Two models, showing Thompson's Dish-ended Lancashire Boiler front sections
- c. 1920
Model (scale 1:8) of front end of Thompson's Dish-ended Lancashire Boiler with corrugated flues.
The 'Lancashire' boiler was a cylindrical boiler with two flues through its length, each containing a fireplace. It was the commonest form of steam boiler for moderate pressures in stationary applications from the middle of the nineteenth century to the middle of the twentieth century. This boiler was the subject of a patent granted to William Fairbairn in 1845, in which he proposed reducing the emission of smoke by alternate stoking of the two furnaces. The actual design originated earlier than this patent. Its main advantages over the earlier 'Cornish' boiler with a single flue was that it afforded both a large heating surface and a large steam space, and that the two smaller flues were less liable than the one large one to collapse when subjected to high pressure.