SECR K and SR K1 Classes - Operational Assessment and Preservation

Operational Assessment and Preservation

For location details and current status of the preserved (rebuilt) locomotive, see: List of K and K1 class locomotives.

Sir Nigel Gresley's independent report on the K and K1 classes during the mainline stability trials stated that they were well designed, mechanically reliable and capable of hauling expresses at high speeds on well-maintained track, which meant that they could have been useful additions to the Southern Railway's suburban commuter fleet. However, they were undoubtedly prone to rough riding and instability, and not only on the poorest quality tracks. The restricted water capacity also limited their use outside the Southern Railway's Central section. The impending electrification of the Brighton Main Line, scheduled for 1932 also meant that fewer duties suitable for heavy passenger tank locomotives would be available in the 1930s. The lack of a suitable role for both classes was considered when the decision was made to rebuild them as U/U1 tender engines following the Sevenoaks disaster. In rebuilt form they continued to operate until the 1960s, and were capable of attaining speeds in excess of 70 mph (110 km/h) with a greater degree of stability.

One K class rebuild has survived: No. A806 River Torridge – converted to U class No. 1806 – was rescued from Woodham Brothers scrap yard in Barry, Vale of Glamorgan, South Wales in October 1976 for use on the Watercress Line. It was restored to ex-British Railways condition as No. 31806 and is under overhaul as of November 2009.