P2 monobloc preview delights donors


Following years for careful design work, in August 2021 an order was placed with Howco at Irving
to manufacture a fabricated monobloc for the P2 class locomotive Prince of Wales – and this block took a
small break from machining to wow supporters at the recent A1 Steam Locomotive Trust Annual Convention.

Revealed by chairman Steve Davies MBE, commercial director Graeme Bunker and
engineering director Ben McDonald, supporters of the charity were able to appreciate the sheer
scale of this behemoth and see up-close the skilled work that has gone into the monobloc so far.

Mr Davies said: “The construction of the P2’s three-cylinder monobloc constitutes a seminal moment in the delivery of the locomotive and also represents a further milestone in the engineering achievements of railway heritage more broadly. This is an impressive piece of work and we look forward to mounting it in the frames.”

To date, the components have been cut and formed, the fabrication has been welded together, and
machining is underway. While the cylinders themselves are nearing the end of the manufacturing
process and the time is closer to final delivery to Darlington, ready to be united with the frames of
No. 2007, fundraising for this impressive engineering feat continues. Costing in the region of
£250,000, generating further donations towards this behemoth is vital if we wish to see the P2 steam
in 2025.

The remaining work is to shrink fit the cylinder liners and valve seats then final machining, after
which the whole block will be hydraulically tested to 1.5-times boiler pressure, which requires many
unique covers to be manufactured and associated fasteners fitted. The final operation is the
application of a high temperature paint.

Find out more about the project at a1steam.com/P2monobloc where you can join The Monobloc Club for £1000 in up to eight payments of £125, or make a one-off contribution of any size at a1steam.com/P2donation

Work is ongoing to manufacture a fabricated monobloc for the P2 class locomotive Prince of Wales.

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