Albion Nimbus
   HOME

TheInfoList



OR:

The Albion Nimbus was an underfloor-engined, ultra-lightweight (dry weight 2.4 tonne)
midibus A midibus is a classification of single-decker minibuses which are generally larger than a traditional minibus but smaller than a full-size single decker and can be anywhere between and long. While used in many parts of the world, the mi ...
or coach chassis, with a four-cylinder horizontal
diesel engine The diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel engine is a so-call ...
and a gross vehicle weight of six tons. It was largely operated on light rural bus duties and private hires. Operators who used it on heavy-duty bus routes found it insufficiently robust. It was the first Albion bus chassis to have a name that did not begin with the letter V. The design was revised twice and was produced from 1955 to 1965.


Background

Albion Motors Albion Motors was a Scottish automobile and commercial vehicle manufacturer. Founded in 1899, Albion Motors was purchased by Leyland Motors in 1951. Vehicles continued to be manufactured under the Albion brand until 1972, after which they cont ...
had been taken over by
Leyland Motors Leyland Motors Limited (later known as the Leyland Motor Corporation) was a British vehicle manufacturer of lorries, buses and trolleybuses. The company diversified into car manufacturing with its acquisitions of Triumph and Rover in 1960 and 1 ...
in 1951: after the merger, Albion were to concentrate on export models and lightweight chassis for the home market. With this in mind, Albion developed the EN219 engine, a horizontal four-cylinder unit sharing design and components with the six-cylinder Leyland O350. It was launched in 1953 for the underfloor-engined Albion Claymore delivery truck. During 1954, Scottish Omnibuses (SOL) used Claymore units in an integrally constructed rubber-suspended 32-seater bus, this being announced in May 1955 with the Nimbus being unveiled, in the autumn, at the 1955 Scottish Motor Show at
Kelvin Hall The Kelvin Hall, located on Argyle Street in Glasgow, Scotland, is one of the largest exhibition centres in Britain and now a mixed-use arts and sports venue that opened as an exhibition venue in 1927. It has also been used as a concert hall, ...
, Glasgow. The vehicle on the show stand had an
Alexander Alexander is a male given name. The most prominent bearer of the name is Alexander the Great, the king of the Ancient Greek kingdom of Macedonia who created one of the largest empires in ancient history. Variants listed here are Aleksandar, Al ...
body and was an Albion demonstrator in SOL livery, whilst the bus in the demonstration park in Highland Omnibuses livery carried a body by SOL, now preserved.


Description

The Nimbus had a bolted lightweight steel frame with channel section longitudinals and tubular cross-members, similar to the Claymore, also featuring a down-sloping front section. During its production life, component changes followed those of the Claymore.


MR9N

The frame was slightly wider than that of the longest MR7L Claymore but the wheelbase was identical and the radiator was mounted in an inclined position above the front axle, to obviate intrusion into the passenger gangway. Wider and longer springs were fitted and the axles were of wider tack, suitable for wide bodies. Like the MR 5 and 7 Claymore the 3.83-litre EN219 developing at 2200 rpm drove through an Albion single-plate hydraulically assisted clutch and Albion four-speed
constant-mesh gearbox A manual transmission (MT), also known as manual gearbox, standard transmission (in Canada, the United Kingdom, and the United States), or stick shift (in the United States), is a multi-speed motor vehicle transmission system, where gear changes ...
, with
synchromesh A manual transmission (MT), also known as manual gearbox, standard transmission (in Canada, the United Kingdom, and the United States), or stick shift (in the United States), is a multi-speed motor vehicle transmission system, where gear changes ...
on third and top, to an Albion overhead worm rear axle, the Nimbus rear axle was heavier-duty than that of the heaviest Claymore and had larger brakes. Braking was provided by two-leading-shoe
drum brakes A drum brake is a brake that uses friction caused by a set of shoes or pads that press outward against a rotating cylinder-shaped part called a brake drum. The term ''drum brake'' usually means a brake in which shoes press on the inner surfac ...
all round, hydraulically actuated with vacuum assistance from an Albion-patented engine bypass valve. The engine had an oil-bath air-cleaner and a centrifugal oil filter. Automatic chassis lubrication was standard.


