According to ASME B30.10, a latch is a mechanical device used to close the throat opening of a hook.
The purpose of the latch is simply to reduce the possibility of the rigging becoming detached from the hook, primarily in slack conditions. The use of a hook with a latch does not preclude the inadvertent detachment of a slack sling or a load from the hook.
Tilt-up is a method of construction whereby large concrete panels are cast on-site and then raised into position with a crane. The building system, which was conceptualized in the early 1900s, is used throughout North America and across the globe. It is employed on virtually every building type, from distribution centers, to schools, churches, libraries, retail centers, and office buildings.
The object shown appears to be a homemade below-the-hook lifting device.
Who manufactured it? Has it been tested? Is it safe to use?
Crosby Group has completed training and overhauled rigging best practices at an
end user’s facility where problems where encountered due to shock loading of a
Crosby IP vertical lifting clamp.
distribution partner, B.C. Wire Rope & Rigging, which delivers heavy
lifting services throughout California, Arizona, and Nevada, contacted Crosby
when a customer had broken a cam segment in a plate clamp. The rigging
component, suited to vertical lifting, turning, and transfer, was being used
with a forklift truck to lift domes during a manufacturing process related to
tank heads and accessories.