Sold January 2001 Back to Archive

Part-built Guy compound launch engine - stock code 1374

Another one of those large interesting projects that came in a couple of years ago and I squirrelled away for a rainy day - I even kept it hidden away at the steamup in May!

This is a part-machined set of castings which were produced in the 1960s as a replica of the nineteenth century Guy compound launch engine. The pattern-making was to a high standard and the castings have been very professionally cast. As far as I have been able to ascertain, of the small batch produced (probably ten sets), only two have ever made it into a boat - one in France and another near Cambridge.

The engine is a twin cylinder compound, slide valve actuated by Stephenson's reversing gear. The majority of the castings are in cast iron or bronze, with light alloy crossheads fitted with slippers and steel blanks for the expansion links.

This set of castings was purchased by the owner of a local engineering company who bored the cylinders and made up a roller bearing crank. The remainder of the castings are unmachined and, I believe, comprise a full set to finish the engine, including pumps. The remainder of the work could be done on modest sized machinery. The finished engine will be a rather magnificent thing, capable of propelling a 30 to 40 foot boat.

Intrepid builders should note that, apart from a sheet of AutoCAD drawings which I did last year in preparation for making a start on this engine, there are no drawings.

LP bore 4 7/8 inch
HP bore 2 3/8 inch
Stroke 4 1/4 inch

Overall height 26 inches
Weight approximately 1 1/2 cwt