Chock Block
A cheap and simple alternative to catch points or a derail is a chock block, which is a piece of timber that can be positioned and locked over one of the rails at the end of a siding to protect the main line from runaways. In order for the siding to be used the chock block must be removed.
Read more about this topic: Catch Points
Famous quotes containing the word block:
“Get behind me, Satan! You are a stumbling block to me; for you are setting your mind not on divine things but on human things.”
—Bible: New Testament, Matthew 16:23.
Jesus to Peter.