What is "towlines"

Usage examples of "towlines".

Spellbound, she forgot about safety lines and towlines, for she saw a multibranched lightning tree etch itself between stars.

At the Great Bear, overcome by the common dread of the Unknown Lands, their voyageurs began to desert, and Fort of Good Hope saw the last and bravest bending to the towlines as they bucked the current down which they had so treacherously glided.