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For the chocolate bar, see Double Decker
A double-decker is a bus, aeroplane, train, tram, ferry or any public transit vehicle that has two levels for passengers, one deck above the other. The term can also refer to a sandwich with three layers of bread and two fillings.
Bus
Double-decker buses are taller than other buses. They are extensively used in the United Kingdom, where perhaps the most famous was the London Routemaster, removed from normal service in December 2005 - they still operate on heritage routes. Elsewhere in Europe, double-deckers are used throughout the Dublin Bus network and some Bus Éireann routes in Ireland, where they are making a comeback on Dublin's outer suburban routes (e.g. Dublin-Navan) and also the streets of Cork, Limerick, Galway and Waterford. They are a common sight in Berlin, where the BVG makes extensive use of them. Double-decker long-distance coaches are also in widespread use throughout Europe.
Most buses in Hong Kong and about half in Singapore are double-deckers as well. The only areas in North America that use double-decker buses for public transport are the western Canadian province of British Columbia and the United States city of Las Vegas. The city of Davis, California, in the United States uses vintage double-decker buses for public transport run by Unitrans. Unitrans is affiliated with the University of California, Davis, and has run these buses since 1968. Davis, California is also home to the first vintage double-decker bus converted from diesel gasoline to run on CNG. The city of Victoria, BC, the city of Vancouver, British Columbia, and a couple of others use Dennis Tridents. A few are also used as tour buses, especially in New York. Double-deckers are have also been used in Mumbai since 1937.
In Brazil, where buses are sometimes the only interstate transport, some companies use double-decker buses, like those that Viação Cometa uses in the route between Campinas and Rio de Janeiro. Double-deckers are not a good option for use outside rodovias (most roads in Brazil are in very poor condition), and their use is being discouraged by transportation authorities.
Double-decker buses are in widespread use in India in many of the major cities. Most of the buses are local derivatives of either Roadmaster or Leyland.
Some double-decker buses have an open upper deck, with no roof and shallow sides. These are popular for sightseeing tours.
Airplane
Many early seaplane airliners, such as the Boeing 314 Clipper and Short Sandringham, had two decks for passengers. Following World War II, a double-decked derivative of the B-29 Superfortress called the Stratocruiser became popular with airlines around the world.
For years the only double-deck airliner in service was the Boeing 747, though the top deck is smaller than the main level. The new Airbus A380, however, has two decks extending the full length of the airplane.
Train
Main article: Bilevel car
Because of the standard height of tunnels and overhead power wires, many double-deck trains set the bottom deck lower down, between the trucks (bogies in UK and Australasian parlance). Usually the entrance doors are above the bogies, and there is only one deck at the entance area. From there one can go upstairs or downstairs. For example, for the DD-IRM (see below) it is one step up from the station platform to the entrance, and from there seven steps up or four steps down. Some double-decker trains have their entrance doors on the lower level and no steps are needed to get to the lower deck.
France runs double-deck cars on heavily loaded high-speed TGV services and commuter lines such as the Paris suburban RER. The French loading gauge dictates that the double-deck cars have a maximum height of 4200 mm or 13'-9.35".
Other double-deck cars do not have a full upper deck but have a gallery on each side, each with a row of single seats. An example is the bilevel cars provided and leased in the U.S. by Midwest Transportation & Development Corporation of Chicago. They are of a design proven in service and steadily refined since their introduction in the 1950s. These cars, known as "bilevel gallery cars", are among the most successful designs developed, and are currently in daily use in Chicago, San Francisco, and Montreal (Agence métropolitaine de transport). They provide high capacity (155 to 169 passengers each) and use standard, off-the-shelf components, without relying on proprietary, expensive and hard-to-get replacement parts. Chicago's commuter rail system Metra is currently receiving new versions of these cars and Caltrain, the San Francisco area commuter rail authority, has recently overhauled its fleet.
Another advantage of bilevel gallery cars is the relatively low first step of the vestibule entrance to the car, which is 14 5/8" (371 mm) above the head of the rail. The advantage of this is that commuter rail operators do not have to spend scarce funds on building high-level platforms; a low-level platform is all that is necessary, at a far lower cost.
