Offshore drilling structure

Claim 2

An offshore-drilling structure comprising: a. a hull, b. a working platform, c. support means for connecting said working platform to and in spaced relation above said hull, d. a movable stabilizing member extending substantially perpendicular to said platform and having a height greater than the maximum depth of water to which said hull is submerged, e. a hinge assembly attached to said structure and including an arm member rotatable about a vertical axis and fixedly attached to said movable stabilizing member for horizontally moving said movable stabilizing member between a first portion immediately adjacent said hull and a second position substantially outboard of said hull, f. means for adding ballast to said structure to submerge said hull, and g. means for removing ballast from said structure to float said structure with said hull having freeboard.

Claim 3

A structure as described in claim 1 wherein the hull of subparagraph (a) has a pointed bow and the bottom of said movable stabilizing member is located above the load water line when said hull has freeboard.

Claim 4

An offshore-drilling structure comprising: a. a hull, b. a working platform, c. support means for connecting said working platform to and in spaced relation above said hull including first vertically elongated stabilizing members, d. second vertically elongated stabilizing members positioned on both sides of said hull, e. means adapted for horizontally moving said second vertically elongated stabilizing members between a first position immediately adjacent said hull and a second position substantially outboard of said hull, including a pair of hinge assemblies for each second vertically elongated stabilizing member, each hinge assembly comprising a base member fixedly attached to said support means, a hinge plate rotatably attached to said base member and a sleeve fixedly attached to said hinge plate and rotatable therewith, and an arm extending between and fixedly attached to said sleeve and said second vertically elongated stabilizing member, f. means for adding ballast to said structure to submerge said hull, and g. means for removing ballast from said structure to float said structure with said hull having freeboard.

Claim 5

An offshore-drilling structure comprising: a. a hull, b. a working platform, c. support means for connecting said working platform to and in spaced relation above said hull including first vertically elongated stabilizing members, d. second vertically elongated stabilizing members positioned on both sides of said hull, e. means adapted for horizontally moving said second vertically elongated stabilizing members between a first position immediately adjacent said hull and a second position substantially outboard of said hull, including a pair of hinge assemblies for each second vertically elongated stabilizing member, each hinge assembly comprising a base member fixedly attached to said support means, a hinge plate rotatably attached to said base member and a sleeve fixedly attached to said hinge plate and rotatable therewith, and an arm extending between and fixedly attached to said sleeve and said second vertically elongated stabilizing member, f. means for adding ballast to said structure to submerge said hull, and g. means for removing ballast from said structure to float said structure with said hull having freeboard.

Claim 6

A structure as described in claim 3 including means to rigidly secure each second vertically elongated stabilizing member in said second position comprising brace members extending between and fixedly attached to said second vertically elongated stabilizing member and said support means and a ring fixedly attached to said sleeve and said base member.

Claim 7

An offshore-drilling structure comprising: a. a hull, b. a working platform, c. support means for connecting said working platform to and in spaced relation above said hull including first vertically elongated stabilizing members, d. second vertically elongated stabilizing members on both sides of said hull, e. mEans adapted for horizontally moving said second vertically elongated stabilizing members between a first position immediately adjacent said hull and a second position substantially outboard of said hull, f. means for adding ballast to said structure to submerge said hull, g. means for removing ballast from said structure to float said structure with said hull having freeboard, said hull includes recesses complementary to the configuration of the lower ends of said second vertically elongated stabilizing members and positioned to receive said lower ends when said second vertically elongated stabilizing members are in said first position.

Claim 8

An offshore-drilling structure comprising: a. a hull, b. a working platform, c. support means for connecting said working platform to and in spaced relation above said hull including first vertically elongated stabilizing members, d. second vertically elongated stabilizing members on both sides of said hull, e. mEans adapted for horizontally moving said second vertically elongated stabilizing members between a first position immediately adjacent said hull and a second position substantially outboard of said hull, f. means for adding ballast to said structure to submerge said hull, g. means for removing ballast from said structure to float said structure with said hull having freeboard, said hull includes recesses complementary to the configuration of the lower ends of said second vertically elongated stabilizing members and positioned to receive said lower ends when said second vertically elongated stabilizing members are in said first position.

Claim 9

A structure as defined in claim 1 wherein the hinge assembly of subparagraph (e) further includes a base member fixedly attached to said support means, a hinge plate rotatably attached to said base member and a sleeve fixedly attached to said hinge plate and said arm member and rotatable therewith.

Claim 10

A structure as defined in claim 6 including means to rigidly secure said movable stabilizing member in said second position comprising brace members extending between and fixedly attached to said movable stabilizing member and said support means and a ring fixedly attached to said sleeve and said base member.

Claim 11

A structure as described in claim 1 wherein said hull includes a recess complementary to the configuration of the lower end of said movable stabilizing member and positioned to receive said lower end when said movable stabilizing member is in said first position.

Claim 12

A structure as described in claim 1 wherein the support means of subparagraph (c) includes fixed vertically extending stabilizing members, a movable stabilizing member as described in subparagraph (d) is positioned on each side of said hull, and a hinge assembly as described in subparagraph (e) is provided for each movable stabilizing member.

Claim 13

A structure as described in claim 9 wherein each hinge assembly of subparagraph (e) further includes a base member fixedly attached to said support means, a hinge plate rotatably attached to said base member, and a sleeve fixedly attached to said hinge plate and said arm member and rotatable therewith.