METHOD AND APPARATUS FOR UNDERWATER COUPLING

PROCEDE ET APPAREIL DE COUPLAGE SOUS-MARIN

English Abstract

A method and apparatus for underwater coupling of an underwater craft and an underwater package. The underwater craft has a centre of mass with a winch positioned in a winch pocket directly below the centre of mass. A first underwater coupling assembly is provided having two or more first coupling components positioned symmetrically around the winch pocket. The underwater package has a centre of mass with a lift line receiver positioned in a receiver pocket directly above the centre of mass. A second underwater coupling assembly is provided having two or more second coupling components positioned symmetrically around the receiver pocket. A lift line is lowered and engages the lift line receiver. The winch is activated to draw the underwater craft down onto the underwater package and bring the coupling components into coupling engagement.

French Abstract

Procédé et appareil de couplage sous-marin dune embarcation sous-marine et dun paquet sous-marin. Lembarcation sous-marine comporte un centre de masse doté dun treuil positionné dans une pochette de treuil, directement sous le centre de masse. Un premier ensemble de couplage sous-marin est prévu et doté dun ou de plusieurs premiers composants de couplage positionnés de façon symétrique autour de la pochette de treuil. Le paquet sous-marin comporte un centre de masse doté dun élément daccueil de câble de levage positionné dans une pochette daccueil directement au-dessus du centre de masse. Un deuxième ensemble de couplage sous-marin est prévu et doté de deux ou de plusieurs deuxièmes éléments de couplage positionnés de façon symétrique autour du paquet daccueil. Un câble de levage est abaissé et entraîne lélément daccueil du câble de levage. Le treuil est activé pour attirer lembarcation sous-marine vers le bas, sur le paquet sous-marin, et réunir les éléments de couplage de façon à ce quils soient engagés.

Claims

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What is Claimed is:
1. A method for underwater coupling, comprising:
providing an underwater craft which operates through an umbilical connection
to a
surface vessel floating on a surface of an ocean, the underwater craft having
a centre of mass
with a winch positioned in a winch pocket directly below the centre of mass
and a first
underwater coupling assembly having two or more first coupling components
positioned
symmetrically around the winch pocket;
providing an underwater package having a centre of mass with a lift line
receiver
positioned in a receiver pocket directly above the centre of mass and a second
underwater
coupling assembly having two or more second coupling components positioned
symmetrically
around the receiver pocket;
lowering a lift line from the winch of the underwater craft and engaging the
lift line
receiver of the underwater package; and
activating the winch to bring the first coupling components of the first
underwater
coupling assembly of the underwater craft into coupling engagement with the
second coupling
components of the second underwater coupling assembly of the underwater
package.
2. The method of Claim 1, wherein the underwater craft is drawn down by the
winch onto the
underwater package for seabed coupling.
3. The method of Claim 1, wherein the underwater package is drawn up by the
winch to the
underwater craft for mid-water coupling.

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4. An apparatus for underwater coupling, comprising:
an underwater craft which operates through an umbilical connection to a
surface vessel
floating on a surface of an ocean, the underwater craft having a centre of
mass with a winch
positioned in a winch pocket directly below the centre of mass and a first
underwater coupling
assembly having two or more first coupling components positioned symmetrically
around the
winch pocket; and
an underwater package having a centre of mass with a lift line receiver
positioned in a
receiver pocket directly above the centre of mass and a second underwater
coupling assembly
having two or more second coupling components positioned symmetrically around
the receiver
pocket.

