Works on the seabed


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Here you can read about the general guidelines for works on the seabed, works with submarine cables and pipelines as well as raw material extraction.

Before you start working, you must apply for a permit from the responsible Government authority:
Danish Coastal Authority: Fixed installations and geotechnical investigations in territorial waters. 
Danish Energy Agency: Laying electrical cables and oil and gas pipelines on the seabed.
Danish Nature Agency: Extraction of raw materials from the seabed.

As regards safety of navigation, you must follow the general guidelines for construction works at sea.

Submarine cables and pipelines

During the construction phase, the Danish Maritime Authority will establish a protective zone of 200 metres on both sides of the cable and/or pipeline lay-out, which applies from its publication in Notices to Mariners. In the protective zone, anchoring, dredging, boulder fishing and using dragging gear are prohibited. The permanent protective zone is established by drawing the submarine cable or the pipeline in the chart.

The protective zone is established in pursuance of order no. 939 of 27 November 1992 on protection of submarine cables and submarine pipelines (the cable order), which does however not apply within the territorial waters of a port. The main purpose of the protective zone is to protect the interests of the submarine cable or the pipeline owner.

Submarine works or activities must not be made within the protective zones of submarine cables or pipelines without previous agreement with the submarine cable or pipeline owner. Details about submarine cables and pipelines in the area can be sought from the register of pipelines www.ler.dk or from the pipeline owner. Submarine cables can also be seen on www.dkcpc.dk (Danish Cable Protection Committee).

Register of pipeline owners

As already described, mandatory registration of submarine cables and submarine pipelines as well as examination of the existence of such cables and pipelines in a planned work area is made on the webpage of the Register of pipeline owners: www.ler.dk

Loss of fishing potential

If you as a fisherman experience a loss of commercial income, you can apply for compensation from the owner, cf. the act on fishing. Alternatively, the pipeline owner can consider locating the submarine cable or the pipeline as deep into the seabed that they are protected against damage from dragging tools and, thus, be granted an exemption from the prohibition. The owner of a submarine cable or pipeline can forward an application to the Danish Maritime Authority for an exemption from the prohibition against the use of dragging tools in the protective zone of submarine cables or pipelines by forwarding a declaration stating that the submarine cable or the pipeline would not be at risk of being damaged if dragging tools are being used.

Work vessels

Click for information about work vessels and guard vessels in connection with works on the seabed.

Work areas

If there is a need to establish areas with navigational restrictions in connection with the work, an application must be forwarded to the Danish Maritime Authority. Click here to get a template for the establishment of areas of restriction.

HSC routes in or around work areas

If the area where the work takes place is traversed by a HSC route, it must be noticed that, especially in calm weather and in connection with voyages or anchoring at low water depths, waves from HSC may involve an increased risk of shipwreck and groundings. Small vessels should display special attention when navigating or anchoring close to HSC routes. At larger depths, the nuisance caused by the HSC waves is reduced. The measures to be taken to counter these waves will be the same as in connection with voyages in areas with other types of ship traffic.

Furthermore, you must

  • contact the shipowner to ensure that the work does not affect the safe operation of the HSC on the route plotted in the chart that the HSC is obliged to follow;
  • be aware that the depth conditions within 1000 metres of a HSC route must not be changed.

Areas of prohibition in work areas, etc.

Each year's first edition of Notices to Mariners includes, in article A/7, notices about areas in which warnings have been issued against anchoring, fishing with dragging tools as well as works on the seabed.
 
Order no. 135 of 4 March 2005 on prohibition against navigating, anchoring and fishing, etc. in certain areas in Danish waters (Danish) issued by the Danish Maritime Authority lays down restrictions for works on the seabed in certain areas.
 It must always be examined whether special restrictions for works on the seabed, etc. apply in the area concerned.

Ammunition and suspicious objects on the seabed

Stop the work and contact the Naval Staff, telephone +45 8943 3099 and email: VFK@mil.dk if, during the work, ammunition remains are found on the seabed (Unexploded Ordnance UXO) or other suspicious objects.

Permit to work in areas of prohibition

Order no. 135 of 4 March 2005 on prohibition against navigation, anchoring and fishing, etc. in certain areas in Danish waters contains a prohibition against navigation, etc. due to deployed mines and other objects containing explosives. The following procedure must be followed in order for the Danish Maritime Authority to grant exemptions from the prohibition against navigation in these areas:

  1. The corridor in the area of prohibition that is to be investigated in connection with coming cable work must, initially, be investigated and checked for deployed mines and other objects containing explosives. A plan for this pre-investigation and work method is to be forwarded to the Naval Staff/Mine Service for approval with a copy to the Danish Maritime Authority. The coordinates of the corridor must be given in datum WGS 84 and information must be provided about the ship or vessel used for this purpose.
  2. Once the Naval Staff/Mine Service has approved the pre-investigation plan in writing, with a copy to the Danish Maritime Authority, a permit may be granted for navigating the corridor with the purpose of making a pre-investigation for deployed mines and other objects containing explosives. In case any objects are found, the guidelines issued by the Naval Staff/Mine Service must be observed. Furthermore, the pre-investigation must state to which depth below the seabed investigations have been made.
  3. The results of the pre-investigations are forwarded to the Naval Staff/Mine Service, which is subsequently to approve subsequent navigation by large ships, any more in-depth cable investigations in the area as well as any subsequent works in the seabed to the depth investigated. Then, the Danish Maritime Authority will grant a written permit for navigation in the corridor with the purpose of carrying out the works planned.

 Contact

Safety of Navigation, National Waters
Flemming Sparre Sørensen, Nautical Adviser
+45 72 19 61 78