When you want to lift or pull more than your own strength will permit, or when you want to make a heavy lifting job a little easier, the rope tackle is a device that can be used.
The idea behind a rope tackle is similar to that of a tackle using blocks and pulleys. In a rope tackle, one lead (end) of the rope has to be fixed. That is, it has to be anchored
around a spar or tied through a ring or other piece of hardware that doesn’t move.
Follow this link for a full description with diagrams and illustrations: ROPE TACKLE FOR PIONEERING USE