Underwater Demolition – Bridge Demolition
Divers must also hold a construction diving Certificate of Competence, which is issued by the Department of Labour. Underwater demolition is also notifiable under the Regulations. The primary danger to divers who are cutting or welding is from electric shocks and explosions of trapped gas in the structure being worked on. Divers must be familiar with the precautions necessary to keep safe when doing this type of work.
Underwater electrical circuits should have a positive on/off switch located where the tender has immediate access. Unless the diver is actually welding, the switch must be in the open or “off” position.All welding machine frames must be earthed before starting operations. An earth wire should be used to connect the machine directly to the work.Power supply cables must be kept clear of welding cables. Insulated gloves should be used by the diver during underwater electrical welding or welding operations.Any underwater compartments containing unidentified or explosive gases, or residues that could release gases, must be purged or flooded prior to cutting or welding operations.Compartments of structures, which could accumulate welding gas, should be vented prior to the start of operations