Preparation before Torpedo Anchor Installation Operation

  1. Test winch and chain lock/release system on deck of DP installation vessel.
  2. Check condition of shackle and mooring chain connection (pad-eye).
  3. Lay the anchor on deck of DP installation vessel.
  4. Connect mooring chain with the Torpedo anchor by using shackle as designed.
  5. Safety briefing and make sure that all the involved working crews in operation understand every steps of installation operation.

Installation Procedure for Torpedo Anchor Mooring

  1. Position DP installation vessel at design position.
  2. Lay the Torpedo anchor at stern of installation vessel.
  3. Start lowering the Torpedo anchor from the DP installation vessel.
  4. Monitor the length of the released chain and prepare to lock the mooring chain at the design free fall depth.
  5. Lock the mooring chain by using the 1st chain locking/release system on deck when the Torpedo anchor reaches the design free fall depth.
  6. Start lowering left part of the mooring chain at stern of the DP installation vessel.
  7. Continue lowering the mooring chain.
  8. Lock the mooring chain by using the 2nd lock/release system when the mooring chain reaches at the design length and prepare for the free falling the Torpedo anchor.
  9. Release the 1st lock/release system on deck
    .
  10. The Torpedo anchor free fall to seabed
    .
  11. The Torpedo anchor penetrates into the seabed and reaches the penetration depth and prepare for tension test.
  12. Start the tension test.
  13. Monitor the tension and stop tension at design tension value.
  14. Start moving the DP installation vessel to the mooring buoy or floating structure.
  15. Connect the mooring chain to the mooring buoy or floating structure.
  16. Disconnect the mooring chain from the DP installation vessel.

List of Equipments for Torpedo Anchor Installation Operation

    Torpedo Anchor Installation
  1. The DP installation vessel with enough deck space
  2. Winch system with design capacity and ability for free falling function
  3. Lock/release system on deck of the DP installation vessel

Materials for the Torpedo Anchor Installation Operation

For Torpedo anchor type 1 (140 ton holding capacity)

  • The 140 ton tension capacity Torpedo anchor and pad-eye
  • 105 mm heavy duty shackle at 150 ton safe working load (2 shackles for each mooring chain)
  • 58 mm studlink mooring chain - offshore grade 4 at 145 ton safe working load (290 ton proof load and 370 ton MBL)

For Torpedo anchor type 2 (300 ton holding capacity)

  • The 300 ton tension capacity Torpedo anchor and pad-eye
  • 140 mm heavy duty shackle at 300 ton safe working load (2 shackles for each mooring chain)
  • 87 mm studlink mooring chain – offshore grade 4 at 308 ton safe working load (616 ton proof load and 783 ton MBL)

For Torpedo anchor type 3 (750 ton holding capacity)

  • The 750 ton tension capacity Torpedo anchor and pad-eye
  • 210 mm heavy duty shackle at 800 ton safe working load (2 shackles for each mooring chain)
  • 147 mm studlink mooring chain – offshore grade 4 at 767 ton safe working load (1534 ton proof load and 1946 ton MBL)

Schedule

Some of the typical projects that we undertake include the engineering, procurement and installation of deepwater mooring systems of 8-15 torpedo anchors. Such a project will usually require 60 days from conception to realisation. Below is the planning of a typical project.
typical mooring project-shedule

The following assumption were made:

  1. This project is approx. 400 km from shore
  2. Water depth is approx. 500 m
  3. There are 8 Torpedo mooring anchors to be installed
  4. Vessel transit speed is 10 knots

Time saving features

One of the key features of our new series is that the weight of the anchor can adapt easily by changing the density of the filling material. Thus, the shape and dimensions of the anchor are kept at the three standardised sizes while the penetration depth can vary in order to achieve the require mooring capacity.

The previous feature allows us to maintain a stock of anchors that are ready to employed in a very short time.