Class M4

Class M4 Specifications:

Locomotive Class: M4

Manufactured Country: Canada

Manufactured Company: Montreal Locomotive Works

Imported Year: 1975

Type of Locomotive: Diesel Electric

Prime Mover: ALCO Bombardier V12 251-C3 4-Stroke

Maximum Power: 1750hp (Originally 2000hp)

Maximum Speed: 65mph

Axel Arrangement: Co-Co

Weight: 97 Tons

Colour: Light blue, Dark blue, Silver & a Yellow colour strip

No. of Locomotives Imported: 14

Locomotive Numbers: 743-756

These locomotive class is also a successful & efficient locomotive like the M2. The most important fact is all imported M4 locos are still in service. Mostly these locomotives are used to haul express trains and the trains which need high power. For an example “Udaya Devi” train from Colombo to Batticaloa uses a M4.

Like the M2s, the M4s too have unique names as follows. These are named after the names of special places in Sri Lanka like Rivers, Waterfalls, Reservoirs etc.

Locomotive Number	Name
743	Madhu
744	Sigiri
745	Ruwanweli
746	Namunukula
747	Kelani
748	Walawe
749	Dunhinda
750	Isurumuni
751	Diyaluma
752	Point Pedro
753	Samanala
754	Menik
755	Mahawali
756	Lakshapana

These locomotives were specially imported to run on up country railways. In the early days of these giants they had run up to Badulla. But these locomotives had to face several problems of running on up country tracks. To run on the upcountry tracks, the Bogie Wheel Base length (The distance between the front & the rear axles in a wheel set) should be less than 10feets & 7inches. But the Bogie Wheel Base length of M4 was 11feets & 2inches. Therefore when they run on up country lines, the rail road got seriously damaged due to the widening of rails. As a solution to this officers decided to increase the width of the rail road by 0.75inches. But this decision was not practical because if they do so the other locomotives like W1 could occur difficulties in running.  Another opinion is after the M5 locomotives arrived Sri Lanka, the up country journeys of M4s have ended because M5s were more successful.  So now these giants normally don’t run beyond Polgahawela on main line. But they are able to run up to Kandy & Nawalapitiya on the main line without any trouble. At present these locomotives run on almost on every line except on Kelani Valley & Matale lines.

These are able to run over 100kmph. Even though the original power of M4 was 2000hp, it has reduced to 1750 to prevent unwanted wearing. Countries like Canada, Africa, Tanzania, Iraq & Bangladesh uses these MLW type locomotives other than Sri Lanka.

Locomotives No.753, 754, 755 & 756 has added Dynamic Brakes. Class M4 752 “Point Pedro” was painted in the ICE (Inter-City Express) colour scheme around 1984. Another important fact is that Montreal Locomotive Works had closed entirely around year 2000.

Credits to Gehan Chandika & Nipuna Dodanthenna

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