The 40 class was one of the first mainline diesel locomotives to ply the rails of the New South Wales Government Railway system. Introduced on the 30th November 1951, the Montreal Locomotive Works in Canada built engines, were basically a slightly modified version of Alco’s RSC-3 Road Switcher series. With an Alco ‘V’ configuration 12 Cylinder 244 series diesel prime mover rated at 1650 traction horsepower, the engines were quite versatile.

Modifications for the Australian purchaser included a lower profile cab with the upper sides curved inward, buffers and mounting steps beside the buffers as opposed to on the sides of the locomotives. With an A1A-A1A power configuration to the wheels, the 40’s proved to be a bit slippery as the powered outer wheels would wear due to tractive forces, whereas the centre idler wheels in the trucks would maintain their full 40” diameter almost indefinitely. The resultant imbalance of wheel diameters in the six wheel trucks did not take to exerting maximum tractive force kindly.

Nonetheless, these were a versatile locomotive, but due to a manual ‘transition’ (read - gearbox!), the units were incapable of multiple unit operation with other classes of “automatic” transition locomotives. If used with other engine types, a crew was required on each locomotive, in effect creating a double header situation, ‘not’ a multiple unit consist.

The four position selector lever was the drivers floor shift, so to speak. At 19mph, the handle would be changed into the 2nd position, 2nd ‘gear’ propelling the locomotive to a speed of 27mph, where once again the driver would ‘change gear’ with the selector handle  selector position 3 would be good to 55mph where selector position four would then be chosen to take the locomotive to its maximum road speed allowed of 70mph. This would of course depend on load and track conditions as well as the type of service the locomotive was in at the time.

Goods trains of the time were typically limited to 35mph due to the 4 wheel rolling stock still in use, in these situations, the driver would have to use just 1 and 2 selector positions whereas the throttle settings would be set in notch eight to achieve maximum revs of 1000 and subsequent full traction horsepower.

I don’t recall a lot about working on these engines except for one extremely memorable trip on the main southern line one time. It could have been the Southern Highlands Express from Sydney to Goulburn on a Saturday, regular working for the 40 class, I do however remember that it was a single 40 class on one of these afternoon rushes south from Sydney.

All had been going well and we were running to time, although this could be a tough call for these engines. We were at Moss Vale and about to enter the last leg of the run to Goulburn. This section of the trip was a sprint of kinds, but there were a few intermediate stops to be made along the way.

Leaving Moss Vale was no drama and went as expected, transition up and get the ball rolling in readiness to tackle the stiff climb into the next station - Exeter.

Then all hell let loose, into the grade, the chant of the four cycle Alco suddenly changed to an explosive crescendo as a thick cloud of black smoke accompanied by white hot metallic fragments belched high into the cold early night air, alarm bells started to ring and then silence from the once roaring engine as the revs died down to a sickly idle, the crescendo from the bells deafening as they retorted there disgust at the V-12’s failure to function.

Quickly rolling to a halt on the steep grade, the driver set the brakes to stop the train from rolling back, we were just out of the platform and the station staff were watching in bewilderment. The 40 class turbo charger had let go in a big way, we weren't about to go anywhere in a hurry.

Communications were made with the station master and it was decided to pirate a 44 class off a goods train heading to Enfield that would be along shortly.

The 40 class finally got to double head with another Alco, but it didn’t contribute anything to the rest of the trip other than a dead weight of 100 plus tons of broken engine.

4001 resides at Thirlmere Railway Museum in Sydney as a cosmetic display, and two exist in the Pilbara’s, one converted to a Bo-Bo configuration, these latter engines are also non-operational.