An immersed tunnel connection of 18 km length will be constructed between Denmark and Germany: the Fehmarnbelt tunnel. FBC (Fehmarn Belt Contractors) is busy with site investigations for future dredging works and work harbor construction whereby we have to guarantee safe access for our equipment. For that specific purpose we hired Deep to execute the necessary UXO detection surveys. By means of the Deep Volans, a ship that is equipped with a ROTV (Remote Operated Towed Vehicle), they searched the seabed for potential UXOs.

Check
The project is worked upon according to NINA, which is perfectly in line with Deep's ‘stop work policy’, says Ad Blaauw, HSEQ specialist. “Check check and double check is second nature to our people.” During such a check at sea, the Captain noticed that the nut of the shackle was missing. The shackle is the fastener with which the pulley, with tow line for the ROTV, is attached to the A frame. An essential part, says Party Chief Dennis Oltheten. “The Captain and I looked at each other and we knew ‘this is dangerous’. You run the risk of the pulley detaching from the shackle, which could hurt somebody or cause damage to the equipment.” At that moment there were two options: secure a new nut on the spot or return to the harbour. The latter was chosen. “The sea was quite rough and someone would have to perform the repair work at height, which we considered irresponsible”, says Dennis. Not a difficult decision for that matter: “In 20 seconds it was evident that we did not want to take that risk.” Eventually the Volans was out of service for not even two hours.

Pride
Ad Blaauw is proud of the crew: “This is exactly what we want: taking your responsibility and choosing safety. I always emphasize this: do not do anything that makes you feel unsafe. In this case they had to do something at sea they could not have prepared. This is always risky.” Looking back, the cause was an improper securing: a tie-wrap was used instead of a steel cotter pin. This was shared in a newsletter as a learning experience.

“Do not do anything that makes you feel unsafe.”