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).
Maersk Forwarder discharging deck cargo at Tiffany August 2015.
Glomar Java Sea
The rig's last dry dock was in San Francisco just prior to leaving for China circa 1982
With the BALDER VIKING,BOA BISON and the TOR VIKING II in the Cromarty Firth 30.3.16
Sailing in to Floroe, Norway.
Latitude 61.60207 Longitude 5.01275