From Wiktionary, the free dictionary
From whip + line.
whipline (plural whiplines)
- A cable, typically made of braided steel, used to lower and retrieve tools and instruments into oil or gas wells.
2005, Paul Carter, Don't Tell Mum I Work on the Rigs, Crows Nest: Allen and Unwin, page 45:Because the seas were a bit rough that morning the crane was using the whip line.