Bulleid MN "Merchant Navy" Class 4-6-2
| When in March 1938 the Board of the Southern Railway authorised construction of ten locomotives of a new mainline passenger design neither they, nor anyone who knew of CME Oliver Bulleid's work whilst assistant to Nigel Gresley on the GNR and LNER, could scarcely imagine the machine that eventually emerged from the works. After an eight coupled configuration had been turned down by the Civil Engineer a more conventional Pacific wheelbase was settled upon, but thereafter very little else was conventional about this engine. Bulleid was an imaginative and perhaps intuitive (rather than precise) designer leading to many changes of mind throughout the design and construction process. The boxy bodywork, described as "air-smoothed" rather than streamlined (being designed to go through carriage washing plants) and Bulleid-Firth-Brown (BFB) wheels were merely the cloaking for a host of innovative features - some untried and untested - and methods of construction introduced with the laudable aim of easing the workload for (and no doubt reduce the costs of) loco crew and maintenance staff. In fact some innovations introduced cause and effect to ripple through the design with one innovation introducing extra weight somewhere in the loco requiring another innovation elsewhere to reduce weight. |
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This is a photograph of a Southern Railway poster featuring the new MN
class portraying by its technology the railway company as being a modern
progressive organisation.
photograph by Michael Taylor |
| 21C1 Channel Packet caused quite a sensation when
first unveiled to the public on 18th February 1941 with her unusual shape and,
for Britain, number. In the early years of these locomotives they were
frequently known by the nick-name "Channel Packets" rather than
"Merchant Navies", after the first in the class. She is in matt
malachite and has cast number plates, though that on the sloping front will
soon be removed and replaced with a painted number on the vertical face
immediately below.
photograph: Roy Vandersteen collection |
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| Novel features included an all-time high boiler pressure of 280lb p.s.i., clasp brakes, welded steel firebox with thermic syphons, steam operated firedoors (novel in Britain), a steam driven electrical generator providing comprehensive headcode, inspection and cab lighting, a cab layout permitting the driver and fireman to work without getting in each other's way, but chief of all a totally enclosed motion encased in an oil bath situated between the frames. This motion itself included the new feature of a chain driven three throw crank shaft operating valve gears for each cylinder. In his motion gear Bulleid was strongly influenced by automobile design with its potential increased reliability and reduced maintenance compared to conventional locomotive motion design. |
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21C3 Royal Mail engaged in changing engines at Salisbury on a
Plymouth-bound train. The number can now be seen to be painted on the vertical
face. The letter 'C' is also noticeably larger than the numerals.
photograph: Mike Morant collection |
| The "Southern" plate on the smokebox door was unpopular with loco crews as it resembled an upside-down horseshoe so was soon replaced with a "Southern Roundel" with the added section carrying the date of the manufacture. Despite a wooden mock-up being made immediately after nationalization, the roundel was not replaced with a similar one bearing the legend "British Railways". In the early days of BR the numbers, by now simply painted, carried the prefix 'S' in front of the Southern number, but when the locos were renumbered in the 350xx series, this was replaced by a cast LMS-style plate on the smokebox door, hidden in the photograph below by the train headboard. |
| 21C4 Cunard White Star at Waterloo with a special
train for the maiden ordinary passenger carrying voyage of the "Queen
Elizabeth", 16 October 1946. Note the "quartering" of the
buffers and the letter 'C' which is now slightly smaller than the
numerals!.
Whilst an Exmouth Junction engine, a low flying German aircraft shot at 21C4 on 30 November 1942 at Crannaford, near Whimple. photograph courtesy Jerry Ricketts and stated to be in the
Public Domain when posted on the alt.binaries.pictures.rail newsgroup. |
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All photographs are copyright
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This page was last updated 18 May 2004
