A bus (also known as a trailer bus) is a trailer vehicle designed specifically for the transportation of passengers (a bus). Trailer buses typically comprise one of two forms:
*a
semi-trailer
A semi-trailer is a trailer (vehicle), trailer without a front axle. The combination of a semi-trailer and a tractor truck is called a ''semi-trailer truck'' (also known simply as a "semi-trailer", "tractor trailer", or "semi" in the United Sta ...
pulled by a
tractor unit
A tractor unit, also known as a truck unit, lorry unit, power unit, prime mover, ten-wheeler, semi-tractor, semi-truck, semi-lorry, tractor cab, truck cab, lorry cab, big rig tractor, big rig truck or big rig lorry or simply a tractor, truck, ...
(in the same way as a
semi-trailer truck
A semi-trailer truck (also known by a wide variety of other terms – see below) is the combination of a tractor unit and one or more semi-trailers to carry freight. A semi-trailer attaches to the tractor with a type of hitch called ...
). The tractor unit may either be a purpose-built unit designed specifically for operation with the trailer bus, or a regular conventional tractor unit.
*a full trailer pulled by a conventional bus, typically to provide extra capacity. Also referred to as a 'bus trailer'.
Although semi-trailer buses are now typically obsolete and have been retired, full trailer buses attached to conventional buses remain in use in limited applications around the world, including as tourist vehicles.
History
In 1922 a 65-seater passenger trailer bus went into service for the Department of Parks and Boulevard of
Detroit
Detroit ( , ) is the List of municipalities in Michigan, most populous city in the U.S. state of Michigan. It is situated on the bank of the Detroit River across from Windsor, Ontario. It had a population of 639,111 at the 2020 United State ...
, which was developed by
Fruehauf Trailer Corporation
Fruehauf Trailer Corporation, previously Fruehauf Trailer Company (1918–1963) and Fruehauf Corporation (1963–1989), was an American company engaged in the manufacture and sale of truck Semi-trailer, trailers, and other machinery and equipment ...
, also from Detroit. The bus was 29 ft long, made up of steel chassis and cabin built of natural
oak
An oak is a hardwood tree or shrub in the genus ''Quercus'' of the beech family. They have spirally arranged leaves, often with lobed edges, and a nut called an acorn, borne within a cup. The genus is widely distributed in the Northern Hemisp ...
with
tram
A tram (also known as a streetcar or trolley in Canada and the United States) is an urban rail transit in which Rolling stock, vehicles, whether individual railcars or multiple-unit trains, run on tramway tracks on urban public streets; some ...
like interior. For comfort the trailer had leaf spring suspension, air vents and four doors for easy access, the doors were interconnected with brakes and were controlled via the tractor unit hauling the trailer. The tractor was a six wheeled
Packard
Packard (formerly the Packard Motor Car Company) was an American luxury automobile company located in Detroit, Michigan. The first Packard automobiles were produced in 1899, and the last Packards were built in South Bend, Indiana, in 1958.
One ...
tractor unit which was coupled with the trailer via a fifth wheel, making the turning radius as small as 39ft.
An early trailer bus was designed in
Amsterdam
Amsterdam ( , ; ; ) is the capital of the Netherlands, capital and Municipalities of the Netherlands, largest city of the Kingdom of the Netherlands. It has a population of 933,680 in June 2024 within the city proper, 1,457,018 in the City Re ...
in the 1920s as bus designs got longer. As a solution to possible grounding hazards on humped bridges, three prototypes were built in 1924, but proved to be problematic, and later converted to rigid bodies in 1927.
