Projects Archives - DUC Marine Group

Installation of a boatlanding

ducmarinegroup — Thu, 04 Mar 2021 11:35:03 +0000

INSTALLATION BOATLANDING

30 km North of Helgoland, Germany.

Because the distance of the fenders of several CTVs to the existing current sports of the boatlanding was not sufficient, the Client asked DUC Marine Group to install two extension pieces. For this job DUC mobilised a big Multicat, a CTV, a RIB and a Rope Access Team. The ladders were loaded in the port of Delfzijl (Holland) and were prepared on deck for installation.

Because of the lifting height and the movement of the vessel on the swell, DUC was careful not to damage the steel structures and decided to hoist the pipes with an electric hoist and a Rope Access Team. Due to the existing inter array and export cables anchoring was prohibited. Mooring with ropes to the jacket was also prohibited.

To overcome this problem the extension pieces were gently lowered into the water with the Multicats Deckcrane and connected to a 5 ton lifting bag underwater. The lifting bag was then towed to the boat landing and hoisted into position. All bolts were tightened to the correct torque. In total 4 pieces were installed.

Categories: Boat landing, Maintenance and Repairs, Offshore, Offshore Construction and Installation, Oil and Gas, Renewables, Wind Park, Rope Access

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Salvage of lost suspension bridge parts

ducmarinegroup — Thu, 04 Mar 2021 11:21:33 +0000

SALVAGE OF LOST SUSPENSION BRIDGE PARTS

IJmuiden Approach Channel, Netherlands

The outbound vessel “Wilson Leer” lost her deck cargo of steel modules for a suspension bridge, during her way out of IJmuiden to Sweden.

Six elements of 20 m x 6,5 m x 1,5, weighing 31 tonnes in air, were lost.

A crane vessel, a fully equipped diving team and materials including a decompression tank and a Nitrox unit were mobilised.

It took only four days to complete the work and clear the channel of the debris.

Categories: Salvage, Offshore, Offshore Salvage, Bridge

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Western Europe, Swimming pool maintenance (2000 – present)

ducmarinegroup — Fri, 01 May 2020 08:41:51 +0000

Western Europe, Swimming pool maintenance (2000 – present)

Maintenance and repair on moveable floors in about 200 swimming pools a year. High-tech underwater work in warm circumstances with excellent visibility and no chance on decompression sickness.

In cooperation with Variopool a leading company which is specialized in the design, installation and maintenance of movable swimming pool floors and bulkheads for swimming pools.

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Install a separation wall in the cooling tower basin

ducmarinegroup — Fri, 01 May 2020 08:10:08 +0000

Install a separation wall in the cooling tower basin In the basin of the cooling towers of a metal processing company, a dividing wall has been realized under water with a length of approximately 15 meters and a height of 1 meter. 4 valves were placed in the wall. The wall had to withstand an aggressive environment, environmental class XS4. The wall had to have sufficient structural strength to support the new cooling towers.

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Salvage of broken vibrocore pipe

ducmarinegroup — Wed, 09 Nov 2016 15:50:17 +0000

SALVAGE OF BROKEN VIBROCORE PIPE

Near the coast of Zeebrugge (B) and windfarm Rentel a broken vibrocore pipe had to be searched and salvaged.

With our vessel RAM, a team of divers and the use of an airlift we successfully managed to retrieve this pipe from the seabed.

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Making a condenser pit watertight

ducmarinegroup — Thu, 14 Jan 2016 16:59:30 +0000

MAKING A CONDENSER PIT WATERTIGHT

Tunisia, Middle East

In 2004 in Tunisia, DUC Marinegroup used shotcrete injection to repair and apply a watertight layer to a condenser pit.

Categories: Civil Underwater Construction, Inshore, Maintenance and Repairs

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Aquatic Centre London

ducmarinegroup — Thu, 14 Jan 2016 16:52:50 +0000

AQUATIC CENTRE LONDON (GB)

London, UK

For the construction of the Olympic Swimming Pool in London, DUC assisted with the installation of four movable floors, 2 booms and 1 submersible boom. With our assistance the pool was ready in time for the Olympics in 2012.

Categories: Civil Underwater Construction, Inshore, Swimming Pool Construction

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Removal of grout blocks

ducmarinegroup — Thu, 14 Jan 2016 16:45:21 +0000

REMOVAL OF GROUT BLOCKS FROM A DIAPHRAGM WALL IN FRANCE

Le Havre, France

During the construction of a new harbour in Le Havre (France), grout blocks adhered to the diaphragm wall at a depth of 22 metres.

DUC came up with a creative solution to remove the blocks that was faster and safer than the original method.

The intention was to use a chain connected to two winches mounted above the work to ‘saw’ the blocks away from the wall. To do this, local divers had to cut grooves in the bottom of the blocks through which the cable could pass.

Using explosives to cut the grooves would have been very time consuming. Therefore, DUC Marine Group was asked if a quicker method was available. As the blocks were made of a fairly hard material, DUC suggested to use our 2500 Bar high-pressure water jet to cut the initial grooves for the cable that would be used to saw through the blocks.

However, the cable ‘saw’ continually broke and little progress was made.

DUC provided the solution of using the water jet to make a 100 x 100 x 10 cm opening between the diaphragm wall and the block from above. A 68-tonne air bag was then positioned in this opening that was then inflated to force the grout block from the wall.

This resulted in the safe removal of the 15 to 45-tonne blocks. The job was concluded to the satisfaction of the client, Dragage Atlantique, who were able to put quay into service on time.

All of the activities were carried out using company equipment, which included a 2500 UHP unit, air bags, a decompression chamber and a Nitrox unit.

Categories: Civil Underwater Construction, Inshore, Offshore, Projects

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Replacing oil pipeline

ducmarinegroup — Thu, 14 Jan 2016 16:29:53 +0000

REPLACING OIL PIPELINE

In Ashkelon, DUC Marine Group helped with the replacement of two 1500-m sections of pipeline. These oil pipes ran from a refinery to the sea where they were connected to a SPM (Single Point Mooring) buoy.

DUC was assigned the task of using PLIDCO clamps to connect the two new sections of pipe to the oil pipelines.

The four clamps were installed at a depth of 33 metres. This meant that there was limited diving time and a team of 13 divers and two decompression chambers were required to be able to work through the day.

After installing the PLIDCO clamps, they had to be welded with an ‘A height’ of 10 mm (eight beads of weld to make one weld!)

This was done in the dry in a habitat. Two divers entered the habitat at the same time to achieve a certified weld.

The project was concluded successfully, on time and within budget.

Categories: Civil Underwater Construction, Inshore, Offshore construction, Oil and Gas, Pipelines

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Enecogen Rotterdam

ducmarinegroup — Thu, 14 Jan 2016 16:00:32 +0000

ENECOGEN ROTTERDAM

Power Plant, Rotterdam

DUC Marinegroup in cooperation with BAM installed two cooling water inlets for a power plant in Rotterdam.

This was completed to the complete satisfaction of the client.

In addition DUC installed concrete “slides” for the outlets of the cooling water pipes, so prevent the water being pumped back into the harbour from producing too much foam.

Categories: Civil Underwater Construction, Inshore, Maintenance and Repairs

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