For a detailed history of this large (156 engines) and long lived class Part Seven of 'The Locomotives of the Great Western Railway' published by the RCTS is essential reading. Also useful are GW Engines Vol 2 by J.H.Russell, Standard Gauge G.W. 4-4-O's by 0S Nock & Locomotives Illustrated 50 GWR double-framed 4-4-O's.
From this kit any of the straight framed engines (the last 115 built) can be built from circa 1904 to 1951.
The locomotives were built in Lots 124,137,142,148, 162 & 163, with the standard depth of outside frame, will be referred to as Bulldogs and to Lot 177, with the deep frames, as Birds. Lot 124 differed from the later Bulldogs because of the smaller cab cutout and curved rear steps. Two boilers are provided in the kit, the half cone D2 and the three-quarter cone D3. This means that Lots 124 and 137 cannot be built in their original condition with the DO parallel boiler.
Because the outside frames of the kit have the snap head rivets half etched Lots 124,137 & 142 cannot be built in their original condition with flush frame rivets. The first Lot, therefore, that can be built in original condition is Lot 148. The early Lots can of course be built in slightly later condition as they appear to have acquired frame strengthening plates and snap head rivets surprisingly quickly, probably during their first major shopping. Lot 163 was built with the frame strengthening plates and the Birds also were built with them but only on the rear axle.
Bulldogs originally had Dean swing-hanger bogies, fluted coupling rods, steam brake and steam reverse whereas the Birds were built with De Glehn type bogies, plain coupling rods, vacuum brake and screw reverse. It is believed that all of the Bulldogs were later rebuilt with screw reverse.
There are also many detail differences both between individual locomotives and as the class changed through time.
Chimneys. Three different types provided.
Safety valve casing. With or without top-feed.
Bogies. Many rebuilt to De Glehn type without swing-hangers and fitted with strengthening patches - built with bogie splashers.
Smokebox. Originally quite short and later front and back rings riveted.
Smokebox saddle. Early flush rivets, later snap head rivets.
Sandboxes. Originally below footplate on leading coupled wheels only, later larger and above footplate on all wheels. The Birds were built with the larger type.
Cab roof. Early canvas covered wood, later steel.
Splashers. Built with beading which was later removed with rivets visible.
Cab spectacle windows. Plated over during the late 1920's.
ATC Equipment. Fitted from 1928
Vacuum pipe. Originally tall, later a shorter pattern was introduced.
When built the locomotives were fitted with standard Dean 2500 gallon or 3000 gallon tenders. Later many of the class acquired standard Churchward 3500 gallon tenders.
Bogie wheels - 3’ 8" diameter, 10 spoke, 5/32” diameter axle Slater's Ref. 7843SWMF
Driving wheels - 5’ 8", 18 spoke, 3/16" diameter axle (2) Slater's Ref. 7868O/C Extended axles with outside cranks
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.
Name Plates. A range of name plates are available from Finney7. Please enquire.
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.