Block and tackle systems. A block is a set of pulleys or sheaves mounted on a single frame. An assembly of blocks with a rope threaded through the pulleys is called tackle. A block and tackle system amplifies the tension force in the rope to lift heavy loads. They are common on boats and sailing ships, where tasks are often performed manually. In the diagram shown here, the number of rope sections of the tackles shown is as follows: Note that the gun tackle, double tackle and threefold purchase all have the same number of pulleys in both blocks (one, two and three,
Dump tackle are those who slow down or stop before contact. Dump tackle The dump tackle is a tackling technique favoured mainly by rugby league players. The tackler wraps his arms around the ball carrier's thighs and lifts him a short distance in the air before forcibly driving him to the ground. The tackler must go to ground with the ball carrier for the tackle to be legal. In 2005 the IRB ruled that "the act of lifting an opponent off his feet in a tackle AND dropping or 'spearing' that player so that his head and/or upper body comes into contact