In 1930 Nairn Transport Company which ran 550 miles of transport services from
Damascus
Damascus ( , ; ) is the capital and List of largest cities in the Levant region by population, largest city of Syria. It is the oldest capital in the world and, according to some, the fourth Holiest sites in Islam, holiest city in Islam. Kno ...
to
Baghdad
Baghdad ( or ; , ) is the capital and List of largest cities of Iraq, largest city of Iraq, located along the Tigris in the central part of the country. With a population exceeding 7 million, it ranks among the List of largest cities in the A ...
experimented with a trailer bus which was hauled by a
Buick
Buick () is a division (business), division of the Automotive industry in the United States, American automobile manufacturer General Motors (GM). Started by automotive pioneer David Dunbar Buick in 1899, it was among the first American automobil ...
Roadster which had a very successful run motivated by this the company later built a customized double-decker trailer bus in 1934 which had carry capacity of 40 passengers divided in first class and normal class. The bus also had reclining seats, an onboard kitchen and a luggage capacity of approximately 700kgs. The trailer was hauled by a Marion-Herrington6x6 tractor powered by a 188hp Hercules engine, which helped it cover the route in 24 hours. At that time, it was the longest bus ever made with a length of 80ft and weighed 26 tons, making it one of the first successful trailer buses.
During
World War II
World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...
and in the immediate post-war years, trailer buses were turned to as a simple and economical way of providing bus transport to replace worn out conventional bus fleets. The semi-trailers were basic and uncomfortable, but each could carry more passengers than an ordinary single-decker bus, and nearly as many as a
double-decker bus
A double-decker bus is a bus that has two storeys or decks. Double-deckers are used primarily for commuter transport, but open-top models are used as sightseeing buses for tourists, and there are coaches too for long-distance travel. They app ...
. In India
BEST
Best or The Best may refer to:
People
* Best (surname), people with the surname Best
* Best (footballer, born 1968), retired Portuguese footballer
Companies and organizations
* Best & Co., an 1879–1971 clothing chain
* Best Lock Corporatio ...
of
Mumbai
Mumbai ( ; ), also known as Bombay ( ; its official name until 1995), is the capital city of the Indian state of Maharashtra. Mumbai is the financial capital and the most populous city proper of India with an estimated population of 12 ...
Bangalore
Bengaluru, also known as Bangalore (List of renamed places in India#Karnataka, its official name until 1 November 2014), is the Capital city, capital and largest city of the southern States and union territories of India, Indian state of Kar ...
had double-decker trailer buses in its fleet during the 1970s and 1980s.
In Australia, 123 semi-trailer type buses were built from 1939. Large purchasers included Parramatta-Ryde Bus Service and Rover Coaches. A 1947 semi-trailer coupled with an American-built 1943
White
White is the lightest color and is achromatic (having no chroma). It is the color of objects such as snow, chalk, and milk, and is the opposite of black. White objects fully (or almost fully) reflect and scatter all the visible wa ...
Sydney
Sydney is the capital city of the States and territories of Australia, state of New South Wales and the List of cities in Australia by population, most populous city in Australia. Located on Australia's east coast, the metropolis surrounds Syd ...
. The Sydney exhibit was the last trailer bus used in NSW, withdrawn in 1977.
Trailer buses were also used in
Perth
Perth () is the list of Australian capital cities, capital city of Western Australia. It is the list of cities in Australia by population, fourth-most-populous city in Australia, with a population of over 2.3 million within Greater Perth . The ...
, Western Australia by several private bus companies from 1943 onwards, including Metro Buses (formerly Metropolitan Omnibus), Pioneer Omnibus and Scarborough Bus Services. The units were bodied by various companies, including Boltons, Campbell & Mannix and Motor Body Builders, a subsidiary of Scarborough Bus Services. From 1958 onwards, many trailer buses passed to the state-owned Metropolitan Transport Trust as the private operators were bought by the Western Australian Government. A number were also purchased by the
Western Australian Government Railways
Western Australian Government Railways (WAGR) was the state owned operator of railways in the state of Western Australia between October 1890 and June 2003. Owned by the state government, it was renamed a number of times to reflect extra respon ...
from 1945 to 1948, with the trailer bodies built by Fowler Constructions and Campbell & Mannix.
