How to Use Rigging Blocks & Marine Pulleys

Pulleys provide a mechanical advantage.

Boatyards use rigging to lift and lower boats, marine engines and equipment. This rigging is also used to pull laterally when positioning heavy objects. Some launch facilities continue to use block-and-tackle rigging to hoist craft in and out of the water. Rigging blocks and marine pulleys can be arranged in several ways, depending on the job to be done and the mechanical advantage needed.

Instructions

1. Insert the end of a rope into the block and under the pulley. Lay the pulley on the ground and attach the same end of the rope to an overhead stay, such as a hook or steel rail. A bowline knot works with either attachment.

2. Attach a rope or cable truss around the object you want to lift, say out of a hold or engine compartment. Hook the pulley to the truss. Position yourself on an elevated level, grip the tag end of the rope and take up the slack between the stay and the pulley. Pull the rope to lift the object.

3. Set up a gun tackle using two marine pulleys and a single rope. Attach the end of the rope to the eye at the underside of the first pulley. Pass the other end of the rope under the wheel on the second pulley and pull the slack out of the rope.

4. Pass the same end of the rope over the top of the first pulley and pull the slack out of the rope. Hook the first pulley to an overhead stay. Hook the second pulley to a cable truss or directly onto the object if possible.

5. Grip the tag end of the rope and pull down to lift the object. Use a gun tackle rigging to pull an object laterally and position it for lifting. Connect the first pulley to a stationary object and attach the second pulley to the object you want to move. Stand near the stationary object and pull the tag end of the rope.

Tips & Warnings

• Use marine pulleys that have corrosion-resistant components.

References

• Aurora Rents: Block And Tackle
• Flinn Scientific: Block and Tackle Pulley Demonstration