March construction update

GENERAL – Design and manufacturing resources have continued to be diverted from time to time to support Tornado’s return to the main line, however some good progress has been made on Prince of Wales.

FRAMES – Daniela has completed the FEA study of the pony truck crosshead which has emphasised that it is satisfyingly over engineered! She is presently working on the completing the study for the pony truck frame. North View Engineering Solutions in Darlington are asking good progress with the outside motion brackets with delivery expected in March.

WHEELSETS – The saga of the pony truck cannon box continues! Due to a machining error, one of the bearing seats was bored oversize which has necessitated having it welded by a specialist in this field. This inevitably caused some distortion in the castings so they were stress relieved to restore them to the correct shape. Unfortunately, the stress relieving caused some of the manganese steel wear plates which form the liners where the cannon box slides up and down in the pony truck to crack. At the present time, under instruction from Timson Engineering who were contracted to machine all the cannon and axle boxes, North View Engineering Solutions in Darlington are welding on new liner plates. Based on satisfactory experience with Tornado, we have encouraged North View to maintain a welding code and procedure in welding manganese steel liners to steel axleboxes or hornblocks – hence their use for this work.

Otherwise Ian Matthews has got as far as he can with preparing and painting the wheel centres and spokes of the coupled wheelsets – we have had to leave the areas around the built-up balance weights until the lead/antimony alloy is poured into the spaces between the balance weight plates and the spokes to provide the desired level of rotary and reciprocating mass balance. These areas will be painted once the balancing is complete which can be concluded when the motion parts are weighed. Our volunteers have started sanding down the outer tyre faces as similar to the original P2 No. 2001 Cock o’ the North, Prince of Wales will run with polished wheel tyres.

BOILER – We are expecting receipt in the near future of the updated design for the boiler from Meiningen incorporating all the modifications and improvements fitted to Tornado’s boiler over the years. Once this is complete we will be in a position to make a final decision on where the boiler is to be built.

The machining of the superheater header is complete at MultiTech Engineering of Ferrybridge. Two sets of regulator castings have been ordered from H Downs of Huddersfield. This one set to for a regulator for No. 2007, the other as a set of spares for both locomotives.

CYLINDERS – With Daniela having produced detailed models of external steam pipes and elbows for the cylinder block, she has refined the design using Finite Element Analysis and created manufacturing drawings. This has enabled us to seek pattern and casting costs for these items. In the meantime, David Elliott has been developing the Lentz/Franklin valve gear and detailing the cylinder block design.

BRAKE RIGGING – The brake cross stays have been ordered from North View Engineering Solutions.

CAB – The first attempt to fit the cab spectacle windows was not successful due to the sloping front plates of the cab not being sufficiently flat. Ian Matthews has partially dismantled this area and applied much heat and controlled percussion to rectify this problem and both spectacle windows are installed and fit properly. Daniela has modified the window catch design to suit the thicker frames which are required to hold the 21mm thick glazings required to meet current Railway Group Standards.

Daniela is also working up a slightly modified version of the electrical cubicles which form the bases of the cab seats. These are closely based on the design used on Tornado but amended to suit the different cab profile and curved in rear edges of the P2 cab.

TENDER – With a total of four quotes to build the tender tank, we are near to making a decision on which supplier we will select.

Unilathe at Stoke on Trent, which is supplying the tender axles, have delivered the three plain axles, but have had problems with the 4th axle (which has an extra seat on it to carry the tender alternator pulley). Two attempts to manufacture this axle have failed when the finished axles have been rejected during the final Non-Destructive Testing procedures. This has resulted in Unilathe’s axle forging supplier carrying out further tests on their stock blank forgings resulting in a sizeable batch being scrapped. A new forging has been made and we are promised delivery of the finished axle in April. Once it is received, the four axles will be sent with the wheels to South Devon Railway Engineering for assembly (they already have the tyres).

Ian Howitt is making good progress with the tender frames at his Crofton works. Castings are being machined and bolted to the frame plates and several other components have been manufactured.

FITTINGS – Progress on steam and air fittings has been limited by the diversion of time to the Tornado repair and the difficulty in finding machining capacity in our contractors. Fortunately, Alan Parkin, whilst taken on part time for electrical design, has proved to be a good mechanical designer so has been producing 3D models of several fittings to help us catch up which will enable detailed pipe work layouts to be designed.

Following a trawl through the project plan, we have identified three person-years of machining work so have taken the decision to advertise for a machinist and to acquire some better machinery with digital readouts and power feeds on all axes so that we can carry out this machining in-house.

ELECTRICAL – The new trial turbine wheel for the turbo-generators has been completed and at the present time an arbor and attachment cone are being made to enable it to be dynamically balanced. Alan Parkin is continuing to oversee manufacture of the structural components of the new design of belt driven alternator for the locomotives and support coaches.

Rob Morland is continuing to develop the electrical design and specification of equipment. A start-up meeting has been held between Alan Parkin, Rob Morland, Paul Depledge (the electrician who installed most of the electrical system on Tornado) and David Elliott to discuss design and routing of the conduits and trunking for the wiring. Following experience with Tornado it is intended to use stainless steel for this equipment to minimise corrosion.