Neptune ehf has successfully completed munitions detection, identification and clearance services in the 125km long Russian sector survey corridors in preparation for the laying of two 48 inch diameter (1200mm) gas pipelines to link the Russian Federation and the European Union via the Baltic Sea. The project started in December 2008 and was completed in June 2010.
After successfully being awarded several extensions to the original contract, the final works ultimately comprised almost 2000km of gradiometer surveys, sixteen cable crossing surveys and nineteen wreck inspection surveys.
The ROV mounted Innovatum 12 gradiometer array proved to be an outstanding instrument that was capable of accurately detecting the localised distortion of the earth’s magnetic field by very small ferro-magnetic causative bodies, performing above and beyond the required parameters.
As the results from the initial works were being compiled in near real time, they provided a highly dynamic follow-up work scope for the close visual inspection of more than 2500 magnetic gradient anomaly locations, two highly detailed sidescan and ROV surveys of wrecks that were considered of significant cultural and historical value, and the de-burial of numerous sites where potentially dangerous munitions were suspected to be concealed by the seabed sediments.
Ultimately, scores of individual munitions related targets were detected on initial survey data and verified by subsequent visual inspections. Forty nine munitions items were considered to be dangerous and were cleared by Neptune ehf in conjunction with a specialist contractor using controlled explosions to allow the safe installation and operation of the Nord Stream Pipelines.
The Ice Class DP1 MV Neptune, which is fully equipped for both geophysical survey and ROV operations, performed extremely well in this demanding environment where typical annual temperatures range from -13 to +21°C.
More information can be found at www.nord-stream.com.
