Sri Lanka Railways M4
The Sri Lanka Railways M4 is a class of diesel-electric locomotive manufactured in Canada by Montreal Locomotive Works. Fourteen of the manufacturers' model MX-620 were imported in 1975.
This was the longest locomotive in the Sri Lanka Railways previously. All units are still operational. On regular operation they are rarely used beyond Polgahawela on the main line, and are not used beyond Nawalapitiya. They used to travel on the full main line regularly until the previous decade.
They are painted in a livery of dark blue, light blue, silver with yellow striping; although No. 752 Point Pedro was painted in a special ICE livery.
Fleet
| Number | Name | Notes |
| 743 | Madhu | Air Brakes Added |
| 744 | Sigiri | Air Brakes Added |
| 745 | Ruwanweli | Air Brakes Added |
| 746 | Namunukula | Air Brakes Added |
| 747 | Kelani | Air Brakes Added |
| 748 | Walawe | Air Brakes Added |
| 749 | Dunhinda | Air Brakes Added |
| 750 | Isurumuni | Air Brakes Added |
| 751 | Diyaluma | Air Brakes Added |
| 752 | Point Pedro | Special ICE livery was on this locomotive. Now normal livery. |
| 753 | Samanala | Imported with Dyn Brakes. Air Brakes Added |
| 754 | Menik | Imported with Dyn Brakes. Air Brakes Added |
| 755 | Mahaweli | Imported with Dyn Brakes. Air Brakes Added |
| 756 | Laxapana | Imported with Dyn Brakes. Air Brakes Added |