0-8-4T

[1] These were designed for hump shunting and so required high tractive effort, good adhesion and traction for starting from rest.

The three cylinder tank locomotive was in fashion at this time, as a means of achieving good acceleration from rest, owing to their more even power delivery and the reduced risk of wheelslip.

[3] This three-cylindered pattern had begun with Holden's Decapod of 1902 and carried through into Worsdell and Raven's fast passenger tank locomotives of 4-6-2T and 4-4-4T layout for the North Eastern Railway in 1910 and 1913.

These were a simple stretched version of the inside-cylindered 0-8-2T 1185 Class, which had been derived from the LNWR's numerous 0-8-0 freight locomotives, with a larger coal bunker.

[5] The class was intended for both shunting, banking[6] and as mineral engines for the heavy coal or iron train use in the South Wales coalfield.