Is it necessary to test hollow structures like railings before doing hot work on them?
Yes. The small amount of air that is present inside railings and similar hollow structures must be tested before performing hot work. Usually, small holes are cold-drilled in order to provide an opening as a means to insert atmospheric testing instrument probes. On vessels and in shipyards, the interior of structures like masts, stanchions, skegs, and bilge keels are required to be tested.
