In 1873, Stirling decided to make a new design, later known as GNR Class J6, based on the J7s but with the cylinder stroke increased to 26 in (660 mm).

That year, Stirling introduced the GNR Class J5, with the boiler diameter increased to 4 ft 5 in (1.35 m) but still domeless, and ten were built.

After Stirling's death, Ivatt amended this design to use a domed boiler of the same size and produced a further 145 between 1897 and 1901, of which twelve were supplied to the Midland and Great Northern Joint Railway (M&GN) in 1900 as their Class DA.

In 1912, Gresley produced a new boiler with a 4-foot 8-inch diameter and a total firebox area of 105 square feet.

Twenty-six J5s were loaned to the ROD during the First World War, being sent to France alongside many other locomotives from other companies.