Offshore Pipe Lay Vessel Jobs
Pipelaying Vessel Jobs
Ashore amenities to arrange the pipeline have innate plus points
that they are not influenced by sea
rough conditions and are much economical than on site sea operations.
Some vessels are additionally fitted with the pipelaying facilities
on board along with their main activity. For these offshore ships to work,
first pipelines are assembled ashore and then winded up on the large winches.
installed on board such a ships or barges.
Then these ships sail to the provided location for the pipelaying
project, and this process is called “reel lay method”. The supply of pipeline can be lined up: whilst one ship is engaged
in pipelaying job at location, another ship will be prepared for these work.
But this reel lay method, on the other hand, is only practical to
handle pipelines of lesser diameter of approx up to 350mm to 400 mm.
In addition, these pipes should be made of such a steel which should
be capable to go through the essential level of plastic bends when reeled
around the winch on which they are bent to appropriate curvature by a
spiral J-tube and also straightened back
by a straightener at the pipelaying location.
The foremost categories of vessels used for pipe laying are the
Pipelay Barge -LB, Derrick Barge-DB and Derrick-Lay barge-DLB which is a
combination of both LB and DB.
The offshore diving team in offshore construction uses a metal
basket driven from an "A" frame from the deck in water depth up to
120 feets i.e, upto 40 meters. The basket is lowered to the sea water, and the
divers then go into the water from it to a maximum of 120 feet (40 m).
In sea water deeper than that diving team deploys a “Diving Bells”.
The diving bells can be submerged up to 1,500 feet (460 m), but they are
generally applied at 400 to 800 feet i.e, from 120 to 240 meters.
