Marine Constuction Boat Job US Employment Search
Maritime Jobs US Search
Offshore Construction
is the installation of structures and facilities in a marine environment, usually for the production and transmission of electricity, oil, gas and other resources.
Free Advertising - Get millions of visitors for your website for FREE!
Construction in the offshore environment is a difficult and dangerous activity. Construction and pre-commissioning is typically performed as much as possible on land or inshore areas. To optimize the costs and risks of installing large offshore platforms, different construction strategies have been developed.
Offshore construction includes the design, construction, and or repair of offshore structures, both commercial and military, including: Subsea oil and gas developments
Offshore platforms - Fixed Platforms, Semi-submersibles, Spars, TLPs, FPSOs, etc.
Floating Oil and Gas Platforms - Semi-submersibles, Spars, Tension-leg platforms (TLP's), FPSO
One strategy is to fully construct the offshore facility inshore, and tow the installation to site floating on its own buoyancy. Bottom founded structure are lowered to the seabed by de-ballasting (see for instance Condeep or Cranefree), whilst floating structures are held in position with substantial mooring systems.
The size of offshore lifts can be reduced by making the construction modular, with each module being constructed onshore and then lifted using a crane vessel into place onto the platform. A number of very large crane vessels were built in the 1970s which allow very large single modules weighing up to 14,000 tonnes to be fabricated and then lifted into place.
Tweet-for-Cash with SponsoredTweets
Specialist floating hotel vessels known as flotels are used to accommodate workers during the construction and hook-up phases. This is a high cost activity due to the limited space and access to materials.
The main types of vessels used for pipe laying are the "Derrick Barge (DB)", the "Pipelay Barge (LB)" and the "Derrick/Lay Barge (DLB)" combination. Diving Bells in offshore construction are mainly used in water depths greater than 120 ft, less than that, the divers use a metal basket driven from an "A" frame from the deck. The basket is lowered to the water level, then the divers enter the water from it to a maximum of 120 ft. Bells can go to 1500 ft, but are normally used at 400 to 800 ft.
