Despite considerable pressure to use another member of the class for his experiments, Thompson couldn't be dissuaded from rebuilding Gresley's first ever Pacific "Great Northern" when the urge came upon him to try out some new ideas. Reputedly little of the original engine was left at the end of the rebuild, its original A1 designation was changed to A1/1 (via A10, which it had metamorposed into along the way) - in the end none of the original class nor the rebuilds survived into preservation.
This is a beautifully made engine, the work of a professional engineer, built to LBSC's "Hielan Lassie" design. It is a three cylindered Pacific, with Walschaert's gear - it's worth taking a look at the closeups of the inside gear if you've never seen Walschaert's between the frames before - the huge ecentric you can see in the centre of the crank axle taking the place of the more familiar return crank.
The boiler is copper, silver-soldered throughout with superheaters, built by Chambers of Weymouth. The rolling chassis is complete and runs on air, the tender is largely complete,requiring buffers and some plumbing.
There is virtually nothing left to be spent on the engine, which comes complete with a box of boiler fittings including water gauge, whistle valve, clack valves and blowdown, a complete set of drawings and copies of some of the original "Model Engineer" articles on construction. Platework and plumbing are the main jobs to complete, workmanship thus far gives the potential for a superb, powerful engine when completed.
Locomotive 36 inches
Tender 20 inches
|gauge||3 1/2 inch|