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The Bulleid Firth Brown wheel (BFB) was a locomotive wheel developed for the Southern Railway in the late 1930s. It was a disc wheel, in contrast to the usual spoked wheels in general use on British railways. The wheel was designed by Oliver Bulleid and developed by the steel company Firth Brown of Sheffield.
The BFB comprises a single disc, with teardrop-shaped indentations to give rigidity, and lightening holes to reduce weight. The advantage over a spoked wheel is that a disc wheel carries the tyre (the metal hoop shrunk onto the wheel to provide contact with the rail) more efficiently; spoked wheels are prone to shrink over time, causing the tyre to work loose, whilst in a disc wheel this is less pronounced. Disc wheels also distribute the weight more evenly, reducing hammer blow on [ citation needed ] (and thus the damage to) the rail.
In conventional spoked wheels, the tyre is shrunk onto the centre and then locked in place by a retaining 'Gibson ring' at the rear. The BFB pattern avoids this ring, and the risk of it loosening in service. The tyre is turned with a lip in the outer face, then a similar lip at the rear is cold-rolled into place, after the tyre has been mounted. [1]
The BFB weighed about 10 [2] [3] or 12 [1] per cent less than a spoked wheel of the same size.
The Bulleid Firth Brown, or BFB, is sometimes, but inaccurately, referred to as a Boxpok in reference to the wheel used by a number of US railway companies. The BFB is visually similar to the Boxpok, but is of a different design; the Boxpok is composed of sections fixed together to make a hollow shape, while the BFB is cast in a single piece, like a spoked wheel, the shape giving the rigidity needed.[ citation needed ]
The wheel is named for Firth Brown as well as Bulleid to give equal credit for the design: while the idea was Bulleid's, the development work, and how to cast them, was done by the company. Therefore, both shared the patent. In fact one source[ which? ] gives BFB as meaning Beaumont Firth Brown, referring to the engineer at the firm who oversaw the development.
The BFB was developed in 1938 for use on Bulleid's innovative Merchant Navy class of Pacific locomotives. He later used them on all subsequent designs: the Q1 "austerity class" in 1942; his Light Pacifics (the West Country and Battle of Britain classes) in 1945; and his Leader class in 1946. The pacifics also used a similar design of BFB for the non-driving carrying wheels. He also used them in his modifications to the Maunsell Diesel shunters then in use on the Southern.
Despite the advantages for which it was designed and well suited, the BFB had a number of drawbacks. It was difficult to maintain, the hollows collected undesired particles like oil, sand and water. In addition, the wheels were found to be prone to cracking, though this was later attributed to the poorer quality of available steel used during and after the Second World War than to some intrinsic design flaw.
The use of the BFB was discontinued in 1948 after the amalgamation of the Southern into British Railways and Bulleid's departure to work for CIE in Ireland. The next generation of steam traction in Britain, e.g. the BR Standards, would all use spoked wheels. Although many of the Bulleid pacifics were rebuilt and major features such as their valvegear replaced, the BFB wheels were retained.
Oliver Vaughan Snell Bulleid CBE was a British railway and mechanical engineer best known as the Chief Mechanical Engineer (CME) of the Southern Railway between 1937 and the 1948 nationalisation, developing many well-known locomotives.
The Southern Railway (SR), sometimes shortened to 'Southern', was a British railway company established in the 1923 Grouping. It linked London with the Channel ports, South West England, South coast resorts and Kent. The railway was formed by the amalgamation of several smaller railway companies, the largest of which were the London and South Western Railway (LSWR), the London, Brighton and South Coast Railway (LB&SCR) and the South Eastern and Chatham Railway (SE&CR). The construction of what was to become the Southern Railway began in 1838 with the opening of the London and Southampton Railway, which was renamed the London & South Western Railway.
The British Rail Class 12 is a diesel locomotive built primarily for shunting duties around London.
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The SR Q1 class is a type of austerity steam locomotive constructed during the Second World War. The class was designed by Oliver Bulleid for use on the intensive freight turns experienced during wartime on the Southern Railway network. A total of 40 locomotives were built. Bulleid incorporated many innovations and weight-saving concepts to produce a highly functional design. The class lasted in service until July 1966, and the first member of the class, number C1, has been preserved by the National Railway Museum.
The SR West Country and Battle of Britain classes, collectively known as Light Pacifics or informally as Spam Cans, are air-smoothed 4-6-2 Pacific steam locomotives designed for the Southern Railway by its Chief Mechanical Engineer Oliver Bulleid. Incorporating a number of new developments in British steam locomotive technology, they were amongst the first British designs to use welding in the construction process, and to use steel fireboxes, which meant that components could be more easily constructed under wartime austerity and post-war economy.
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The Leader was a class of experimental 0-6-0+0-6-0T steam locomotive]], produced in the United Kingdom to the design of the innovative engineer Oliver Bulleid. The Leader was an attempt to extend the life of steam traction by eliminating many of the operational drawbacks associated with existing steam locomotives. It was intended as a replacement for the ageing fleet of M7 class tank engines still in operation on the Southern Railway (SR). Design work began in 1946 and development continued after the nationalisation of the railways in 1948, under the auspices of British Railways (BR).
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A Boxpok is a steam locomotive wheel that gains its strength through being made of a number of box sections rather than having traditional solid spokes. Being hollow, they allow better counterbalancing and stability than conventional drivers, which is important for fast locomotives. The Boxpok wheel was patented by General Steel Castings Corporation of Granite City, Illinois.
BFB may refer to:
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Firth Brown Steels was initially formed in 1902, when Sheffield steelmakers John Brown & Company exchanged shares and came to a working agreement with neighbouring company Thomas Firth & Sons. In 1908 the two companies came together and established the Brown Firth Research Laboratories and it was here, in 1912, under the leadership of Harry Brearley they developed high chrome stainless steel. The companies continued under their own management until they formally merged in 1930 becoming Firth Brown Steels. The company is now part of Sheffield Forgemasters.
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The South African Railways Class 16DA 4-6-2 of 1928 was a steam locomotive.
The South African Railways Class 16DA 4-6-2 of 1930 is a class of steam locomotives.
