How does a blizzard affect trains?

Here in the northeast along with cars & planes rail service is being suspended due to the weather.

How bad does a blizzard have to be to shutdown trains? And what exactly are the problems? How deep does snow have to be before it could actually stop or derail a 100+ ton diesel locomotive? And given the nature of tracked transport (combined with modern communications systems) how bad does visibility have to be before it becomes a hazard to operating a locomotive?

I don’t know that it’s so much the snow that stops train traffic, but the snow and ice disabling track switching mechanisms. Of course, if the snow gets deep enough, it could inhibit train movement, but the more immediate concern is whether other hardware is operating efficiently and unhampered.

Also, along the NE corridor, the trains are electric, not diesel, so they need to be able to maintain contact with either the overhead wires (called catenary) that carry the juice, or the trackside third rail that performs the same function. A buildup of snow and ice can make that a problem.

If its a British train then it hasn’t got a chance of running in blizzards. Even a leaf on the line will stop it… :rolleyes:

The UP passenger train City of San Francisco was stuck in the snow in Donner Pass over the Sierra Nevada range for 4 days in 1953 or thereabouts.

So what did they feed the passengers those four days?


There was a History Channel program on it (Wrath of God or something along that line), and it reruns now and then.

I remember the incident reasonably well. They cut the passengers down to short rations and made do with what the train had for a couple of days. Then they managed to get the highway through the pass cleared and used snow cats to bring in supplies. As I remember, they finally cleared the tracks close enough to bring up a relief train and walked the passengers to it to finish the trip to Oakland.

This wasn’t only falling snow as I recall. I think there might also have been a small avalanch that buried the tracks several feet deep. In some of the cuts on the rail line at the time the snow could drift in 10 ft., or thereabouts, deep and they weren’t all protected by snow sheds.


Visiblilty is another factor. It’s critical that the engineer can see the signal lights to know when to slow down or stop, lest he ass-end a train in front of him.

Are these snow cats feline American versions of a St. Bernard with a bottle of brandy tied to their necks? Because that would be really funny.

Primarily, it affects traction. The engineer can dump sand to assist, but that has limited use.

As said, snow and ice can jam switching mechanisms, annd can also affect the electrical circuit a train needs to close across the rails to activate signals and level/grade crossings etc.

Also, as snow is water, it’s a similar situation to a flood, and an electric locomotive (diesel-electric too) can only handle water a few inches over the rails without stalling or suffering damage. A steam locomotive can generally travel through water up to the level of the footplate.

Several pics here