Haycock boiler

In 1840, Stephenson produced their 2-2-2 design which avoided the dome altogether, in favour of a raised firebox in the Bury style of ten years earlier.

Stephenson used the Gothic arch firebox for their long-boiler locomotives as well, including their 2-2-2 North Star of 1841[5][6] and outside-cylindered 2-2-2s for the Yarmouth and Norwich Railway in 1844.

[6] The Gothic arch firebox was also notably used by a number of Gooch's Great Western Railway broad-gauge locomotives,[4][7] including the Firefly, Leo and Hercules classes of 1840-1842.

[8] GWR locomotives after this, from the Pyracmon class, used Gooch's stronger round-topped firebox with its wrapper raised above the boiler barrel.

When restored for historical display at the L&MR centenary of 1930, this was then hidden beneath a purely decorative brass facsimile of the original haycock boiler.

[9] This simplified round-topped firebox within an external brass pyramid was reproduced in LBSC's 1953 5" gauge model engineering design Titfield Thunderbolt.

The American-built 4-2-0 Norris locomotives for the Birmingham and Gloucester Railway resembled a Bury design with outside cylinders, and retained the small D-shaped inner firebox.