F.T.Harker compound launch engine

A fine vintage compound launch engine by F.T.Harker of Stockton on Tees, a company which built marine and stationary engines, founded in 1878.

It's recently come to us as part of a large collection which included locomotives, other marine engines and a steam launch. Dry stored in the owner's house for many years it remains in good condition and turns over freely - there's some video of it running on air here.

An elegant design, with cast in steam passages for inlet and exhaust, the engine is largely complete bar the pumps.

Both HP and LP cylinders are fitted with slide valves; curiously one is controlled by Stephenson's gear, the other by slip eccentric - even more curiously it's not the way round you'd expect.

There's no sign of either later bodgery or parts assembled wrongly, so we're assuming that this is what Mr Harker intended but would welcome further information (with first hand knowledge rather than speculation preferred - we're happy to guess at how it was supposed to work ourselves!)

In remarkably original condition, possibly even carrying its original paintwork, the engine is a two man lift (although you wouldn't want to carry it far).