Operated by lines 13 and 19, it serves the area of Nordstrand and the neighborhoods of Ekeberg, Jomfrubråten, Bekkelaget and Ljan.

[3] It runs up Ekeberg on the east side of Kongsveien,[2] passing Sjømannsskolen at 59.5 meters (195 ft) above mean sea level (AMSL) and 0.8 kilometers (0.50 mi) from Oslo Hospital.

The next station is Jomfrubråten, which is located 2.0 kilometers (1.2 mi) from Oslo Hospital and at 115.0 meters (377 ft 4 in) AMSL.

[2] The next station is Sørli, which is located 4.0 kilometers (2.5 mi) from Oslo Hospital and at 111.7 meters (366 ft) AMSL, followed by Kastellet located 4.4 kilometers (2.7 mi) from Oslo Hospital and at 112.0 meters (367 ft 5 in) AMSL.

The line continues past Bråten, located 4.9 kilometers (3.0 mi) from Oslo Hospital and at 117.6 meters (386 ft) AMSL and past Sæter, located 5.6 kilometers (3.5 mi) from Oslo Hospital and at 116.0 meters (380 ft 7 in) AMSL.

[6] Ljabru is the terminus and is located 7.6 kilometers (4.7 mi) from Oslo Hospital and at 100.0 meters (328 ft 1 in) AMSL.

Line 13 run alternate departures along the full route to Bekkestua where the lack of a balloon loop mandates the use of SL95 trams, and shortened services to Lilleaker where the SL79 can be turned.

In 1897, a public meeting was held regarding transport in the upper parts of Nordstand, the Ekeberg area.

On 15 March 1899, Solicitor Einar Borgen, Engineer A. J. Jackwitz and Robert Iversen sent an application to build an electric railway from Oslo to Ljan.

It was again considered a year later, this time it was placed on hold because the politicians wanted to see how the new Railway Act would affect the plans.

[8] A new application for the same route was made on 16 April 1907, this time from Solicitor H. M. Helliesen, Wholesaler A. Thune-Larsen, and Works Manager T. Poppe of Kristiania Sporveisselskab (KSS), the company which operated one the city tramways.

[9] On 5 June 1914, permission was granted where the concession was transferred from Thune-Larsen and Helliesen to the company Ekebergbanen, which was founded on 27 March 1914.

They had pointed ends to ease meeting the shorter trams in the city, and had a low-floor center section, with internal steps.

[11] However, because of World War I and problems receiving supplies from Germany, it was not until November that all five trams were delivered and a 15-minute headway could be introduced.

[12] In 1919, the company ordered seven new trams from Skabo, with electric equipment from Norsk Elektrisk & Brown Boveri (NEBB).

In addition, six trailers were built from Hannoversche Waggonfabrik (HaWA) The delivery of new rolling stock required a new depot building at Holtet, two new electric arc transformers and a ticket price increase.

[16] In 1925, the Østfold Line was rebuilt to double track, and the section past Hauketo was moved, including the demolishing of the Ljan Viaduct.

In June 1926, Aker Municipality started the process to demand that the line be extended onwards from Sæter.

The company instead applied for concession to extend the line 5 kilometres (3.1 mi) southwards towards Hvervenbukta on Ljanskollen's west side.

In exchange for not being allowed to extend the line, Aker Municipality agreed to not press the issue of their preferred extension for the time being.

[16] At the time, Akersbanerne was working on building the Lambertseter Line, which is located further east in Aker.

In March 1948, Oslo Sporveier, the municipal company that operated among other things the street tramways, offered to purchase Ekebergbanen.

[22] The use of a unique voltage gave operational difficulties, as fuses could regularly blow at Oslo Hospital if errors were made while switching from the one supply to the other.

Oslo Sporveier took over all employees and rolling stock, but Ekebergbanen remained a holding and real estate company.

Traffic had decreased on the Ekeberg Line, but proponents for keeping it stated that this was because Oslo Sporveier had reduced the frequency and moved the end station out of the core of the city center.

Therefore, locals suggested that the trams continue along the track from Jernbanetorget to Skøyen, on the west side of town.

Oslo Sporveier calculated it would cost NOK 3.6 million for investments, including rebuilding 20 Gullfisk trams, new rectifiers and new tracks.

Ordinary service with Gullfisk trams from Ljabru to Jar on the Lilleaker Line started on 29 September.

[38] From 1988 to 1991, the section of the Gamleby Line along Schweigaards gate was rebuilt to light rail standard in its own right-of-way.

The extension will allow better correspondence southwards, including transfer to the Oslo Commuter Rail and Ruter buses.