The restrictions on locomotive weight and length were keenly felt by the Great Eastern Railway and whilst James Holden’s S46, D56 and H88 Claud Hamilton 4-4-0 designs were not unduly restricted, when he came to consider a 4-6-0 design for high performance express work, the inside cylinder was his only real option.To gain power, Holden was quick to embrace the idea of superheating and so in 1911, the first order was placed for his S69 class locomotive.
Under the GER, seventy one S69 engines were built, fifty one at Stratford and twenty at Wm Beardmore & Co. in Glasgow. The reason for the ‘odd’ locomotive arose when No.1506 was destroyed in a collision at Colchester when only five months old, the number was not re-used, the replacement being included as part of order M77 at Stratford.
During 1944, due to their wide route availability, a number of the B12/3s were utilised to work on ambulance trains hauling air braked, American built stock, mainly in the West Country. To improve the loading gauge, the footsteps were cut back and holes cut into them, making them instantly recognisable in later years.