Maintenance & Repairs Archives - DUC Marine Group

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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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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Wall thickness measurements in Georgia

ducmarinegroup — Thu, 14 Jan 2016 15:54:49 +0000

WALL THICKNESS MEASUREMENTS IN GEORGIA

Georgia, Europe

At the end of 2011, DUC Marinegroup performed wall thickness measurements on a quay wall made of sheet piling with a cap. The quay wall was 360 metres long and measurements had to be taken at four places to a depth of 10 metres. Using a wall thickness meter, a diver took readings at the specified places.

Categories: Maintenance and Repair, Inshore, Non-Destructive Testing, Offshore, Preservation, Survey and Inspection

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Mauritanian iron ore jetty

ducmarinegroup — Thu, 14 Jan 2016 15:46:53 +0000

MAURITANIAN IRON ORE JETTY

Mauritania, Africa

During a five-year project, DUC Marinegroup performed maintenance to an iron ore jetty in Mauritania, Africa.

The jetty was protected by anodes that had to be checked. As anodes decay in the course of time, regular maintenance and repair is necessary.

DUC Marinegroup has its own equipment to carry this out, including C.P. meters and wall thickness meters for use under water. Anodes that did not function correctly were replaced or additional anodes were installed.

Categories: Maintenance and Repair, Inshore, Offshore, Cathodic Protection, Civil Underwater Construction, Non-Destructive Testing, Preservation

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Inspect, testing and replacing of anodes

ducmarinegroup — Thu, 14 Jan 2016 15:37:34 +0000

INSPECT, TEST AND IF REQUIRED REPLACE ANODES

Port of Rotterdam and Amsterdam, The Netherlands

In the Port of Rotterdam and Amsterdam, DUC Marine Group regularly checks anodes and replaces them if necessary. Not only in the Netherlands we inspect and replace anodes but all over the world. Regular exchanging of anodes are performed in United Kingdom, Africa and Europe.

Categories: Maintenance and Repairs, Inshore, Offshore, Non-Destructive Testing, Survey and Inspection, Cathodic Protection, Civil Underwater Construction

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M.E.T. pile encapsulation

ducmarinegroup — Thu, 14 Jan 2016 15:29:48 +0000

M.E.T. Pile Encapsulation

Port of Rotterdam, The Netherlands

At the Maatschap Europoort Terminal (M.E.T.) in the 7th Petroleum harbour of Rotterdam, DUC Marinegroup together with Henskens B.V. cleaned the piles on which the sea mooring is built and preserved them both above and below the waterline.

This was done using a company-developed robot jet. This robot is first suspended and then used to clean the piles (using a water jet) both above and below the waterline. A polyester jacket is then wrapped around the pile and sealed. From below, this jacket is flushed out and then injected with two-component epoxy resin.

Categories: Cathodic Protection, Civil Underwater Construction, Inshore, Maintenance and Repairs, Oil and Gas, Preservation

Watch the video:

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Vopak pile encapsulation

ducmarinegroup — Thu, 14 Jan 2016 15:19:18 +0000

VOPAK PILE ENCAPSULATION

Port of Rotterdam, Nederland

At Vopak in the port of Rotterdam, DUC Marinegroup blasted and preserved steel piles in a five-year project by high-pressure water cleaning and installing polyester shells to then inject them with a 2-component epoxy resin so that the shell is glued to the pole. ” is going to be.

This gives the steel pole a kind of paint coating of approx. 1 cm thick. This will stop the pole from rusting on the wind water line.

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Salvage of a dry dock

ducmarinegroup — Tue, 22 Dec 2015 20:57:12 +0000

SALVAGE DRY DOCK

In Sluiskil, DUC Marinegroup was contracted to salvage the sunken Dry Dock B of the Schroef shipyard. After being awarded this contract, DUC immediately sent its seaworthy diving vessel and workship “RAM” to the scene.

The dock that weighs approximately 1,700 tonnes and measures approximately 96 m x 21.50 m has walls approximately 9 m high. The dock sunk following a technical fault.
As the dock sunk it listed, which ripped the guides around the guide piles from the sides of the dock. This created two extremely large holes of approximately 6 x 3 m.
The DUC divers cut various holes in the walls to gain access to the side tanks. The holes were repaired from the inside out using steel plates and then sealed using underwater concrete and epoxy.

