea ships, ferries and cruise ships and as a propulsion engine in motor-barges, tugs, service-craft and land based power stations. In the marine application the A25's would run at constant speed and get a much easier life than when used for traction. Diesel engines do not like cyclic operation because of the fluctuating thermal and mechanical stresses - the majority of the engine problems came from this fundamental principle. The design of the two engines is so similar that one of the UK engineers (Geoff McEwen), involved with D1702 - D1706 and HS4000 Kestrel needed a minimum amount of training before he was familiar with the A25 engine! Hindsight is a wonderful thing but it does prompt a whole lot of other questions.
One offshoot of the LVA series as it transitioned into the A25 series was its brief sortie into the American market. A number of railroads had approached the manager of Sulzer, New York asking for locomotive engines to break the monopoly of General Electric and General Motors and the high prices charged for their spare parts. Morrison Knudsen assisted in fitting 6A25 and 12AV25 engines into locomotives from the Union Pacific, Rock Island Line and Santa Fe railroads. Engineers from Switzerland were sent to oversee the whole project. In service the locomotives encountered conditions somewhat different from European operations, principally long trains headed by multiple locomotives, long tunnels and great distances between depots when failures occurred.
The combination of the above meant that in long tunnels, all except the leading locomotive were taking hot dirty air into the intakes. Serious overheating was the result with burnt valves and scuffed cylinder liners etc. In the UK a much better valve material had been developed for BR's LDA28 engines, but Winterthur did not immediately apply it to the A25 engine, because in marine service it wasn't necessary. The US railroads lost patience, General Electric & General Motors saw sense and lowered their prices and Sulzer withdrew with their tails between their legs and big bills to pay!
LVA Production 1960 - 1972
The number of LVA series engines produced was not large, a total of 109 of which most were for use in locomotives. A brief summary below records the usage of the engines built - the number in parentheses indicates the number produced for each line item.
Resources and other reading materials
Personal recollections from Christopher Brooks & Geoff McEwen.
Page added November 14th 2008