D5185/25035 Castell Dinas Bran

History

This page is aimed at giving the detailed general history of the Darlington built Sulzer Type 2 (Class 25) machines from design to production - service life and finshing with withdrawal/scrapping

The second part of this page has a detailed history of our very own D5185-25035 from a new build - BR service - Preservation career.

The pictures on this page are copyrighted to the people who own the original copies

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Techincal Data - This is a website link showing the basic techincal data & dimensions of the Class 25 locomotive.

A Brief history of the British Rail Diesel Electric Type 2 Sulzers (later known as Class 25)

First introduced in 1958 the British Railways built, Sulzer engined Type 2s were designed for mixed traffic work as such an austerity design. The first batch were built at Derby Works but later examples were also built at Darlington, Crewe & Manchester works respectively. The power units were designed by Sulzer (Switzerland based company at the time) but most/all british used power units were built at Vickers Armstrong at Barrow-in-Furness. Electrical equipment was B.T.H but changes in the suppliers company and progress meant later builds were equiped with A.E.I. equipment and Davis & Metcafe (D&M) braking systems were employed on all of the fleet of 327, early examples were vacuum braked only but later "dual braked" to include air braking, later examples were built for dual braking. The Class 25 were sub-classed in four class to denoting various design alterations and improvements during the building process:

25/0

The 25/0 sub-class were built at the BR Darlington works using the uprated 1,250 hp "B" Sulzer engine, modified generator assembly and traction motors to the precursor Class 24. This increased power ouput was obtained from a charge air intercooler from 1,160bhp to 1,250bhp at 750rpm this did not employ a seperate water circuit but incorpated in the engine cooling group to avoid expense and complication of seperate radiator elements and an extra pump.The BTH generator, Type RTB 15656, was rated as 817.5 kW, 1,500 A, only slightly different from that used in the earlier Class 24s. (Note all Class 25 locomotives used a generator designated as RTB 15656 but its rating and characteristics changed over production). The generator supplied four Type BTH 137BX traction motors connected in parallel and rated 245 hp, 545 V, 375 A at 560 rpm with a gear ratio of 16:81 to give a 90 mph maximum speed. Maximum tractive effort was 39,000 lb and continuous tractive effort was 20,800 lb at 17.1 mph, the latter standard for all Class 25s. Power at rail was 949 hp, now available between 9.3mph and 77.6 mph. For the first 15 locomotives fuel capacity was 520 gallons (design type 25 AV) and the final 10 had larger 620 gallon fuel tanks installed (design type 25 BV) all were built with Stones Vapor OK4610 steam heat generators for carriage warming purposes.

25/1

The Class 25/1 sub-class were built at BR Darlington and Derby locomotive works. They featured the new Type AEI 253AY traction motor, a result of the collaboration between BTH (AEI), MV and American builder Alco building companies. They were higher rated in an attempt to overcome the loss of tractive effort normally found on the starting point. The 6 stage field divert system was also modified to allow increased capability throughout the power curve.

The main generator was a 12-pole machine with the rating changed to 819 kW, 1,500A at 750 rpm. The four traction motors were now connected as series parallel pairs being rated at 234 hp, 315V, 650A at 460 rpm, with a gear ratio 16:81. Pairs of motors connected in series provided a higher maximum tractive effort but the downside being that a series pair connected machine was more prone to slipping than one with an all parallel grouping. Full power was available between 7mph and 77.5 mph, an improvement over Class 25/0 locomotives with all other ratings unchanged from the earlier series. The traction motor�s continuous rating of 650 amps was not far removed from its one hour short term or 'emergency' rating of 680 amps, and this could only be monitored by driver judgement. On heavy trains close monitoring of the ammeters was necessary to avoid traction motor damage. Though the body shell remained similar to the 25/0 there were a number of changes. The air horns were relocated to one either side of the headcode panel. The cab skirting and body fairing were discontinued, though the support lugs remained. A new driving control panel was designed for more comfort and ease of use. The fuel and water tanks were also redesigned with a fuel capacity of 510 gallons.

