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Third Overhaul, 1995 to Date

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The new tender body was built at DG Welding in Gloucester and this view shows the work nearing completion on 16th March 1996. Photo Simon Marshall.

Since 2857’s boiler certificate expired in February 1995 we have been steadily working on the Heavy General Overhaul, solely in a volunteer capacity. The first task was to start stripping the engine down at Bewdley whilst keeping the outward appearance as intact as possible. We also organised a new tender body, which was made by DG Welding at Innsworth Industrial Estate, Gloucester. The tender was transported by road to DG’s works on 4th March 1995 and quickly stripped down to a bare chassis. While the tender body was declared scrap it was retained as a pattern and also as a mine of all the various fittings, handrails, steps etc. After some severe de-rusting of the front structure housing the engine to tender buffers and coupling, known as the front dragbox, it was decided that it could be re-used. The same could not be said of the rear dragbox and a new one was fabricated from steel sections and plate. The frames were given a thorough examination for cracks, using the magnetic particle technique, and any cracks were then welded up and some wasted areas also made good by welding. On dismantling it was found that the pivoting trunnions for the vacuum brake cylinder had seized up, causing the piston rod to become worn. The whole cylinder assembly was overhauled and tested by Joe Rosagro of Cheltenham as a separate contract and then re-fitted in the frames.

Over the summer of 1995 this tender was seen as something of a fill-in job by DG Welding and work slowed to a crawl, but the slow progress meant that our volunteers could assist at weekends, completing a vast array of the lower skilled de-rusting and painting tasks which were found to be needed. This then allowed DG staff to work unencumbered by wet paint on their higher skilled, higher cost areas during the week. In January 1996 full time work was re-started in earnest. Gradually the platework was built up, starting with the tender well between the frames, followed by the internal baffle plates. A problem was found with the side plates as first delivered – the curve for the flare at the top had been formed upside down! Replacements were quickly provided. The intention was to use welding for those parts which were not visible from the outside, but to use riveted construction on all visible surfaces. This necessitated some new skills to be learned by DG Welding staff and we were grateful to the SVR engineers who made themselves available for advice as the job progressed. One useful trick was to use bituminous paint in the joints, the heat from the red hot rivets then melting the bitumen into the joint and forming a water tight seal. The inside of the tank was painted using a black paint called ‘Intex’, manufactured by the Bitumastic Company, which had been specially formulated for protecting the inside of water tanks. To provide adequate ventilation for this job an elaborate pressure ventilation system was set up utilising the air output from the works heater piped directly into the tender water space, using specially made adaptors. The tender complete with new body was finally delivered back to the SVR on 30th March 1996, having taken rather in excess of the original 13 weeks estimate!

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A new petticoat pipe, or Chimney Bell, was required and the Society organised the tooling for a batch of new ones to be produced. The old and new are seen side by side at Bewdley on 4th April 1999. Photo Simon Marshall.

As well as the new tender we have provided or made various other new parts, including a new smokebox door, a new cab and a new petticoat pipe. This latter item was quite a major project in its own right. We contacted no less than 15 different metal spinning companies and boilermakers before finding one capable of producing such a heavy spun item at a reasonable price. Even so we had to invest over £2,000 in tooling costs, but were able to defray this by organising a batch quantity for a fair portion of all the suitable GW locos in preservation. Contacting all the loco owners was no mean task either. We are proud to have been able to help not only other owners of ex Barry scrapyard engines in this way but also the builders of the replica ‘Saint’ at Didcot and the replica ‘Grange’ at Llangollen, this spinning being the first piece of metal purchased for that project!

The brake rigging was dismantled and all the pins and bushes either replaced or re-machined. Interestingly there were quite a lot of holes in pull rods etc that had always been left plain, un-bushed, from when the engine was new, but as they appeared to have become badly worn they had ‘non-authentic’ bushes fitted this time around.

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The vacuum reservoir was life expired, and a replacement made in stainless steel is seen alongside the original on 19th November 2000. Photo Simon Marshall.

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A new cab was built by the volunteers at Bewdley and this is the newly finished result on 6th May 2002. Photo Simon Marshall.

