A STREAMLINED version of the exclusive Cock o’ the North class of the London and North Eastern Railway, No. 2003 Lord President is one of the few eight-wheels-coupled express passenger locomotives at work in Great Britain. These exceptionally powerful engines are of the Mikado, or 2-8-2 type. They were built to haul trains of 500 tons or more on the heavily graded main line between Edinburgh and Aberdeen, which includes both the Forth and the Tay Bridges. On this route, before the advent of the Mikados, double-heading was common.
It is unusual for a modern British express locomotive to have a leading two-wheeled radial truck instead of a leading bogie. Had these locomotives been given bogies, making them 4-8-2s, they would have been unusually long, though not too long for the existing turntables. Other considerations, therefore, influenced the decision to adopt the shorter 2-8-2 wheel arrangement.
Built at the Doncaster Works of the company in 1936, Lord President is generally similar in design to Cock o' the North, which dates from 1934. The most striking difference is that the newer engine is streamlined almost in the same way as the A 4 Pacifics of the LNER.
The engine has three simple cylinders 21-in diameter by 26-in stroke, and piston valves, with a maximum valve travel of 5⅝-in. All three cylinders drive the second coupled axle. The outside cylinders are actuated by Walschaerts valve gear and the inside cylinder by a special form of valve gear devised by Sir Nigel Gresley, designer of the locomotive and Chief Mechanical Engineer of the LNER.
The eight driving wheels are of 6 ft 2-in, the leading wheels of 3 ft 2-in and the trailing wheels of 3 ft 8-in diameter.
The boiler, with a maximum external diameter of 6 ft 5-in, has 121 small tubes, of 2¼-in diameter, and 43 superheater tubes, with a diameter of 5¼-in. The evaporative heating surface is made up: firebox 237, small tubes 1354·2, flue tubes 1122·8 square feet; total 2,714 square feet. To this must be added the 776·5 square feet of the superheater, giving a total heating surface of 3490·5 square feet. The grate area is 50 square feet.
Two Ross “pop” safety valves are fitted; the working pressure is 220 lb per square inch. The tractive effort, at 85 per cent of the boiler pressure, is 43,462 lb, more than that of any other express passenger locomotive so far built in Great Britain, except others of the same class.
The engine weighs 107 tons 3 cwt and the tender 57 tons 18 cwt in working order. Total weight of engine and tender is 165 tons 1 cwt. Of the engine weight no less than 78 tons 19 cwt are available for adhesion.
