Moorings

Secure Mooring System

Tri-Catenary mooring systems (TCMS) provide a secure mooring system, particularly when used with storage tankers and floating production, storage and offtake (FPSO) vessels

All mooring system design codes require there to be a means of safe positioning in the event of a single line failure. The TCMS offers a choice of options to ensure that there are no single point failure modes; this can either be with the use of additional mooring legs and a redundant chafe chain; or, as has been approved by a number of Classification Societies, a package of individual measures which together have been accepted as providing an adequate level of protection. One of these measures is an enhanced strength factor of safety for non-redundant systems, which is recognised in the latest version of the DNV Position Mooring Code OS-E-301. This measure takes advantage of the efficiency of this type of mooring system, where the peak mooring forces can be reduced by “tuning” the mooring system’s response to match the vessel’s response in severe weather.

The Tri-Catenary Mooring System can be tuned by the careful design of such factors as the length of the chafe chain and the mass of the node. Thus, use of larger components to increase the strength, and reduce the risk of equipment failure, is not financially burdensome.

By using three lines compared with other mooring systems including CALM buoys and turrets which have typically 6, 8, or more legs, the TCMS is quicker to deploy and less ‘stiff’ than other tanker moorings. This ensures that the tanker’s natural fore and aft motions, with the right engineering, can be damped by the mooring catenaries and the pendulum effect of the chafe chain.

Contact Details

Aberdeen Tel:+44 (0) 1224 624666

Montrose Tel:+44 (0) 1674 671895

Montrose Fax:+44 (0) 1674 671474

Email Address:d.duncan@mooringsystemsltd.com

Projects

DIDON TCMS Installation

Location: Tunisia Client: PA Resources Water Depth: 80m No. of Risers: 1 + Umbilical Seastate: Hs = 7m

Westaf Stand Alone Mooring

Location: Nigeria Client: ABC Maritime Water Depth: 65m Tanker: 250,000 DWT Seastate: Hs = 5m

Riser Installation

Location: India Client: ONGC Mooring Systems installed a 400mt high pressure riser offshore India. Due to the nature of...

Blue Water /KD Marine Project

Location : Montrose quayside facility Client : Blue Water /KD Marine Services provided:Spooling operation,cranes, forkliftsrigging teams,storage, inside and outside.

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Equipment Hire

Mooring Components

The mooring node is for connecting the three legs for the TCMS mooring, and the chafe chain on the upper lug of the node. Built by Vicinay in Spain, the node weights 12 tonne and fits 130mm Shackles .

76mm RQ4 Chain

Mooring systems Limited has presently 20,000 ft of 76mm anchor chain grade R4 new and unused in stock. Manufactured by Vicinay in Spain this chain is available for rental or purchase.

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Recent Projects

PA Resources Project

Services provided: Engineering / Mooring team / rigging container c/w equipment / spooler and riser.

TruAxis Project

Services provided: Supply of Spooling equipment, installation rigging team .

PetroSA Project

Services provided: Supply of 500mt of Manuli riser. Spooling equipment / buoyancy / Riser design – analysis.

Kris Energy Project

Services provided: Project design, Supply of 4km of 4” and 6” Manuli hose . Buoyancy and inserts, Rigging supervision.

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