Patent Description:
Offshore crane operations, such as those performed on or from floating vessels at sea, are plagued by a lifted object's oscillations a result of the vessel's pitching and rolling which displaces a crane wire's equilibrium pivot point, at the boom tip sheave, in relation to the lifted object's center of gravity, which results in a restoring force due to gravity acting on the object's mass, causing it to oscillate around the pivot point as it seeks to reestablish equilibrium. As the object swings, inertia is built in direct relation to its mass, the length of the pendulum, and the angular displacement from equilibrium. Inertia causes the lifted object to overshot equilibrium and it tends to oscillate about the equilibrium position, swinging back and forth, uncontrollably.

Since the seas are a continuous stream of influence to the vessel's motion, the induced object motion will continue to build in amplitude despite the effects of air resistance. Harmonic divergence between the vessel motion and that which the object exhibits further complicates the objects motions in all three axis and the more chaotic and uncontrollable the object becomes and the less likely the object can be safely landed and transferred to a fixed platform.

Successful installations from floating vessels to fixed structures require a twofold approach whereby motion of the object is minimized to begin with and secondarily, critical dampening is applied to arrest any motion just prior to landing the object.

<CIT> relates to an apparatus for deployment from a base for installing a component (<NUM>) at an underwater facility (<NUM>), comprises a carriage (<NUM>) for suspension from the base in use of the apparatus, the carriage (<NUM>) being adapted to releasably retain the component (<NUM>) and damping means (<NUM>) located between the carriage (<NUM>) and the base in use for resisting relative motion of the carriage (<NUM>) and facility (<NUM>) caused by substantially vertical motion of the base.

Various figures are included herein which illustrate aspects of embodiments of the disclosed inventions.

As used herein, a "critically dampened system" is one in which the dampening is designed to return the object back to equilibrium within one cycle, as illustrated in <FIG>.

In a first embodiment, referring generally to <FIG>, <FIG>, motion arresting and dampening device <NUM> comprises damper <NUM> (<FIG>) dimensioned to fit a predetermined dimension of tubular <NUM> (<FIG>); lifting spreader bar deployment assembly <NUM>; lift <NUM> (<FIG>); damper support <NUM> (not specifically called out in the figures); and a set of hoses and controller <NUM> (<FIG>) which are operative to allow activation of winches, e.g. <NUM>, and bladders, e.g. <NUM> (<FIG>), as needed.

In most embodiments, lifting spreader bar deployment assembly <NUM> comprises lifting spreader bar <NUM>; a set of object connector connection receivers 15a,15b; a set of lifting connector receivers 21a,21b disposed about lifting spreader bar <NUM> at a first offset from a center of lifting spreader bar <NUM>; a set of lifting connectors 11a,11b operatively connected to the set of lifting connector receivers 21a,21b; a set of restraining connector receivers 22a,22b disposed about lifting spreader bar <NUM> at a second offset from a center of lifting spreader bar <NUM>; and a set of adjustable restraining connectors 12a,12b operatively connected to the set of restraining connector receivers 22a,22b. In embodiments, the set of lifting connectors 11a,11b comprises one or more first lifting wires; the set of adjustable restraining connectors 12a,12b comprises one or more second lifting wires; lifting connector <NUM> comprises one or more third lifting wires; and deployment connector <NUM> (<FIG>) comprises one or more fourth lifting wires; each of these lifting wires (also known as "downlines") connected to lifting spreader bar <NUM>.

In embodiments, the set of adjustable restraining connectors 12a,12b comprises the second lifting wires may comprise first restraining wires operatively connected to lifting winch <NUM> and to first corresponding lifting connector connection receiver 22a of the set of lifting connector connection receivers 22a,22b and second restraining wires operatively connected to lifting winch <NUM> and second corresponding lifting connector connection receiver 22b of the set of lifting connector connection receivers 22a,22b. These first restraining wires and second restraining wires may further be operatively connected to lifting winch <NUM> via an intermediary connection such as lifting connector <NUM> and connector <NUM>.

