{"product_id":"5-inch-gauge-thomson-l1-2-6-4t-stock-code-12793","title":"5 inch gauge LNER L1 2-6-4T","description":"An exceptionally well made LNER L1 2-6-4T, Thompson's wartime design intended to augment the V1 and V3 tanks designed by his predecessor Gresley. New and unsteamed, it's come to us direct from the builder.\u003cp\u003e\u003c\/p\u003e\u003cp\u003e    Constructed to the highly-regarded Clarkson design, standard of workmanship is excellent throughout. Machining is crisply done, \u003ci\u003e\"fit and finish superb\"\u003c\/i\u003e according to the workshop notes. The British Railways lined gloss black livery has been applied to an exhibition finish.\u003c\/p\u003e\u003cp\u003e    The silver soldered copper boiler is a beautifully made thing, we've hydraulic tested it and issued certification for same. Fitted with four radiant superheaters, it's a mark of the builder's attention to detail that the elements are individually removable if required.\u003c\/p\u003e\u003cp\u003e    The engine ran very quietly on air in either direction with some leakage past the PEEK piston rings when cold - when hot, it was a different matter...\u003c\/p\u003e\u003cp\u003e    Given the new and unsteamed condition, rather than put a fire in it and risk damaging the paintwork, we ran the engine from a remote test boiler. All was well for the first few turns of the wheels, whereupon everything came to a juddering halt as the piston rings expanded in the presence of steam, locking up the piston on one side and, in the process, shearing a small pin in the valve gear.\u003c\/p\u003e\u003cp\u003e    Whilst PEEK is a material we know - it's a tough engineering plastic - it's not one we've seen used in this application before. PTFE is the preferred choice for rings if you want to go all high-tech, although we still prefer cast iron rings on grounds of dimensional stability, longevity and reliability.\u003c\/p\u003e\u003cp\u003e    The engine now needs stripping, new rings making and fitting, then reassembling. Inexpensive in material, but a time-consuming, fiddly job, particularly given the immaculate state of the paintwork.\u003c\/p\u003e\u003cp\u003e    Complete with drawings and a purpose built storage crate.\u003c\/p\u003e","brand":"Station Road Steam","offers":[{"title":"Default Title","offer_id":54019668738389,"sku":"12793","price":6500.0,"currency_code":"GBP","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1023\/0094\/2677\/files\/12793-1.webp?v=1779906061","url":"https:\/\/stationroadsteam.com\/products\/5-inch-gauge-thomson-l1-2-6-4t-stock-code-12793","provider":"Station Road Steam","version":"1.0","type":"link"}