Block and tackle sheave to change the direction of the pulling line, which increases friction losses without improving the velocity ratio. Situations in which reeving to disadvantage may be more desirable include lifting from a fixed point overhead; the additional pulley allows pulling downwards instead of upwards so that the weight of the lifter can offset the weight of the load. The formula used to find the effort required to raise a given weight using a block and fall: where formula_3 is the force applied to the hauling part of the line (the input force), formula_4 is the weight of the load (the
Off-tackle run ball carrier. The Maryland I used the 2nd back to lead through the hole and block the linebacker. More complicated versions of the play have pulling guards block the linebacker or combination blocks by a tight-end and tackle to create the hole and block the linebacker. The off-tackle play is a key feature of the single wing offense. Off-tackle run An off-tackle run in American football is a play in which the running back carries the ball through a running lane off of the tackle's block. The lead block kicks out the end man on the line of scrimmage, and