What was the fastest Great Western Railway steam locomotive?

Question

Great Western Railway of Great Britain originally from London Paddington to Bristol via Swindon, Wiltshire, where their main locomotive building facility was located

Answer 1

King George V

Answer 2

think it was City of Truro many years ago

Answer 3

Don't know if it belonged to Great Western but the Mallard ran that journey after the first Electric trains took over going to Scotland.  It was the fastest anything ever to be powered by Non-atomic steam

Answer 4

The Great Western didn't have much interest in high speed running as it didn't really have much competition on its main routes. The Southern was really only competing on the Westcountry to London lines of which neither the Great Western (via Westbury) or Southern (via Salisbury) is suited to high speed running.

Mallard was an LNER engine and though it did break the record for the fastest steam engine (126mph) it sustained severe damage in the attempt and was out of service for a while for repairs. Most expresses in the UK cruise at 125mph (though that is limited by signaling as UK regulations require in-cab signaling for faster)

Answer 5

As city of Turo is thought to have gone 100 MPH or near you have to assume it's this locomotive. Latter locos were more powerful, but I have never heard a claim any went this fast. The Cheltanham Flyer was for many years the worlds fastest train, but this was measured using average speed. As the Great western Tracks were laid out exceptionally flat and straight by Brunnel it was relatively easy for them to achieve fastest average speed.

Answer 6

Tough question to answer as the GWR didn't really go for all out speed records and left those up to the LNER and LMS that were better suited to high speed running.

Thier most powerful locomotive was the King class while some of their fastest service trains hauled by Castle class engines that were noted for their performance on the Cheltenham Flyer, the fastest steam service in the world for many years.

City of Truro is the only GWR engine I can think of that was officially reported at 100mph, though both Castle and King not to mention  many other express locomotives built for the GWR were all capable of eclipsing this effort.