Originally designed by Adams for the London South Western Railway in the 1880s, the O2 tanks quickly gained a reputation for great power for their size. They were gradually superceded on the mainland by Drummond's M7s which succeeded them - this worked out well for the Southern, who inherited the engines at grouping in 1923, as it came at a time when that vast network comprising the Isle of Wight railway system was short of engines. Nine were swiftly despatched over to the Island, where they ran around until the end of steam.
This engine is an older model, built to the Don Young design in 1979. Silver-soldered superheated copper boiler with twin safety valves, feed by injector and auxiliary hand pump in tender, working pressure 80psi. Inside cylinders with slide valves actuated by Stephenson's valve gear with pole reverser in cab. The closely coupled wheelbase of 7 inches, combined with the radial rear truck allows, as in full size, negotiation of tight curves whilst still accomodating a decent-sized boiler and firebox.
It has to be said that the paintwork is now rather worn, but the engine goes well and was nicely made in the first place. It has just had a new boiler certificate, expiring May 2006 and comes complete with a good fitted wooden travelling case.
Length 31 inches