British Rail HS4000
HS4000, named Kestrel, was a prototype high-powered mainline diesel locomotive built in 1968 by Brush Traction, Loughborough to demonstrate its wares to British Railways. The number indicated Hawker Siddeley (the owner of Brush) 4000hp (the power rating of its Sulzer engine).
It was of Co-Co wheel arrangement and was fitted with a Sulzer 16LVA24 engine of 4000hp. It had a maximum speed of 125mph and weighed 133tons. It was painted yellow with a broad brown band around the lower bodyside.
BR encountered difficulties in testing the locomotive because of its high axle load (even though it is no more than class 56 which encountered no such resistance), but were able to test it on freight workings on the Eastern Region, where it successfully demonstrated the potential of its high power rating. Brush were keen to see the prestigious engine on the front of a passenger train and in 1969 new bogies were fitted to reduce the axle load, and it was then used on passenger services out of London Kings Cross.
In March 1971 it was withdrawn from service in the UK and sent back to Brush for refitting. Whilst British Rail haggled and argued over politics (which directly lead to the class 56 heavy freight and the HST express passenger train rather than a locomotive that could do both) it became clear to Brush that there was no chance of home orders and so with Kestrel looking more and more like an ugly duckling, a deal was sealed with Russia. In April 1971 she was sent to Crewe Works, overhauled and re-gauged for Soviet track. She was shipped from Cardiff on board the M.V. Krasnokamsk on 11th June 1971. On arrival in Russia, she was exhibited at the Moscow Rolling Stock Exhibition in July and then was moved to the Soviet Railways Research Institute at Shcherbinka.
A picture (thought to be 1972) of her shows a large roof-mounted headlight at one end only, different design bogies (similar in appearance to Commonwealth as fitted to class 31) and large, "clasp" style couplers. The Headlight appears to be out of gauge suggesting she was not used in normal service. Nothing has been heard of her since. Meanwhile, BR had decided to proceed with more modest Type 5 locomotives in the form of their Class 56.