British Railway History Item
BR Class Riddles British Railways Standard Class 7 Britannia 4-6-2
Built 1951-54, Designed by Robert A. Riddles.
Total Number Built 55.
Introduced 1951. Designed at Derby. Mixed Traffic Pacific Locomotive Power Classification 7P6F. The sanctioned cost of the first locomotive 70000 on 17 November 1947 was ?17,520-00.
Number Series 70000-70054.
Built at British Railway's Crewe Works.
No Lot Nos. yet available.
The name 'Britannia' was chosen by R. A. Riddles and G. S. Hussey to commemorate the Britannia and Lion emblem of the London and North Western Railway. No. 70000 'Britannia' was named at Marylebone Station, London, on 20th January, 1951, by Alfred Barnes, Minister of Transport. The name Britannia already belonged to an LMS Jubilee Class loco No. 45700, but this was renamed 'Amethyst'.
Patterns were found for three more names intended for Britannia locos: Sir John Aspinall; Samuel Johnson; and John Ramsbottom - all had been CME's of railway companies which were absorbed into the LMS.
Officially designated a mixed traffic locomotive, the Britannia class was primarily llocated to express passenger duties.
The first batch of twenty-five locomotives were produced in 1951 and numbered 70000-70024 and sent to work on Eastern, Western and Southern Regions of British Railways.
On the Eastern line the locomotives, allocated to stratford and Norwich Thorpe sheds, were well-liked, replacing the old Sandringham 4-6-0?s.
Southern Region received two locomotives which were allocated to Stewarts Lane (London) to work the heavy 'Golden Arrow' boat trains. These engines included 70004 'William Shakespeare' and 70014 'Iron Duke'.
A further twenty engines were delivered in 1952/53 and distributed to the Western Region Plymouth and Cardiff Canton sheds and London Midland Region.
The final batch of ten locomotives were delivered in 1954. Five were allocated to Holyhead shed on the London Midland Region and five to Polmadie shed on the Scottish Region. these locos had the larger curved-sided type BR1D 4,725 gallon tender with 9 tons coal capacity. In addition to providing a greater capacity the shape of the new tender produced a smoother airflow around the cab creating less swirling dust and dirt.
Despite their all up weight of over 94 tons the Britannias enjoyed wide route availability due to an axle loading of just over 20 tons. With a wheelbase of 58' 3" it could also be accommodated on a 60ft turntable.
The tractive effort was 32150 lb compared to a re-built Royal Scot and Castle at 33150 ad 31625 respectively.
However, the 4-6-0 designs placed more of their weight on to their driving wheels and the Britannias needed a sensitive hand on the regulator to guarantee getting away without wheel slip.
The first loco withdrawn was 70007 'Coeur-de-Lion' in June 1965 from Carlisle Kingmoor Shed, followed by 70043 'Lord Kitchener' in August from Crewe South Shed.
Eleven more were withdrawn in 1966 and 41 (Forty of them from Carlisle Kingmoor Shed) in 1967.
70013 'Oliver Cromwell' was the last locomotive to receive a full works repair at Crewe in February 1967. It lasted until the end of steam on BR in August 1968 and was withdrawn from Carnforth shed. It is preserved, along with 70000 , for main line running.
The first loco withdrawn was 70007 on 19 June 1965 from Carlisle Kingmoor shed.
The last loco withdrawn was 70013 on 17 August 1968 from Carnforth shed.
Locos 70000 'Britannia' in private ownership and 70013 'Oliver Cromwell' at Bressingham Gardens, Diss Norfolk are preserved.
Motive Power Details
Weight: Loco 94 tons 4 cwt
49 tons 3 cwt BR1 4,200 gallons, 7 tons coal
52 tons 10 cwt BR1A 5,000 gallons, 7 tons coal (a)
54 tons 10 cwt BR1D 4,725 gallons, 9 tons coal (b)
Driving Wheel: 6' 2"
Bogie Wheels: 3' 0"
Trailing Truck: 3' 3?"
Total Wheelbase Loco & Tender: 58' 3"
Cylinders: Two 20" x 28" (outside)
Boil Press: 250lb/sq in Su
Evaporating Heating Surface: 2472 sq ft
Grate Area: 42 sq ft
Superheater Surface: 677 sq ft
Adhesion Factor: 4.23
Minimum Radius Curve: 6 chains
Length Over Buffers: 68' 9"
Valve Gear: Walschaerts (piston valves)
TE: 32,150 lb
Class Total: 55
Allocation and Withdrawal Details
Last Updated : Monday 5th May 2003 09:17