There were initially two variants of this sub-class. They were fitted with Stones Vapor OK4610 steam heat generators for carriage warming purposes and designated 251 AV. The four without train heating were designated 251 BV. In due course with changes in braking technology to air braking, it was decided by the BRB to refurbish a number of locos to dual braking, those previously 251 AV became 251 CX and one of the 251 BV (25032) became 251 DX

25/2

The Class 25/2 locomotives featured redesigned body as a result of the below tests and sported an attractive two-tone green livery. The majority were built at BR Derby although a few examples came from Darlington works. The redesign principally affected two areas, the cab layout and the location of the air intakes. The gangway doors fitted to the earlier examples were rarely used and deemed a poor design, their presence adding to the complaints from crews of draughts in the cab. The removal of the ganyway door meant a cleaner, lighter and less cluttered layout for cab controls for crews. The removal of the air filters from the lower bodyside louvers to above the cantrail was the result of a comparison test carried out at Inverness depot between a batch of Derby built Type 2s and a batch of BRCW Type 2s (Class 26 & Class 27), the tests targeting the air quality within the engine room. These tests revealed the location of the grilles on the Derby build machines allowed for much more debris to reach the filters (especially the lower ones) clogging them quicker leading to poorer air quality within the engine compartment, and so affecting performance output and potentially engine wear. With such a large numbers to be produced it was deemed that a redesign of these areas would have a considerable cost savings in the long run. In 1962 Sulzer designed and began development of a prototype power unit for higher outputs based on the LDA range. Rated initially at 1,700 hp at 850 rpm (with a development potential to 2,000 bhp at 850 rpm) it was approximately the same overall size as the 6LDA28 and designated LDA28-R. BRB was approached with the idea that one of the Derby built Type 2s could be fitted with this engine but development work proceeded too slowly and problems with the 12LDA28-C diverted resources. In the end development was terminated and the locomotive set aside for its use, D5299, was completed as a standard Class 25/2.

There were six variants of this sub-class, reflecting that locos were fitted with Stones Vapor OK4610 steam heat generators for carriage warming purposes with vacuum braked/dual braked. Steam heat fitted locomotives included the first five (252 AV) and final thirty Class 25/2 (252 DV). Only members of the latter batch were modified for dual brake operation becoming 252 CX with the exception of 25242 that had had its steam heat generator removed and was designated 252 FX. The non-steam heat fitted vacuum braked locos were 252 BV and when dual braked became 252 EX

25/3

The final batch of locomotives were designated Class 25/3 and was to be built by Derby Works and Beyer, Peacock & Company in Manchester. However because of financial difficulties Beyer Peacock was unable to complete the final 18 locomotives and these remaining examples were built at BR Derby Works.

Though these locomotives still carried a RTB 15656 generator, this variant was now a ten pole machine with a modified assembly incompatible with earlier equipment. The regulated (full 1,250hp) part of its characteristic was substantially the same as before but the unloading point, that is the point at which full power could no longer be utilised, was altered to 900 A, 910 V from 1,050 A, 780 V. Only 2 stages of field weakening were required, previous machines had 6, and this provided �full power� at speeds between 7mph and 80 mph, and maximum tractive effort was reduced to 41,500 lb.

The latter half of the 1960s had seen the introduction of solid state electronics and these locomotives incorporated a control system where speed was detected electronically rather than mechanically. A signal from an axle driven tachogenerator attached to close contactors in sequence at given speeds to activate the motor's field weakening process, rather than through contacts and relays as in earlier sub-classes. The control system ensured the traction motors and main generator were all operated within the continuous rating of the machines except in full field conditions when the driver was able to judge how long to remain in the short-term rating condition. There were two variants of the Class 25/3 sub-class. Early 25/3 AV locomotives were fitted with vacuum brakes and in due course many of these were dual braked and redesignated 253 BX. By the time the last few locomotives were under construction dual braking had become the standard and ten of the last batch from Derby were built new as 25/3 BX locomotives for work out of Willesden depot on the then recently upgraded West Coast Main Line

In total 327 examples were built and used in all regions of BR and due to their mixed traffic design they were employed on just about every type of working BR had to over, notably seen on passenger workings on the Cambrian line in their later years. Followers gave the name to the class as Rats, this appears to be based on there was alot of them and they were everywhere. A small number of 25/2 & 25/3 were re-classified as 25/9 to denote a special working for the chemical sector within BR freight working timetable. A noted running period was a re-instated 25 after the end of the classes BR service, 25322 Tamworth Castle this was rebuilt by a depot fitters and used on a couple of charter services. Sadly due to there medium size power rating it is unlikely we will see any 25s on returning to the mainline however a single Class 25/2 D7628 based at the NYMR is certified for restricted running on NR metals on a low speed branch line from Grosmont to Whitby in the North East.

D5185/25035 Castell Dinas Bran British Rail Career

D5185 was built at Darlington Works in 1963 and was released to traffic on May 24^th of that year after the usual works test runs to Corby and back under the headcode 1T48. It was initially delivered to Toton along with 34 other members of the class. However the locomotives stay was short lived for a few months later being transferred to Leicester (Midland) in January 1964. This state of affairs did not last long and indicated the shape of things to come. In May the locomotive was again transferred to Nottingham and then once more on to Cricklewood in September 1964, this being the same depot as D5401 during that time. It is highly possible the locos may have been seen close together, but it is also strongly suspected they never worked together in BR service.

