Review of milestones
Introduction
GWR Class 3700 No. 3440 City of Truro is a 4-4-0 steam locomotive built in 1903 for the Great Western Railway (GWR) at the Swindon Works, from a design by George Jackson Churchward. It was partially rebuilt in 1911 and 1915, and renumbered 3717 in 1912. Although controversial, it was apparently the first locomotive to reach a speed of 100 miles per hour (160.9 km/h), which occurred while on a run from Plymouth to Paddington Station (London) in 1904.
Construction and modifications
The locomotive was the eighth of a batch of ten engines that formed part of Class 3700 (or 'City' Class) of the GWR, and was delivered from the Swindon Works in May 1903. In accordance with the usual GWR nomenclature, all ten were in this case named after cities. The batch was originally numbered 3433–42, with the "City of Truro" being numbered 3440. Like most of the GWR's 4-4-0 machines, they were renumbered in December 1912, and this batch became 3710-19, of which the "City of Truro" received number 3717. She received a superheater in September 1911, as did the rest of the machines in the series, which were modified between 1910 and 1912. This changed their appearance significantly, receiving a longer smoke box. Later, in November 1915, the original slide valves were replaced with piston valves, a modification that was also introduced in its sister locomotives.[1].
Speed record
On May 9, 1904, the "City of Truro" was timed traveling the distance between two quarter-mile poles in 8.8 seconds, while towing the special train Ocean Mails between Plymouth and Paddington Station in London. This time was recorded from the train by Charles Rous-Marten"), who wrote reviews for The Railway Magazine") and other magazines recounting the events. If accurate, this time would correspond to a speed of 102.3 mph (164.6 km/h); but Rous-Marten's chronometer read multiples of a second, so the next best time he could record would have been 9 seconds, which corresponds exactly to 100 miles per hour.
Initially, aware of the need to preserve its reputation for safety, the railway company only allowed total journey times to be published. Neither the report published by the following day[2] nor Rous-Marten's article in of June 1904 mentioned the maximum speed. However, the morning after the run, two local Plymouth newspapers reported that the train had reached a speed of between 99 and 100 miles per hour while descending the Wellington grade&action=edit&redlink=1 "Wellington Ramp (Somerset) (not yet redacted)") in Somerset. This claim was based on the chronometer times of a postal worker, William Kennedy, who was also on the train.[3].