Even when no large and impressive parts feature in our news, work continues at Darlington Locomotive Works to machine and fit many of those that have been cast or manufactured. In these photos by Bob Hughes Ian Matthews is seen machining part of the front drawbar spring block which was originally a casting and has been re-designed as a steel fabrication.
Profiles for the smoke box door hinges, hinge brackets and the door centre boss
The kit of parts to make a temporary stay to fit where the cylinders will eventually go. This needed to keep the front frames straight to enable completion of the front footplating and also to act as a temporary support for the smokebox pending the cylinder block being fitted.
Although thay may not be obvious, the P2s possessed splashers, albeit rather small and hidden under the footplating. Work to fabricate and fit these has been progressing well at Darlington Locomotive Works – all photos by Bob Hughes.
Wesley Atkinson at South Lincs Foundry has completed the pattern for the Kylchap double chimney. It may look simple but the fabrication of this pattern and the cores has consumed many man hours and pattern making is one of the biggest expenses in the casting process. We think the effort has been worth it for the finished article is superb! You can sponsor this important pattern for £2400 or 40 monthly payments of £60 – contact Mark & Mandy Grant by emailing
On the basis that a picture is worth a thousand words, here are a selection taken by Wesley Atkinson.
The first of the large frame stays which have been re-designed as fabrications is presently being manufactured by North View Engineering Solutions in Darlington. This is the Frame Stay and Inside Motion Bracket.
Apart from holding the frames together, it also supports the inside cylinder slide bars. On the original P2 design it also had a saddle incorporated to support the front of the boiler where it joins onto the smokebox.
Apart from the decision to use Tornado’s shorter boiler causing the saddle to be in the wrong place, firmly attaching the back of the smokebox to the frames, in addition to bolting the front of it to the saddle on the top of the cylinder block gives the potential for cracks in the smokebox. This arises from the smokebox becoming much hotter than the frames when the locomotive is operating setting up severe stresses due to the smokebox expanding more than the frames.
Original P2 frame stay and boiler support
Modified stay for No. 2007
This problem was avoided with the A1 design by supporting the front of the boiler (and hence the rear of the smokebox) on a sliding foot to permit expansion. We are using the same arrangement for Prince of Wales. Meanwhile the next of the large frame stays, the Intermediate Frame Stay which as well as being redesigned as a fabrication has been modified to carry one air brake cylinder and an air pump instead of the original two vacuum cylinders has been ordered from North View Engineering Solutions.
Application of the Finite Element Analysis simulation package recently acquired to use in conjunction with Solidworks 3D CAD has indicated that the revised design has similar strength margins as the original, even with the addition of a 370 kg air pump.
The cab is making good progress with roof having been assembled on a specially made cradle, and the sides and spectacle panels added temporarily using bolts. Once the cab assembly has been proved, it will be completely dismantled and grit blasted and primed prior to riveting together. The profiled plate work for the cab is presently being rolled and pressed to shape.
The pattern for the chimney is making good progress at South Lincs Foundry at Spalding.
The front boiler support and pony truck top centre castings have been delivered following machining and have been trial fitted to the frames. The Cartazzi horn blocks have been removed from the frames and sent to North View Engineering in Darlington for adjustment and welding on the manganese steel liners. North View has also manufactured the Cartazzi horn stays.
Back at Darlington Locomotive Works the footplating has reached the stage where it has all been removed for grit blasting and priming prior to final fitting North View has also started manufacture of the first of four large fabricated frame stays, the frame stay and inside motion bracket which apart from keeping the frame plates the correct distance support the inside slide bars.
Timsons Engineering at Kettering have been awarded our largest single machining order to date to machine all the engine axle and cannon boxes and manufacture all the spacer, abutment and thrower rings and details for the roller bearings and axle boxes.
Cab side trial fit – David Elliott
Fitting the spectacle plate to the cab side – David Elliott
Mick Robinson works on the cab – David Elliott
The whole assembly begins to take shape – David Elliott
Uprighted, the classic shape of Gresley’s wind-cutting cab is apparent – Bob Hughes
The major visible progress has been the delivery of the cab kit comprising laser profiles plates, rolled or pressed into curves where necessary.
The cab roof – David Elliott
The plate work for the smoke box has been ordered. Timsons Engineering at Kettering have started manufacturing the smoke box door frame – a complex shape being made by CNC machining from a piece of 90mm thick boiler plate. North View Engineering Solutions at Darlington have completed machining of the front boiler support and the pony truck top centre castings.
Back at Darlington Locomotive Works progress continues with permanent assembly of the frame stays and brackets, and on forming and fitting the footplating. As sections of the footplating are finished, they are dismantled, grit blasted and primed prior to bolting on permanently. Gritblasting removes mill scale from the steel work which saves many hours later when the paint finish is applied.
Progress with the footplating – Bob Hughes
Steve Wood has completed machining the buffer casings which are trial fitted to the front buffer beam.
Buffer casings in place – Bob Hughes
He has since turned the engine draw bar pin.
The engine draw bar pin – David Elliott
The first of the non-ferrous fitting castings have arrived at DLW, being injector valve bodies and handwheels and Cartazzi top wedges.
The first non-ferrous castings – David Elliott
Quotations have been received for the machining of all the engine axle and cannon boxes with their roller bearing spacers and thrust rings. An order for this work will be placed shortly.