‘P2’ pony truck is delivered as cylinder manufacturers are sought
THE pony truck for underconstruction Gresley ‘P2’ No. 2007 Prince of Wales has been delivered to the A1 Steam Locomotive Trust’s (A1SLT) Darlington Locomotive Works following its fabrication by North View Engineering Solutions in the town. The new pony truck is of a modified design to those fitted to the original members of the class, in order to avoid issues that afflicted the ‘P2s’ in this area. The A1SLT therefore commissioned DeltaRail (now Resonate) to use Vampire software to construct a virtual ‘P2’ and analyse the performance of the original Gresley swing link suspension design and a modified pony truck using side control springs. This data, together with an LNER-revised design for the ‘V2’ 2-6-2 pony truck arrangement, was used to redesign the pony truck for No. 2007 using side control springs and incorporating roller bearings.
Monoblock
Construction of the truck was carried out at several sites across the UK, but with all parts now in Darlington, a Finite Element Analysis study for approval of the new design will be completed, along with the manufacture of spring gear details, final assembly of the cannonbox onto the wheelset, and the machining of the spring planks, bearer cup and spherical side bearers. Meanwhile, the A1SLT has approached five engineering companies to manufacture No. 2007’s complex monoblock cylinder block, which is to be fabricated rather than cast in the traditional manner. This bold approach has also allowed the design to be altered to slim the new ‘P2’ down, thereby improving its route availability. The cylinders on the original ‘P2s’ were two inches wider overall than those on the Peppercorn ‘A1s’, and the trust wanted to ensure that Prince of Wales is no wider than No. 60163 Tornado. The use of a 250psi boiler on No. 2007 permits reduction in cylinder diameter to 19¾in, thereby reducing the overall width. Funding for the locomotive continues to come in, with fundraising having now passed with two-thirds point and about £3.4 million spent to date, and over three-quarters (£3.8 million) of the estimated £5 million required now donated.