Block And Tackle – A Good Way To Pull Heavy Loads
A block and tackle is a system of two or more pulleys with a rope or cable threaded between them, usually used to lift or pull heavy loads.The pulleys are assembled together to form blocks and then blocks are paired so that one is fixed and one moves with the load. The rope is threaded, or reeved, through the pulleys to provide mechanical advantage that amplifies that force applied to the rope.
Block And Tackle System are among the simplest and most useful machines that man has ever invented. Both are used for lifting loads and for controlling the motion of a rope or cable. A block is a set of pulleys designed to rotate separately but along the same axis; such a construction is often referred to as a block and tackle, and may be rigged in different ways, for many purposes- gun tackle, gyn tackle, double tackle, and others. In sailing, a single or multiple pulley may also be called a block; they are used to block and tackle hoist sails.
Generally, Block And Tackle are used to change the direction of an applied force, transmit rotational motion, or realize a mechanical advantage in either a linear or rotational system of motion. They can be used in ships, cars, and many other places.
Two or more pulleys together are called a block and tackle. It is also call the Block And Tackle Hoist. The simplest theory of operation for a pulley system assumes that the pulleys and lines are weightless, and that there is no energy loss due to friction. It is also assumed that the lines do not stretch.
Logging blocks, as their name suggests, are built for use in the logging industry. They are made strong enough to support the weight of large, heavy logs, and range in size from the small rigging block to the large haul back block. A rigging block has a wide “throat” that allows the rigging and the eyes of the rope to pass through. It is typically made of manganese. A haul-back block is made of lightweight, long- lasting high- strength alloy steel and consists of a sheath mounted on tapered roller bearing. Another type is the medium- duty logging block, which looks similar to, and may be used as, a haul back block, but is made of manganese. It has a heavy- duty alloy yoke and pins.
The micro pulley is indeed physically stronger than any other type of pulley, but it can be just as strong. It may be used in a “mechanical advantage system,” or in the “split tail climbing system” that has become popular among mountain climbers. It has a sheave and side plates (in single- piece construction) made of aluminum, and a solid steel pin that sticks through the center.
Trolleys come in many different makes, with side plates of either aluminum or steel. There are tandem and high-speed, as well as zip and classical cable, trolleys; the first two are used when the load being hauled is to be moved at high-speed. Crosby blocks (manufactured by the Crosby Group, Inc.) consist of a pulley attached to a hook. The rope may be put through while the block is hanging from a pole.
Block And Tackle Rigging are the mechanical sailing apparatus attached to the hull in order to move the boat as a whole.