Class S12 is a diesel multiple-unit (DMU), built for Sri Lanka Railways by China’s CSR Corporation. The first batch arrived in Sri Lanka in August 2012. They were built to replace locomotive-hauled passenger trains. Seven of the S12 DMUs were ordered to strengthen long-distance travel on theMain line from Colombo to Badulla. Four of S12s will serve the Kelani Valley Line. The remaining two designed as luxury trains.
| Engine Class | S12 |
| Built Country | China |
| Builder | China South Locomotive and Rolling Stock Corporation (CSR) |
| Imported Year | 2012 |
| Power Type | Diesel Electric |
| Engine Type | MTU V12 4000R41 |
| Power Output | 1950hp (1450kW) – 1800RPM |
| Maximum Speed | 100 km/h – Derated to 80 km/h |
| Axel Arrangement | Bo-Bo |
| Weight | 76 T |
| Livery | Blue |
| Total Imported | 13 Power Sets 917-939 |
Update in – progress
