Drilling Rigs - Semi-Submersible
A Semi-submersible platform or rig, is a mobile structure used for drilling for oil and natural gas in offshore environments. Their superstructures are supported by columns sitting on hulls or pontoons which are ballasted below the water surface. They provide excellent stability in rough, deep seas. Semi-submersible rigs can be moved from place to place; and can be ballasted up or down by altering the amount of flooding in buoyancy tanks; they are generally anchored by cable anchors during drilling operations, though they can also be kept in place by dynamic positioning. Semi-submersibles can be used in depths from 600 up to 35,000 feet (180 to more than 10,600 m).
JW Mclean and Stena Spey
You go on a holiday to Scotland, have a nosey along the Cromarty Firth and lo and behold there are t...
Ocean Princess in dock at Invergordon. Taken October 2011.
Taken May 2011 Signal shipyard, Pascagoula MS.
This is the old Kingsnorth UK, which has had various...
Transocean Driller leaving Port of Rio after shipyard period. January 2010 Rio de Janeiro, Brazil.
Newly completed Petrobras 56 leaving shipyard.
Brasfels, Angra dos Reis, Brazil, June 2011