The Steamers at McLeans Island have some largish steam locomotives with rails round the periphery pf the park,  a small gauge set up, a lot of stationary engines and several traction engines in several large sheds as well as a lot of engines needing restoration lying about outside. 

They had a gathering there in September 2001 called the "History of Steam" and I took some photographs of an engine which took my eye. 

It stands about shoulder height and is obviously a marine engine. Now there were a lot of locally made marine steam engines made here. They ranged from small singles, larger tandel (steeple) compounds made by Seager Brothers in Auckland in the early 1900s to very large triple expansions made for the NZ war effort by the Railways Department. 

The engine in question was made by a firm B Williams and Sons of Wellington and is quite out of the ordinary for this part of the world though commonplace in the USA and UK. 

It is a quad tandem compound with bores 4", 7", 11" and 13" by 9" stroke. The higher pressure cylinders have piston valves and the two lower pressure cylinders have slide valves on the cover of which is cast the makers' name. 

The valve gear is sort of Sissons. There is a lug on both crossheads to take a rod for two ram pumps as well as an offset peg on the end of the crankshaft which presumably engaged a scotch crank to run a further two pumps for which there is provision for bolting to the sole plate. 

The whole engine would not be out of place in a 40' boat intended to achieve a decent speed. Certainly a more pedestrian commercial plodder would have a compound with Stevenson's (actually Howe's -he invented it apparently) reversing gear. Oh the flywheel was fitted for a trial run which they were still plucking up the courage to do! 

I guess it comes to this: Either someone who had served his time in the Northern hemisphere made patterns and finished them; or The whole design was copied from an engine from overseas; or B Williams and sons heavily modified an existing overseas engine and saw fit to put their name on it. 

Most interesting.