[1] City of Truro was timed at 8.8 seconds between two quarter-mile posts whilst hauling the "Ocean Mails" special from Plymouth to London Paddington on 9 May 1904.

However, the morning after the run two local Plymouth newspapers did report that the train had reached a speed between 99 and 100 miles an hour whilst descending Wellington Bank, Somerset.

[3] Rous-Marten first published the maximum speed in 1905, though he did not name the locomotive or railway company: On one occasion when special experimental tests were being made with an engine having 6 ft. 8 in.

In a previous trial with another engine of the same class, a maximum of 95.6 miles an hour was reached.Before his death in 1908, Rous-Marten did name the locomotive as City of Truro.

Official confirmation from the Great Western Railway came in 1922, when they published a letter written in June 1905 by Rous-Marten to James Inglis, the general manager, giving further details of the record.

However, in May 1904, City of Truro was not the fastest vehicle in the world, as 130 mph (210 km/h) had been reached the previous year on an experimental electric railway near Berlin.

[13] During World War II York was considered to be a likely bombing target so the locomotive was evacuated to the small engine shed at Sprouston railway station (near Kelso) on the Tweedmouth to St Boswells line in the Scottish Borders.

[citation needed] It was only by chance that City of Truro made an appearance on the continent as the original choice was LNER A4 Mallard which failed a boiler test.

[citation needed] A year later 3440 made a guest appearance in an exhibition called "National Railway Museum on Tour" which visited Swindon in 1990.

[citation needed] City of Truro is now based semi-permanently at the Gloucestershire Warwickshire Railway, often hauling trains between Toddington and Cheltenham Racecourse.

[citation needed] City of Truro was withdrawn from traffic at the Bodmin & Wenford Railway in early September 2011 with serious tube leaks,[14] and was moved to Shildon Locomotion Museum and placed on static display.

It was back in service in 2012, but in early 2013 the NRM declared the locomotive was to be withdrawn ahead of its boiler ticket expiry due to a hole being discovered in one of its tubes.

The NRM did state that they would repair the leaking tubes after they had restored 4472 Flying Scotsman, but after examination it was found that the locomotive required more work than first thought and was unlikely to be operational in the foreseeable future.

City of Truro starred in the 1957-8 serial "Will o'the Whistle" in the D.C. Thomson comic The Wizard, in which it was used by resistance fighters after the Kushanti invasion of Britain.