As the fledgling Bluebell Railway’s third engine BR No 31027 arrived on Bluebell metals in the summer of 1961, still retaining her un-lined BR black livery she was named “Primrose” & re-number to her original South East & Chatham number 27. Two years later in 1963 she started the running season having been repainted into full SECR passenger livery, and with her sister No 323, became a mainstay of the Bluebell’s operational fleet for much of that decade helping to carry the early flag of preservation into the 1970’s.
Withdrawn from active service in 1974 an attempt to return her to service in 1983 saw No 27 Primrose stripped down to a rolling chassis but, as was so often the case at the time, this was found to be beyond the skills of the basic workshop capability back then, so the restoration stalled. Fast forwarding on 32 years following the launch of Baxter the Villa’s Gang with the backing of the Fenchurch Fund turn their attention to the old girl.
Project 27 Begins
Starting out in 2015 the group took on the challenge of restoring 27 back to a serviceable & working order. But after a comprehensive survey of the engine it became quite apparent that her years by the sea in Dover & many years having been dismantled and left out in open storage had let time take its toll!
It was soon discovered that apart from just having a tired boiler and historical damage from a shunting incident that 27’s frames where severely corroded at the dragbox end and that cracks had started to propagate from around the center driving axle position on the frames. To add to this much of the running plates,bunker & tanks where found to be life expired as well as the cylinder block which had also corroded through into the top internal passages! Undeterred by the state of 27 the group have pushed on and plan to restore her back to her 1920’s condition in fully lined Southern olive green.
Progress to Date
2019 to many of the working group will be remembered as the year where it seem’d every working day was either another riveting session or drilling, reaming & preparing for one! But with no surprise after spending the first part of the year finally squaring up and setting up the frames, with over 200+ rivets to put down the theme for the year was set! Over the year and with each regular monthly working day the group, by the end of the year, had successfully riveted up the main frame assembly and rear Dragbox, a major task in itself, & finally made a rigid foundation from which to start building up the rest of the engine from!
Offsite, having sent our valve rods to Statfold Barn, these received attention being re-metaled and machined back to original specification. On site the Works machine shop foreman Steve Heckford has been undertaking the job of machining & matching the valve chest cover to the new cylinder block for us. We have also been discussing with Steve the best way to machine out the valve face relieving grooves, hopefully in the new year.
Meanwhile our volunteer machinist Ian Furgeson, over the school breaks, has been hard at work completing a multitude of tasks for the project including the manufacture of a machining jig for re-machining the eccentrics round which followed shortly after, manufacture of new piston rods & cotters to suit as well as re-machining the piston heads, machining the blast pipe casting to finish as well as a multitude of other re-bushing and machining work!
With the new frame plates on site a start was made on marking out the various 200 odd holes that needed to be drilled all being referenced from the original Ashford frame drawing and datum points located either side of the horn openings as specified on the drawing. After a good couple of weeks of marking out and laying out the frames one on top of the other, as a drilling template,each hole was carefully drilled through the two plates helping to ensure that the two sides mirrored one another.
From here on with the original frames now at a stage ready for final dismantling, over a weekend the original frames where finally “flat packed” and the new frames leveled and erected to take their place, a major first milestone on the road to seeing No 27 Primrose steam once again!
On other fronts the freshly cast cylinder block casting was sent away to Statfold Barn for machining, returning finished apart from a few final fettling jobs later in the year. Meanwhile in house a start was made on repairing the leading horn castings, machining the working surfaces square ready for new surface plates to be welded on to bring them back into “as new spec”. Also the Vacuum brake cylinder was inspected & overhauled being fully tested to BR Spec CESP 1019 on the testing rig at the railways C&W facilities Horsted Keynes & should hopefully see trouble free operation for the first years of her eventual renew’d 10 year ticket.
Following the set backs of the previous two years with the main frames & cylinder block both respectively found to be life expired the group started off to a good year making a start at dismantling the original frames! This was a laborious job carefully cutting out all of the 100’s of rivets holding everything together in order to save the frame stretchers,brackets and other re-usable components for use on the new frames.
Meanwhile the wheelsets having finally been cleaned and the rough original casting flash ground back smooth, at the request of those who had cut themselves years back in the 70’s whilst cleaners, received their first coats of primer and filler! From this point, with work concentrating on the leading wheels set, by the Summer the first of the wheelsets had been painted up into Southern Olive Green top coat!
With Matt having completed the CAD models towards the end of the Summer an order was placed for the new frames to be cut and cylinder block cast! With the frames being plasma cut at TATA steel and the Poly-patterns being CNC machined down the road at Premier patterns the members of the group took the opportunity to go on a road trip and watch the new frames being cut and pop in to see progress on the cylinder block both memorable experiences! Following our trip a month later, with a fortnight between, the newly cast cylinders and flat packed frame kit arrived at Sheffield Park just in time for Christmas!
The year started well with a start being made at cleaning up the wheelsets, the main frame’s being needled gunned back to bare metal and the life expired running plates being removed.
Following NDT testing of the main frame’s it was discovered that the frame’s unfortunately where life expired with cracks propagating out from the driving horn openings. An attempt was made to weld up the defective plate-work but every attempt at making a good weld resulted in more cracks, caused by the old steel not taking to being welded!
With the prospect of having to get a specialist welders in & also having to cut off & replace the rear drag-box it was decided that the 100 year old frames where life expired! So began the job for Matt to produce CAD models for new frame plate’s to be cut!
Meanwhile all was not doom & gloom as the steam reverser, as part of a night College course run by machinist Ian Ferguson had been busy helping Ben Dingley, re-machining and re-manufacture various parts of the steam reverser! This included a re-bore of both working cylinders, re-bushing and re-setting of the various internal components and the manufacture of a brand new stainless steel combined piston rod! Also by the end of 2016 Matt had successfully completed the CAD drawings for both the cylinder block & frames.
With the official start on 27 & following the frames being lifted, the wheelset where sent down to the South Devon for tyre turning and re profiling of the axle journals. Meanwhile the group initially turned their attention to cataloging the various components of 27 which had become scattered across the railway over the 30 year period of inactivity.
Unfortunately also at this time it was discovered that the top of the cylinder block, which had been exposed to the elements, had severely corroded around the inner exhaust passages with large holes breaking through & wall thickness reduced to a tenth of their original size! Although these holes could have been patched the group, reflecting on the overall condition & wanting to out-shop a trouble free and reliable engine, therefore took the decision to deem the cylinder block as being life expired.
Matt Holloway, our CAD designer, took on the challenge of producing new cylinder block CAD model drawings to be used to produce the Poly-Patterns & subsequent casting, a first for the Bluebell!