FEColumns - stability columns for semisubmersible offshore units

The concept is based on a symmetrical installation of, for example, two columns, port and starboard, which will increase the deckload capacity by about 1,000 tonnes for a North Sea semisubmersible. Optionally, the diameter may be adjusted to suit individual deckload requirements. The column is prefabricated to make the yardstay as short as possible.

Main features:

The FEColumn provides the following features:

• Rigid lower foundation, which takes the load from seawater tank and structure, and bending moments from collision or waves
• Flexible upper foundation, which takes horizontal loads and no moments
• Void space in the lower part with leak detection
• Bilge ejector in case of leakage in the void space
• Seawater tank in the upper part for improved roll and pitch motions in case of small amount of deckload onboard
• Filling line to the seawater tank from general service line
• Dump valve with big diameter in bottom of seawater tank, for quick dumping of content
• Air and Sounding pipe above top of column
• Boat bumper with rubber tires from airplanes
• Internal ladder for access, inspection, and maintenance of structure, valves and equipment

References:

“Byford Dolphin”
“Borgsten Dolphin”
“Borgny Dolphin”
“Borgland Dolphin”