Gullfisk tram
Encyclopedia
Class B and Class E, normally referred to as Gullfisk (Norwegian
for "goldfish"), were a class of 46 tram
s built by Strømmens Værksted
and Skabo Jernbanevognfabrikk
for Oslo Sporveier
and Bærumsbanen
of Oslo
, Norway, in 1937 and 1939. They were the first aluminum trams to operate on the Oslo Tramway and the first bogie
trams to operate on street lines. They had contemporary modern electronic equipment, a streamlined
shape, and comfortable accommodation. Till 1964, they were also faster than any other Norwegian tramcar or suburban railcar.
Six prototype trams were delivered by Strømmen in 1937, with four different motor solutions, from AEG
, Siemens
, Vickers
and Norsk Elektrisk & Brown Boveri
(NEBB). None of these were particularly successful, and the 40 serial production trams used conventional motors from ELIN. These were delivered in 1939, with 20 (class E) being used by Oslo Sporveier mainly on the Kjelsås Line
, but also on other services. The remaining 20 trams (class B) were leased to Bærumsbanen, that used them on the Kolsås and Østensjø Lines, and later on the Ekeberg Line
.
From 1967, Oslo Sporveier transferred all its trams to Bærumsbanen, where they remained in use until 1985. The class has been involved in several fatal incidents, including the Strømsveien tram fire
in 1958. Six trams (prototype no 163, nos 166, 170, 196 and 199) remain at the Oslo Tramway Museum
; whilst Oslo Sporveier has kept two and converted them to maintenance vehicles (nos 185 and 198), painted them yellow with zebra stripes. They also kept one themselves as a veteran tram (no 183).
, so the tramway could operate 2.5 metres (8.2 ft) wide and 15 metres (49.2 ft) long trams.
The use of an aluminum body was controversial, and international experts recommended that the tram company should not chose that solution. The goal was to decrease the weight so the trams could operate with less powerful motors, giving a lower cost. The first prototype was a full-scale model of a tram, built at Homansbyen Depot in 1935, using an undercarriage from disused horsecar
s.
railcars, streamline construction would afford a power reduction of 17% at as low speed as 32 km/h (19.9 mph).
Shortly after being taken into use, no. 158 lost braking power, killing one person when it landed on the sidewalk. The initial plan was to use the six trams to operate all services on the Kjelsås Line, with one vehicle in reserve, but this was not possible because of more out-of-service vehicles than estimated.
A further 40 units were ordered—20 from Strømmens Værksted and 20 license-built by Skabo Jernbanevognfabrikk
. The various experimental configurations fitted to the prototype trams did not work too well; and instead a conventional motor solution was chosen. The serial units were also not equipped with regenerative brake
s. The series from Strømmen and Skabo received the same motors and bogies, but the electrical equipment was different. The Skabo series had electrical equipment from AEG and was optimized for street-tram operation, while the Strømmen trams were optimized for the suburban tramways and equipped with electrical equipment from Vickers. The Strømmen series was delivered from February to June 1939 and leased to Oslo Sporveier's subsidiary Bærumsbanen, that gave them the designation Class B. They were put into service on the Østensjø–Kolsås Line, with both end stations far outside Oslo's city limits that time. The trams partially ran through a relatively rural landscape, and more than any other Norwegian tramway this line may be called an interurban. The Oslo Sporveier trams were numbered 164–183, while the Bærumsbanen trams were numbered 184–203. The tram's body was streamlined and had a tail at the end that made them look like a goldfish. They were therefore nicknamed "Gullfisk", the Norwegian term for goldfish; this later became the most common term for the class.
, the rationing of petroleum fuels gave a boom to the riderships on the electric tramways. To handle the massive increase in ridership, the trams were equipped with two conductors
. The single center-door solution that worked excellently before the war, became a bottle-neck as the trams became packed with riders. Lack of parts, particularly for the British Vickers-motors, caused long waits for defect vehicles at the depots. From 1942, the Kolsås Line was transferred to terminate at Nationaltheatret
in the city center, and the Class B was operated along the Lilleaker Line from the west. Trams 164–166 were sent to Düsseldorf
in Germany, but were never used because the city lacked balloon loop
s and the trams were too wide.
