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Donate to the N Class Project!
To keep the N Class Project on track, we are launching the Trailing Truck Fundraiser.
The trailing truck is the final major component we need to source for N441. Because our donor locomotive K154 was not built with one, it falls to us at the Locomotive Restoration Group to manufacture a brand-new trailing truck from the original Victorian Railways drawings—and we need your help to make it happen.
So, what exactly is a trailing truck?
To answer that, it helps to compare our donor engine, the K class, with the N class locomotive we are building.
The Victorian Railways K class is known for having the “Consolidation” wheel arrangement: two pony wheels at the front to guide the locomotive through curves, eight driving wheels that transfer power from the cylinders to the rails, and no wheels behind the drivers. This arrangement is written as 2-8-0.
The N class, however, adds an extra set of trailing wheels behind the drivers giving it a 2-8-2 or “Mikado” arrangement. These trailing wheels carry part of the weight of the larger N class boiler, mounted in a heavy casting called the trailing truck. The trailing truck is pinned to the firebox support frame stay (a frame stay is a metal plate that holds the two main frames together) so it can move with the curves of the track—providing both stability for the locomotive and a smoother ride for the crew in the cab.
The VR K class were not built with a trailing truck.
PROV: VPRS 12800/P0001, K CLASS STEAM LOCOMOTIVE No.107 SIDE VIEW
The VR N Class, with the trailing truck highlighted.
PROV: VPRS 12800/P0001, N CLASS STEAM LOCOMOTIVE No.110 SIDE VIEW
Building a lost design
The trailing truck required for N441 is a KW type. Unfortunately, none of these survive in Australia; they were all scrapped long ago along with their engines.
To recreate one our engineering team has engaged Advanced Rail in NSW, who have converted the original VR drawings into a 3D digital model. From this, a pattern will be made so the trailing truck can be cast.
Casting such a large component is no small task. The VR themselves recognised this when they first built the KW trucks. Early examples were cast in four separate pieces that were then bolted and welded together.
Later, as more N class locomotives were produced, the Commonwealth Steel Company (USA) supplied one-piece trailing truck castings to the VR. Today, producing a large one-piece casting would be difficult and cost prohibitive, so we are following VR’s original four-piece method.
When complete, the casting will measure over 2.5 metres in length and we estimate that it will weigh more than 2 tonnes. The materials, machining, and specialist skills required come at significant cost, and our goal is to raise $100,000 to fund the work.
The good news: we already have the trailing wheelset ready. Once the new trailing truck is complete, it will be fitted beneath the locomotive frame, marking a huge milestone—the completion of N441’s rolling frame. With your support, we can build this crucial component and push the N Class Project into the next phase of construction.
You can contribute to the Trailing Truck Fundraiser below.
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