The next step was installing pipes to facilitate the installation and connection of suction hoses. With ten large salvage pumps, the water was then pumped out of the buoyancy tanks to refloat the dock. The adhesion of the bottom of the dock to the bed of the harbour was overcome using chains and air lances.

As the dock was raised, the other side wall proved to be in such poor condition that as the water was pumped out, the sides buckled inwards completely and tore. As a preventive measure, the dock was allowed to settle back down and the entire length of the side buoyancy tank was filled with air bags between the frames. Air compressors and individual hoses were then used to fill all of these bags to provide sufficient support against the water pressure.

The dock was then successfully refloated. After being refloated, all of the remaining cracks and holes were repaired, which took two weeks. The salvage pumps were used to keep the dock afloat. The general condition of the dock was so bad that it can no longer be used and had to be demolished in situ. Salvage dry dock!

Categories: Inshore, Salvage, Maintenance and Repairs

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Grout lines removed

ducmarinegroup — Tue, 22 Dec 2015 08:49:56 +0000

GROUT LINES 28.4 KM REMOVED

Contract
In the middle of August 2013 DUC Marinegroup received a contract from RWE Innogy, for works on the offshore windfarm Nordsee Ost, located some 30 km North-East of the Island of Heligoland in the German Bight. The contract comprised the removal of temporary grout and hydraulic lines, which were utilized during the installation of 49 offshore foundation jackets during the winter season in the North Sea.

The jackets were installed for the later mounting of the 6 megawatt turbines. The hoses run from a service station at the top of the jacket (25 m above MSL), on the outside of the structure over the bracings to the foundation sleeves at the bottom (25 m below MSL). A typical jacket was fitted with 4 hydraulic lines and 8 grout lines.

Partnership
For the industrial climbing works DUC Marinegroup teamed up with the Rope Access Group from the Netherlands. It proved to be a very fruitful partnership between DUC and the Rope Access Group teams, to be continued again.

Personnel and equipment
Directly after signing the contract a project team was set up and work preparations commenced. Instead of a DP-2 vessel DUC chose to deploy a big multicat to be converted into a dive support vessel. In less than three weeks DUC mobilized the following:
–   A full Rope Access Team;
–   A crew transport vessel;
–   A full dive team;
–   A dive support vessel with a three point mooring, a LARS-system, a combined dive control/deco container, a nitrox container, 3 extra TLQ’s with 8 persons capacity and an office;
–   A 10 m RIB with a SRS-system.

Home port for the operations was the island of Heligoland. In the south-harbour a temporary stockpile was set up to store the removed hoses. Whenever possible, the dive support vessel stayed offshore and divers worked in 24-7 shifts, whereas the Rope Access team worked 12 hr shifts and sailed every day by CTV to and from Heligoland.

The grout lines were left partly filled with grout. The hydraulic lines still contained hydraulic oil. Before cutting the hydraulic lines all underwater valves had to be opened by the divers. The RAT-team flushed the lines with fresh water and detergent. All out coming fluids were collected and disposed. The service stations were then removed.
In total DUC had to remove some 28.4 km of hoses. The divers and the RAT-team used special hydraulic tools to cut the lines in easy manageable lengths, which were then stored in skips onboard the dive support vessel.

Satisfied by the accomplished work DUC Marine Group was assigned – during the job by RWE Innogy to carry out extra diving activities in the wind farm:
– The installation of several sonar- and motion transponders;
– The removal of debris in the proposed cable array;
– Inspection of several J-tube bellmouths;
– Inspection – and repairs of gratings, railings etc. after recent storm damage.
During the project the DUC fleet increased. During the busiest period DUC was in Heligoland with two dive support vessels, two dive teams, three CTV’s, an anchor handling tug and two RAT-teams.
Logistically, DUC Marine Group faced a lot of downtime due to inclement weather conditions during the winter working season.
However the project was successfully completed in good time and much quicker than anticipated, without any injuries and to the full satisfaction of our client RWE Innogy.

Categories: Offshore, Maitenance and Repairs, Offshore Construction and Installation, Renewables, Rope Access, Survey and Inspection, Wind Park

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