After the end of the war, Oslo Sporveier decided to transfer all the remaining trams to Bærumsbanen. Their high speed made them well suited on the light rail, but the center door reduced their capacity. The order of the SM53
-series from Høka
gave Oslo Sporveier sufficient stock to operate the street lines, and from 1952 to 1957, the company transferred the 19 trams to Bærumsbanen. Here, they were given the designation Class E. No. 163 was in too bad condition to be used on the line, and was retired. In October 1949, no. 184 burned up and was taken out of service. On 2 August 1958, five people perished and 17 were injured in the Strømsveien tram fire
, the worst disaster in the tramway's history.
The Østensjø Line became part of the Oslo Metro in 1967, and several of the Class E trams were transferred to other parts of the tramway. However, the Lilleaker Line was instead tied to the Ekeberg Line on the east side of the city, and the trams started operating on the Jar
–Ljabru
service. After the last bus route had been converted to single-man operation and the conductor replaced with a ticket-selling motorman
, Oslo Sporveier started the process to convert their tram fleet. No. 176 was converted as a trial, and after 1971, all the remaining Gullfisks were converted. Because the trams had been delivered with a single front door, the cost of converting the trams was very little, and the single-manning highly profitable.
In 1976, no. 1976 was retired after it had lost braking power and crashed. After this, only selected trams were given overhauls, the last being no. 170 in 1980. Following the delivery of the articulated SL79
, the Class B and E were gradually retired, with the last tram running into 1985. Oslo Tramway Museum
has kept six trams, while Oslo Sporveier kept two, converted them to maintenance vehicles and painted them yellow with zebra stripes.
.
The trams were unidirectional and had a single door at the front and a double door in the middle, both on the right side. Class E also had a single door at the back. The trams were originally delivered with two apartments, with a wall and inside door in front of the center door. This was removed after the trams became smoke-free. They had a partial wooden interior, with linoleum floors. Various renovations changed the paneling, usually variations of brown and yellow. The trams originally had incandescent light bulbs, but these were replaced with fluorescent lamp
s after 1955. From 1970 to 1974, the trams were rebuilt to remove the conductor, and the driver was given place for a purse and ticket machine, as well as an announcement system. The E-series eventually had the back door taken out of use and blocked with an extra seat.
All but one of the trams had a SV36-bogie
from Strømmens Værksted. The two bogies, each with two axle
s, were attached to the steel crossbeam. The aluminum body was attached to the crossbeam with leaf spring
s. The bogie frames were fastened to the axle box via a revolute joint
and a spiral spring
. Each bogie had two motors, each controlling one axle. In 1941, no. 187 was equipped with a SV41-bogie from Strømmen; it had a different spring system that allowed the tram to remain at the same height independent of the weight.
Class E was equipped with disc brake
s, while the Class B was equipped with drum brake
s. All the trams were equipped with rail brakes, and dynamic brakes. The serial production models were equipped with four 36.6 kW ELIN BBFa20 motors. This gave a maximum speed of 65 km/h (40.4 mph). They were built with two serial motors connected in parallel to the two other serial motors, so each motor used 300 V.
s. The trams had sixteen regulating notches and were very complicated to operate. The technology had previously been used in Birmingham
, but there the tram company had discontinued them quickly because of their complexity. This complicated set-up was part of the reason for the fatal accident in Sannergata in 1937. The regenerative brakes were removed in the late 1940s. The two trams' motors were prone to technical failures, and spent the much time in the workshop. They weighed 12.87 tonnes (12.7 LT).
No. 160 was equipped with four 33.5 kW Siemens DW331e motors. The motor controller and electrical equipment was run by a battery that was charged by the overhead wire. The motorman regulated the motor controller that again magnetized the motors. The tram was also equipped with regenerative brakes. Particularly the battery charging system had a lot of defects, and the tram needed a lot of repairs. Eventually the controller and regenerative brakes were removed. It weighed 13.16 tonnes (13 LT).
No. 161 and 162 were equipped with four 33 kW AEG USL2039 motors. They had a conventional design and regenerative brakes, although the latter was eventually removed. They had many technical difficulties, and held Bærumsbanen's record in maintenance time. They weighed 13.57 tonnes (13.4 LT).
No. 163 was equipped with two 50 kW NEBB GLM1303 motors, one on each bogie that powered both axles. This caused problems because the monomotor
required the wheels to be grinded regularly to avoid uneven driving, but this was not discovered until 1941. It weighed 13.44 tonnes (13.2 LT).
