Kristiania Elektriske Sporvei
A/S Kristiania Elektriske Sporvei or KES, nicknamed the Blue Tram (Norwegian: Blåtrikken), is a defunct operator of parts of the Oslo Tramway, Norway. It opened the first electric tramway in Scandinavia in 1894, and remained in service until 1924 when it was merged into the municipal owned Oslo Sporveier.
Tram transport in Oslo (at the time called Kristiania) started in 1875 with horsecar services provided by Kristiania Sporveisselskab (KSS). Economically this was an inferior operating method, and Christiania (later Kristiania) Elektriske Sporvei was founded to establish an electric tram service. The initiative came from H. E. Heyerdahl, A. Fenger-Krog and L. Samson and KSS immediately attempted to buy the company, but the purchase failed, and on 2 March 1894 the first line, from the Eastern Railway Station (Østbanen) via Briskeby to Majorstuen was established, along with a branch line to Skillebekk (today part of the Skøyen Line). At first a shuttle service was provided on the branch line, but by April a through service was offered to Østbanen. The Skillebekk Line was extended on 31 December 1894 to Nobels Gate, to Thune in 1901 and to Skøyen on 21 June 1903.
The last street line was opened in 1902 from Østbanen to Frogner Plass—known as the Frogner Line. It was extended to Majorstuen, where the depot was located, on 15 May 1914, along with a line from Frogner Plass to Skarpsno on the Skøyen Line. From 1909 the company introduced numbered services, and had the following lines:
The company bought 78 cars and 66 trailers; 20 of the cars were later rebuilt to trailers. The main manufacturers were Herbrand, Falkenried and Skabo, delivering a continual stream of stock to the company until 1914, after which only ten units were delivered. The second delivered unit, number 102, has been preserved and can be found at the Norwegian Museum of Science and Technology.
From 1912 a number of connections were built between the KES and KSS networks, and the two companies started cooperating on certain lines. On 9 May 1919 the company extended the Skøyen Line to Lilleaker as a suburban tramway, now called the Lilleaker Line. In 1924 the concession of both the street tram companies expired, and they were taken over by the municipal owned Oslo Sporveier. The section from Skøyen to Lilleaker was not located in Oslo, but in Aker, and the municipality was not interested in operating it. Instead the ownership was transferred to the company Bærumsbanen, with the same owners as KES.