Ivatt Diesel-Electric Locomotives
Ben Brooksbank / Pioneer LMS Diesel no. 10000 on Down fast WCML freight south of Tring (Wikimedial Commons)
Technical Data
Introduced: 1947
Number built: 2 (1 built by the LMS, 1 built by British Railways).
Number built: 2 (1 built by the LMS, 1 built by British Railways).
Although diesel power had been experimented with prior to World War II, it had been confined to either shunting engines, or single diesel railcars. Right at the very end of the company's existence, just before Nationalisation, the LMS introduced a diesel electric locomotive design intended to haul main-line services in the same manner as a steam locomotive. Two were built; as individual units, they were considered comparable to a class 4 locomotive; when used together, the power output was comparable to one of the larger express steam locomotives.
The locomotives were built as a joint venture with English Electric, with EE supplying the power units and the LMS dealing with the mechanical parts. The initial livery was black with silver numerals, although only 10000 carried "LMS" on its side. Other liveries would be used throughout their lives.
The locomotives were not a great success in their lives, some of the problems being down to the fact that only two were built, and drivers used to steam locomotives weren't given may opportunities to become familiar with them. There is at least one story of a driver who drove them with his head out of the side window like he would have done on a steam locomotive, despite the fact that the cabs had front windows. Spares also became harder to obtain once EE ceased producing the power units used by the locomotives. Keeping the locomotives in steam sheds was not conducive to their reliability; ash and diesel engines didn't mix very well (a fact that would help to accelerate the demise of the steam locomotive in the 1960s).
The locomotives were perhaps a case of "Right Idea, Wrong Time". In the aftermath of World War II, the nationalised (and extremely battered) railways had little money to spend on developing diesel locomotives, when producing steam locomotives - a proven technology - was much cheaper. There was also the issue that unlike coal, which could be obtained domestically, oil - for the most part - had to be imported. The state of the British economy at the time, plus the fact that another world conflict could result in the supply lines being cut, meant that coal over oil was the preferred fuel for powering locomotives. It would be another decade or so before switching to diesel locomotives would be given more serious thought.
No. 10000 was withdrawn in December 1963. No. 10001 was withdrawn in March 1966, probably kept in service by spares from 10000. Both had been scrapped by April 1968.
Preservation
Neither of the locomotives was preserved, possibly due to preservation in the 1960s being geared towards steam locomotives rather than diesel ones. However The Ivatt Diesel Re-creation Society is attempting a new build of the design.