Boskalis Nordic Today No.02/2018-2019

12 PORT OF TURKU, FINLAND | MAINTENANCE DREDGING OF MAIN CHANNEL AND REPLACEMENT OF SEA MARKS TURKU MAIN CHANNEL CLEARED OF RIVER AURA SEDIMENT

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TEXT : MARKKU SALONEN | PHOTO 01: MARKKU ALAHÄME, PORT OF TURKU

T he busy main channel of the Port of Turku, located in southwest Finland on the coast of the Archipelago Sea, needs regular maintenance due to the River Aura that runs through the city. The Rajakari–Turku channel and Turku’s main harbour are located at the mouth of the River Aura, which carries sediment into the area. The sedimentation in the harbour area and channel requires maintenance dredging at regular intervals. This ensures that the channel and the harbour basin maintain their officially stated navigation depth and safety. Terramare began maintenance dredging at the site in autumn 2018. The contract included 13 different dredgings in the ar- eas of the main channel and the harbour basin, with the minimum depth varying between −11.00 and −8.10 metres. The dredging work covered an area of ap- proximately 120,000 m 2 . The contract also included the replacement of the channel’s

sea marks, with the old ice buoys being replaced by spindle buoys.

Terramare’s backhoe dredger Attila in con- junction with the towable barges SCG 3 and SCG 4. Each vessel has a load capac- ity of 500 m 3 . Terramare’s Site Manager Markku Pöyhönen supervised the project’s progress. “The dredging of the Turku harbour basin and channels involved delicate clearance

DREDGING WITH A LIP BUCKET In the Turku maintenance dredging, an average 20 centimetre layer of sediment deposited by the River Aura was removed from the bottom of the harbour basin and channel. The dredging was carried out by

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MAINTENANCE DREDGING OF THE PORT OF TURKU and the main channel was carried out using the backhoe dredger Attila. Pictured alongside it is the towable barge SCG 4. THE SEA MARKS OF THE TURKU MAIN CHANNEL were replaced. The old steel ice buoys were replaced with plastic spindle buoys.

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THE VIKING LINE AND SILJA LINE CAR FERRIES OPERATE in the Turku channel through the Archipelago Sea.

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