HS4000, named Kestrel, was a prototype high-powered mainline diesel locomotive built in 1967 by Brush Traction, Loughborough as a technology demonstrator for potential future British Rail and export orders. The locomotive number is a combination of the initials of Hawker Siddeley (the owners of Brush Traction) and the power rating of its Sulzer diesel engine (4000 HP).

It was of Co-Co wheel arrangement and was fitted with a Sulzer 16LVA24 engine rated at 4,000 horsepower (3,000 kW) providing a maximum speed of 110 mph (180 km/h) and weighed 133 tonnes. It was painted in a livery of yellow ochre with a broad chocolate-brown band around the lower bodyside separated by a thin white line running around the body.

Background and design

In the mid 1960s British rail produced specifications for type 5 locomotives weighing less than 126t with more than 3,000 hp (2,200 kW) of power for both passenger and freight working. Brush Electric Engineering Ltd. (Brush Traction) in association with Sulzer Brothers Ltd. responded with a 4,000 hp (3,000 kW) locomotive for British Rail's appraisal. The design principle was that a single engine would require less maintenance than twin-engined vehicles, and that the very high power would mean that double heading for freight trains would be unnecessary.

British Railways 10800 was a diesel locomotive built by the North British Locomotive Company for British Railways in 1950. It had been ordered by the London, Midland and Scottish Railway in 1946 but did not appear until after the 1948 nationalisation of the railways.

Design was by George Ivatt and the locomotive was intended as a possible replacement for steam locomotives on secondary and branch lines. The single-cab layout (long bonnet forward) gave the driver a poor view of the road ahead. The view was no worse than a steam locomotive's, so it would have been considered acceptable at the time.

During its brief time on the Southern Region, 10800 gained the nickname 'The Wonder Engine', from the locomotive department's daily query, 'I wonder if it will go today'.

Description

Due to having been ordered by the LMS before the creation of British Railways (BR), 10800 became the first BR mixed-traffic Diesel-Electric locomotive when it was delivered in 1950. Operationally it was successful enough for BR to order two classes of 54 similar locomotives in 1955 although these, destined to become BR Class 15 and BR Class 16, used the improved YHXL engine.

British Railways 10100 was an unusual experimental diesel locomotive known informally as The Fell Diesel Locomotive (after Lt. Col. L. F. R. Fell, who was one of the designers). It was the joint production of Davey Paxman & Co, Shell Refining & Marketing Co and Lt-Col L. F .R. Fell, built for them by the London, Midland and Scottish Railway at Derby. Sir Harry Ricardo was also involved. By the time it emerged in 1950, nationalisation had taken place and it carried British Railways livery. The locomotive had six diesel engines, four of them used for traction. There were two auxiliary engines, both of which were 150 hp (110 kW) AEC 6-cylinder units, and these drove the pressure-chargers for the main engines and the purpose of this arrangement was to enable the main engines to deliver very high torque at low crankshaft speed.

Design

The design for 10100, a collaboration between Fell Developments Ltd and H. G. Ivatt of the LMS, aimed to address several of the weaknesses perceived of diesel powered rail traction. Weight was reduced by using several small engines, meaning that both the engines and their supporting structure could be lighter. This was also expected to save time in maintenance as an individual diesel could be exchanged more easily and with lighter equipment.

The London, Midland and Scottish Railway (LMS) pioneered the use of diesel shunting locomotives in Great Britain. The variety of experimental and production diesel shunters produced by the LMS is summarised below. In each heading, the first number(s) carried are shown first, with subsequent renumbering(s) following the "/".

Note on numbering

The initial experimental diesel shunter retained the number of the steam locomotive that it was nominally rebuilt from. However, when the LMS decided to procure a further nine prototype locomotives from a variety of manufacturers, it allocated the number series 7400–7408 to them. It was soon realised that this number range was too limited for the number of production diesel shunters that were anticipated, and a new series commencing at number 7050 was used. Only 7050–7053/7058 carried their original numbers (7400–7403/7408), and they were all renumbered in November/December 1934, some before they had actually entered service.

1831

This was the original experimental shunter, nominally rebuilt from a Midland Railway steam locomotive originally built in September 1892 by the Vulcan Foundry, whose number it inherited (1831), though very little of the steam locomotive was actually re-used. Of itself, it was not very successful, but it did provide useful data for the further development of the diesel shunter design. It was withdrawn from service in September 1939 and converted to a mobile power unit, emerging in its new guise as MPU3 in November 1940. It was scrapped in the 1950s (sources disagree exactly when).