For a detailed history of this last completely new class of 2-4-O tender engines built at Swindon, Part Four of The Locomotives of the Great Western Railway published by the RCTS is essential reading.
The locomotives were built in two lots that appear to differ only in the arrangement of the front end framing. This affects the guard iron struts and the length of the bracket attaching the outside frame to the buffer beam. Parts are provided to allow these differences to be modelled.
The original boilers were of the 'Sir Daniel' class with the dome on the front ring (S2) with a very short smokebox. They were first reboilered with similar boilers with extended smokebox or with back dome versions of the same class (S4). All were eventually fitted with boilers with a Belpaire firebox of two quite different types, either a 'Standard Goods' (B4c) or the 'Sir Daniel' (B4). The kit provides for the S4 and B4 boilers. To make an engine in as built condition is not difficult, a new boiler wrapper and smokebox wrapper will be needed and the S4 wrappers can be used as templates. To make an engine with the B4c boiler is, however, much more difficult as the boiler was pitched some 5" higher necessating new smokebox, firebox and cab.
There are many detail differences both between individual engines and as the class changed through time. For an accurate model it is important that photographs are used and the following books should be of help.
A Pictorial Record of Great Western Engines - Vol. 1 - OPC (Note the drawing on page 57 fig.147 is for the 3232 class and not the 22XX class as stated)
The Locomotives of the Great Western Railway - part 4 - RCTS.
GWR Locomotive Allocations 1921 - Wild Swan
GWR Engine Sheds - London Division - Wild Swan
Didcot Newbury and Southampton Railway Supplement - Wild Swan
Great Western Portrait 1913 - 1921 - OPC
Great Western Steam Through the Years - 2 - Bradford Barton
Great Western Album Number 2 - Ian Allan
Rivet Patterns. Most of the differing rivet patterns are catered for.
Brass Beading. The splasher fronts and tops, and the coupling rod splasher fronts and tops can be reproduced with and without beading.
Top Feed. The B4 boiler can be modelled with and without top feed; two different boiler wrappers are provided.
Cab Front. Differences in the cab front with two different sizes of spectacle windows.
Cab Roof. Both the early canvas covered wooden type and the later steel type are included.
The kit also contains a complete set of cabside numerals so that any member of the class can be constructed.
Leading wheels 4' 1½" diameter, 12 spoke, 3/16" diameter axle, Slater's Ref.7849
Driving wheels 6’ 8½", 24 spoke, 3/16" diameter axle, (2), Slater's Ref.7881W
Motor/Gearbox. A Canon motor with a SDMP 40L/15 gearbox (available from Finney7) or an alternative such as an ABC VML2 gearbox.
Crankpins. Heavy duty crankpins are available from Finney7.
Inside Motion. A separate kit is available from Finney7 to construct the working inside motion.
To obtain a pdf copy of the instructions please click on the links below; the pdf will open in a new window. Unfortunately the A4 and A3 pages have to be in different files.