In June 1966 D5185 was noted to be working the final Peterborough East to Leicester via Rugby service on the Peterborough/Northampton line which was closed soon afterwards. July of 1969 saw the much travelled 25 again transferred to Willesden depot. Other noted workings for D5185 was on March 14th 1970 when the Wembley WI had a hockey tourment at Kensington Olympia with D5185 headed a thirteen coach train from Crewe. Moving on to 1972 saw the locomotive transferred once more � this time to Yorkshire at Leeds Holbeck depot for three years before being moved again, this time to Haymarket depot in Scotland. As you have guessed by now this Class 25 didn't stay on any depots books for a long period of time, as the considerable area covered by this particular locomotive shows the Class 25s route avaliability and "go anywhere and do anything" austerity design. 1976 May time saw D5185 between Alloa & Dollar on a track lifting train, its fair to say this would be one of the final type 2 sulzer locos to use that section of line. During 1978 the now numbered 25035 under the TOPS system (thus a 25/1 sub-class member) was taken to Glasgow works for overhaul and conversion to dual braking

On 12th May 1979 25034 & 25035 tookover an SRPS charter to Fraserburgh from Aberdeen. This was probably the last a passenger train ran over the line north of Dyce Junction as the line was to close that weekend. November 1979 to April 1980 25035 was noted at Glasgow works receiving generator repairs

In November 1980 25035 made its last depot move, this time to Crewe and once again in December the loco was once more receiving generator repairs at Derby Works. However a collision with class mate 25190 at Crewe fuelling point on 6th October 1982 nearly put an end to the locomotive. Quite surprisingly a repair was authorised and the No. 2 cab from recently withdrawn 25036 was substituted. Released back to traffic in February 1983 the loco provided a strange appearance in that the body side numbers showed 25035 but the No.2 end cab still showed 25036. The repair was obviously worthwhile one as 1984 would see 25035 knock up more than 3,000 miles in passenger service alone. At some point during the mid-late 1986 25035 unoffically gained a hand painted "Castell Dinas Bran" it has been suggested that this loco and a handful of other class mates gained these welsh landmark names while parked up on a weekend at Humberside oil refinery during the Holyhead - Humberside Oil Refinery service around that time. This name continues to stay with the locomotive with a proper set of cast nameplates were made and fitted.

It was obvious that the writing was on the wall for the class by the mid 1980�s with withdrawals quickly reducing numbers. The end came in March 1987. On 14^th March 25035 took over the 1V05 07:09 Holyhead to Cardiff service at Chester when 47424 failed. �035 took the failed locomotive and train forward to Crewe and in due course becoming the last member of the class to work a scheduled passenger train (excluding 25322Tamworth Castle which was a later reinstatement). The following day the locomotive was withdrawn from service and thus ended a distinguished career for a workaday mixed traffic locomotive. 25035 remained at Crewe depot until 14^th July 1987 when it travelled in convoy as the 9L37 Basford Hall to Leicester Humberstone Road sidings along with 25265, 25057 and 25109 It is interesting to note that of the four locomotives in the convoy only 25109 failed to escape the cutter�s torch. 25035 remained at Humberstone Road until 9^th September when it was moved to Vic Berry�s scrap yard as part of the 08.00 trip working 9T16.

Detailed information above with thanks to www.derbysulzers.com

D5185/25035 Castell Dinas Bran Preservation Career

The fledgling Northampton Steam Railway was becoming established and in need of some suitable motive power for the future. 27056 had already been purchased and was expected to arrive on site shortly. The famous stack of redundant locomotives at Vic Berry�s was growing rapidly and it was realised that there was no time like the present. Therefore a bid was made for a class 25. The locomotive in question was 25035 which became available on a BR tender list for resale. It was felt to be the best one available as it had been the last of the class in active service excluding class mate 25322Tamworth Castle which was a later reinstatement. Following the asbestos examination it finally arrived by Low loader at the NSR on 14^th July 1988, 25035 is currently the "elder statesman " of the remaining class 25 fleet as it the oldest suriving member . The diesel team at Pitsford & Brampton were by this time busy with 27056 and then the subsequent arrival of 45118 The Royal Atilleryman pushed the 25 to the back of the queue for attention. In fact it was not until the later part of 1992 that any significant work took place. Upon a detailed inspection it became evident that 5 years of storage had taken their toll. The first discovery was that the turbo-charger was seized and inspection showed that it had become very badly corroded. As a result it was replaced by a spare unit that had been purchased with the expectation that it would be required.

