The epic voyage of Bulleid’s Merchant Navy Pacifics
The epic voyage of Bulleid’s Merchant Navy Pacifics
Pete Kelly traces the history of one of his favourite locomotive classes, and takes a look at Hornby’s latest OO-scale releases of the ‘Packets’ in their original form.
Bulleid’s Merchant Navy Pacifics were fast and smooth, copious steam producers, and bristled with innovation, but sadly not everything worked out in practice for these airsmoothed wonders. Pete Kelly traces the history of one of his favourite locomotive classes, and takes a look at Hornby’s latest OO-scale releases of the ‘Packets’ in their original form.
SOON after Oliver Vaughan Snell Bulleid succeeded Richard Maunsell as Chief Mechanical Engineer of the Southern Railway in 1937, he and his drawing room team were tasked with designing a new and powerful class of locomotive to cope with the railway’s increasingly heavy boat trains and other main line duties.
Having worked under Sir Nigel Gresley during the development of the LNER’s Cock o’the North and its five P2 2-8-2 classmates, Bulleid’s first thoughts had been for an eightcoupled locomotive, but sadly this was ruled out by the railway’s chief civil engineer, and he had to plump for a Pacific.
The project couldn’t have occurred at a more unfortunate time, because with the outbreak of the Second World War, and the consequential shortages of materials, the government decreed that only mixed-traffic locomotives could be built. On the assumption that this meant unsophisticated yet powerful and easy-to-maintain locomotives, how the SR got away with placing the Merchant Navies into that category, perhaps on account of their 6ft 2in driving wheels, has remained a matter of debate ever since! Prototypes
There was nothing remotely simple about the first two prototypes, No. 21C1 Channel Packet and 21C2 Union Castle, when they emerged as the first of an initial batch of 10 from Eastleigh Works in February and June 1941 respectively.
Bulleid had waited a long time to make his mark, and the new locomotives featured a high boiler pressure of 280psi (later reduced to 250psi); chain-driven valve gear enclosed in a sealed oil bath (the original intent was for gear, rather than chain-driven, but there simply wasn’t enough room for that); thermic siphons to improve water circulation; and Bulleid Firth Brown ‘Boxpok’ driving wheels which were stronger and lighter than
Left: In spotless blue livery, and beautifully prepared along with its Royal Pullman special train on the occasion of a state visit by the President of France in the early 1950s, No. 35019 French Line C.G.T. passes Shorncliffe on the long climb from Dover to Westenhanger. Built in 1945, the locomotive worked out of Paddington during the Locomotive Exchanges of 1948. It was rebuilt in May 1959 and withdrawn in September 1965. RAILWAY MAGAZINE ARCHIVE
spoked ones.
Steam-generated electric lighting was provided on the locomotive itself and inside a warm and spacious fully-enclosed cab. Thought went into positioning controls perfectly for the driver and fireman, and a steam-powered treadle operating the firehole door was another practical touch, because the boilers could consume coal at an extraordinary rate.
Much use was made of welding on the new locomotives, including the steel inner firebox and the tender’s steel water tank.
After the prototypes were found to be several tons over their specified weight limit, there was a delay in producing the remaining eight while the necessary lightening measures were carried out.
It soon became clear that drifting smoke and steam from the soft exhaust beats of the wide multiple-jet blastpipe chimney was seriously hampering the vision of footplate crews, and although various experimental smoke-lifting modifications were carried out, the problem was never completely solved.
Sadly, the steam-operated firehole door treadles were not fitted to the remaining engines in the first batch – Nos. 21C3 Royal Mail, 21C4 Cunard White Star, 21C5 Canadian Pacific, 21C6 Peninsular & Oriental S. N. Co., 21C7 Aberdeen Commonwealth, 21C8 Orient Line, 219 Shaw Savill and 21C10 Blue Star – and because of wartime supply issues their boilers were wrapped in a different type of cladding. The batch was completed between September 1941 and
July 1942.
Having joined the French division of the Westinghouse Electric Corporation as a test engineer in 1908, Bulleid soon rose to the post of assistant works manager, amassing a wide knowledge of French railway practices in the process. When he joined the Southern, he quickly adopted the French wheel-arrangement system, which used numerals to denote the number of carrying axles and letters to denote the number of driving axles for his new Pacifics, which duly became 21Cs. Had either of his 4-8-2 or 2-8-2 ideas been approved, they would have become 21Ds or 11Ds respectively.
Construction
Two more Merchant Navy batches followed, the second built by the Southern Railway in 1944-5, and the third ordered by the SR just before nationalisation, and therefore built by British Railways (which quickly abandoned the French numbering system) in 1948-49.
Because of the war, the boat trains for which the initial batch of ‘Merchant Navies’ had been designed disappeared for the duration, but the class put in some good work on normal services to Southampton and Exeter.
As their mileages built up however, so did a variety of troubles, ranging from valve-gear chain wear, leaks from the supposedly sealed oil baths, and steam reverser problems. The locomotives spent many days out of service, and gained an unwelcome reputation for unreliability.
