초록 ▼

There is described a vessel such as a semi-submersible drilling unit having a drilling deck structure with a plurality of columns depending from the deck. Pontoons are provided at the ends of the columns and a buoyant configuration modifying sleeve-like element is mounted around the columns. The sle

There is described a vessel such as a semi-submersible drilling unit having a drilling deck structure with a plurality of columns depending from the deck. Pontoons are provided at the ends of the columns and a buoyant configuration modifying sleeve-like element is mounted around the columns. The sleeves are annular in cross-section and of generally cylindrical form and terminate at their lower ends in cuffs of reducing outer diameter. This provides an inwardly tapered or curved end to the sleeve. A cable and pulley arrangement is provided for vertically moving the sleeves along the columns and for locating them on the columns close to the unit transit waterplane and at a survival waterplane position.

대표청구항 ▼

A semi-submersible column stabilized vessel of the type that is afloat and at anchor or dynamically positioned when in on site operation and which has its centre of buoyancy located beneath its centre of gravity, comprising a deck structure; a plurality of columns depending therefrom; pontoon means

A semi-submersible column stabilized vessel of the type that is afloat and at anchor or dynamically positioned when in on site operation and which has its centre of buoyancy located beneath its centre of gravity, comprising a deck structure; a plurality of columns depending therefrom; pontoon means on at least one of said columns; said deck structure, columns and pontoon means being of fixed permanent configuration with respect to each other, a buoyant configuration modifying element on at least one of said columns; and means for translating the buoyant configuration modifying element along its associated column with respect to the waterline when the vessel is afloat and for locating said element close to a transit waterplane of the vessel and at a survival waterplane position, on said associated column, without essentially changing the height of the vessel.