Monitoring elongate subsea elements.

Abstract

A sensor system for monitoring elongation or bending of an elongate element such as a rope comprises at least two supports that are attachable to the element at respective positions spaced along the element. At least one of the supports carries an emitter for emitting a signal and at least one of the supports carries a receiver for receiving the signal. The emitter and the receiver are offset laterally from the element on a signal transmission path that extends along and beside the element. A processor is configured to determine the distance between the supports by measuring time of flight of the signal from the emitter to the receiver along the signal transmission path.