Abstract: A fluked burying device (1, 1A), for augmenting the burying and holding capability of a drag embedment marine anchor and chain cable system while being fixedly located thereon, comprises a fluke member (8) inclinedly attached to a body member (7) including pockets (12A, 12B, 12C) for accommodating links (16, 17) of a chain cable (4) passing there-through in a defined attitude such that axial and transverse loading is impressed in the chain cable (4) via separate links (17A, 17C) to maintain bending stresses therein similar to that occurring in a 5-pocket wildcat of a chain windlass and such that emergent links (16A, 16B) have sufficient articulation in service while embedded to permit the chain cable (4) to perform the function of and eliminate need for heavy expensive shackles.

Abstract: A marine anchor (1, 40, 40A, 40B, 40C) for deep embedment in a seabed soil (2) including a fluke member (4, 41) and a shank member (7, 49) and means (12, 62, 62A) for constraining a load application point thereon (13, 15, 63, 63A, 65) to lie in first and second directions from a centroid (9,46) of said fluke member (4, 41) forming, with respect to a fore-and-aft direction (10, 47) of the fluke member (4, 41), an acute forward-opening angle (A) and an acute rearward-opening angle (C) respectively whereby said marine anchor (1, 40, 40A, 40B, 40C) can be pulled rearward to bury deeply in a rearward direction (R) after having been pulled forward to bury deeply in a forward direction (F).

Abstract: A marine anchor is described which has a fluke with a shank pivotably attached thereto wherein the shank is remotely lockable pivotably and subsequently remotely unlockable pivotably with respect to the fluke.

Abstract: An anchor data communication system (1) for communication of measurement data, provided by instrumentation (2) mounted on a marine anchor (3) buried below a surface (5) of a mooring bed (4), including a first transponder (10) mounted on a line member (7, 3D) attached to said anchor (3) and connected by conductor means (11) to said instrumentation (2), and a second transponder (12, 12A) mounted on said line member (7, 3D) or suspended from a floating structure (8, 21A) and connected to a transceiver (9, 9A) on said floating structure (8, 21A), wherein an axis (10A, 12B) of an emission beam (10B, 12C) of at least one of said transponders (10, 12, 12A) is constrained in heading by said line member (7, 3D) to maximize the strength of signals from said first transponder (10) arriving at said second transponder (12, 12A).

Abstract: A marine anchor is described which has a fluke with a shank pivotably attached thereto wherein the shank is remotely lockable pivotably and subsequently remotely unlockable pivotably with respect to the fluke.

Abstract: An anchor data communication system (1) for communication of measurement data, provided by instrumentation (2) mounted on a marine anchor (3) buried below a surface (5) of a mooring bed (4), including a first transponder (10) mounted on a line member (7, 3D) attached to said anchor (3) and connected by conductor means (11) to said instrumentation (2), and a second transponder (12, 12A) mounted on said line member (7, 3D) or suspended from a floating structure (8, 21A) and connected to a transceiver (9, 9A) on said floating structure (8, 21A), wherein an axis (10A, 12B) of an emission beam (10B, 12C) of at least one of said transponders (10, 12, 12A) is constrained in heading by said line member (7, 3D) to maximize the strength of signals from said first transponder (10) arriving at said second transponder (12, 12A).

Abstract: A marine anchor (1, 40, 40A, 40B, 40C) for deep embedment in a seabed soil (2) including a fluke member (4, 41) and a shank member (7, 49) and means (12, 62, 62A) for constraining a load application point thereon (13, 15, 63, 63A, 65) to lie in first and second directions from a centroid (9,46) of said fluke member (4, 41) forming, with respect to a fore-and-aft direction (10, 47) of the fluke member (4, 41), an acute forward-opening angle (A) and an acute rearward-opening angle (C) respectively whereby said marine anchor (1, 40, 40A, 40B, 40C) can be pulled rearward to bury deeply in a rearward bury deeply in a forward direction (F).

Abstract: A marine anchoring arrangement is described wherein a marine anchor (1, 23) is drivingly embedded vertically into a mooring bed (10) by an elongate follower (13), especially by its own weight and that of the follower. The follower (13) has a bottom clevis part (103) adapted to hold detachably the anchor (1) via the anchor shank (2) by means of a fulcrum pin (17) whereby the anchor (1) may swing relative to the bottom part (103). For initial penetration, the anchor (1) is held in a position of minimum forward resistance, specifically with the forward direction F of the fluke (3) parallel to the follower axis (20) and this is achieved by a shear pin (109) between the anchor (1) and the bottom part (103).

Abstract: A marine anchoring device (1, 33) for penetration into a sea bed is having at least part of its external surface in the form of a low friction surface (8, 12, 13, 14). The device can comprise (a) a drag embedment anchor (1) or alternatively (b) a direct embedment anchor (1A). The low friction surface can be formed by a low friction coating which is adhered to the external surface of the device, or by a coating which is smeared onto the external surface. A lubricant supply apparatus (16, 19) can be provided to replenish the lubricant lost by the friction action of the soil.

Abstract: Apparatus provided for producing measurement data capable of characterizing a burial trajectory (2) traced out in a sea-bed soil (3), and additionally to be capable of measuring a soils parameter such as the penetration resistance of the soil (3). In particular the apparatus checks for the anchorability of a particular sea-bed location and also provides a certain indication of the nature of the soil in stratae in the bed at this location. Specifically the apparatus achieves measurements via a point on a burying apparatus (5) as the burying apparatus moves in the trajectory. More especially the apparatus includes means (19, 29) located in a body (12) carried by the burying apparatus to sense the distance along the trajectory (2) separating two spaced points on the trajectory, and from that by additional means sense the position of a point in the soil at a particular instant thereby enabling the path of the trajectory (2) to be plotted.

