Despite a number of accidents involving 0-4-4 tank engines, drawing much criticism from Board of Trade inspectors, it was a popular and very reliable type for suburban and branch line work in different parts of the British Isles. Ahrons argued that the type was first introduced by Johnson on the GER in 1872 for the London services, however this is not true as the LBSCR and SER built some in 1866. Despite the GER constructing 180 examples over time, the first three classes were scrapped before WW1 and the last Holden (LNER G4) was withdrawn in 1938. In 1891 the Great Western built 24 convertible 0-4-2 saddle tanks for the West Country service. These proved to be unsteady and were soon rebuilt as 0-4-4 side tanks. At the end of the Broad Gauge they were converted to standard gauge and soon after were rebuilt again as 4-4-0 tender engines. Apart from this handful of engines the GWR and also the LNWR did not adopt the 0-4-4 tank engine arrangement.
The table below summarises the main types built by the other pre-grouping companies. The majority of the 0-4-4 tank engines built in the Victorian and Edwardian eras, had driving wheels with a diameter of 5' 6" or 5' 7" diameter. The largest class of all were the 205 Johnson engines built over a period of 25 years. The SR types including those with smaller wheels not listed below, dominate with over 500 examples ever built.
It is unfortunate that out of the 405 locomotives extant in 1955 only five have survived into preservation, however there is a new build on the distant horizon - a Worsdell G5.
The driving wheels of most of the engines from Scotland designed by McIntosh, Pickersgill, Reid, Drummond and Holmes had a diameter of 5' 9". Fortunately one of these - CR 419 is owned by the SRPS, but at this time a casting is not available with the correct 20 spoke driving wheel.
Numerous examples of the tank engines from the MR, GNR and SER worked in the London suburban area and many of these were fitted with condensing apparatus for working around Kings Cross, Moorgate and the cross Thames service to Victoria. The illustration below from N. Maskelyne's book is of the later GNR design by Patrick Stirling (G1) for the North London service. Earlier examples called Back Tanks did not have an enclosed cab but merely a sheet of steel for protection.
Two examples of the LSWR Drummond M7 class have survived into preservation enabling the builder to reproduce a faithful model of this large class.
Drawings and other references
The first step before cutting metal is to produce a full size scale drawing of the chosen prototype. The National Railway Museum can provide General Arrangement drawings of most types from their vast collection of circa 17,000 drawings. The NRM website provides an order form for the "Search Engine Copying Service". The service is excellent and the table below is a list of some of the drawings that are available in sizes A4, A3, A2 and A1. The drawings might seem to be duplicates as they cover modifications to the engines throughout their lifecycle.
The A2 size of the GA drawings are the best as these are easier to read, although at £7.50 they can be expensive. It also helps to obtain as many photographs as you can get hold of. A good starting point for larger format pictures is the series of "Locomotives Illustrated".
Books on the historical background also contain some of the more difficult to find photographs and an overview of construction details and engine history. There is an excellent series of books on locomotive history by D L Bradley covering all of the Southern companies. The three volumes by R J Essery and D Jenkinson cover the Midland Railway engines.