The triple-pump, or to give it the correct title the combined pump set was also seized. This was man-handled out of the locomotive for refurbishment, not an easy job in the confined space available. A new water pump impellor was fitted and the pump returned to position. The cooling circuit was filled only to find that the water pump seal was leaking. The pump was stripped again only this time in situ and a new seal fitted. The cooling system was then filled with water, the battery levels topped up and charged and the oil was changed prior to any attempt to start the power unit. The engine finally burst into life on Thursday 27^th May 1993.

The engine was not running smoothly at this point and investigations soon pointed to No.6 cylinder not firing properly. The problem was cured by a cylinder head change. Itself not a ten minute job as the inlet air box and the exhaust system have to be removed before the head can be lifted. With the engine running smoothly and the braking system working properly the locomotive finally made its first move in preservation on Wednesday 30^th June 1993. During its time at Northampton 25035 ran in corporate Rail Blue with small yellow ends, Red-stripe Railfreight, Infrastructure Dutch Yellow & Grey as 25735 and Western Region Maroon with small yellow ends. The name Castell Dinas Bran had been hand painted on the locomotive sides sometime during mid-late 1986. We have never found out why this was done but it was honoured by having a set of Aluminium plates cast and bolted on to complete the job. So that is how a nomadic locomotive came to bear the name of a ruined Welsh castle that overlooks Llangollen! By the end of the 1990�s the condition of the cab floor at No.1 end had rotted to the point where something needed to be done. The original plan had been to remove the cab, replace the entire cab structure with another un-used cab shell obtained from gentleman who had it in his back garden!!! Rebuild the floor structure by up-ending the cab structure in the yard to provide easy access. To this end all of the electrical cabling between the cab and the loco was removed. Unfortunately work stalled at this point and the loco remained untouched for some time. Luckily the cab was not actually removed.

In 2002 a contract was let for the bodywork repairs to be carried out on the Great Central Railway and the locomotive moved to Rothley for the work to be completed inside the carriage works. The locomotive was turned out in all over green without yellow warning panels as D5185. Once the bodywork was completed in the spring of 2004 the long job of restoring the electrical systems commenced. There were many problems with identification labels that had fallen off and number collets that were completely unreadable that the job of reinstatement was made very difficult. By the autumn of 2004 the locomotive was able to move around under its own power but this was only after the battery had been charged for a couple of hours and then you only got one go at starting. Such was the state of the cells after so long out of use. The vacuum system was also in poor condition with only one of the exhausters able to create a vacuum at all � and this only amounted to 15 inches. The problem was finally cured by a strip down of the A exhauster to find that it was full of rusty water and the paddles were jammed in the drum. The non-return valve was also sticking hence the 15 inches from the other. It was not until September 2005 that a proper test run was made with Class 73 E6003 along as insurance.

D5185 returned to passenger operation on the Great Central Railway on 6^th May 2006 piloting Class 20 D8098 on a passenger train. It then settled down to regular passenger operation although lacking the punch that it used to have. The problem was finally resolved after some considerable investigation work when the inter-cooler was removed for inspection. To say that the core was blocked was an under statement. Where there should have been airways there was a solid oily black mess that took two long and dirty weekends to clean out. Since moving to Loughborough D5185 has become a very popular locomotive. It has even been recorded by South West Digital for a model locomotive sound unit and very good it sounds too. She is currently cleared for 45 M.P.H. running and has been used on some GCR contract mileage accumulation test trains. The AWS system has been returned to operation for the first time since preservation and a thorough refurbishment is being currently being carried out of the No.2 cab.

The locomotive has also attended diesel events at the Nene Valley Railway and Keighley & Worth Valley Railways to date hopefully more to follow.

The 2011 season was to be a much quieter season for the "elder statesman" Class 25 as an electrical fault has been plaguing the loco some months now and proving remarkably difficult to trace. Sadly the fault was found in the cable conduit run by the radiator, a perished flexible joint from the radiator settling tank to the triple (combined) pump appears to have leaked coolant into this conduit run and as a result the insulation has been damaged to the cables in that area. This will involve a considerable amount of dismantling work to get the failed cables extracted with a plan to overhaul both Vacuum exhausters and the triple (combined) pump also with a degrease and fresh paint to tidy up this area. It is expected this overhaul work will take around 18-24 months to complete to a high standard.

Hopefully the locomotive will eventually be out on all of its booked workings at the GCR after completion of the repair and currently no hire work at another railway is booked, this may change as we welcome opportunities to travel to other private heritage railways for events. Work shall continue on the comestic repair/repaint of Cab No1. Some external repainting is required at some stage as its showing signs of age but this will happen once the repair work is complete.