Hyperbaric tunnelling is relatively new in Australia with the first pressurized tunnel boring machine (TBM) starting operation in 1996. Since then the industry has grown rapidly and the training requirements for the Hyperbaric Workers and Lock Operators is specified in the Australian standard AS4774.1 and is currently being registered as nationally recognized training.
preparation of the pressurized compartments, known in this industry as locks
checking the pre-requisites and health of all who enter compressed air
compression and decompression
gas analysis and gas usage
responding to emergencies and operating the medical lock.
Responsibilities and Challenges
A lock operator is responsible for operating up to five separate pressurized compartments simultaneously, these being the inner and outer locks, working chamber, excavation chamber and the materials lock.
A Lock Operator must stay focused on the completion of the intervention task which is usually inspection of the excavation face and inspection and replacement as necessary of the excavation tools.
Making sure the intervention team does not overstay the planned times is critical as is calculation and execution of the required decompression which may take up to six hours and requires the lock operators full attention and attendance for the entire time.
These responsibilities also have their challenges. Being underground in high temperatures, in an environment that is poorly lit, noisy, dirty and often cramped are the usual working conditions of a Lock Operator.
Highlights and Rewards
If you’re not put off by the responsibilities and challenges outlined above, working as a lock operator gives you the opportunity to work in a team, enjoy the focus and commitment of completing challenging tasks and mastering high technology.
How to Become a Lock Operator
The prerequisite for Lock Operator training is the three day Hyperbaric Workers course, a current medical certification and workplace first aid. The ADAS Lock Operators course takes 5 days and includes an Oxygen Management certification. Training must include some time on a Tunnel Boring Machine (TBM).
Lock operators are usually permanent employees of the construction company for the duration of the job. They are usually engineers, shift supervisors or experienced tunnellers, however on some projects diving Chamber Operators will be employed on a casual basis just for the intervention periods. As a tunnel worker, being qualified as a Lock Operator assists with employment on future TBM projects.