Two railings of body and a foot, or a block of body railing should be provided on the outside surface of the operation, vertical hanging safety net under the mouth seal, protection height should be 1.5m.
Two guard railings and a foot shield or a body guard railing should be set on the outside of the operating surface, hanging safety net, sealed under the seal, the height of protection should be 1.5m.
Two protective railings, one toe board or one protective railings shall be set outside the operation surface, with safety net erected, lower mouth sealed tightly, and protection height of 1.5m.