Casting off for safer seas

Over the course of the world wars, close to 75,000 mines were laid out in the Baltic Sea. An unknown number remain at the bottom of the sea. The Swedish Navy, together with other nations, annually clears the seabed of mines from this time. A particularly large number of mines were laid out around the Estonian coast, especially the Gulf of Finland. It is the site of this year's Open Spirit, a multinational mine clearance operation. The mine clearance diver support vessel HMS Sturkö cast off and set course for the area last week.

I byssan förbereder Cajsa Olsson middagen.
I byssan förbereder Cajsa Olsson middagen.
In the galley, Cajsa Olsson prepares dinner. Photo: Jimmy Croona/Swedish Armed Forces

Apart from HMS Sturkö, the mine countermeasures vessel HMS Kullen and an EOD team from the 4th Naval Warfare Flotilla. The EOD team (Explosive Ordnance Disposal) consists of specially trained mine clearance divers who can also neutralise mines and ammunition on land. Open Spirit begins this weekend with meetings in Tallinn between the various vessels.

Hectic to the last

It is often most hectic aboard a vessel just prior to casting off. There is a great deal of preparation involved; materials are to be loaded on board and nothing must be forgotten. Once at sea, calm settles in and work continues according to routine. From the dock in the Naval Port of Karlskrona, Henrik Condrup, Marcus Sjöberg and My Nilsson carry equipment on board. Several cylinder packs of compressed air must be taken on board and used by the EOD team's divers. Easier to transport by sea than by truck to Estonia.

Looking forward to the exercise

Experience varies greatly among the crew of HMS Sturkö. For some, this is the first time participating in a major mine clearance operation. For others, this type of operation has been routine for many years. Johan Granqvist is the ship's commander:
"These somewhat longer types of exercises are valuable in raising the level of the crew. You get into the routine and can concentrate fully on becoming better at what you do, without all these distractions. The fact that these are active mines we're clearing, albeit old ones, means the whole team is that much more focused."

Multiple strengths

John Hoffstedt is a tactical command officer:

"The advantage of Sturkö is that she can search for mines in a traditional way, using a sonar that sends out sonic pulses which are reflected off the seabed, whilst also having mine clearance divers on board."

The divers can be used in shallower water, but can also speed up identification of what the sonar detects at the bottom. A submersible with a camera can also be used to see what is down in the depths. If a discovered objects turns out to be a mine, it can be neutralised using a blasting charge, which is placed close to the mine and then remotely detonated. The mines do not constitute a major threat in their current position, of course, though risks can arise in the event of underwater works or fishing. The mines can also move closer to the coastline with the currents and thus become exposed to people.

More than mines lay hidden

Apart from mines, old torpedoes and bombs from conflicts during the wars can also be found. These too can be neutralised by Sturkö. Chemical weapons can also be found at the bottom, something that the crew is training to handle.

"It's not our job to take care of chemical weapons, but we must be prepared for the eventuality that divers or submersibles will come into contact with such weapons, and then decontaminate them as necessary," Johan Granqvist explains.

On Monday 18 May, they cast off from Tallinn and begin the search in the Irbe Strait. The exercise ends on 28 May when the vessels return to their home bases, in the knowledge of having made the waters safer.