Although often exaggerated by some historians, the ‘sum of all fears’ could arise if oil leaked onto the driving wheels and became flung into the boiler lagging, where coal dust could make it even more combustible, and a spark from a hard brake application, for example, could set off serious lagging fires.
The last straw came in 1953, when metal fatigue caused the central driving wheel crank axle of No. 35020 Bibby Line, the last of the 1944-5 batch, to fracture while the locomotive was travelling at speed. While the cause of the incident was investigated, all Merchant Navies were taken out of service and classes from other BR regions had to be called in to deputise for them. Several other MNs were found to have the same fault, and as a result new and improved crank axles were re-engineered for all of the big Pacifics.
Rebuilding
How long could it go on? Should the ‘Packets’, despite their brilliant boilers and other sound features, be withdrawn and replaced, perhaps by the capable and practical BR Standard Class 7 ‘Britannia’ Pacifics, or could another solution be found?
To the relief of many Southern Region devotees, a rebuilding programme was decided upon instead and placed in the hands of R. G. Jarvis, who removed all of the problematic features, including the air-smoothed casings, oil-bath valve-gear and steam reverser (which was replaced by a screw-link type), along with three separate sets of Walschaerts valve-gear.
New round smoke-boxes replaced the original versions, and the mighty boilers and fireboxes could at last show off their handsome lines. High
BR Standard-type running boards and modern smoke deflectors added to the rebuilds’ good looks, and the superb original driving cabs, with their swept-back lookout windows, were retained.
Virtually all of the maintenance problems attributed to the original locomotives were eliminated at a stroke, and the similar rebuilding programme for the lighter ‘West Country’ and ‘Battle of Britain’ Pacifics was well under way when, in the light of the BR modification programme, all such work came to an end – but at least it gives today’s enthusiasts the chance to still see the smaller airsmoothed locomotives in action on heritage railways and the main line.
I was an avid 12-year-old locospotter in the north-west when the first photograph of the rebuilt No. 35018 British India Line appeared in my monthly Trains Illustrated magazine in 1956, and the locomotive’s majestic appearance simply took my breath away. I don’t think I’d ever seen such a handsome locomotive, and I get the same feeling when I watch videos of the spotless British India Line itself, No. 35006 Peninsular & Oriental S. N. Co. or No. 35028 Clan Line performing as well as they ever did more than half a century after their withdrawal from BR service.
Performance
The rebuilt MNs remained impressive performers to the very end, achieving 100mph-plus runs on several occasions. In June 1967 during the final year of Southern steam, No. 35003 Belgian Marine, hauling a very light train of three carriages and two parcels vans, was timed at a speed of 105.88mph between Winchfield and Fleet, and this remained the last 100mph-plus performance for a British steam locomotive until the newbuild Peppercorn A1 Pacific No. 60163 Tornado achieved its own three-figure run 50 years later in 2017.
Today’s MN survivors are No. 35005 Canadian Pacific, built in 1941, withdrawn in 1965 and now part of the Mid-Hants Railway fleet; No. 35006 Peninsular & Oriental S. N. Co, built in 1941, withdrawn in 1965 and now operational at the Gloucestershire Warwickshire Railway; No. 35009 Shaw Savill, built in 1942, withdrawn in 1964, now part of Ian Riley’s fleet; No. 35010 Blue Star, built in 1942 withdrawn in 1966 and now resident at the Colne Valley Railway; No. 35011 General Steam Navigation, built in 1944 and withdrawn in 1966, currently under restoration at the Swindon & Cricklade Railway; No. 35018
British India Line, built in 1945 and withdrawn in 1964, now part of the West Coast Railways main line fleet; No. 35022 Holland-America Line, built in 1948, withdrawn in 1966 and now part of the Royal Scot Locomotive & General Trust collection; No. 35025 Brocklebank Line, built in 1948 and withdrawn in 1964, now awaiting
restoration at Sellindge, Kent;
No. 35027 Port Line, built in 1948 and withdrawn in 1966, now part of the Royal Scot Locomotive and General Trust collection; No. 35028 Clan Line, built in 1948 and withdrawn in 1967, now owned by the Merchant Navy Locomotive Preservation Society, operational on the main line; and No. 35029 Ellerman Lines, built in 1949, withdrawn in 1966, and now displayed in sectional form at the National Railway Museum in York.
I love the distinctive shrill whistles and dancing exhaust beats of today’s
main line stars, their impressive performances whether on flat-out stretches or against the gradient, and the obvious esteem in which their 21st century crews hold them – and long may it continue!
Spirit
However, with lingering respect to the adventurous Bulleid, and never having seen an air-smoothed ‘Merchant Navy’ in my life, I wish all the luck in the world to the imaginative group planning to retro-restore No. 35011 General Steam Navigation to its original condition.
Hornby has announced several versions of Bulleid’s air-smoothed Merchant Navy’locomotives capturing their original lines, with nicely-applied paintwork and crisp nameplates, front number plates, shed plates and cabside transfers.
The 6ft 2in Bulleid Firth Brown ‘Boxpok’ driving wheels and front bogie wheels, along with the outside piston rods and connecting rods, are impressively modelled, and each version seen here comes with a DCCready eight-pin socket and five-pole skew-wound motor.