SM53

SM53
SM53 in Holtegata on the Briskeby Line in 1971
Interior of an original trailer, with the conductor's seat to the left
In service1952–2000
ManufacturerHøka
Hägglund
Family nameMustang
Constructed1952–58
Refurbished1985–91 (SM83)
Number built58
Number scrapped42
Fleet numbers204–253
Capacity116
OperatorsOslo Sporveier
Lines servedOslo Tramway
Specifications
Car body constructionSteel
Car length14,700 mm (48 ft 2+34 in)
Width2,500 mm (8 ft 2+716 in)
Doors3
Maximum speed60 km/h (37 mph)
Weight16.9 t (16.6 long tons; 18.6 short tons)
Prime mover(s)Hägglund MBL 10
Power output180 kW (240 hp)
Electric system(s)600 V DC overhead line
Track gauge1,435 mm (4 ft 8+12 in) standard gauge

SM53, originally designed MBO and colloquially known as Høka, were a class of 58 trams and 50 trailers built by Høka and Hägglund for Oslo Sporveier. The units were used on the Norway's Oslo Tramway from 1952 until 2000. The 14.7-meter (48 ft 2+34 in) long and 2.5-meter (8 ft 2+716 in) wide trams weighed 16.9 tonnes (16.6 long tons; 18.6 short tons). They had four motors providing a combined power output of 180 kilowatts (240 hp), allowing for a top speed of 60 kilometers per hour (37 mph).

The first series of thirty trams in 1950, with delivery in 1952 and 1953. These were designated MBO50. The next order was for new bodies for used Class SS units. The eight motor units were designated MO and nicknamed Chickens, while the twelve trailers were designated TO. These twin-axle units proved unsuccessful and Oslo Sporveier therefore took deliver of more MBO units. The next batch of twelve MBO55 units were delivered in 1957 and the final batch of eight were designated MBO56 and delivered in 1958. These were built for use on the Lambertseter Line, but were found unsuitable for use on light rail service and later moved back to the streets. From 1985 to 1991 eleven units were rebuilt with new cabs, interior and fronts, and designated SM83. Retirement of the class started in 1980 with Chickens. The series were gradually replaced, with the last SM53 units being taken out of service in 1997. The last SM83 were taken out of use in 2000.