A hoist (from the Greek πολύς polýs 'a lot' and σπάω spáo 'pull') or hoist or rig is a machine composed of two or more pulleys and a rope, cable or chain "Chain (object)") that alternately passes through the various grooves of each pulley.[1]​ The tackle is used to lift or to move a load by means of mechanical advantage, since this requires applying a force less than the weight of the load to be moved or lifted.[2]​.

They are used in workshops or industries to lift and place very heavy elements and materials in different machine tools or to load and unload them from the trucks that transport them. They are usually attached to a rotating arm attached to a machine, or they can be mobile guided by rails placed on the ceilings of industrial warehouses.

Hoists have different lifting capacities depending on the load they can lift. It is possible to increase the lifting capacity by increasing the number of legs of a hoist. For example, a 500kg hoist with one leg may have a capacity of only 500kg, but if configured with two legs and the appropriate accessories are used the same hoist can lift 1000kg. In order to achieve very high lifting capacities, it is sometimes necessary to use a set of several hoists with several branches together with a special block.

According to its number of branches:

Depending on the way they multiply force, the most common tackles are:.

Depending on the material of the branches, the hoists can be.

And depending on what power is applied to the machine, they can be:.

At an industrial level, rigging is divided into electric rigging and manual rigging. The difference is the mobility of the chain, while the electric hoist has a command (with single-phase or three-phase current depending on the model) that guides it vertically - raising or lowering the load -, the manual hoist does not have a command, and the person in charge must raise and lower the load using the chain.

Factorial rigging

Its formula includes the "force" that the object or person must apply to lift the "resistance" and the number of mobile pulleys involved in lifting the resistance:

Its formula is:

Example:.

To lift a weight of .[3]​ has been exerted.