Norwegian language
Norwegian is a North Germanic language spoken primarily in Norway, where it is the official language. Together with Swedish and Danish, Norwegian forms a continuum of more or less mutually intelligible local and regional variants .These Scandinavian languages together with the Faroese language...
for "goldfish"), were a class of 46 tram
Tram
A tram is a passenger rail vehicle which runs on tracks along public urban streets and also sometimes on separate rights of way. It may also run between cities and/or towns , and/or partially grade separated even in the cities...
s built by Strømmens Værksted
Strømmens Værksted
Strømmens Værksted A/S was an industrial company based in Skedsmo, Norway, specializing in the production of rolling stock. Founded in 1873, it remains as a part of Bombardier Transportation...
and Skabo Jernbanevognfabrikk
Skabo Jernbanevognfabrikk
Skabo Jernbanevognfabrikk was a mechanical workshop focusing on design and construction of railcars. It was established by Hans Skabo in Drammen, Norway in 1864; it became the first rail car factory in the country when it took delivery of the cars for Kongsvingerbanen...
for Oslo Sporveier
Oslo Sporveier
Kollektivtransportproduksjon AS is a municipal owned public transport operator of Oslo, Norway, the name meaning simply "public transportation producer". It operates the trackage and maintains the stock of the Oslo Metro and Oslo Tramway, as well as owning eight operating subsidiaries...
and Bærumsbanen
Bærumsbanen
A/S Bærumsbanen was a tram company that operated the Lillaker-, Kolsås and Østensjø Line of the Oslo Tramway, Norway, from 1924 to 1971 when the company became part of Oslo Sporveier.-History:...
of Oslo
Oslo
Oslo is a municipality, as well as the capital and most populous city in Norway. As a municipality , it was established on 1 January 1838. Founded around 1048 by King Harald III of Norway, the city was largely destroyed by fire in 1624. The city was moved under the reign of Denmark–Norway's King...
, Norway, in 1937 and 1939. They were the first aluminum trams to operate on the Oslo Tramway and the first bogie
Bogie
A bogie is a wheeled wagon or trolley. In mechanics terms, a bogie is a chassis or framework carrying wheels, attached to a vehicle. It can be fixed in place, as on a cargo truck, mounted on a swivel, as on a railway carriage/car or locomotive, or sprung as in the suspension of a caterpillar...
trams to operate on street lines. They had contemporary modern electronic equipment, a streamlined
Streamliner
A streamliner is a vehicle incorporating streamlining in a shape providing reduced air resistance. The term is applied to high-speed railway trainsets of the 1930s to 1950s, and to their successor "bullet trains". Less commonly, the term is applied to fully faired recumbent bicycles...
shape, and comfortable accommodation. Till 1964, they were also faster than any other Norwegian tramcar or suburban railcar.
Six prototype trams were delivered by Strømmen in 1937, with four different motor solutions, from AEG
AEG
Allgemeine Elektricitäts-Gesellschaft was a German producer of electrical equipment founded in 1883 by Emil Rathenau....
, Siemens
Siemens AG
Siemens AG is a German multinational conglomerate company headquartered in Munich, Germany. It is the largest Europe-based electronics and electrical engineering company....
, Vickers
Vickers
Vickers was a famous name in British engineering that existed through many companies from 1828 until 1999.-Early history:Vickers was formed in Sheffield as a steel foundry by the miller Edward Vickers and his father-in-law George Naylor in 1828. Naylor was a partner in the foundry Naylor &...
and Norsk Elektrisk & Brown Boveri
Norsk Elektrisk & Brown Boveri
Norsk Elektrisk & Brown Boveri A/S also known as NEBB was a Norwegian manufacturing company, which built a large amount of the rolling stock that is used by Norges Statsbaner. The plant was located at Skøyen. In 1988 it merged into Asea Brown Boveri ....
(NEBB). None of these were particularly successful, and the 40 serial production trams used conventional motors from ELIN. These were delivered in 1939, with 20 (class E) being used by Oslo Sporveier mainly on the Kjelsås Line
Kjelsås Line
The Kjelsås Line is a tramway line running from Storo to Kjelsås in the norther part of Oslo, Norway. The line opened by Oslo Sporveier on 25 September 1934 as an extension of the Grünerløkka–Torshov Line that terminated at Storo. It is served by line 11 and 12 of the Oslo Tramway operated by Oslo...