NS3N

In 1958, the Claymore range was revised with a lower specification and greater use of bought-in components in an attempt to reduce costs and thus it was hoped make the line profitable. Nomenclature was now based on model name, the Claymores becoming models CL5N and CL3N or L and the Nimbus model NS3N. Axles were now of Austin (under
British Motor Corporation The British Motor Corporation Limited (BMC) was a UK-based vehicle manufacturer, formed in early 1952 to give effect to an agreed merger of the Morris and Austin businesses.Morris-Austin Merger Company Named. ''The Times'', Friday, 29 February ...
) design, from their 5-ton truck, the rear axle being of spiral-bevel form and a David Brown four-speed constant mesh gearbox was fitted. There was not a wide version of the BMC axles, so the NS3 had a width over tyres of , rather than the MR9s . The engine was the enlarged Albion EN250, a 4.1-litre unit developing at 2,200 rpm.


NS3AN

In 1960, along with the rest of the Claymore range, the Nimbus was uprated, featuring heavier BMC axles and an Albion constant mesh gearbox with either five or six speeds. Vacuum assistance to the brakes was now provided by a Hydrovac system, belt-driven from the engine. Two Nimbus-specific changes were the option of a drop-frame extension at the rear for a luggage boot and the option of a spare wheel mounted on a slide-out carrier, below this extension.


Sales

In Scotland, SBG fleets Alexander (five MR9 and ten NS3 coaches) and Highland (six MR9 coaches) were the largest purchasers new. The BET group were the major purchasers in England and Wales. Devon General had nine, Maidstone & District fifteen, and Western Welsh purchased 48. The municipal purchasers of the type were Wallesey (4) Southampton (3) Great Yarmouth (6) and Halifax (10) Independents bought buses and coaches, bus customers included W Gash & Sons of Newark, Notts, LCW Motors of Llandeillo, North Wales and the Londonderry and Lough Swilly Railway, operating between Northern Ireland and the north-western parts of the Irish Republic. Smiths of Wigan and Dickson of Dundee were among the purchasers of Nimbus coaches, these were generally bodied by Plaxton, to either front or centre-entrance layout. On Guernsey the linked Guernsey Motors and Guernsey Railways concerns took 32 between them and independent Watson's Greys also owned one, these all had narrow bus bodies by Reading of Portsmouth. Coachwork on UK/Channel Island examples, was by Alexanders, Harrington,
Plaxton Plaxton is an English builder of bus and coach vehicle bodies based in Scarborough. Founded in 1907 by Frederick William Plaxton, it became a subsidiary of Alexander Dennis in May 2007. In 2019, the maker was acquired by Canadian bus manufac ...
, Reading, SOL, Strachans, Weymann and Willowbrook. One major export market for the type was Australia, and one independent operator there stretched its examples to 27 ft (8.5 m) before fitting them both with 39-seat bus bodies, although the greatest seating capacity for any Nimbus was a standard-length 41-seat school bus for
Dunbartonshire Dunbartonshire ( gd, Siorrachd Dhùn Breatann) or the County of Dumbarton is a historic county, lieutenancy area and registration county in the west central Lowlands of Scotland lying to the north of the River Clyde. Dunbartonshire borders P ...
County Education Department.


