Underwater inspections save
shipowners’ money

In the Baltic Sea area the market for underwater inspections of vessels has grown remarkably during the last decades. Better underwater hull paints have made the intervals between docking longer, while toxic anti-fouling is used to a much less extent than before for environmental reasons.
Less use of anti-fouling means more foul on the underwater hull, which definitively is not a good thing for the operational performance of the vessel. This is why DG-Diving Group, which is one of the leading diving enterprises in the Baltic region, has noticed the fastest growth in the underwater hull-cleaning sector.
Long experience
DG-Diving Group has developed its own equipment and procedures for efficient underwater work, including cleaning of hulls. Its main market area covers the whole northern Baltic Sea. The company started its operations in 1983, but already before that the founder Mauri Kalliomäki had done diving work for the offshore industry on the North Sea for several years. Today he employs four to six divers, depending on season.
– The hardest thing is not to find talented divers, but they should be good underwater workers too, Mr Kalliomäki explains.
He says that the diving itself is just a means to reach the working area. When you are there the work itself begins.
– First you have to be a good underwater worker, capable of taking own initiatives and mastering a lot of skills, such as underwater welding.
In addition to underwater hull cleaning, the company has specialised in wet welding, NDT-inspection as well as virtually every other kind of underwater service and repair work.
The year 1988 was an important turning point for DG-Diving Group. In that year an agreement about co-operation with Finland’s leading tug and salvage company Alfons Håkans Ltd was signed. Since then DG-Diving Group has done all of Alfons Håkans’ diving work and participated in several of their large salvage operations.
The most significant of these were the pusher Finn and the barge Baltic which capsized outside Hanko in 1990, the cruise vessel Sally Albatross, which ran aground and partially sank west of Helsinki in 1994, and the container vessel Janra, which collided with a navigation mark and capsized on the Åland Sea in 2000.
Although no such large salvage operations were required during last year, it was a very busy time for DG-Diving Group.
– The temperature of the sea water was exceptionally high due to the warm summer and this meant much underwater hull-cleaning work throughout the season, says Mr Kalliomäki.
In Finland DG-Diving Group works along the whole coastline. During the open water season the company had weekly commissions in Estonia as well, mostly on vessels in the ports of Tallinn and Muuga. Sweden is another important market for the company.
The customers are shipping companies operating different types of vessels. For example the hulls of the large cruise ferries in the Northern Baltic were cleaned during the season.
The busy times continue. Mr Kalliomäki says that the season for repairing ice damages has begun much earlier than normally due to the exceptionally cold weather.
Special equipment
The company has several mobile diving bases in trailers and vans, including all equipment needed for most operations. Together with the Finnish company Kemppi DG-Diving Group has also developed compact, low-weight underwater welding equipment, also suitable for transports by air.
– We have 24 hours’ readiness in both Turku and Helsinki, says Mr Kalliomäki.
Hull surveys for classification societies are another major activity for DG-Diving Group. The inspector from the classification society is able to monitor the underwater work from a monitor in the mobile base and he can also communicate with the diver. The diver’s helmet is equipped with a video camera and a spotlight.
DG-Diving Group is certified by the most important international classification societies, such as Lloyd’s Register, DNV, Germanischer Lloyd and Bureau Veritas. The company has a quality assurance scheme, where all operational procedures are documented.
No unpleasant surprises
Another typical commission is underwater hull inspections prior to routine docking. These are carried out one or two months before the scheduled docking. The diver inspects the condition of the hull and if there are any damages on hull, propeller or rudder, spare parts can be ordered in good time before the docking.
– This guarantees that there will be no unpleasant surprises, which could make the docking longer and also more expensive than originally planned, explains Mr Kalliomäki.
//Pär-Henrik Sjöström

Back to SSG 2, 24 January