The challenge
The HDPE pipe was intended to carry a large power cable from sea to shore. The internal diameter of the pipe was less than 60 cm. The pipe sloped downwards and was filled with water.
To reach the earth rod, we entered the pipe and went down 50 metres. Once at the obstruction, the rod was cut and removed. The rod was then pushed both upwards and downwards to completely free it from the outside of the pipe. Afterwards, the resulting holes in the pipe were carefully sealed.
Solution and preparations
Thanks to courage, confidence and teamwork, this job was completed safely and successfully. Crawling down 50 metres into a narrow, water-filled pipe and bringing the situation to a successful conclusion was a remarkable achievement.
The key to success was thorough planning and training. A complete test setup was built to practise the procedure for removing the earth rod and to run through various emergency scenarios.
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The diving team on this project
A dive supervisor
A deck leader
A diver with extensive cave-diving experience
Two standby divers trained in both the operational tasks and all emergency procedures.