In 1948, ten British-built trailer buses saw service as staff canteens for London Transport (in country green livery) with one passing to the Cobham Bus Museum in 1972.
A large order for 1,175 buses from the Dutch Railways for buses from Crossley included an order for 250 trailer buses, each to carry 52 seated and 28 standing passengers. The tractor units were delivered as short Crossley DD42s, and these were matched in the Netherlands with DAF built trailer chassis fitted with bus bodies.
From 1967 to 1968 the
India
India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...
n city of
Mumbai
Mumbai ( ; ), also known as Bombay ( ; its official name until 1995), is the capital city of the Indian state of Maharashtra. Mumbai is the financial capital and the most populous city proper of India with an estimated population of 12 ...
had double-decker trailer buses with seating capacity of 100 passengers, run by
Brihanmumbai Electric Supply and Transport
The Brihanmumbai Electricity Supply and Transport Undertaking (BEST) is an Indian civic transport and electricity provider public body based in Mumbai, Maharashtra. It was originally set up in 1873 as a tramway company called Bombay Tramway Com ...
company. The city of
Kolkata
Kolkata, also known as Calcutta ( its official name until 2001), is the capital and largest city of the Indian state of West Bengal. It lies on the eastern bank of the Hooghly River, west of the border with Bangladesh. It is the primary ...
and
Bengaluru
Bengaluru, also known as Bangalore (List of renamed places in India#Karnataka, its official name until 1 November 2014), is the Capital city, capital and largest city of the southern States and union territories of India, Indian state of Kar ...
also had such buses.
In the late 1980s, a Mexican-built trailer bus was in test service in the
Los Angeles
Los Angeles, often referred to by its initials L.A., is the List of municipalities in California, most populous city in the U.S. state of California, and the commercial, Financial District, Los Angeles, financial, and Culture of Los Angeles, ...
Niagara Falls, Ontario
Niagara Falls is a city in Ontario, Canada, adjacent to, and named after, Niagara Falls. As of the Canada 2021 Census, 2021 census, the city had a population of 94,415. The city is located on the Niagara Peninsula along the western bank of the ...
.
In Greece trailer buses are still often used for tours, usually in small villages. Trailer buses are also used in some kids' attractions.>
Obsolescence
As early as the mid-1940s, trailer buses began to quickly fall out of favor for a variety of factors:
*The length of trailer buses made them difficult to negotiate sharp turns at narrow street corners;
*Each trailer bus normally required a two-person crew, with the driver in the tractor and the conductor in the semi-trailer;
*The perceived danger of a passenger-laden semi-trailer dislodging from its tractor while under way has led to many jurisdictions in the United States, Canada and Australia restricting or prohibiting trailer buses.
Trailer buses saw service until at least 1984 in South Africa, possibly due to the rugged terrain in its remote areas, and the availability of specialist bus builders as opposed to truck dealers and basic body builders.
Trailer buses are still in service in Cuba, where they were introduced under the nickname of "camellos" ("camels", from the twin-humped shape of the trailers) during the
Special Period
The Special Period (), officially the Special Period in the Time of Peace (), was an extended period of economic crisis in Cuba that began in 1991 primarily due to the dissolution of the Soviet Union and the Comecon. The economic depression o ...
after the fall of the Soviet Union. , the trailer buses were being gradually retired from service in
Havana
Havana (; ) is the capital and largest city of Cuba. The heart of La Habana Province, Havana is the country's main port and commercial center.Munich transit authority ordered a batch of trailer buses from Solaris with deliveries starting in 2013. The buses were intended for service on the city's busiest routes. The advantages of such buses were the ability to attach or detach the trailer depending on demand, spaciousness and flexibility.
Munich is experimenting with “bus trains” on heavily used routes as it electrifies its bus fleet. One design by MVG has solar panels on the roof and the trailer is made by Göppel. The interest is how much of the demand for electricity for interior systems can be supplied by the solar panels. Some are conversions of buses in their fleet.