BR Standard Class 6 Clan

The BR Standard programme of 1951 was designed to provide a unified family of British Railways steam locomotives covering every power class from 2 to 7. The Class 7 Britannia of 1951 was the flagship two-cylinder Pacific, but its 20+ ton axle load excluded it from a number of important Scottish routes, particularly the Stranraer line for the Northern Ireland boat-train traffic and parts of the Glasgow & South Western that had been preserved at relatively light axle loadings.

R. A. Riddles' answer was the Class 6, a smaller Pacific with the same general layout as the Britannia but reduced in every dimension to give an axle load light enough for the Scottish secondary routes. The design used the Britannia's general appearance, two-cylinder simple-expansion arrangement, and BR Standard family parts, but with a shorter boiler at 225 psi (against the Britannia's 250 psi), smaller firebox, smaller wheels, and reduced overall weight.

The first Clan, No. 72000 Clan Buchanan, was completed at Crewe Works in November 1951. The remaining nine engines followed through to December 1952. All ten were completed in continuous sequence and named after Scottish clans, a deliberate publicity choice intended to give the lightweight Pacific class a recognisable Scottish identity that would suit its intended Scottish Region service.

An order for an additional fifteen engines was placed in 1952 but cancelled following the 1955 BR Modernisation Plan. The new construction would have brought the class to 25 engines; in the event no further Clans were built and the class remained limited to the original ten.

The Clans worked the Glasgow–Carlisle and Glasgow–Stranraer services from new, supplemented by the Glasgow & South Western route to Stranraer for the Larne boat-train traffic. The class's lighter axle loading made it the preferred choice for the Stranraer line where the Britannia could not be worked. Performance was respectable, drivers reported that a well-handled Clan would manage anything the Stranraer or Carlisle expresses required, although the class was not considered the equal of either the contemporary LMS Princess Coronation Pacifics on the West Coast main line or the Britannia on similar work elsewhere.

By the late 1950s the diesel-electric locomotives of the BR Modernisation Plan were arriving in Scotland. The Clan was particularly vulnerable to displacement because of its small class size, only ten engines, with no follow-on production, and the introduction of Class 47 (Brush Type 4) and Class 26 diesels from 1962 onwards rapidly made the class redundant.

Withdrawal began with No. 72004 Clan Macdonald in May 1962. The remaining nine engines were withdrawn between 1962 and 1965, with the final survivor being 72005 Clan Macgregor in May 1965. None of the ten was preserved, the class was simply too small and too late in BR service for organised preservation efforts to crystallise around it. All ten Clans were scrapped at South Wales scrapyards.

A two-cylinder lightweight Pacific of recognisable BR Standard outline, but smaller in every dimension than the Britannia Class 7. The shorter boiler, smaller firebox, lighter axle loading and overall reduced proportions distinguish the Clan from its larger Standard sister at rest. The class was named after Scottish clans, with brass nameplates on the leading splashers, a deliberate publicity choice intended to give the small lightweight Pacific class a recognisable Scottish identity. The class wore BR Brunswick green throughout its career.

72000 Clan Buchanan, first of class, completed at Crewe in November 1951. Initially based at Polmadie. Withdrawn 1962, scrapped.

72005 Clan Macgregor, initially Polmadie-based for the Glasgow–Stranraer boat-train workings. Famously photographed handling the boat-train through the Galloway hills in the 1950s. Withdrawn 1965.

72009 Clan Stewart, last of the original class, completed at Crewe in December 1952. Withdrawn 1965, scrapped.

72010 Hengist, a new-build engine under construction at the Bridgnorth-based 72010 Hengist Locomotive Group, intended to recreate the Clan class. The engine takes the next-in-series number 72010 (the original sequence having ended at 72009). Construction has been ongoing since 2000; the engine is partly assembled but is at the time of writing not yet operational. The choice of Hengist as the name (a 5th-century Anglo-Saxon king of Kent) is a departure from the original Scottish-clan naming pattern.

BR Scottish Region (1951–1962): all ten Clans were initially allocated to BR Scottish Region, six to Polmadie shed in Glasgow for the Glasgow–Carlisle and Glasgow–Stranraer services, and four to Carlisle Kingmoor for the Carlisle–Glasgow West Coast services and the Stranraer boat-train workings. The Stranraer line's axle-load restrictions made the Clan particularly suitable for the boat-train work to the Northern Ireland ferry connections.

Late BR allocations (1962–1965): by the early 1960s the class was being progressively displaced from front-line work by the rapid arrival of Class 26, Class 27 and Class 47 diesels in Scotland. The surviving Clans were transferred to secondary main-line and parcels work before withdrawal.

BR Brunswick green (1951–1965): from new the class wore BR lined Brunswick green with the early lion-and-wheel emblem on the tender (1951–1956), then the late BR crest (1956–1965). All ten engines wore Brunswick green throughout their entire BR careers; none was ever turned out in any other livery. The brass clan nameplates on the leading splashers were a distinctive feature throughout.

Preservation (Hengist new-build, 2000–): the new-build 72010 is intended to be outshipped in BR Brunswick green to match the original ten. As the engine is not yet complete, no firm livery has yet been applied.