Keith Langston - British Steam BR Standard

First of the 999 BR Standard Class locomotives, 4-6-2 No 70000 BRITANNIA is pictured at Neasden (24E) en-route to Marylebone Station London for an official BR inspection and naming ceremony, by the then Minister of Transport Alfred Barnes MP on 30th January 1951.

Having been first out-shopped in un-lined black and without nameplates No 70000 was repainted into BR passenger green with, black and orange lining, a red background to the nameplate and a bright metal finish to the wheel rims, handrails, buffers and drawgear prior to the ceremony.

The Britannia livery was eventually changed to BR unlined green without bright metal fittings. For many years the cab roof of BRITANNIA was painted white to commemorate the loco hauling the funeral train of HRH King George VI from Norfolk to London, following his death at Sandringham in February 1952. Colour Rail

BR Pacific Britannia Class 7P6F (7MT) 4-6-2

Built: Crewe Works 195154, 54 locomotives built.
Loco Weight: 94 tons 0 cwt
Tenders: BR1 49 tons 3 cwt, BR1A 52 tons 10 cwt, BR1D 54 tons 10 cwt
Driving Wheels Diameter: 6 foot 2 inches
Boiler Pressure: 250lb/psi
Cylinders: (2) 20 inch diameter x 28 inch stroke
Valve Gear: (piston valves) Walschaerts
Coal Capacity: BR1 and BR1A 7 tons, BR1D 9 tons
Water Capacity: BR1 4250 gallons, BR1A 5000 gallons, and BR1D 4725 gallons
Tractive Effort: 32,150lb at (85% pressure)

The Riddles Class 7 Pacific was intended as a fast mixed traffic locomotive with wide route availability. The small (by express locomotive standards) 6ft 2in diameter driving wheels underlined the designers mixed traffic intentions, whilst their low axle loading (a little over 20 tons) satisfied route availability criteria. In addition the wheelbase of 58ft 3in meant that the class could easily be turned on the many 60ft turntables in use around the regions. The locomotives length over buffers was specified to be 68ft 9in.

The tractive effort of the Britannia class was listed at 32,150lb (at 85% boiler pressure) compared with for example the rebuilt Royal Scot class listed at 33,150lb (at 85% boiler pressure). At the time double blastpipes were seen as the norm for large locomotives, therefore observers were surprised by the Standard teams choice of single blastpipe and chimney. Riddles foresaw that the choice of just two 20in x 28in cylinders would appreciably reduce maintenance cost/time, in comparison to multi-cylinder locomotives.

Performance did not suffer either as the class constantly proved capable of maintaining express timings, often with heavily loaded trains. When in the care of a locomotive crew who had taken the time to learn the required technique of handling the two-cylinder Pacifics, performances more normally associated with multi-cylinder Class 8 steam power were regularly recorded.

Locomotives Nos 70000 to 70034 and 70050 to 70054 were fitted with roller bearings and thereafter engines Nos 70035 to 70039 were built with roller bearings fitted only on the leading and trailing coupled axles, in another deviation from original design specification loco Nos 70040 to 70049 were built with plain bearings throughout. Reportedly experience in traffic showed no great advantage with roller bearings when judged by either reliability or cost criteria.

Initial locomotive allocations for operating purposes:

Nos. 7000070014 Eastern Region
Nos. 7001570024 Western Region
Nos. 7002570029 Western Region
Nos. 7003070044 London Midland Region
Nos. 7004570049 London Midland Region
Nos. 7005070054 Scottish Region

However, in practice some early alterations took place with extra locomotives being reallocated to the Eastern Region and some to the Southern Region.