Boskalis Nordic Today No. 02/2019-2020

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Have you ever wondered what it would be like to perform construction work under water up to tens of metres deep? It is certainly challenging to imagine, but in this article professionals of the field shed light on the secrets of their awe-inspiring specialist occupation.

busy at nearly all of Terramare’s marine construction projects. Both companies operate in Finland and the other Nordic countries. “We have been involved at around 100 Terramare work sites since the early 2000s. I can only say that all of the projects have been unique from a construction diver’s per- spective, but there is one thing they have in common, however, just like our hundreds of other sites. It is the very poor visibility in underwater work. Now and then it is just as if you were working blindfolded,” says Oy Baltic Divers Ltd’s founder Jukka Te- leni with a smile. “Often the visibility is only a few centi- metres, but even at best it is only half a metre. So, despite their interesting work, construction divers do not really enjoy un- derwater views, so familiarising yourself with the site beforehand is the key to de- livering high-quality, safe and efficient un- derwater work,” adds Teleni. Teleni has 40 years’ experience of construction diving. He founded his company back in 1993. Experienced construction diver Jari Ve- nemies founded Divecon Ltd in 2012. For him, the visibility challenges are similarly part of everyday work. “The waters off the Finnish coast, with the exception of the outer archipelago, are a rather murky working environment, but you get used to it and your powers of perception develop rapidly. Detailed familiarisation, a good sense of touch and a precise image of the work site facilitate smooth working. And divers, of course, do not work alone; projects are completed with the assistance of a surface crew,” explains Venemies. “The surface crew play an important role in construction diving. They act as the diver’s lungs by controlling the breathing gas and communicating with the diver by phone. The surface crew also maintain contact with all operators working on the site, so the diver is well in control of the situation,” emphasises Venemies.

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DIVECON.FI

EQUIPMENT & WORKING HOURS A construction diver’s basic equipment weighs around 60 kilos. It includes a div- er’s helmet equipped with a diving phone and light and a recording device, as well as a strong dry suit and spare air bottles.

Surface crew have available to them a display and voice connection as well as a compressor and filters ensuring continuous air supply to the diver. The surface crew will also assist the divers in putting on and taking off their equip-

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CONSTRUCTION DIVING COMPANIES TO A LARGE EXTENT use self-developed tools and machines for underwater tasks.

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THE SURFACE CREW ACTS AS THE DIVER’S CONTACT personnel and control the breathing gas.

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A CONSTRUCTION DIVER READY FOR THE INSTALLATION of quay elements at the Stockholm Norvik Port site.

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