It has been suggested in a French-to-German question on the same word that it comes from the German "Kardeel" or "strand". I think this highly likely ... At least I think it highly likely that it is a stranded cable, but what the origin of the word is is another matter.

A number of web references talk about the hazard these "cordelines" present to birdlife because they are thin and high up at the top of the chairlift pylons, so they are being fitted with "balls" at regular intervals so birds can seen them and not fly into them.

Obviously there has to be fast data communication between the two ends (at least) of a skilift so that when the man at the top presses the emergency button, the motor at the bottom will stop, and the easiest "hardwire" way of establishing this communication will be to run a data cable along the pylons.

I can only think of "safety cable" or -- since this might be taken to mean it is a cable that will support the chairs should the main cable (rope) fail -- "safety wire" as a translation, though I have not succeeded in finding an example of it being used in this context.