Single Buoy Mooring - Wikip.
Single Buoy Mooring - Wikip.
Single Buoy Mooring - Wikip.
org/wiki/Single_buoy_mooring
Contents
Single Point Mooring Facility off Puthuvypin, Kochi,
1 Parts of a Single Point Mooring India
1.1 Buoy body
1.2 Mooring and anchoring parts
1.2.1 Mooring components
1.2.2 Hawser Arrangement
1.3 Product transfer system
1.3.1 Risers
1.3.2 Floating Hose String
1.3.3 Product Swivel
1.4 Other Components
2 Major agencies connected with SPMs
Buoy body
Moorings fix the buoy to the seabed. Buoy design must Commercial crude oil supertanker AbQaiq.
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account for the behaviour of the buoy given applicable wind, wave and current conditions and tanker sizes. This
determines the optimum mooring arrangement and size of the various mooring leg components. Anchoring
points are greatly dependent on local soil condition.
Mooring components
Hawser Arrangement
A tanker is moored to a buoy by means of a hawser arrangement. Oil Companies International Marine Forum
(OCIMF) standards are available for mooring systems.
The hawser arrangement usually consists of nylon rope, which is shackled to an integrated mooring uni-joint on
the buoy deck. At the tanker end of the hawser, a chafe chain is connected to prevent damage from the tanker
fairlead. A load pin can be applied to the mooring uni-joint on the buoy deck to measure hawser loads.
Hawser systems use either one or two ropes depending on the largest size of vessel which would be moored to
the buoy. The ropes would either be single leg or grommet leg type ropes. These are usually connected to an
OCIMF chafe chain on the export tanker side (either type A or B depending on the maximum size of the tanker
and the mooring loads). This chafe chain would then be held in the chain stopper on board the export tanker.
A basic hawser system would consist of the following (working from the buoy outwards):
Buoy Side Shackle and bridle assembly for connection to the padeye on the buoy; Mooring Hawser Shackle;
Mooring Hawser; Chafe Chain Assembly; Support Buoy; Pick-up / Messenger Lines; Marker Buoy for retrieval
from the water.
Under OCIMF recommendations, the hawser arrangement would normally be purchased as a full assembly from
a manufacturer.
The heart of each buoy is the product transfer system. From a geostatic location, e.g. a pipeline end manifold
(PLEM) located on the seabed, this system transfers products to the offtake tanker.
Risers
The risers are flexible hoses that connect the subsea piping to the buoy. Configuration of these risers can vary
depending on water-depth, sea state, buoy motions, etc.
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Floating hose string(s) connect the buoy to the offloading tanker. The hose string can be equipped with a
breakaway coupling to prevent rupture of hoses/ hawser and subsequent oil spills.
Product Swivel
The product swivel is the connection between the geostatic and the rotating parts of the buoy. The swivel
enables an offloading tanker to rotate with respect to the mooring buoy. Product swivels range in size depending
on the size of attached piping and risers. Product swivels can provide one or several independent paths for
fluids, gases, electrical signals or power. Swivels are equipped with a multiple seal arrangement to minimise the
possibility of leakage of product into the environment.
Other Components
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