Operation

In contrast with the EN286 through to EN335 series, which were developed for around a decade before release and subject to continual improvement thereafter, the EN218/9 was a rush job, going from concept to production in little over two years. Adams and Milligan quote gasket failures as a particular early problem, comparing the Leyland-inspired use of four securing studs per cylinder rather than the six Albion had used hitherto. They say the Claymore and in particular the Nimbus garnered a reputation for unreliability resulting in uneconomic volumes being sold: that must have applied especially to the 30cwt payload MLH3 Cairn derivative of the Claymore which was barely in production for a year before being dropped. Of course the underfloor-engined concept had advantages in small delivery trucks. Guy had its Seal and Dennis its Stork around the same time but they sold even worse than the Claymore; although Atkinson had a reliable UFE truck, as did Büssing in West Germany. It's undeniable though that the idea of a small OMO bus with the amenity of a full size UFE single deck was appealing to certain customers. Notably Scottish Bus Group who used Claymore units and Metalastic rubber suspension in an integral prototype built by Scottish Omnibuses in 1954. It was in the demonstration park of the 1955 Kelvin Hall show that the Nimbus was unveiled and Buses Illustrated's Scottish Columnist wondered why a firm whose motto was "Sure as the Sunrise" had named a vehicle after a raincloud, going on to say that given its emission of black smoke on starting that perhaps it was a cumulo-nimbus. Geoffrey Hillditch spends a quarter of his chapter on Albion buses detailing the Nimbus and his mostly negative experience of it. His first sight of it was at the 1956 Earls Court show, he had served his time at LNER's Gorton Loco works so he was incredulous at the flimsiness of the frame with a chassis weighing only 2 ton 17.25cwt, but he says "I recognised the logic behind the inception of the design." One of the first problems he encountered with the Great Yarmouth MR9s was, that in order for the automatic bypass vacuum generator to provide sufficient vacuum for braking assistance idling speed had to be kept low, this resulted in an engine straining at its mountings. Eventually failure of the mountings happened on one of them but not before another managed to shed its dynamo whilst in service, others had sheared a number of chassis brackets. He also found the gearchange linkage (although it kept the engine in place when the mountings failed) developed far too much free play and in order to select reverse on one he had to open the half-door on the passenger side of the cab. Others managed to grind to a halt when two gears were selected simultaneously. He ordered the short-tailed
AEC Reliance The AEC Reliance was a mid-underfloor mounted engined single-decker bus and coach chassis manufactured by AEC between 1953 and 1979. The name had previously been used between 1928 and 1931 for another single-decker bus chassis. History Two p ...
s to replace them. Then he returned to Halifax as GM and chief engineer to be greeted by ten NS3ANs. First came gasket failures, and in some cases he found part of the block burned away too, which he ascribed to incorrect combustion chamber design. BMC rear axle design was faulty, with half shafts cutting into sealing rings and starving the differential of oil. The automatic lubrication equipment, driven by an extension of the speedometer cable, frequently failed and failure of chassis brackets (as in the MR9s) was common. The use of a conventional engine driven vacuum-exhauster was given as a good point but the six-speed gearbox was in this implementation imprecise in operation. Whilst praising Albion's service engineers and finding the MR9s good for on the Norfolk coast and the six-speed NS3ANs returned - "and could do even better on a route where the overdrive could be engaged for reasonable periods" his conclusion was " ppy and economical though a heavy town centre route was no place for a Nimbus." Nimbus production amounted to 124 MR9 and 217 NS3. The largest user was
Western Welsh Western Welsh was a Welsh bus operating company, based in Cardiff covering South Wales and the northern parts of the West Country. Formed in 1920, it was nationalised when the BET Group sold their bus interests to the Transport Holding Company ...
, who kept them to deeply rural routes. In contrast 471
Albion Aberdonian The Albion Aberdonian was an underfloor-engined bus designed and manufactured by Albion Motors between 1957 and 1960, it was introduced as a longer derivative of the Albion Nimbus. The Aberdonian, development code "Nimbus-Six", was designed to ...
s were built over a shorter period. Although operators using the Nimbus on intensive one-man-operated routes found it troublesome, on the lightly trafficked rural routes for which it was designed it could put in a long life. Harvey of Mousehole,
Cornwall Cornwall (; kw, Kernow ) is a historic county and ceremonial county in South West England. It is recognised as one of the Celtic nations, and is the homeland of the Cornish people. Cornwall is bordered to the north and west by the Atlantic ...
operated an ex-Halifax bus from 1966 to 1986, while other rural operators who got good value out of second-hand Nimbuses were Wiles of Port Seton in East Lothian, Scotland, and Booth and Fisher who operated on the borderlands of Yorkshire and Nottinghamshire.


Preservation

One MR9L and 21 NS3N/NS3AN Nimbuses are preserved. The body from one of the Western Welsh examples was removed by the operator and refitted to the prototype
Bristol LH The Bristol LH was a single-decker bus chassis built by Bristol Commercial Vehicles (BCV) in Bristol, England. Nearly 2,000 were built between 1967 and 1982 in a variety of sizes and body types, including some as goods vehicles. Models The LH de ...
S6L chassis which was registered XBO1F and is now preserved with Thornes Independent of Selby, Yorks.


