LNER 4-6-4 Locomotives in Great_Britain

Class W1 (Locobase 3774)

Data from Richard Marsden, "The Gresley W1 4-6-4 "Hush-Hush" Locomotive" on his LNER Encyclopedia website at [], last accessed 4 November 2020. (Thanks to Patrick Shivley for his 17 May 2021 email commenting on the 4-6-2-2 proposed by Glover; see below.)

A Gresley original, this large passenger engine had a watertube boiler that probably contributed to its position as the only Hudson-type tender engine to run in Great Britain; it was a four-cylinder engine rebuilt in 1937 to the three-cylinder layout shown here.

Glover (1967) comments that pedants would probably classify this engine as a 4-6-2-2 as each of the trailing axles was independently suspended. According to Glover, the forward non-powered axle had Cartazzi axle boxes for lateral movement and the after one was a Bissell truck.

Patrick Shivley's comment that the two axles were not independently suspended led Locobase to wonder if any other locomotive had ever been Whyte-classified using two numbers for the trailing non-powered axles. Finding none, he rules that Glover was mistaken: No matter how the trailing-truck's suspension was laid out, its position in the Whyte system was taken up by only one number-hence, 4-6-4.