GER A55 Class

Strange Locomotives - GER Class A55 0-10-0 "Decapod"

The GER Class A55, or Decapod, was an experimental 0-10-0T steam locomotive designed by Chief Mechanical Engineer (CME) James Holden in 1902.

Background

The locomotive was built purely for political purposes in order to block the passage through Parliament of a new rival scheme for an electric railway, with the goal of producing a locomotive capable of a rate of acceleration on passenger trains comparable to electric traction on the Great Eastern Railway (GER) over long distances.

As the first Ten-coupled locomotive in Britain, the Decapod was larger than any previous design built for domestic UK service, using a unique 3-cylinder arrangement with a boiler pressure of 200 PSI to achieve the results desired.

Performance

The specifications from the Great Eastern's Stratford Works required a locomotive capable of accelerating a 315-ton train to 30 MPH from a standstill in 30 seconds. With an axle load of 16.75 tons, total weight for the Decapod was by no means excessive, but with a rigid wheelbase of 19.5 ft, the construction of an entire class of this type would have necessitated a considerable strengthening of bridges throughout the GER mainline system.

Rebuild / Class A55R

In 1906, the Decapod returned to Stratford Works for a rebuild, converted to a conventional, 2-cylinder 0-8-0 tender engine designed for freight work and reclassified as A55R.

The new design consisted of a new boiler reduced to 180 PSI, combined with a Belpaire firebox and 39-ton GER standard tender.

For a short period, she was re-assigned to coal train service on the March district, but as the only Eight-coupled locomotive on the GER roster, she proved no more capable than Holden's G58 Class 0-6-0's, and was quietly scrapped in 1913.

Trivia

• This engine was the basis for Hurricane from Thomas and Friends.

Gallery

GER Decapod and James Holden.jpg

Decapod rebuilt as an 0-8-0 Tender Engine