The GER Class A55 or Decapod was an experimental steam locomotive with an 0-10-0T wheel arrangement designed by James Holden for the Great Eastern Railway.

The locomotive was built for purely political purposes in order to block the passage through Parliament of a new rival scheme for an electric railway.

It had 10 driving wheels for maximum grip and prevention of wheelspin, each of which was four-foot-six-inches in diameter which gave high tractive effort.

"[3] Axle load at 16.75 tons (17 tonnes) was not excessive, but weight per foot run of wheelbase was very high and using a class of these engines would have necessitated considerable strengthening of bridges.

The rebuild included a new boiler with a Belpaire firebox and a standard GE high-sided goods locomotive tender.