Abstract: A system for hoisting a load on a drilling rig includes: a hoisting means having an elongated hoisting member and an elongated hoisting member drive means; a drill string rotation means suspended from an end of the elongated hoisting member; a support structure having a first side and a second side and being adapted to support at least a portion of the weight the drill string rotation means; a first elongated hoisting member guiding means connected to the support structure; and a counterweight connected to the elongated hoisting member at the second side of the support structure. The elongated hoisting member is reeved over the first elongated hoisting member guiding means from the first to the second side of the support structure.

Abstract: A travelling crane arrangement provided on a floating vessel having a deck and a pair of substantially parallel tracks comprises a pair of uprights configured to move along the respective tracks. In addition, the travelling crane arrangement comprises a transverse beam extending between said uprights across the deck of the vessel in spaced relation thereto. Further, the travelling crane arrangement comprises a trolley configured to move along the beam. The trolley carries at least part of a lifting mechanism configured to lift a load above the deck. Still further, the crane arrangement includes a support selectively positionable in a brace position extending between the deck and the trolley. In the brace position, the support is configured to at least partially support the beam in compression during use of the lifting mechanism to lift or otherwise support the weight of a load.

Abstract: A method for changing a chain wheel, a first chain wheel being on an axle, the method comprising (a) positioning a hydraulic cylinder at least partially within the axle. In addition, the method comprises (b) moving the first chain wheel off the axle with the hydraulic cylinder. Further, the method comprises (c) connecting the first chain wheel to a conveying device while the first chain wheel is held in position by the hydraulic cylinder. Still further, the method comprises (d) connecting a second chain wheel to the hydraulic cylinder while the second chain wheel is held in position by the conveying device. Moreover, the method comprises (e) moving the second chain wheel onto the axle with the hydraulic cylinder.

Abstract: A travelling crane arrangement provided on a floating vessel having a deck and a pair of substantially parallel tracks comprises a pair of uprights configured to move along the respective tracks. In addition, the travelling crane arrangement comprises a transverse beam extending between said uprights across the deck of the vessel in spaced relation thereto. Further, the travelling crane arrangement comprises a trolley configured to move along the beam. The trolley carries at least part of a lifting mechanism configured to lift a load above the deck. Still further, the crane arrangement includes a support selectively positionable in a brace position extending between the deck and the trolley. In the brace position, the support is configured to at least partially support the beam in compression during use of the lifting mechanism to lift or otherwise support the weight of a load.

Abstract: A method for changing a chain wheel, a first chain wheel being on an axle, the method comprising (a) positioning a hydraulic cylinder at least partially within the axle. In addition, the method comprises (b) moving the first chain wheel off the axle with the hydraulic cylinder. Further, the method comprises (c) connecting the first chain wheel to a conveying device while the first chain wheel is held in position by the hydraulic cylinder. Still further, the method comprises (d) connecting a second chain wheel to the hydraulic cylinder while the second chain wheel is held in position by the conveying device. Moreover, the method comprises (e) moving the second chain wheel onto the axle with the hydraulic cylinder.