The downside of systems with a 5 1 or higher mechanical advantage is you have to pull a lot of rope to move the load a short distance.
Z rig rope rescue.
It requires less rope than a non piggybacked 2 1 system is reasonably easy to rig is easy to add a progress capture device provides an appropriate amount of mechanical advantage to raise one or two people and with a few tweaks it can be converted into a simple 5 1 system.
For the construction of the z rig attach a single pulley.
Notice however that the end of the rope on 2 1 systems is attached to the anchor whereas the end of the rope on 3 1 systems is attached to the load.
With a few modifications the z rig can give a rescue team as much as a 22 1 mechanical advantage.
This is handy if you rig a 3 1 and don t quite have enough pulling power.
Rig for rescue people have used rope access techniques to undertake work at height for decades.
Each organisation has subtle differences in approach but they all strive to provide a framework for safe places of work.
3 1 system the 3 1 is the classic mechanical advantage system used by rescuers.
The multi plate allows for these plans to be quickly implemented if needed.
River rescue z rig kit 907 this package includes the water compatible components you need for setting up a 3 1 mechanical advantage system for water rescue incidents.
These techniques are now quite specific and well defined by various industry groups and their codes of practice cop.
The z rig is reasonably easy to rig is easy to add a progress capture device and provides an appropriate amount of mechanical advantage to raise one or two people.
As with any rescue always have a plan a plan b and plan c.
Rope used in rescue 1 1 1 a.
Eo 1 1 6 demonstrate constructing mechanical advantage systems such as the z rig and piggyback z rig.
The final illustration on this page shows how to rig a 5 1 as a reeving system.