City of Truro in full Victorian Great Western express livery. At GWR175 the locomotive will appear in the livery it carried for most of its working life, with black frames (Photograph: Geoff Sanders)  

1903: 3700 (City) class 4-4-0 no. 3717 City of Truro
Owned by the National Railway Museum, resident at Toddington

'City of Truro' needs little introduction although for most visitors it will be carrying an unfamiliar number and livery.  The locomotive has just undergone a repaint to the livery it carried for most (if not all) of its GWR existence.  When built in 1903, it was given the number 3440.  It was equipped with slide valves and carried an un-superheated boiler but was rebuilt with a new Swindon standard no. 4 superheated boiler in 1911.  This resulted in a longer smokebox, top water feeds either side of the safety valve bonnet and a number of other detail differences.  In the early part of the 20^th century, the elaborate fully-lined-out Victorian livery with Indian red frames carried by express locomotives was disappearing in favour of a rather more plain, but nevertheless elegant, green unlined livery with black frames.  In 1912, the number series was changed to 37xx and City of Truro received its new number 3717.  So the way it is being presented at GWR175 is historically accurate for the engine in its current condition.

What is interesting is that the locomotive was in its as-built non-superheated condition when allegedly timed 'doing the ton' with an ocean mails train from Plymouth to Paddington as it descended Wellington Bank at Whiteball in Somerset in 1904.  It thus became the fastest man-made machine on the planet and the rest, as they say, is history.  You can read a little of the story of that historic occasion with some historic pictures of City class locomotives in a review of the excellent DVD: '102.3' here.  The DVD (named after the speed that no. 3440 was recorded as achieving, and running for 102.3 minutes!) is available in the Toddington station shop.  3717 is owned by the National Railway Museum and is normally based at Toddington.  It was designed by G J Churchward, based on Dean's 'Atbara' class, at Swindon works for express passenger work but as trains became heavier, larger locomotives were needed and the City class soon found themselves on secondary duties.  By 1932 all of the class had been withdrawn and broken up, apart from City of Truro which found its way to the embryonic National Railway Museum, then operated by the London & North Eastern Railway at York.