In the June issue of BoatUS magazine, Evan Starzinger wrote a basic yet interesting article about three gripping hitches used to join two lines together while one line is under load. These are particularly useful when for one reason or another the load on a line is too great to manage by hand and requires transferring it to a winch or block to safely or more easily deal with.
I’ve used the icicle hitch to transfer a fully loaded jib sheet to a cleat because overwraps on the winch had tightened to the point I could no longer ease out the jib. Another use was at anchor. Voyager has an eight-foot bowsprit and leading the anchor rode to the end of the bowsprit eliminates chafing problems as the boat swings on the tides. By running a line through a block at the end of the spar then back to the bow and hitching it to the anchor rode, the rode can then be moved well forward and away from the shrouds that support the bowsprit.
Gripping hitches are useful and important and should be in every sailor’s inventory of quickly deployable knots.
You can read the article here.