Definition(s)
Snub-Line
Wire rope, one end of which is fastened to the end of a pipe tong handle attachment point and the other end secured to hold the tong stationary while the tong is in use.
NOTE: Snub-lines do not work over a sheave or bend.
Source: API SPEC 7K, Drilling and Well Servicing Equipment Upstream Segment, Fifth Edition, June 2010 (August 2010). Global Standards
Source:API SPECIFICATION 7K, Drilling and Well Servicing Equipment, Sixth Edition, December 2015. Global Standards