This is my wagon on a weighbridge at a local factory in 2002. The recorded weight was 7700kg (approximately 7 3/4 tons). At the time there was a load of approximately 15cwt of coal on the back and the tank was full of water.
Brief History of Garrett Undertype Wagons
Garrett undertype wagons were built between the years 1921 and 1932, during which period several significant changes were made. The exact number of wagons built is debateable since at least one was rebuilt as a new vehicle and some that had been built for stock were dismantled and the parts used in other wagons. It is generally accepted that 307 wagons were built. The first wagons were of 6 tons capacity, soon to be followed by 4 and 8 tonners, supplied with platform bodies or as tipping wagons. In 1925 experiments were being undertaken with poppet valve engines. In 1926 the first six-wheeled wagon was made and in 1927 the piston valve engine was superseded by the poppet valve engine. Three "Suffolk Punch" six wheeled tractors designed for the export market were built; two of them remained in England and were sold to John Sadd & Sons timber merchants.
A list of Garrett undertype wagons is available to download here.
The lorry pictured above is fitted with a piston valve engine, the valves are actuated by Joy valve gear, which is driven by a linkage attached to the connecting rods. The water tube boiler has a working pressure of 250 psi. A tubular superheater is provided at the base of the chimney.
Wagons in the United Kingdom
My wagon no. 34841 a 6 tonner of 1926.
A little known Garrett wagon built at Leiston Works in about 1928.
In addition to these Simon Bass in Kent has obtained parts of a wagon which he is rebuilding.
There are the remains of three wagons in Australia
6 ton tipper 34315, which is almost complete and is under restoration.
6 ton tipper 34405,which has no engine.
4 tonner 34625 of 1924, which was dismantled as a source of nuts, bolts and other materials.
Wagons in New Zealand
The boiler of 34535 is displayed in Pigeon Park, South Island, New Zealand. The boiler was removed from the wagon and built into this "lokey" a log hauler.
6 ton wagon 34661 of 1924 is in New Zealand but this wagon also requires an engine.
6 ton tipper 35358 (a wagon with a poppet valve engine) is at the James Hall Museum, Pioneer Park, Johannesburg.