Other designs, including rolling stock made by Colorado Railcar Manufacturing, Budd, Pullman-Standard, Bombardier (Toronto (GO Transit)) and others, have the entrance on the lower deck rather than an intermediate level. Amtrak Superliners are double-decker cars of this variety, with the entrance a step or so up from the lowest station platform level, or at the level of slightly higher platforms, and allow passage from car to car at upper-deck level.
In countries such as the United Kingdom, the railway system cannot accommodate double-deck trains. A modest attempt at double decking was made in 1948 on the Southern Railway with the two trains of the Bulleid 4DD class. Although innovative, with stepped compartments, where the bottoms of the upper seats are above the heads of the people on the lower level, but the feet of the people above are not, see the loading gauge severely restricted their use and they were removed from service in 1971. The north eastern US can accommodate split level (double deck) cars only if they are no higher than 14'-6" or 4420 mm. These double deckers run on the Long Island Rail Road: New Jersey Transit: *:" target="_blank" >(contact Bombardier Transportation: [http://www.bombardier.com/index.jsp) because the loading gauge is too small (i.e. bridges, tunnels, etc. are too low).
Double-deck trains often have curved windows upstairs. In the dark and in tunnels this causes a distorting mirror effect.
In Finland, VR started operating double-decker sleeping cars on February 1, 2006. The two-bed cabins on the upper deck have toilets and showers while cabins on the lower deck use shared ones. VR also operates double-decker Inter City trains with at-seat power supplies for laptops.
Indian Railways operates intercity trains between Mumbai and Surat, and Mumbai and Pune .
In the Netherlands, there are two types of double-deck trains, the DDM and the DD-IRM, also called Regiorunner: see Trains in the Netherlands.
In Spain several lines of Cercanías (Renfe's commuter rail service) use double-deck trains.
All electric commuter trains in Sydney are double deck. They all have two doors per side per carriage, with a vestibule at each end at platform height. Well-known examples of these trains are the Tangara and Millennium trains. The Sydney double deck commuter trains are 14'-4.5" or 4380 mm high.
In intermodal freight transport, many modern types of container well cars cars are designed to accommodate "double-stacking."
See also
Cable Car (Aerial Tramway)
Main article: Aerial tramway
The double-deck Vanoise Express cable car carries 200 people in each cabin at a height of 380 m (1250') over the Ponturin gorge in France.
Tram
Main article double decker tram
There are also double-deck trams. Hong Kong Tramways is the only tram company that operates double-deck trams exclusively.
Double deckers also operate in Blackpool and Alexandria. Until the 1950s double-deck trams were common in the United Kingdom. Some can still be seen at the National Tramway Museum.
From 1910 to 1964, double-decker trams were in use in Mumbai.
Bridge
The term double-decker is also used for bridges, such as the San Francisco-Oakland Bay Bridge, with two road levels. Tsing Ma Bridge and Kap Shui Mun Bridge in Hong Kong have six lanes on their upper decks and on their lower decks, there are two lanes and a pair of tracks for MTR metro trains.
Tunnel
Some tunnels are double-deck, for example the Eastern Harbour Crossing in Hong Kong, where roads and rails (the MTR metro) occupy different decks of the tunnel.
The first double-decked tunnel with both decks for motor vehicles is the Fuxing Road Tunnel in Shanghai, China. Cars travel on the two-lane upper deck and heavier vehicles on the single-lane lower.
Double decker trailer
A double-decker trailer is a two-level trailer with living quarters in it. When travelling the trailer is only as high as a regular trailer, but when set up it increases in height to two full levels. Built by Jexcar and others, and used in motion picture production as portable dressing rooms.
See also
Elevator
A double-deck elevator is an elevator with two elevator cars on top of each other. This increases passenger capacity while occupying less building core space.
Food-related meanings
Double Decker is a brand of chocolate bar from Cadbury UK.
See also
External links
- Double Decker Bus & Tours
- British Columbia Transit
- Jexcar
- List of railroad car manufacturers by country (in French)
Doppelstockwagen | Duplex | Dubbeldekstrein | 2階建車両 | Dobbeltdekker (kjøretøy) | Dubbeldäckare
"Double decker"