Doncaster (5 Gauge)

Overview
Doncaster is a 4-6-2 Tender locomotive based around the Sir Nigel Gresley designed A1/A3 3 Cylinder Pacifics. It was designed by Don Young, who unsurprisingly included a lot of detail as he had previously worked in the Drawing Office at Doncaster Works. Most are designed to represent the most famous of the A3 class, No. 4472 "Flying Scotsman".

Technical details
Doncaster uses three cylinders with piston valves, the outside pair actuated by Walschaert's valve gear, the centre operated by Gresley-Holcroft conjugated gear.

Dimensions
Cylinder bore: 1.75"

Driving wheel diameter: 7.093".

Drawings
The drawing list is unusual in that it contains details intended for those building a 5" Gauge A4 as well as the intended A3.
 * Sheet 1 - GA of engine circa 1933, side view of flush sided non-corridor tender
 * Sheet 2 - End views of tender, frames assembly & part details
 * Sheet 3 - Tender wheels, spring gear & part brake gear
 * Sheet 4 - Concluding tender details including vacuum brakes, engine coupled wheels, bogie wheels & axleboxes
 * Sheet 5 - Boiler, part steam circuit, blower, superheater, safety valves & regulator
 * Sheet 6 - Inside & outside cylinders, bogie arrangement & part details, smokebox saddle
 * Sheet 7 - Remaining bogie details, frame plan, mainframes, horns, axleboxes & springing
 * Sheet 8 - Beams, stays, stiffeners, motion plates, brackets, weighshaft, slide bars & trailing frames
 * Sheet 9 - Cartazzi truck, crossheads & side rods, bogie & expansion link variations
 * Sheet 10 - Valve gear
 * Sheet 11 - Reverser, brake gear, part sanding gear & lubricators
 * Sheet 12 - Gravity sanding, drain cocks, smokebox arrangement & details
 * Sheet 13 - Grate, ashpan, damper, valance, running boards & splasher
 * Sheet 14 - Cab platework & fittings
 * Sheet 15 - Name & works plates, dummy whistle, later A3 variants & GN style tender body
 * Sheet 16 - GA of engine circa 1963, side view of GN tender
 * Sheet 17 - GA of Mallard circa 1938, side view of non-corridor streamlined tender