, but also on other services. The remaining 20 trams (class B) were leased to Bærumsbanen, that used them on the Kolsås and Østensjø Lines, and later on the Ekeberg Line
Ekeberg Line
The Ekeberg Line is a long light rail line of the Oslo Tramway which runs from Gamlebyen to Ljabru in Oslo, Norway. Operated by lines 18 and 19, it serves the area of Nordstarand and the neighborhoods of Ekeberg, Jomfrubråten, Bekkelaget and Ljan. The line is operated by Oslo Sporvognsdrift using...
.
From 1967, Oslo Sporveier transferred all its trams to Bærumsbanen, where they remained in use until 1985. The class has been involved in several fatal incidents, including the Strømsveien tram fire
Strømsveien tram fire
The Strømsveien tram fire was a fire erupting in an Oslo Tramway car in the street Strømsveien in Oslo, Norway.On 2 August 1958, a set of two cars of the Gullfisk type was trafficking the Lilleaker-Østensjø Line, en route from Bøler to Jar. This connection was opened in 1937, and the Gullfisk cars...
in 1958. Six trams (prototype no 163, nos 166, 170, 196 and 199) remain at the Oslo Tramway Museum
Oslo Tramway Museum
Oslo Tramway Museum with 450 members. The museum also operates a heritage tramway in Vinterbro outside Oslo.LTF was founded in 1966, six years after the city council had decided to close down the tramway and trolleybus. This followed the closing of the Bergen Tramway, where only a single tram had...
; whilst Oslo Sporveier has kept two and converted them to maintenance vehicles (nos 185 and 198), painted them yellow with zebra stripes. They also kept one themselves as a veteran tram (no 183).
Background
During the 1930s, Oslo Sporveier operated a fleet of 150 trams and 130 trailers. The latest series, the HaWa Class, had been delivered during the early 1920s and were, by the late 1930s, becoming old fashioned, with low speed, uncomfortable interiors and a two-axle wheel arrangement. Increased competition from cars and buses made the tram company start a process to find a new "generation" of trams and buses. In 1935, an agreement was made with Stømmmens Værksted to build a series of aluminum bogied trams and buses. Since the last order, the tracks had been relaid farther from one anotherLoading gauge
A loading gauge defines the maximum height and width for railway vehicles and their loads to ensure safe passage through bridges, tunnels and other structures...
, so the tramway could operate 2.5 metres (8.2 ft) wide and 15 metres (49.2 ft) long trams.
The use of an aluminum body was controversial, and international experts recommended that the tram company should not chose that solution. The goal was to decrease the weight so the trams could operate with less powerful motors, giving a lower cost. The first prototype was a full-scale model of a tram, built at Homansbyen Depot in 1935, using an undercarriage from disused horsecar
Horsecar
A horsecar or horse-drawn tram is an animal-powered streetcar or tram.These early forms of public transport developed out of industrial haulage routes that had long been in existence, and from the omnibus routes that first ran on public streets in the 1820s, using the newly improved iron or steel...
s.
Construction
Strømmens Værksted delivered six prototypes for Oslo Sporveier in 1937, all with slightly different specifications. They were numbered 158–163. The four main types of prototypes were lated designated B2 (158–159 with motors from Vickers), E4 (160 with motors from Siemens), E3 (161–162 with motors from AEG) and E2 (163 with motors from NEBB). The trams were taken into use in February 1937 on the Kjelsås Line. They were capable of 65 km/h (40.4 mph), compared to the maximum 35 km/h (21.7 mph) possible by the older trams. According to tests by J. G. Brill Co., which was a specialist on high-speed interurbanInterurban
An interurban, also called a radial railway in parts of Canada, is a type of electric passenger railroad; in short a hybrid between tram and train. Interurbans enjoyed widespread popularity in the first three decades of the twentieth century in North America. Until the early 1920s, most roads were...
railcars, streamline construction would afford a power reduction of 17% at as low speed as 32 km/h (19.9 mph).
Shortly after being taken into use, no. 158 lost braking power, killing one person when it landed on the sidewalk. The initial plan was to use the six trams to operate all services on the Kjelsås Line, with one vehicle in reserve, but this was not possible because of more out-of-service vehicles than estimated.