Some of the original structural steelwork on the loco was terribly corroded, particularly the structure below the cab floor and the front dragbox and bufferbeam area, the front bufferbeam actually having become bent outwards. Drawings were prepared for new parts for the front dragbox and steel purchased ready cut to shape by laser, the resulting kit being welded up by the SVR coded welders at Bridgnorth. In order to reduce these corrosion problems for future restorers of our engine we have had as many as possible of these components galvanised. The vacuum reservoir, another item under the cab floor subject to much corrosive water and coal dust mixture, had also rusted very badly, and a new one was manufactured in October 2000 by Crossley’s of Stockport in stainless steel. New steps and the new cab were built entirely by the society volunteers at Bewdley and great delight was taken in copying various lop-sided idiosyncrasies as accurately as possible to preserve the unique character of our engine.

The valve liners had not lasted as well as had been hoped from the 1984 rebuild. Hardness testing on these liners indicated the grade of iron used was the actually same hardness as the original BR specification and therefore was unlikely to be the cause of the accelerated wear rates we had experienced. Two liners on one side had been subject to damage caused by a valve breaking up in service, and after sufficient machining to clean up the damage had been completed this left only enough material for one more lot of machining, and so these two liners are scheduled to be replaced during the current overhaul. The two liners on the other side have sufficient metal for about three further lots of machining, given the use of improved boring equipment, and will be retained for the present. However, we have had new castings made for the total set of four and have used a much harder grade of iron, interestingly based on David Wardale’s re-engineering work on the South African Railway’s class 26 ‘Red Devil’ 4-8-4, which we trust will give an improved life in the future, whatever the actual cause of the previous wear.

The original chimney has corroded beyond repair and a new one has been cast accurately to the original profile. This was done from a pattern on the North Yorkshire Moors Railway, but required further minor refinements to satisfy our exacting, some could say pedantic, standards!

Since 1995, while we have been undertaking various rebuild tasks on our own, we have also been pressing the SVR Company to honour its commitment to overhaul the locomotive. What is clearly general economic stringency of the tourist railway movement as a whole has meant that our engine has taken something of a back seat in the SVR overhaul queue, several engines perceived at the time as being easy overhauls being leapfrogged ahead of ours. While 2857 was in the Bridgnorth boiler shop having the new front bufferbeam riveted in place early in 2004 the opportunity was taken to lift the boiler for better access to the frames of the engine, this lower section then being towed back to Bewdley for further overhaul work.

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2857 Society volunteers work on the boiler inside Bridgnorth boilershop preparing the foundation ring for removal.

This has prompted the most exciting push forward with 2857 this overhaul, when it was realised that by working under the direct guidance of the SVR boilersmiths we, the 2857 Society volunteers, could carry out work ourselves on the boiler while saving the SVR Company a considerable sum financially. The work attempted has been quite extensive and has surprised everyone, us included. The first visits to the boiler shop saw general stripping work such as chimney off, various brackets and studs removed etc, but before long we were making a start on removing stays. By April 2005 all the firebox stays had been removed and several new crown stays fitted. Bit by bit our skill and confidence increased such that the SVR boilersmith was allowing us to drill the copper stays from the inner firebox side, in other words drilling copper stays out from copper plate. The skill here was to keep the drill on the centre of the stay, as if the drill is allowed to wander off centre it ends up drilling away at perfectly good copper plate. The rivets securing the smokebox to the front tubeplate of the boiler have been extracted, with some considerable difficulty, to facilitate removal of the smokebox, which is to be scrapped and replaced. Also we have removed all the rivets and screws securing the foundation ring ready for its removal from the bottom of the firebox. It has been decided that the two vertical back corners of the outer firebox, in the front corners of the cab on the assembled engine, require strengthening patches to be riveted on, and one corner has been ground smooth ready to accept this strengthening plate. A large area of the firebox outer wrapper has been cut away, at the bottom of the left hand side, for replacement. This has revealed extensive local corrosion, or ‘grooving’, in this plate adjacent to the foundation ring. This is a defect common to all locomotive boilers and, once the foundation ring has been removed, it allows access to this area around the whole of the firebox, enabling the less extreme sections of this grooving to be repaired by welding.

This brings the 2857 story up to July 2005 and we hope you have found this account interesting. For more recent news please refer to our News section.

 

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