In embodiments, the set of lifting connector receivers 21a,22b comprises first lifting connector receiver 21a, disposed about lifting spreader bar <NUM> at a first offset from a center of lifting spreader bar <NUM>, and second lifting connector receiver 21b, disposed about lifting spreader bar <NUM> at a second offset from the center of lifting spreader bar <NUM> distally opposite the first offset.

In embodiments, the set of restraining connector receivers 22a,22b comprises first restraining connector receiver 22a, disposed about lifting spreader bar <NUM> at a third offset intermediate the center of lifting spreader bar <NUM> and the first offset, and second restraining connector receiver 22b, disposed about lifting spreader bar <NUM> at a fourth offset intermediate the center of lifting spreader bar <NUM> and the second offset.

Referring still to <FIG> and <FIG>, lift <NUM> (<FIG>) typically comprises crane <NUM>; lifting connector <NUM> operatively connected to the set of adjustable restraining connectors 12a,12b; and lifting winch <NUM> operatively connected to lifting connector <NUM> and to crane <NUM>. Crane <NUM> may comprise vessel mounted crane 31a (<FIG>) to which lifting winch <NUM> is operatively connected. In this embodiment, the set of adjustable restraining connectors 12a,12b typically comprises set of adjustable restraining connectors 12a,12b operatively connected to vessel mounted crane 31a.

Referring now additionally to <FIG>, damper <NUM> typically comprises inflatable restorative inflation device <NUM>. In an embodiment, the predetermined tubular dimension typically comprises an interior of tubular <NUM> and inflatable restorative inflation device <NUM> comprises an inflatable bag or an inflatable ring dimensioned to fit within the interior of tubular <NUM>. In an alternative embodiment, the tubular dimension comprises an exterior of tubular <NUM> and inflatable restorative inflation device <NUM> comprises an inflatable bag or an inflatable ring dimensioned to fit about the exterior of tubular <NUM>.

Damper support <NUM> (not specifically called out in the drawings) typically comprises deployment connector <NUM>, operatively connected to damper <NUM>, and bar mounted winch <NUM> disposed about a predetermined portion of lifting spreader bar <NUM>, proximate a center of lifting spreader bar <NUM>, and operatively connected to deployment connector <NUM>.

In contemplated embodiments, controller <NUM> (<FIG>) comprises a mechanical connection release system circuit.

In contemplated embodiments, one or more sensors <NUM> (<FIG>) may be operatively in communication to controller <NUM> (<FIG>), where sensors <NUM> may comprise an inclinometer, a potentiometer, an accelerometer, a camera (see, e.g., <FIG> illustrating a view from a camera), a taut wire sensor, or the like, or a combination thereof (each of which is referred to herein without a separate callout as each is a type of sensor <NUM>).

In the operation of exemplary methods, referring back to <FIG> and to <FIG>, motion may be arrested and dampened using motion arresting and dampening device <NUM> as described herein by attaching object <NUM> which may comprise a platform or the like, to lifting spreader bar assembly <NUM>, positioning object <NUM> above tubular <NUM> (<FIG>); operatively connecting the set of adjustable restraining connectors 12a,12b to lifting winch <NUM> mounted on crane <NUM> and to lifting spreader bar <NUM> to restrain movement of lifting spreader bar <NUM> during a lifting operation; positioning damper <NUM> about a predetermined portion of tubular <NUM>; inflating damper <NUM> to engage tubular <NUM>; inducing forces into tubular <NUM> by movement of crane <NUM> as it deploys <NUM> tubular into an installation position; attenuating the induced forces by adjusting the set of adjustable restraining connectors 12a,12b to physically restrain movement of tubular <NUM>; and using the set of adjustable restraining connectors 12a,12b to rotate tubular <NUM> during alignment of tubular <NUM> during installation. Tubular <NUM> may comprise an installation mono-pile.