A further 40 units were ordered—20 from Strømmens Værksted and 20 license-built by Skabo Jernbanevognfabrikk
Skabo Jernbanevognfabrikk
Skabo Jernbanevognfabrikk was a mechanical workshop focusing on design and construction of railcars. It was established by Hans Skabo in Drammen, Norway in 1864; it became the first rail car factory in the country when it took delivery of the cars for Kongsvingerbanen...
. The various experimental configurations fitted to the prototype trams did not work too well; and instead a conventional motor solution was chosen. The serial units were also not equipped with regenerative brake
Regenerative brake
A regenerative brake is an energy recovery mechanism which slows a vehicle or object down by converting its kinetic energy into another form, which can be either used immediately or stored until needed...
s. The series from Strømmen and Skabo received the same motors and bogies, but the electrical equipment was different. The Skabo series had electrical equipment from AEG and was optimized for street-tram operation, while the Strømmen trams were optimized for the suburban tramways and equipped with electrical equipment from Vickers. The Strømmen series was delivered from February to June 1939 and leased to Oslo Sporveier's subsidiary Bærumsbanen, that gave them the designation Class B. They were put into service on the Østensjø–Kolsås Line, with both end stations far outside Oslo's city limits that time. The trams partially ran through a relatively rural landscape, and more than any other Norwegian tramway this line may be called an interurban. The Oslo Sporveier trams were numbered 164–183, while the Bærumsbanen trams were numbered 184–203. The tram's body was streamlined and had a tail at the end that made them look like a goldfish. They were therefore nicknamed "Gullfisk", the Norwegian term for goldfish; this later became the most common term for the class.
Operation
During World War IIWorld War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
, the rationing of petroleum fuels gave a boom to the riderships on the electric tramways. To handle the massive increase in ridership, the trams were equipped with two conductors
Conductor (transportation)
A conductor is a member of a railway train's crew that is responsible for operational and safety duties that do not involve the actual operation of the train. The title of conductor is most associated with railway operations in North America, but the role of conductor is common to railways...
. The single center-door solution that worked excellently before the war, became a bottle-neck as the trams became packed with riders. Lack of parts, particularly for the British Vickers-motors, caused long waits for defect vehicles at the depots. From 1942, the Kolsås Line was transferred to terminate at Nationaltheatret
Nationaltheatret (station)
Nationaltheatret is an underground metro station and tram stop serving Vika and the city center of Oslo, Norway. It is located on the Common Tunnel of the Oslo Metro and on the Briskeby Line of the Oslo Tramway. Also located at the same place is Nationaltheatret Station of the Drammen Line. The...
in the city center, and the Class B was operated along the Lilleaker Line from the west. Trams 164–166 were sent to Düsseldorf
Düsseldorf
Düsseldorf is the capital city of the German state of North Rhine-Westphalia and centre of the Rhine-Ruhr metropolitan region.Düsseldorf is an important international business and financial centre and renowned for its fashion and trade fairs. Located centrally within the European Megalopolis, the...
in Germany, but were never used because the city lacked balloon loop
Balloon loop
A balloon loop or turning loop allows a rail vehicle or train to reverse direction without having to shunt or even stop. Balloon loops can be useful for passenger trains and unit freight trains, such as coal trains....
s and the trams were too wide.
After the end of the war, Oslo Sporveier decided to transfer all the remaining trams to Bærumsbanen. Their high speed made them well suited on the light rail, but the center door reduced their capacity. The order of the SM53
SM53
The SM53, also called Høka trams after the manufacturer Hønefoss karosserifabrikk, were a tram model which operated for more than 40 years on the Oslo Tramway. A number of these trams were later rebuilt and became known as SM83 trams....
-series from Høka
Høka
Hønefoss Jernbanevogn- og Karosserifabrikk A/S, trading as Høka and at first known as Hønefoss Karosserifabrikk A/S, was a manufacturer of bodywork for buses, trucks and trains. The company was in existence from 1936 to 1968 and was based in Hønefoss, Norway...
gave Oslo Sporveier sufficient stock to operate the street lines, and from 1952 to 1957, the company transferred the 19 trams to Bærumsbanen. Here, they were given the designation Class E. No. 163 was in too bad condition to be used on the line, and was retired. In October 1949, no. 184 burned up and was taken out of service. On 2 August 1958, five people perished and 17 were injured in the Strømsveien tram fire
Strømsveien tram fire
The Strømsveien tram fire was a fire erupting in an Oslo Tramway car in the street Strømsveien in Oslo, Norway.On 2 August 1958, a set of two cars of the Gullfisk type was trafficking the Lilleaker-Østensjø Line, en route from Bøler to Jar. This connection was opened in 1937, and the Gullfisk cars...
