Editing Block and tackle (section)

== Overview ==
[[Image:Tackles.png|thumb|upright=1.5|Various ways of rigging a tackle. All these are "rove to disadvantage"<ref name="advantage" /> (see below).]]
A block is a set of [[pulley]]s or [[sheave]]s mounted on a single frame. An assembly of blocks with a rope threaded through the pulleys is called tackle. The process of threading ropes or cables through blocks is called "'''reeving'''<!-- bolded per [[WP:MOSBOLD]] as a redirect -->", and a threaded block and tackle is said to have been "rove".<ref>[[wiktionary:reeve]]</ref> A block and tackle system amplifies the tension force in the rope to lift heavy loads. They are common on [[boat]]s and [[sailing ship]]s, where tasks are often performed manually, as well as on [[Crane (machine)|crane]]s and [[drilling rig]]s, where once rove, the tasks are performed by heavy equipment.

In the diagram shown here, the number of rope sections of the tackles shown is as follows:
* Gun tackle: 2
* Luff tackle: 3
* Double tackle: 4
* Gyn tackle: 5
* Threefold purchase: 6

Note that in the gun tackle, double tackle and threefold purchase, both blocks have the same number of pulleys (one, two and three, respectively) whereas the Luff tackle and Gyn tackle have mis-matched blocks with differing numbers of pulleys.