Noun
A block and tackle composed of two pulley blocks, each of which has two sheaves (pulleys).
(rugby) A tackle by two players of the same time on an opposition player.
Source: en.wiktionary.orgA double tackle has two pulleys in both the fixed and moving blocks with four rope parts supporting the load W. Separation of the pulleys in the double tackle show the force balance that results in a rope tension of W/4. Source: Internet