, the worst disaster in the tramway's history.
The Østensjø Line became part of the Oslo Metro in 1967, and several of the Class E trams were transferred to other parts of the tramway. However, the Lilleaker Line was instead tied to the Ekeberg Line on the east side of the city, and the trams started operating on the Jar
Jar (station)
-External links:*...
–Ljabru
Ljabru (station)
Ljabru is a light rail station on the Oslo Tramway.Located at Ljabru in Nordstrand, it is the current terminus of the Ekeberg Line. It was opened on 17 September 1941 as an extension of that line from Sæter. Until 1967, the stretch between Sæter and Ljabru was the only single track rail in Oslo. A...
service. After the last bus route had been converted to single-man operation and the conductor replaced with a ticket-selling motorman
Motorman
A motorman is the person who operates an electrified trolley car, tram, light rail, or rapid transit train.The term refers to the person who is in charge of the motor in the same sense as a railroad engineer is in charge of the engine. The term was gender-neutral...
, Oslo Sporveier started the process to convert their tram fleet. No. 176 was converted as a trial, and after 1971, all the remaining Gullfisks were converted. Because the trams had been delivered with a single front door, the cost of converting the trams was very little, and the single-manning highly profitable.
In 1976, no. 1976 was retired after it had lost braking power and crashed. After this, only selected trams were given overhauls, the last being no. 170 in 1980. Following the delivery of the articulated SL79
SL79
SL79 is a class of 40 articulated trams operated by the Oslo Tramway of Norway. The trams were a variation of the Duewag trams that had been developed by the German manufacturer since the 1950s. The six-axle vehicles are unidirectional with four doors on the right side. The trams can seat 77...
, the Class B and E were gradually retired, with the last tram running into 1985. Oslo Tramway Museum
Oslo Tramway Museum
Oslo Tramway Museum with 450 members. The museum also operates a heritage tramway in Vinterbro outside Oslo.LTF was founded in 1966, six years after the city council had decided to close down the tramway and trolleybus. This followed the closing of the Bergen Tramway, where only a single tram had...
has kept six trams, while Oslo Sporveier kept two, converted them to maintenance vehicles and painted them yellow with zebra stripes.
Specifications
The Gullfisk were built as self-contained aluminum riveted bodies. This gave a light body that was strong as steel, giving what at the time was regarded as a more elastic structure which would not break as easy. However, this resulted in the bodies sinking somewhat at the ends and between the bogies. It also caused more deformation during accidents, increasing the costs of repairs. The bodies were 15.4 metre long and 2.5 metre wide. The center beam between the two bogies was made of steel, and was intended to compensate for the soft aluminum structure; these were prone to rust and needed repeated replacement. The bodies had a very streamlined shape and a distinct tail, that in addition to the aesthetic purpose was chosen because it strengthened the structure. During prototyping, the vehicle was tested in a wind tunnelWind tunnel
A wind tunnel is a research tool used in aerodynamic research to study the effects of air moving past solid objects.-Theory of operation:Wind tunnels were first proposed as a means of studying vehicles in free flight...
.
The trams were unidirectional and had a single door at the front and a double door in the middle, both on the right side. Class E also had a single door at the back. The trams were originally delivered with two apartments, with a wall and inside door in front of the center door. This was removed after the trams became smoke-free. They had a partial wooden interior, with linoleum floors. Various renovations changed the paneling, usually variations of brown and yellow. The trams originally had incandescent light bulbs, but these were replaced with fluorescent lamp
Fluorescent lamp
A fluorescent lamp or fluorescent tube is a gas-discharge lamp that uses electricity to excite mercury vapor. The excited mercury atoms produce short-wave ultraviolet light that then causes a phosphor to fluoresce, producing visible light. A fluorescent lamp converts electrical power into useful...
s after 1955. From 1970 to 1974, the trams were rebuilt to remove the conductor, and the driver was given place for a purse and ticket machine, as well as an announcement system. The E-series eventually had the back door taken out of use and blocked with an extra seat.
