Train Physics and Video




In this video we have a Canadian Pacific (CP) container train leaving the yard after a crew change. Note how he gradually increases the power. You can tell when he grabs each ‘notch’ (which means the slot on the control stand) as they get up to speed. I can hear the question: “Why didn’t he just give it full power and take off?” Well, here’s why:

The standard drawbar on a car is rated for 350-390k pounds of force, so if the engineer took off too hard, then he could exceed that and pull the train apart. That’s not good. If it’s a broken knuckle, that can be replaced fairly easily. If a drawbar is pulled, then that can require the car department to come fix it-and they could be in that yard or at another one several hours away. Either way, it’ll tie of the RR, get the Trainsmaster’s upset an truly anger the Dispatchers because it ruins the flow.