In most embodiments, referring additionally to <FIG> and <FIG>, object <NUM>, which may comprise a platform or the like, may be guided about a position of tubular <NUM> visually by an operator using camera <NUM>. In alternate embodiments, a position of tubular <NUM> may be guided automatically under the control of taut wire sensor <NUM> mounted on or otherwise attached to motion arresting and dampening device <NUM> or to a load comprising object <NUM> and/or tubular <NUM>, once the motion arresting and dampening device <NUM> has been set and one or more wires tensioned. Using taut wire sensor <NUM>, verticality may be sensed such as by an inclinometer with respect to a vertical offset of object <NUM> and/or tubular <NUM> or by a potentiometer with respect to lifting spreader bar <NUM> and data from taut wire sensor <NUM> fed to controller <NUM> of crane <NUM> to make adjustments to the position of a boom that is part of lift <NUM> in three-dimensional ("3D") space to align the X, Y and Z axis of motion arresting and dampening device <NUM> with that of object <NUM> and/or tubular <NUM>.

Damper <NUM> may be supported by using lifting spreader bar deployment assembly <NUM> and creating a temporary connection point between lifting spreader bar <NUM> and a center of tubular <NUM>. In embodiments, dampening returns tubular <NUM> back to an equilibrium point within one cycle.

As described above, in an embodiment restorative inflation device <NUM> comprises an inflatable restorative bladder or an internal circumferential restorative inflation ring. In such embodiments, inflating damper <NUM> to engage tubular <NUM> typically further comprises inserting restorative inflation device <NUM> into an annulus of tubular <NUM> to create a temporary friction connection between restorative inflation device <NUM> and an interior portion of the annulus of tubular <NUM> and providing a fixed point in a horizontal plane defined by object <NUM> and/or tubular <NUM> from which a restorative force can be applied to lifting wires, e.g. lifting connectors 11a,11b and/or restraining connectors 12a,12b.

As also described above, in alternate embodiments restorative inflation device <NUM> further comprises an inflation ring. In such embodiments, the inflation ring is typically positioned about an outer circumference of tubular <NUM> and inflated to engage the outer circumference of tubular <NUM>, establishing a fixed point on the outer circumference of tubular <NUM>.

In either of these two embodiments, inflation may be accomplished using compressed gas or fluid.

In contemplated embodiments, restorative inflation device <NUM> may be deflated and retrieved back to lifting spreader bar <NUM>. Mechanical connections securing object <NUM> may be released and motion arresting and dampening device <NUM> lifted and retrieved back to floating vessel <NUM>. Releasing the mechanical connections securing the object may occur remotely.

Additionally, a restorative force may be controlled by applying constant or adjustable winch tension via lifting wires; allowing payout and pull-in of the lifting wires which can be adjusted to set motion arresting and dampening device <NUM> in place; and after inflation, selectively increasing or decreasing the righting and securing force applied to a load created or otherwise present with respect to object <NUM> or tubular <NUM>.

Claim 1:
A motion arresting and dampening device (<NUM>), comprising:
a. a damper (<NUM>) dimensioned to fit a predetermined tubular dimension of a tubular (<NUM>), the damper comprising an inflatable restorative inflation device (<NUM>);
b. a lifting spreader bar deployment assembly (<NUM>), comprising:
i. a lifting spreader bar (<NUM>);
ii. a set of object connector connection receivers (15a, 15b);
iii. a set of lifting connector receivers (21a, 21b) disposed about the lifting spreader bar at a first offset from a center of the lifting spreader bar;
iv. a set of lifting connectors (11a, 11b) operatively connected to the set of lifting connector receivers (21a, 21b);
v. a set of restraining connector receivers (22a, 22b) disposed about the lifting spreader bar at a second offset from the center of the lifting spreader bar; and
vi. a set of adjustable restraining connectors (12a, 12b) operatively connected to the set of restraining connector receivers (22a, 22b);
c. a lift (<NUM>), comprising:
i. a crane (<NUM>);
ii. a lifting connector (<NUM>) operatively connected to the set of adjustable restraining connectors (12a, 12b); and
iii. a lifting winch (<NUM>) operatively connected to the lifting connector (<NUM>) and to the crane (<NUM>);
d. a damper support, comprising:
i. a deployment connector (<NUM>) operatively connected to the damper (<NUM>); and
ii. a bar mounted winch (<NUM>) disposed about a predetermined portion of the lifting spreader bar and operatively connected to the deployment connector;
e. a predetermined set of winch and bladder activation hoses operatively in communication with the winches and bladders; and
f. a controller disposed proximate the lift and operatively in communication with the predetermined set of winch and bladder activation hoses.