All but one of the trams had a SV36-bogie
Bogie
A bogie is a wheeled wagon or trolley. In mechanics terms, a bogie is a chassis or framework carrying wheels, attached to a vehicle. It can be fixed in place, as on a cargo truck, mounted on a swivel, as on a railway carriage/car or locomotive, or sprung as in the suspension of a caterpillar...
from Strømmens Værksted. The two bogies, each with two axle
Axle
An axle is a central shaft for a rotating wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels, rotating with them, or fixed to its surroundings, with the wheels rotating around the axle. In the former case, bearings or bushings are provided at the mounting points where the axle...
s, were attached to the steel crossbeam. The aluminum body was attached to the crossbeam with leaf spring
Leaf spring
Originally called laminated or carriage spring, a leaf spring is a simple form of spring, commonly used for the suspension in wheeled vehicles...
s. The bogie frames were fastened to the axle box via a revolute joint
Revolute joint
A revolute joint is a one degree of freedom kinematic pair used in mechanisms. Revolute joints provide single-axis rotation function used in many places such as door hinges, folding mechanisms, and other uni-axial rotation devices. -See also:* Cylindrical joint* Kinematics* Degrees of freedom *...
and a spiral spring
Spring (device)
A spring is an elastic object used to store mechanical energy. Springs are usually made out of spring steel. Small springs can be wound from pre-hardened stock, while larger ones are made from annealed steel and hardened after fabrication...
. Each bogie had two motors, each controlling one axle. In 1941, no. 187 was equipped with a SV41-bogie from Strømmen; it had a different spring system that allowed the tram to remain at the same height independent of the weight.
Class E was equipped with disc brake
Disc brake
The disc brake or disk brake is a device for slowing or stopping the rotation of a wheel while it is in motion.A brake disc is usually made of cast iron, but may in some cases be made of composites such as reinforced carbon–carbon or ceramic matrix composites. This is connected to the wheel and/or...
s, while the Class B was equipped with drum brake
Drum brake
A drum brake is a brake in which the friction is caused by a set of shoes or pads that press against a rotating drum-shaped part called a brake drum....
s. All the trams were equipped with rail brakes, and dynamic brakes. The serial production models were equipped with four 36.6 kW ELIN BBFa20 motors. This gave a maximum speed of 65 km/h (40.4 mph). They were built with two serial motors connected in parallel to the two other serial motors, so each motor used 300 V.
Prototypes
No. 158 and 159 were equipped with four 36.5 kW Vickers 116E motors. This was a compound motor with regenerative brakeRegenerative brake
A regenerative brake is an energy recovery mechanism which slows a vehicle or object down by converting its kinetic energy into another form, which can be either used immediately or stored until needed...
s. The trams had sixteen regulating notches and were very complicated to operate. The technology had previously been used in Birmingham
Birmingham
Birmingham is a city and metropolitan borough in the West Midlands of England. It is the most populous British city outside the capital London, with a population of 1,036,900 , and lies at the heart of the West Midlands conurbation, the second most populous urban area in the United Kingdom with a...
, but there the tram company had discontinued them quickly because of their complexity. This complicated set-up was part of the reason for the fatal accident in Sannergata in 1937. The regenerative brakes were removed in the late 1940s. The two trams' motors were prone to technical failures, and spent the much time in the workshop. They weighed 12.87 tonnes (12.7 LT).
No. 160 was equipped with four 33.5 kW Siemens DW331e motors. The motor controller and electrical equipment was run by a battery that was charged by the overhead wire. The motorman regulated the motor controller that again magnetized the motors. The tram was also equipped with regenerative brakes. Particularly the battery charging system had a lot of defects, and the tram needed a lot of repairs. Eventually the controller and regenerative brakes were removed. It weighed 13.16 tonnes (13 LT).
No. 161 and 162 were equipped with four 33 kW AEG USL2039 motors. They had a conventional design and regenerative brakes, although the latter was eventually removed. They had many technical difficulties, and held Bærumsbanen's record in maintenance time. They weighed 13.57 tonnes (13.4 LT).
No. 163 was equipped with two 50 kW NEBB GLM1303 motors, one on each bogie that powered both axles. This caused problems because the monomotor
Monomotor
A monomotor is a train design where a single motor powers two axles in the same bogie.Conventional bogie design involves either having one motor for each axle, or having one or more axles unpowered. The design causes the motor to give both axles the same number of rounds per minute. When both...
required the wheels to be grinded regularly to avoid uneven driving, but this was not discovered until 1941. It weighed 13.44 tonnes (13.2 LT).