A chain hoist is a mechanical device used to lift heavy objects and equipment. It consists of a pulley connected together by a closed chain that forms a loop, which makes it easy to pull by hand. Worker has several large and small pulleys on the chain hoist. There is a large pulley and a small pulley on the same axis, and a moving pulley to hold the load in place. For loads lifted with a chain hoist, the closed chain must be pulled. When it is pulled, the large pulley releases more chain than the small pulley. The ascension process begins here. While the history of pulleys is unclear, it is known that the original method was used to move heavy objects. One of the early attempts at a pulley system with a single fixed pulley failed because friction prevented the wheels from turning. Rope pulleys, commonly used to pump water from wells and still in use, are considered the next invention. The Greek inventor Archimedes in the early 3rd century BC devised a design of pulleys to pull ships out to sea. This was done with a special sheave and block system that is still in use today. These early pulley inventions led to the development of chain hoists. There are three types of chain hoists: pneumatic, manual and electric. Both manual and pneumatic hoists are designed with reduction gears, hook pivots, and swivels. Suspended from a top hook or by a pusher or gear cart, these units move objects slowly and carefully while making height adjustments. The additional load is well anchored, so it can stay anchored without much supervision. Electric chain hoists, on the other hand, are generally used to lift heavy industrial loads. It allows users to pull from the side and vertically.