A davit system consists of two primary components, a base and an arm. The base is a permanent fixture to the building structure and the arm is typically portable with the ability to be raised, lowered and removed. In most cases a davit system will be used to rig a Powered Platform; however a davit system can be used with other forms of suspended equipment such as a single cage or a bosun’s chair.
Davit systems can be broken into two distinct categories with several subcategories. The first primary category is the ground rigged davit system. This system typically involves a much smaller arm designed to bring a powered platform from the ground up. The davit arm only requires a small amount of space over the parapet or roof edge. The second primary category is a roof rigged davit system. In this scenario a Permanent Powered Platform is stored at the roof. The davit arms are much taller to allow a greater clearance above the parapet. The platform is rigged at the roof and a careful series of maneuvers allow it to be moved to the exterior of the building and lowered. This is more common on buildings with unique conditions.
Typically a davit system will be used in conjunction with Roof Anchors. While the suspended equipment will be rigged to the davit arm; the workers independent lifeline will be attached to an independent roof anchor. This line and roof anchor will protect the worker in the event of a fall.
A common davit system questions is: how many davits will I need? The answer to that question is not very easy. Every building has its own unique conditions, and challenges. Important questions you must ask are: What type/size platform will a contractor use? Is a permanent powered platform required? What type of davit arm or base is necessary? Is one set of arms sufficient or will more be required? Are their local codes and standards that require davits to be used?
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