LNER B12 Class

By 1910 the Great Eastern Railway needed a modern express 4-6-0 to handle the Liverpool Street expresses to Norwich and the East Coast resort towns. Stephen Holden, the GER's Locomotive Engineer at Stratford Works, designed the S69 Class, a two-cylinder 4-6-0 with 6 ft 6 in driving wheels, 20 × 26 in cylinders, and a Belpaire firebox.

The first engine entered service in 1911. The class was the GER's principal express engine through the late Victorian / Edwardian era and into the LNER period. The 1923 Grouping classified the class as B12 in the LNER scheme, and the LNER continued production with 10 more engines in 1928 (the B12/3 variant with larger boilers).

The B12 was the GER's and LNER's principal East Anglian express engine for thirty years. The class worked the Liverpool Street to Norwich, Cromer, and Lowestoft expresses, and various GER inner-suburban services. The arrival of the LNER B17 Class from 1928 progressively displaced the B12 from the heaviest top-link duties.

British Railways inherited the class in 1948. The class continued in BR Eastern Region service through the 1950s. The arrival of BR Standard Class 7 Britannia Pacifics from 1951 (the East Anglian Britannias were the most-celebrated of the class) progressively replaced the B12 on the principal expresses. The last B12 in BR service was withdrawn in 1961.

A clean Edwardian outside-cylinder 4-6-0 outline. The narrow 8 ft 3 in body width is characteristic of GER practice (necessitated by the restricted London suburban loading gauge). Belpaire firebox, modest cab, and the GER proportions distinguish the class from contemporary GWR or LMS designs. The class was unnamed.

8572 (later 61572), the only preserved LNER B12. Preserved by the M&GN Joint Railway Society and based at the North Norfolk Railway, working order. The engine is the only surviving pre-LNER East Anglian express engine of any type.

GER era (1911–1922): the class was concentrated at Stratford and other GER top-link sheds for the principal Liverpool Street expresses.

LNER era (1923–1947): continued at the GE section sheds. The LNER built 10 more engines (the B12/3 variant) in 1928 with larger boilers; older engines were progressively rebuilt to similar specification.

British Railways Eastern Region (1948–1961): continued at the same sheds. The class was progressively withdrawn through the 1950s as Britannia Pacifics took over the principal expresses.

GER blue (1911–1922): the original engines were outshopped in GER blue with red lining, a distinctive GER livery very unlike the dark green of the GWR or the crimson of the MR.

LNER apple green (1923–1947): from the 1923 Grouping the class was repainted into LNER apple green with black-and-white lining, the LNER express livery.

British Railways Brunswick green (1948–1961): from 1948 the class wore BR-standard lined Brunswick green.

Preservation: 8572 has appeared in GER blue (the engine's original livery), LNER apple green, and BR Brunswick green at different periods.