Sometimes a small component can be a very large point of failure if it doesn't operate correctly. One such instance is that of the railroad switch. While small in comparison to many of the other pieces of a functional railroad infrastructure, the switch has the job of making sure the trains get onto the right track. Disaster can occur if a switch malfunctions or is placed into the wrong position.
Here is a picture of a switch that I took this week. This is a manually-operated switch. A person has to actually be there to rotate the handle and put the tracks of the switch into the proper configuration to route a train to the track it should be on.
Manual railroad switch at the CSX yard (formerly B&O) in Grafton, WV
As is easy to imagine, snow can get in the way of the proper operation of a railroad switch. The snow either has to be cleared by hand, or in some cases, heaters are installed to keep the rails at a temperature above freezing.
The animation below demonstrates the operation of a railroad switch:
Animation from Wikipedia Commons
Anyone who has played with the layouts of toy electric trains should readily recognize these small, but vital component, of the railroad infrastructure.