The Albion Nimbus was an underfloor-engined, ultra-lightweight (dry weight 2.4 tonne) midibus

Midibus

A midibus is a classification of single-decker minibuses which generally are larger than a traditional minibus but smaller than a full-size single decker and can be anywhere between and long...

 or coach chassis, with a four-cylinder horizontal diesel engine

Diesel engine

A diesel engine is an internal combustion engine that uses the heat of compression to initiate ignition to burn the fuel, which is injected into the combustion chamber...

 and a gross vehicle weight of six tons. It was happiest 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

Albion Automotive of Scotstoun, Glasgow is a former Scottish automobile and commercial vehicle manufacturer, currently involved in the manufacture and supply of Automotive component systems....

 had been taken over by Leyland Motors 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

Scottish Bus Group

The Scottish Bus Group was a state-owned Scottish holding company that included a number of bus operators covering the whole of Scotland. The group was formed in 1961 as Scottish Omnibuses Group Ltd, to take control of the British Transport Commission's bus operating subsidiaries in Scotland...

 (SOL) used Claymore units in an integrally constructed rubber-suspended 32-seater bus, this was announced in May 1955 and the Nimbus was unveiled in the autumn at the 1955 Scottish Motor Show at Kelvin Hall

Kelvin Hall

The Kelvin Hall in Glasgow, Scotland, is a mixed-use arts and sports venue that opened as an exhibition centre in 1927. It has been a music hall, indoor arena and barrage balloon factory, and is currently home to the Kelvin Hall International Sports Arena and from 1987 to 2010, Glasgow's Museum of...

, Glasgow. The vehicle on the show stand had an Alexander

Walter Alexander Coachbuilders

Walter Alexander Coachbuilders was a Scottish bus coachbuilder and operater based in Falkirk.-History:Walter Alexander, notice a lack expasion by the Falkirk and District Tramways Company's especially in to Grangemouth which never hdd a tram line. In 1913 Alexander's Motor Service was created to...

 body and was a Albion demonstrator in SOL livery, whilst the bus in the demonstration park in Highland Omnibuses livery carried a body by SOL, this is now preserved.

Description

The Nimbus had a similar bolted lightweight steel frame with channel section longitudinals and tubular cross-members to the Claymore 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 8 ft (2.4 m) wide bodies. Like the MR 5 and 7 Claymore the 3.83-litre EN219 developing 60 bhp at 2200 rpm drove through an Albion single-plate hydraulically assisted clutch and Albion four-speed constant-mesh gearbox, with synchromesh 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 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

British Motor Corporation

The British Motor Corporation, or commonly known as BMC was a vehicle manufacturer from United Kingdom, formed by the merger of the Austin Motor Company and the Nuffield Organisation in 1952...

) 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 7 in 1 in (2,159 mm), rather than the MR9s 7 in 7 in (2,311.4 mm). The engine was the enlarged Albion EN250, a 4.1-litre unit developing 72 bhp 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 examples was by Alexanders, Harrington

Thomas Harrington Ltd

Thomas Harrington & Sons Ltd was a coachbuilder in the county of Sussex from 1897 until 1966, initially at Brighton but from 1930 until the end in a purpose built Art Deco factory at Old Shoreham Road, Hove.-Overview:The company began with the construction of horse-drawn carriages...

, Plaxton

Plaxton

Plaxton is a builder of bus and coach vehicle bodies based in Scarborough, England.-History:The Plaxton of today is the successor to a business founded in Scarborough in 1907 by Frederick William Plaxton.-Beginnings:...

, Reading, SOL, Strachans, Weymann and Willowbrook.

One major export market for the type was Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

 and one independent operator there stretched its examples to 27 ft (8.5m) before fitting them both with 39 seat bus bodies, although the greatest seating capacity for any Nimbus was a standard length 41-seat schoolbus for Dunbartonshire

Dunbartonshire

Dunbartonshire or the County of Dumbarton is a lieutenancy area and registration county in the west central Lowlands of Scotland lying to the north of the River Clyde. Until 1975 it was a county used as a primary unit of local government with its county town and administrative centre at the town...

 County Educatuion 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. 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

Buses Magazine

Buses is a United Kingdom magazine, focusing mainly on the UK bus scene.It was formerly known as Buses Illustrated until 1968 and is published by Ian Allan Publishing. The current editor is Alan Millar, based in Scotland. It also produces a yearbook, published in August every year for the next year...

's Scottish Columnist wondered why a firm who’s 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.
Nimbus production amounted to 124 MR9 and 217 NS3. The largest user was Western Welsh

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 and became part of the National Welsh Omnibus Services in 1969....

, who kept them to deeply rural routes. In contrast 471 Albion Aberdonian

Albion Aberdonian

The Albion Aberdonian was an underfloor-engined bus designed and built by Albion Motors between 1957 and 1960, it was introduced as a longer derivative of the Albion Nimbus....

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

Cornwall is a unitary authority and ceremonial county of England, within the United Kingdom. It is bordered to the north and west by the Celtic Sea, to the south by the English Channel, and to the east by the county of Devon, over the River Tamar. Cornwall has a population of , and covers an area of...

 operated an ex-Halifax bus from 1966 to 1986, 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 LHS6L chassis which was registered XBO1F and is now preserved with Thornes Independent of Selby, Yorks.

Derivatives

Bristol Commercial Vehicles

Bristol Commercial Vehicles

Bristol Commercial Vehicles was a vehicle manufacturer of in Bristol, England. Most production was of buses but trucks and railbus chassis were also built....

 built the SU model from 1960 to 1966, this featured the same EN250 engine and BMC axles as the Nimbus NS3AN with a David Brown

David Brown Ltd.

David Brown Engineering Limited is a British engineering company, principally engaged in the manufacture of gears and gearboxes. Their major gear manufacturing plant is in Swan Lane, Lockwood, Huddersfield, adjacent to Lockwood railway station...

 overdrive-top five-speed constant-mesh gearbox, all were bodied by Eastern Coach Works

Eastern Coach Works

Eastern Coach Works Ltd was a bus and railbus body building company based in Lowestoft, England.-History:The company can trace its roots back to 1912, when United Automobile Services was founded in the town to run bus services. United began a coach building business at the Lowestoft site in 1920...

, most to 25 ft (8m) length, seating 36 (buses) or 33 (coaches) although a shorter-wheelbase 30-seat model 23 ft (7 m) 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

Transport Holding Company

The Transport Holding Company 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 Commission ; it came into existence on 1 January...

 fleets. Southern and Western National

Western National

Western National was a bus operating company in South West England from 1929 to the 1990s.-Early history:Western National Omnibus Company Ltd started in 1929 as a joint venture between the Great Western Railway and the National Omnibus & Transport Company...

 had 97 (36 of which were coaches, out of 38 coaches built). Bristol Omnibus Company

Bristol Omnibus Company

The Bristol Omnibus Company is the former name of the dominant bus operator in Bristol, one of the oldest bus companies in the United Kingdom. The company once ran buses over a wide area of Gloucestershire, Somerset, Wiltshire and neighbouring counties. The name was in operational use until 1985...

 had nine short buses. West Yorkshire Road Car had 18 longer buses, United Automobile Services

United Automobile Services

United Automobile Services or United, as it was commonly known, was a major provider of bus services across the North East and North Yorkshire for 80 years or more...

 five, United Counties Omnibus Company had six and United Welsh Services had the other two coaches. At least three Bristol SU 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.

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
• http://www.classsicbusmag.co.uk
• http://aec.middx.net