Of the four main players on the Metropolitan & Widened Lines, the Great Northern had the greater selection of condensing locomotive classes to call upon over the years. Prior to the introduction of Ivatt’s C2 Atlantic tank in 1898, the most recent introduction was Stirling’s 941 class of 0-4-4Ts, a lighter version of the 766 class (a class which they are often considered a part of) comprising of four locos with shortened side tanks, a rearranged cab, and an enlarged bunker with back tank. These alterations enabled them to be used on the LCDR portion of the Widened Lines west of Moorgate Street to Victoria via Ludgate Hill, a route from which the 766 class proper were banned due to their high axle loading. Therefore, these specific duties of the 941 class preclude them from appearing on the Basilica Fields project, despite being ‘Widened Lines locomotives’ of the period.

Not so with the main body of the 766 class – all twenty five were built in three series between 1889 and 1893. These locos were fitted with Stirling’s 4′ 2.½” straightback (domeless) boiler, and all were fitted with condensing apparatus for working the Widened Lines. The first two series followed previous GNR convention and had the condensing pipes running between the frames, but the final series had a revised arrangement with them exhausting from the top of the smokebox sides into the tanks, a style which became standard for succeeding designs.

The 766 class proved to be very successful on Widened Lines duties, the majority of the class surviving the introduction of the C2s, and were not displaced from London until the advent of Ivatt’s powerful N1 0-6-2Ts on Widened Lines services in 1912.

A decision on whether to model one of the earlier series or the final series was something I put off for some time. The early locos had nice clean lines, but the final batch with their big chunky pipework looked like proper condensing locos.

Decisions, decisions, decisions…

I’ve chosen number 824 from the first batch of ten, and she can be seen above at Hornsey in 1904, well looked after by her crew, but bearing the tell-tale signs of hard work in the sulphuric tunnels. The little U bend pipe and tall vents on the tank top betrays the condensing apparatus, and the revolving destination indicator on the top lamp bracket is an interesting contraption – I must find out if it superseded, or was superseded by the more familiar brackets and boards, or if the two types were used concurrently.

Of course there are no kits for such a locomotive as this on the market, so it’s going to be an exercise in scratchbuilding. However, the dearth of a drawing here means that unless I’m able to locate one soon, the building of this loco will be held in abeyance.