Abstract: A drag embedment normal load anchor ("Denla") comprises a fluke with a shank pivotally attached thereto, the shank including an anchor cable attachment point and control or restraint mechanisms whereby the shank can be set such that the cable attachment point can lie selectively in first, second, and third directions relative to the fluke centroid, the directions providing three fluke centroid angles (.alpha., .beta., and .theta., respectively) with the fluke forward direction (F). The Denla is part of an anchoring apparatus including a rear drogue line serving to orientate the anchor correctly at the sea bed without the need for a separate pendant line. In operation, the Denla is embedded by pulling on an anchor cable with the first fluke centroid angle .alpha. present; when the desired horizontal anchor loading is achieved, the shank is moved to the second larger centroid angle .beta.

Abstract: A chain joining link (1) having an assemblage of disaassemblable parts enabling the link (1) to be fitted on two adjacent chain sections, the assemblage having U-shaped end members (2) to retain said chain sections, the U-shaped members (2) including recesses (7) receiving flanges (4) whereby the members (2) are joined for assembly of the link. Each recess (7) has a width greater than that of the corresponding flange (4), and the width difference (gap) is accommodated by a wedge (8). The wedge (8) is fitted into the gap so as to preload the link by a predetermined amount and to this end the wedge (8) is first placed in the gap to a first position with no force fitting, and thereafter the wedge (8) is forced a predetermined distance from said first position to a second position so causing a compressive preload in the flange (4) and a tensile preload in the material surrounding the recess (7). Assembly is completed by the fitting of a columnar stud (15).

Abstract: A marine anchor has an anhedral fluke with a shank attached thereto including an anchor line attachment point. A rear plate assembly behind the fluke is inclined at an obtuse angle .alpha. to the fluke and serves to provide a turning moment about the attachment point countering turning moments produced by friction effect on the fluke and the shank and by edge resistance during anchor burial to give improved anchor holding power while soil escapes the passage between the rear assembly and the fluke allows escape of sand and soft mud passing over the fluke. Peripheral edges of the rear assembly are shaped to cause rolling of the anchor to a burial position. An upturned toe portion at the front of the fluke encourages effective anchor operation in clay soils while also facilitating rock gripping by the anchor.

Abstract: A marine anchor comprising a fluke and a shank attached to the fluke is intended for drag embedment in a mooring bed by pulling the anchor substantially horizontally via the shank. Further, it is a particular feature of the anchor that two modes of operation are possible through use of the line extending between the anchor cable attachment point on the shank and the fluke centroid being variable to provide a first line present for drag embedment of the anchor, and a second line utilized when the anchor is embedded, wherein the pulling force on the anchor via the shank can now be essentially upwards, thereby providing an increased holding force due to the increased fluke area presented in the direction of the upwards force. The change in direction from the first line to the second line can be achieved by having the shank pivotal and by providing pivot control members permitting selective pivoting of the shank.

Abstract: There is provided a tensioning device for pretensioning mooring lines in accordance with the tension-in-a-bight principle. The tensioning device is located at the bight of the mooring lines and includes a link catching device comprising inclined land surfaces and a catching tooth at the lower end of the land surfaces, which catching device catches a link, the caught link, of link chain during heaving up on a riser chain section so enabling the pretensioning to be achieved in the mooring line. Slots are provided in the tensioning device adjacent the land surfaces such that the downline link threading the caught link and the following downline link each have a significant degree of pivotal freedom to preclude bending moment loading in these links during heaving up on the riser line during tensioning.

Abstract: A marine anchor comprises a fluke with a shank attached to the fluke to enable the anchor to be joined to an anchor cable. Additionally there is provided a soil barrier plate located aft of the rear of the fluke but above the level of the fluke, with a soil passage between the barrier plate and the fluke. The barrier plate is set an angle to the fluke, and the barrier plate and the associated soil passage are arranged so as to function in a manner enabling the anchor to operate effectively and without adjustment in cohesive soils such as mud even when the fluke is set (say at an attack angle 0.degree. of 30.degree.) for optimum operation in non-cohesive soils such as sand, without substantially detracting from the performance of the anchor in non-cohesive (sand) soils.

Abstract: A marine anchor including a main fluke with a shank attached to the fluke. To enable the anchor to orientate on the sea bed from an inverted position to an upright working position, auxiliary flukes are supported by respective lugs upstanding from the fluke on either side of the anchor's vertical plane of symmetry. The auxiliary flukes extend laterally from the lugs and are inclined at an acute angle to the main fluke. The anchor includes support means arranged such that when the anchor lies inverted on a firm seabed one of the auxiliary flukes is located in position for digging in when the anchor is pulled forwardly.

Abstract: A chain comprises interconnected links with each link comprising opposed C-shaped ends joined by joining limb portions. Each C-shaped end includes a central crown with shoulders on either side of the crown, and by the present invention the section modulus about an axis perpendicular to the plane of the link of a cross-section at a shoulder is greater than the corresponding section modulus of a cross-section at the crown, and preferably additionally said section modulus of the section at the shoulder is greater than a corresponding section modulus of a cross-section at the associated joining limb portion.