Abstract: A mooring system is disclosed for maintaining a ship shape drilling vessel within alignment limits and for warping it into the sea while drilling a well from the vessel in the sub-surface ground below it. The mooring system absorbs all of the forces on the vessel, such as wind, current, wave, swell, roll, pitch, heave, surge and sway. These forces are measured by sensing load on a motor, electric, hydraulic, and the like, driving the anchor chain wildcat while hauling it in, by sensing load on the brake bands for the windlass wildcats, and by sensing load on the chain stopper, which sensed loads are transmitted to a display device which provides sufficient information to maintain the drilling vessel within the alignment limits and to warp it into the sea to minimize forces and motions of the vessel and to avoid beam sea forces.

Abstract: A chain anchor which provides for manual quick engagement of a chain with a fixed anchor member, and manual quick disengagement of the chain from said anchor member, both readily, conveniently, and without the use of tools; the structural configuration of such chain-engaging anchor member, together with an associated guard, precluding accidental escape of the chain from the anchor member yet without hindering such manual quick engagement and manual quick disengagement of the chain.

Abstract: Disclosed is a chain stopper including a pair of side-by-side support plates pivotally connected to hanger plates which support the chain stopper from the vessel's structure. The support plates releasably engage about the anchor chain to support the anchor from the vessel's structure. To haul in the anchor line, the line is winched in such that the connection between the anchor cable and anchor chain lies above the chain stopper which is suspended from support structure on the vessel. The chain stopper is engaged about the anchor chain and the winch is relieved to transfer the weight of the anchor chain and anchor to the chain stopper. The anchor cable is then disconnected from the anchor chain. A secondary chain hanging from a wildcat is connected to the anchor chain and hauled in whereby the weight of the anchor chain and anchor is transferred from the chain stopper to the secondary chain and wildcat.