SURVEY AND INSPECTION

We provide Survey and Inspection services for Inshore and Offshore locations.

Offshore

For offshore inspection, we deploy our divers and ROV to inspect conditions of soil, underwater structures, pipelines and cables. Our divers are able to dive down to 50 meters to take seabed samples, perform drilling or carry out visual inspections. We use Non-Destructive or Partially Destructive methods to carry out inspections and surveys.

DUC owns specialized equipment such as CP-meters (Cathodic Protection meters), Wall Thickness Gauges, ROV and Side Scan Sonar. Upon request our divers can capture the survey on video with underwater cameras. Furthermore, our vessel ‘Ram’ has capacity for an on-board laboratory, suitable for drying samples and carrying out sieve analysis.
Our expertise with offshore inspection, maintenance, repairs and corrosion protection has helped to prevent damage to numerous pipelines, buoys, construction piles, etc.

Inshore 

For inshore inspection, we often deploy our divers to inspect the condition of the soil or underwater structure. Our divers are able to take sludge samples, perform drilling or visually inspect the soil or structure of the object. Specialized equipment such as CP-meters (Cathodic Protection meters), wall thickness gauges and other materials are at their disposal, and upon request the divers capture the survey on video with underwater cameras.

We use Non-Destructive or Partially Destructive methods to carry out inspections and surveys. Drilling and other Partially Destructive methods can be efficient for survey and soil sampling, however they are slightly invasive to soil conditions or the materials.

When Non-Destructive methods are required, our divers have the necessary skills and experience to see and feel the conditions of the structures in often limited- or zero-visibility conditions.

Offshore Corrosion Prevention

We understand that the underwater environment can be particularly harsh on structures. Corrosion prevention of sheet piles, pipelines and other materials is of paramount importance to maintain the integrity of underwater structures. By performing regular inspections, we are able to detect corrosion or damage at an early stage. Depending on your requirements, we either provide you with a report and recommendations on the condition of the materials, or carry out the repairs and preservation work straightaway.

Non-Destructive and Partially Destructive Testing & Sampling

We also carry out underwater soil surveys. We have specialized equipment to take seabed soil samples, either by Partially Destructive or Non Destructive methods.
Drilling and other Destructive methods can be efficient for survey and soil sampling, however they are invasive to soil conditions or the materials. When Non-Destructive methods are required, we will use ROV, Side Scan Sonar and cameras. Our divers have the necessary skills and experience to see and feel the conditions of the structures in often limited- or zero-visibility conditions.

Side Scan Sonar Inspection

We also offer the possibility of offshore surveys using our own Side Scan Sonar. Side Scan uses a sonar device that emits pulses down toward the seafloor across a wide angle perpendicular to the path of the sensor through the water. The device is pulled along the seafloor by one of our vessels. The intensity of the acoustic reflections from the seafloor of this fan-shaped beam is recorded in a series of cross-track slices. When stitched together these slices form an image of the sea bottom. This is an excellent way to detect objects on the sea bottom and produce an precise map of objects such as boulders, gravel, wrecks, cables and pipelines.

ROV Survey

If required, we can perform a visual survey by remote control using our own ROV (Remotely Operated Vehicle). The digital footage of the ROV’s underwater inspection can be recorded and made available to our customers. Further drilling and vibro-core surveys can also be performed by remote control . Our ROV can be deployed to take samples, detect corrosion, measure wall thickness and other kinds of underwater survey and inspection work.
An example is a recent project in Romania where we performed a complete Remotely Operated Core Sampling. We performed this project using several drills and our ROV.

UXO Clearance

UXO (Unexploded Ordnance) clearance is often a necessary step in many offshore construction projects. Specifically for Offshore Wind Power (Renewables), locating unexploded ordnance on the seabed is an important first step. Most renewables projects in the North Sea, for example, require UXO detection and clearance. DUC Marine Group has extensive expertise with UXO detection and clearance. Currently we are working at the DolWin project in German waters. With our combination of experienced divers and experts, equipment and specialized vessels, we are able to provide complete UXO solutions.

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