Underwater Construction Services- DSV Pipeline Scene

Underwater Construction Services - Coastal In Port Limits Geo Coverage (2)

Underwater Construction Services - Coastal-In-Port-Limits-Resources-2

Underwater Construction Services

We carry out a very wide range of underwater construction services in the offshore division, coastal division as well as inland:

Offshore Division

Underwater Pipeline Competencies:

Our service providers offer pre- tender consultancy services covering all managerial aspects of underwater pipeline construction services. Ranging from the pre- design phase through surface assembly, installation, operation, monitoring and survey routine from initial installation throughout the operational life span of the pipeline.

Such services include:

  • Seabed geotechnical video and photographic surveys during pre-tender consultancy phase and pipeline route feasibility studies
  • Flow assurance through adopting periodic pipeline pigging to de-wax and remove debris build up inside the line
  • Diffuser blanking installations, maintenance, repairs and surveys to facilitate efficient control of pipeline discharges
  • Cathodic protection surveys, supply and installation to control corrosion damage and subsea spool piece tie- ins
  • On- bottom pipeline stabilization through concrete collar and mattress installations or trenching and burial
  • Pipeline excavation for repairs, surveys and maintenance as well as subsea support services including anode supply and installation
  • Internal pipeline surveys and de- scaling as well as internal pipeline blanking with inflatable vetter bags


Coastal work covers all types of underwater port infrastructure development such as:

  • Caisson removals
  • Installations
  • Debris removals
  • Salvage
  • Quay wall repairs
  • Construction
  • Marina mooring installations
  • Surveys and routine maintenance

Hydrographical & Marine Geophysical Surveys

These services include:

  • Advanced marine geophysical surveying/ Single beam bathymetric survey/ Multi beam bathymetric survey
  • Side- scan sonar surveys/ Single channel seismic surveys/ Magnetometer surveys
  • Cable route surveys/ harbor development and debris surveys
  • Marine engineering site surveys/ Well site investigations
  • Marine GIS/ Vibrocoring and sample surveys
  • Scientific diving surveys/ Specialist instrumentation development



Underwater work carried out in dams and at hydro- electric power schemes is multi- faceted and involves surveys, repairs and routine maintenance.

Integrity Check Assessment

Assessments can be made on the following:

Splash pools, Sluice gates, Tailraces downstream for debris, Buoyancy service gates, Trash grid/ beams, Rack fins and screens, Sealing strips, Hydraulically operated valves, Pipes and scour intakes


Repairs And Maintenance Services

The following repairs and maintenance can be performed

  • Locating, measuring and fabricating of plates for underwater grouting purposes
  • Fitment of cofferdams
  • Fitment of plugs into sleeve valves
  • Cleaning/ unblocking or removal of collapsed of damaged trash rack tins
  • Placement of plug type service gates in front of bank silt outlets
  • Stop log installation or removal

Other Services

Blasting, Jetting coring, Drilling, Welding, Cutting, Dewatering, Pumping, Pressure grouting, Salvage, Silt dredging, Debris removal, Leak detection and repair of reservoir linings, River depth surveys, Bridge corrosion and scouring surveys.