Boatswain’s chairs were originally just a piece of plank that a person sat on. These were intended to suspend a sailor to perform work aloft and evolved to raise commodores or admirals on-board of navy ships whilst at sea. This required the use of a block and tackle rigging system to provide the necessary mechanical advantage.
Modern bosun’s chairs are based on the naval officer hoisting chairs but using modern equipment and safety devices. The piece of plank has been replaced with a moulded seat made from a polymer matrix and glass fibres. The suspension system is a modern version of a block and tackle with a 4:1 reeving arrangement and fitted with a controlled descent apparatus. The person (operator) in the chair is secured to it with a built-in webbing harness.
In addition, the operator wears a conventional full body harness (PPE) with a short lanyard. A separate / independent safety line hangs down the full height of the chair’s working range onto which an inertia trip fall arrest device is fitted. These chairs are used internationally as complementary systems to suspended platforms.
GENERAL ARRANGEMENT MODERN BOATSWAIN’S CHAIR & SAFETY DEVICES
Modern bosun’s chairs fill the gap between electrically powered Temporary Suspended Platforms and Rope Access operations. They are designed to be used by persons that need to perform work using both hands whilst in elevated positions. These persons are trained in the safe use of the system but do not need to be certified as rope access technicians. These chairs can be used on structures with heights up to 30m and fit comfortably through trapdoors in silo / tank roofs.
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