3 1/2 gauge BR Franco-Crosti 9F No.92021

A 3 1/2 inch gauge BR 9F 2-10-0. Modelled to represent one of the ten locomotives built as a sub-class in 1955, with experimental Franco-Crosti boilers, a design featuring a pre-heater drum mounted beneath the main boiler. Flue gases were directed from the smokebox back through secondary flues in the pre-heater, emerging from a single, side-mounted chimney.

Loading gauge considerations meant that the standard 9F boiler had to be reduced in diameter to allow room for the pre-heater beneath - the resulting loss of heating area causing the engine to be de-rated to 8F.

The boiler had had a twice working pressure hydraulic test, the chassis runs on air. It's fair to say that steaming it is something of an acquired art...

Rarely modelled - we've only seen one other, that in 5 inch gauge - this is a well made, detailed representation of a well known experimental class. It needs a new owner with an interest in the design, and the experience to get the best from it; we see the model, like the full-size prototype, as something of a development project.