The Stuart Turner Swan was one of the successful engines used in full-size steam launches, and many are fitted to boats in the Steam Boat Register. It was effectively two Stuart Turner 5A engines mounted on a single bed plate and fitted with reversing gear. Bore is 2.25” and stroke 2”. While the 5A is still listed in the Stuart Models catalogue, the Swan is no longer there, although sets of castings occasionally appear from beneath benches to be sold. Or it might be possible to make one based on two sets of 5A castings.Today’s Stuart Models‘ largest boat engine is the unrelated Stuart 6A of 2.5” bore x 4” stroke which gives up to 4bhp at 750rpm, enough power for an 18 - 22 foot boat. The Stuart Swan here was shown by F G Moon at the 2015 Midlands Model Engineering Exhibition.