| Class S | |
|---|---|
 KKS Class S tram no. 208 in Karl Johans gate in 1900 | |
 Interior in 1960 | |
| Manufacturer | Schuckert & Co. Busch |
| Constructed | 1899 |
| Number built | 20 motor cars 12 trailers |
| Capacity | 20 seated, 14–20 standing |
| Operators | Kristiania Kommunale Sporveie (1899–1905) Kristiania Sporveisselskab (1905–24) Oslo Sporveier (1924–67) |
| Specifications | |
| Car length | 7.8 m (25 ft 7 in) |
| Width | 2.0 m (6 ft 7 in) |
| Weight | 9.3 t (motor car) 6.4 t (trailer) |
| Traction system | 2× Schuckert AB71 |
| Power output | 51 kW (68 hp) |
| Electric system(s) | 600 V DC Overhead wire |
| Current collector(s) | Trolley pole / Bow collector / Pantograph |
| Track gauge | 1,435 mm (4 ft 8+1⁄2 in) |
Class S (Norwegian: type S) was a class of 20 twin-axle trams and 12 trailers built by Schuckert & Co. and Busch for Kristiania Kommunale Sporveie (KSS) in 1899. The trams were originally 7.8 meters (25 ft 7 in) long and 2.0 meters (6 ft 7 in) wide. They featured wooden benches in the longitudinal direction seating twenty. The motor cars had two motors providing a combined power output of 51 kilowatts (68 hp). The motor cars weighed 9.3 tonnes (9.2 long tons; 10.3 short tons), while the trailers weighed 6.4 tonnes (6.3 long tons; 7.1 short tons).
Ownership of the class moved to Kristiania Sporveisselskab (KSS) in 1904, when it bought KKS. The trams were variously rebuilt from 1918. One was converted to a snow plow, while three motor cars and three trailers were converted to cargo trams for hauling grain. The remaining units were rebuilt and lengthened in 1919 and 1920. The wheelbase was extended from 1.8 to 3.0 metres (5 ft 11 in to 9 ft 10 in) and the platform bays covered. A further rebuilding took place between 1921 and 1925, when they received new motors and undercarriages from Siemens Schuckertwerke. They passed on to Oslo Sporveier when it took over KSS in 1924. There the trams remained in service until 1967.