LMS Route: Rugby to Tamworth
Trent Valley Lineside - Cathiron: lnwr_cath1143
A pair of unidentified LMS 5P4F 2-6-0 'Crabs' are seen at
the head of a down excursion train comprised on ex-L&YR coaching stock
resplendent in two-tone brown livery circa 1928. Designed by George Hughes the
LMS's first Chief Mechanical Engineer (CME) the 'Hughes Crab' or 'Horwich
Mogul' was a class of mixed traffic 2-6-0 steam locomotives built between 1926
and 1932. It was their unusual appearance which created their nickname as the
their large highly-angled cylinders at work were seen as being reminiscent of
crabs scuttling about.
The use of the high-angled cylinders was the result of
Hughes' desire to keep the boiler pressure down to 180 pounds per square inch
(psi) to reduce wear and tear compared to 225 psi and higher - adopted by many
other railways. Consequently to deliver the traction required larger cylinders
were required which to be accommodated with Britain's's restricted loading
gauge had to be angled upwards.