Derivatives

Bristol Commercial Vehicles Bristol Commercial Vehicles was a vehicle manufacturer located in Bristol, England. Most production was of buses but trucks and railbus chassis were also built. The Bristol Tramways and Carriage Company started to build buses for its own use i ...
built the SU model from 1960 to 1966, this featured the same EN250 engine and BMC rear-axle as the Nimbus NS3AN with a David Brown overdrive-top five-speed constant-mesh gearbox, all were bodied by
Eastern Coach Works Eastern Coach WorksCompanies House extract company no 318856
...
, most to 25 ft (8m) length, seating 36 (buses) or 33 (coaches) although a shorter-wheelbase 30-seat model long was also built. The major difference from the Nimbus was that the radiator was mounted at the extreme front of the chassis. It was concentrated in the south-west of England, the customers for the 179 built were eight
Transport Holding Company The Transport Holding Company (THC) was a British Government-owned company created by the Transport Act 1962 to administer a range of state-owned transport, travel and engineering companies that were previously managed by the British Transport C ...
fleets. Southern and
Western National Western National was a bus company operating in South West England from 1929 until the 1990s. Early history Western National Omnibus Company was founded in 1929 as a joint venture between the Great Western Railway (GWR) and the National O ...
had 97 (36 of which were coaches, out of 38 coaches built).
Bristol Omnibus Company The Bristol Omnibus Company was a dominant bus operator in Bristol, and was one of the oldest bus companies in the United Kingdom. It ran buses over a wide area of Gloucestershire, Somerset, Wiltshire and neighbouring counties. History ...
had nine short buses.
West Yorkshire Road Car The West Yorkshire Road Car Company was a major bus operator operating in North and West Yorkshire between 1906 and 1987. History West Yorkshire The Harrogate Road Car Company was formed in 1906, running at first steam buses in Harrogate, then ...
had 18 longer buses,
United Automobile Services United Automobile Services was a bus company, which operated local and regional bus services in County Durham, Cumbria, Northumberland, North Yorkshire and Tyne and Wear, England. It provided bus services across a wide geographical area, stret ...
five,
United Counties Omnibus Company United Counties OmnibusCompanies House extract company no 176586
had six and United Welsh Services had the other two coaches. At least three
Bristol SU The Bristol SU was a single-decker bus and single-decker coach chassis built by Bristol Commercial Vehicles between 1960 and 1966. The bodies for these vehicles were built by Eastern Coach Works (ECW). Some of them were built as medium length ch ...
survive, one each from Western National and Bristol, and the last West Yorkshire example, EWT386C which was re-engined with a Perkins H6-354 engine as part of the Bristol LH development programme. Thornes Independent also preserve this bus as part of their heritage fleet.


See also

{{Commons category, Albion Nimbus *
List of buses Year refers to the first year introduced. A range of years is the period the bus was manufactured. # A B C D E F G H I J K L M N O P Q R S T U V W ...


Sources


Manufacturer's brochures

*Albion Motors Brochure 2001, November 1955 *Albion Motors Brochure L688, September 1958 *Albion Motors Brochure L716, September 1960


Books

*Kaye, Buses and Trolleybuses since 1945, London 1968 *Adams & Milligan Albion of Scotstoun, Paisley 1999 *Hillditich, A Further Look At Buses, Shepperton 1981 *Jack, Leyland Bus Mark Two, Glossop 1982


Magazines

*Smith (ed) Buses Illustrated 26, Shepperton, December 1955 *Booth (ed) Classic Bus 30, Edinburgh, July 1997


Websites

*http://www.buslistsontheweb.co.uk *https://web.archive.org/web/20130715182127/http://classsicbusmag.co.uk/ *http://aec.middx.net
Nimbus Nimbus, from the Latin for "dark cloud", is an outdated term for the type of cloud now classified as the nimbostratus cloud. Nimbus also may refer to: Arts and entertainment * Halo (religious iconography), also known as ''Nimbus'', a ring of ligh ...
Vehicles introduced in 1953