White hope

Snow and trains are not a good combination. Rail users everywhere are used to shivering on platforms when the weather turns bad, waiting for the train to negotiate the slippery rails and frozen points. For railway engineers, coming up with new ways to keep trains running when the winter closes in is a complex problem — and it’s one where increasingly high-powered simulation software is now being brought to bear.

The problems that snow present go far beyond slippery rails. In regions with low temperatures and high snowfalls the loose, powdery snow blows around easily. A train passing over this will whip up a whirlwind of snow particles — and snow, of course, tends to stick to things.

For modern trains snow accretion is serious. Locomotives and carriages have many structures attached to their undersides, all of which can become encrusted with snow. This can have dire consequences for comfort and safety. Trains use many systems requiring air, particularly airconditioning and pneumatic braking, which run off compressors. The air intakes for these tend to be mounted underneath the train, and if they become blocked the results can be costly or even disastrous.