Trams have been used since the 19th century, and since then, there have been various uses and designs for trams around the world. This article covers the many design types, most notably the articulated, double-decker, drop-centre, low-floor, single ended, double-ended, rubber-tired, and tram-train; and the various uses of trams, both historical and current, most notably cargo trams, a dog car, hearse tram, maintenance trams, a mobile library service, a nursery tram, a restaurant tram, a tourist tram, and as mobile offices.
Passenger levels and floor height
Low-floor
From around the 1990s, light rail vehicles not made for the occasional high platform light rail system have usually been of partial or fully low-floor design, with the floor above top of rail, a capability not found in older vehicles. This allows them to load passengers, including those in wheelchairs or with perambulators directly from low-rise platforms that are not much more than raised footpaths/sidewalks. This satisfies requirements to provide access to disabled passengers without using expensive wheelchair lifts, while at the same time making boarding faster and easier for other passengers. Passengers appreciate the ease of boarding and alighting from low-floor trams and moving about inside one hundred per cent low-floor trams. Passenger satisfaction with low-floor trams is high. In some jurisdictions this has even been made mandatory since the 1990s, for example by Her Majesty's Railway Inspectorate in Britain and the Disability Discrimination Act in the United Kingdom and other Commonwealth countries.
Various companies have developed low-floor designs, varying from part-low-floor (with internal steps between the low-floor section and the high-floor sections over the bogies), e.g. Citytram and Siemens S70, to one hundred per cent low-floor, where the floor passes through a corridor between the drive wheels, thus maintaining a constant (stepless) level from end to end of the tram.
Prior to the introduction of the Škoda ForCity,, that carried the mechanical penalty of requiring bogies to be fixed and unable to pivot (except for less than 5 degrees in some trams) and thus reducing curve negotiation. This creates undue wear on the tracks and wheels.
Low-floor trams are now running in many cities around the world, including Adelaide, Amsterdam, Bratislava, Dublin, Gold Coast, Helsinki, Hiroshima, Houston, Istanbul, Melbourne, Milan, Prague, Sydney, Lviv, Warsaw and many others.
The Ultra-Low Floor or (ULF) tram is a type of low-floor tram operating in Vienna, Austria, as of 1997 and in Oradea, Romania, with the lowest floor-height of any such vehicle. In contrast to other low-floor trams, the floor in the interior of ULF is at sidewalk height (about 18 cm or 7 inches above the road surface), which makes access to trams easy for passengers in wheelchairs or with baby carriages. This configuration required a new undercarriage. The axles had to be replaced by a complicated electronic steering of the traction motors. Auxiliary devices are installed under the car's roof.
Most low-floor trams carry the mechanical penalty of requiring bogies to be fixed and unable to pivot. This creates undue wear on the tracks and wheels and reduces the speed at which a tram can drive through a curve. Some manufacturers such as Alstom deal with the issue by introducing partially high floor trams. Others, such as Škoda, developed pivoting bogies at the ends and with jacobs bogies between the articulations for the Škoda 15 T, but this solution proved expensive.
Double-decker
A double-decker tram is a tram that has two levels. Some double-decker trams have open tops. The earliest double-deck trams were horse drawn. The first electric double-deck trams were those built for the Blackpool Tramway in 1885, one of which survives at the National Tramway Museum.
Double decker trams were commonplace in Great Britain and Dublin in Ireland before most tramways were torn up in the 1950s and 1960s. New York City's New York Railways experimented in 1912 with a Brill double deck Hedley-Doyle stepless centre entrance car, nicknamed the "Broadway Battleship", a term that spread to other large streetcars. Hobart, Tasmania, Australia made extensive use of double decker trams. The most unusual double-decker tram used to run between the isolated Western Australian outback town of Leonora and the nearby settlement of Gwalia.
Double decker trams still operate in Alexandria, Blackpool, Hong Kong, Dubai and Oranjestad.
Drop-centre Many early 20th century trams used a lowered central section between the bogies (trucks). This made passenger access easier, reducing the number of steps required to reach the inside of the vehicle. These cars were frequently referred to as "drop-centres". It is believed that the design first originated in Christchurch, New Zealand, in 1906 when Boon & Co Ltd. built twenty-six such trams in three series. A number of these trams have been preserved. They were a favored design in Australia and New Zealand, with at least 780 such tramcars being built for use in Melbourne alone. Trams built since the 1970s have had conventional high or low floors.
Articulation
Articulated trams –like articulated buses– have increased passenger capacity. In practice, these trams can be up to long (such as CAF Urbos 3 in Budapest, Hungary), while a regular tram is much shorter. With this CAF design, the articulation is suspended between carbody sections; the wheelsets under the supporting carbodies have a very small pivoting capacity. This type is also used with the Alstom Citadis series, the Siemens Combino and several former types of Bombardier. Theoretically, trams may be up to long and carry 510 passengers at a comfortable ; at crush loadings this would be even higher.
