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:
“The chess pieces are the block alphabet which shapes thoughts; and these thoughts, although making a visual design on the chess-board, express their beauty abstractly, like a poem.... I have come to the personal conclusion that while all artists are not chess players, all chess players are artists.”
—Marcel Duchamp (1887–1968)