The GER Class N31 was a class of eighty-two 0-6-0 steam locomotives designed by James Holden for the Great Eastern Railway.

Eighteen passed to the London and North Eastern Railway (LNER) at the 1923 grouping and received the LNER classification J14.

Although nicknamed Swifts, they were sluggish locomotives, due to the placement of the valve chests underneath the cylinders.

[1][2] Withdrawals started in 1908, and by the end of 1922, only eighteen were left in service.

The LNER allocated numbers 7000 higher than the locomotives' GER numbers, but withdrawals continued, and by 1925 the class was extinct.