Notes from Northern Ontario
Early this February I rode the head end on the CP line between Winnipeg and Thunder Bay. From Winnipeg I took number 2, the eastbound Canadian as far as Ignace. This is double track in good condition and the two A units and the GP9 could easily maintain the schedule. There was a light snow blowing and. I was surprised at how, when we hit the occasional drift, did it not only come right over the front of the A unit but also how the cab filled with fine snow - even though the windows were closed.
At Ignace a crew had been called to follow number 2 to Thunder Bay and so I transferred to the cab of 5639 the lead unit of train 956. The two units had a light train of 65 cars, some 4500 tons and after making the brake test we were very quickly running at the 60 mph maximum for freight trains. The cab of this new unit was warm and comfortable and it was quite an impressive sight to look back on our train rapidly snaking through the Northern Ontario woods and raising its own miniature snow storm.
We proceeded uneventfully to Baith, 53 miles from Thunder Bay. It was here that we encountered some grades, not difficult because of their strain on the locomotive but in how they test the skill of the engineer in controlling his train. The first downgrade occurs just after Raith and the engineer eased his train down this one with the dynamic brake. The trick is to gradually bunch up the train before applying the brake hard - otherwise the guys in the van get a rough ride. The dynamic brake was sufficient to hold the train on this grade and as we approached the dip at the bottom it was gradually eased off. The engineer has to be careful how he does this because if it releases too quickly the momentum of the heavy locomotives will cause them to surge forward and this could break a knuckle. The independent brake has a much finer control than the dynamic and this was used for the final transition from braking to running free.
As we reached the bottom of the grade the throttle was advanced into the first position and was gradually advanced to notch 4 by the time the van was at the bottom of the grade. We felt a slight tug, indicating that the van was also on the grade.
"Its now safe to open her up" said the engineer and did. so. We remained intact.
The next downgrade was a little steeper and the dynamic brake wouldn't hold our speed down so we used as well a seven pound train brake application. This held speed nicely to 45 mph and the procedure was repeated as we reached the bottom of this dip.
The approach to Thunder Bay has a further wrinkle in the form of a piece of level track in the middle of a down grade. This causes its own problems and many trains have pulled apart almost within a stone's throw of their destination.
It is evident that the engineer handling a fast heavy freight has to be a very skilled artist. He must know intimately not only the territory (grades, curves, etc.) but also must have an intimate knowledge of his train. The size and characteristics of the train are very important, A block of new cars will respond far more quickly to braking action than will older cars and can set up stresses within the train. Different techniques have to be used on longer trains - the train brake would be used on the down grades but with the throttle open to keep the train stretched out,
I saw .a very strong reminder of train dynamics problems - a boxcar lying upside down at the side of the track. A train was traversing a crossover at 5 mph. The slack ran out with such force that the empty boxcar was "popped" over on to its roof.
Bytown Railway Society,, Branchline, April 1977