An articulated tram may be low-floor variety or high-floor (regular) variety. In the Škoda ForCity, which is the world's first 100% low floor tram with pivoting bogies, a Jacobs bogie supports the articulation between the two or more carbody sections. The articulated Stadler TINA also features a 100% low floor tram with pivoting bogies, but without the use of Jacobs bogies.
History
The articulated tram was invented and first used by the Boston Elevated Railway in 1912–13 at a total length of about 18.8 meters long (61.7 ft), these trams were called "two rooms and a bath". Each pioneering example of the three-section articulated tram car, had two body sections with fixed wheelsets, connected by flexible joints and a suspended midsection.
Italian engineer Mario Urbinati designed one of the first trams with a Jacobs bogie, the first prototype was finished in 1938. The twin-section articulated tram car, was connected by flexible joints and a round pivoting platform. This so called "Urbinati carousel" paved the way for the articulated tram in Europe. Some of these trams from the 1940s are still in use in Rome.
Short-articulated tram
A short-articulated tram (German Kurzgelenkwagen) is a type of articulated tram. This tram type is carried on a single bogie in the center of each section. These car sections are directly linked by a pivoting joint (articulation) and enclosed by protective bellows inside and outside and a cover plate on the floor. The sections may be controlled by rods and/or hydraulics. Alternatively with low-floor trams, this type is also termed Einzelgelenkwagen; and sometimes directly translated into single-articulated tram. This term is the opposite of the multi-articulated tram.
The need to build large tramcars can be seen in the development from two-axle cars to four-axle cars with two bogies. These four-axle cars were mostly 13 m to 15 m long; longer bodies would limit the usability in curves. Bigger trams needed an articulation resulting in six-axle trams with a Jacobs bogie, and around the same time, three section two-rooms-and-a-bath cars appeared. The first –with their three pivoting bogies– were expensive to build; the latter –having only two fixed bogies– were uncomfortable and caused additional wear of the rails. To cope with these problems, the "short-articulated tram" was developed. The German word kurz (meaning "short") was applied because the inititial tramtypes were shorter than the six-axle cars. Over time, the "short-articulated tram" grew to about 20 m, almost the length of six-axle cars.
History An early attempt to link sections directly resulted in the RETM tram 501/502. This tram with four fixed axles only ran from 1924 to 1928. Due to its poor running characteristics, initially few models were replicated: a single test tram, such as the Ce160/162, was put on rails in Bern, Switzerland. In Munich four four-axle trams were coupled in pairs in 1936/37, resulting in two eight-axle trams.
Bremen Type
A prototype of this concept was built in Bremen in 1959. These following series were locally called GT4, chronologically supplemented by a letter from the alphabet: GT4a through GT4f. Series a, b, and c were built in the 1960s, while series d, e, and f were a further development and were built in the 1970s. These four-axle trams have better running characteristics than the pre-war articulated four-axle trams in other cities, because they are equipped with bogies instead of a fixed truck.
Progression In 1965, a set of two prototypes for the Munich tram was delivered. In the following years, series of trams were delivered (P2/3 motor cars and P2/3 trailers). The Czech tram type Tatra KT4 was also constructed according to this concept, and in total 1,767 were built. The first prototype (still having the body design of the Tatra T3) was tested in Prague in 1970. Two prototypes (with the final body design) were sent to Potsdam in December 1974.
Low-floor short-articulated tram The city of Bremen also had the first low-floor version (from AEG/ADtranz) in 1990, at the same time being the first fully low-floor tram. The prototype for Bremen had standard gauge bogies, it was the city of Augsburg to receive the first version with metre gauge bogies. Munich and many other (primarily German) cities followed in later years. As of 2025, this concept is still in use, although no longer by the original manufacturer, but by companies such as Siemens (Avenio), Solaris, Astra and CRRC.
Multi-articulated tram
Two-rooms-and-a-bath car (or multi-articulated tram) is a type of tram or streetcar with one or more suspended sections. The shortest examples consist of three sections; so called car bodies. The sections at the ends each have two axles or four wheels. The centre section is suspended between the end sections, spanning like a bridge. The centre section has no wheels and appears to be floating or suspended. Though experimental examples appeared late 19th century, this type only became popular in the 1960s in Europe and again in the late 1990s.
History
In 1892 a patent was registered by inventors Brewer and Krehbiel. The next year one streetcar was built for Cleveland. Only starting in 1912, a series was built for Boston.
The first city in Europe to use this type of tram was Gothenburg: ten were used in service from 1922. Other cities followed but with only one or two pieces: Oslo (1924), Dresden and Leipzig (both in 1928), Amsterdam and Milan (both in 1932). In Milan and later also in other Italian cities several series were put into service. Whereas in the United States the high floor version was only built before the Second World War, it became a success in Europe and mostly in Germany. One of the most successful models was the Gotha G4, named after its four axles, of which 319 units were built. The G4-61 followed the two-rooms-and-a-bath lay-out that was marketed in West-Germany by Credé. The production started in 1961; this tramtype is sometimes referred to as G4-61 and an updated version G4-65. Late 20th and early 21st century, the multi-articulated tram was the most popular low-floor tram globally.