Description

CA 02802875 2013-01-18
TITLE
[0001] Method and Apparatus for Underwater Coupling
FIELD
[0002] There is described a method and apparatus for underwater coupling
intended to be
used by an underwater craft connected by an umbilical connection to a surface
vessel floating on
a surface of an ocean.
BACKGROUND
[0003] The method of underwater coupling that will hereinafter be described
is applicable to
an underwater craft that is connected by an umbilical connection to a surface
vessel that floats on
a surface of an ocean. A number of difficulties are encountered when an
underwater craft
attempts an underwater coupling with a package on a seabed. One difficulty is
movement
communicated through the umbilical connection as the surface vessel rises and
falls with the
heaving of the ocean. Another difficulty is aligning a first coupling assembly
on the underwater
craft with a second coupling assembly on the package to complete the
underwater coupling.
There will hereinafter be described a method and apparatus that was developed
for the purpose of
making an underwater coupling under such demanding conditions.
SUMMARY
[0004] According to one aspect there is provided an apparatus for
underwater coupling,
which consists of a combination of an underwater craft and an underwater
package. The
underwater craft is one that operates through an umbilical connection to a
surface vessel floating
on a surface of an ocean. The underwater craft has a centre of mass with a
winch positioned in a
winch pocket directly below the centre of mass. A first underwater coupling
assembly is
provided having two or more first coupling components positioned symmetrically
around the
winch pocket. The underwater package has a centre of mass with a lift line
receiver positioned in
a receiver pocket directly above the centre of mass. A second underwater
coupling assembly is
provided having two or more second coupling components positioned
symmetrically around the
receiver pocket.

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[0005] According to another aspect there is a method of underwater
coupling using the
underwater craft and the underwater package described above. A first step
involves lowering a
lift line from the winch of the underwater craft and engaging the lift line
receiver of the
underwater package. A second step involves activating the winch to bring the
first coupling
components of the first underwater coupling assembly of the underwater craft
into coupling
engagement with the second coupling components of the second underwater
coupling assembly
of the underwater package.
[0006] There are two ways in which underwater coupling may occur. One
way is for the
underwater craft to be drawn down by the winch onto the underwater package.
Another way is
for the underwater package to be drawn up by the winch to the underwater craft
for a mid-water
coupling.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] These and other features will become more apparent from the
following description in
which reference is made to the appended drawings, the drawings are for the
purpose of
illustration only and are not intended to be in any way limiting, wherein:
[0008] FIG. 1 is a bottom perspective view of an underwater craft.
[0009] FIG. 2 is a a top perspective view of an underwater package.
[0010] FIG. 3 is a side elevation view of the underwater craft of FIG. 1
docking on the
underwater package of FIG. 2.
[0011] FIG. 4 is a perspective view of the underwater craft of FIG. 1
righting the underwater
package of FIG. 2.
[0012] FIG. 5 is a perspective view of the underwater craft of FIG. 1
performing a mid-
water docking with the underwater package of FIG. 2.

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3
DETAILED DESCRIPTION
[0013] A combination apparatus will now be described with reference to
FIG. 1 through 5.
Structure and Relationship of Parts:
[0014] Referring to FIG 1, an underwater craft 12 is illustrated which
operates through an
umbilical connection 14 to a surface vessel floating on a surface of an ocean
(not shown).
Underwater craft has a centre of mass generally identified by arrow C. A winch
16 is positioned
in a winch pocket 18 directly below centre of mass C. A first underwater
coupling assembly,
generally indicated by arrow 20, is provided having two or more first coupling
components 22
positioned symmetrically around winch pocket 18. Winch 16 is positioned within
winch pocket
18 so that winch 16 does not impinge or otherwise interfere with the
functioning of first
underwater coupling assembly 20. The "belly winch" system described above is
prefembly
incorporated into tool skid 24 that forms part of a Remotely Operated Cable
Laying System
(ROCLS). Winch 16 extends and retracts a lift line 26. Underwater craft 12 has
manipulators 28
that are used to grasp and manipulate undersea objects.
[0015] Referring to FIG. 2, an underwater package 30 is illustrated
having a centre of mass
generally identified by arrow C. A lift line receiver 32 is positioned in a
receiver pocket 34
directly above centre of mass C. A second underwater coupling assembly
generally indicated by
wow 36, is provided having two or more second coupling components 38
positioned
symmetrically around receiver pocket 34.
Operation:
[0016] The belly winch system allows the operator to connect a lift line
to underwater
package 30 and either lift undewater package 30 off the seafloor or pull
underwater craft 12 down
to underwater package 30. It will be appreciated that underwater package 30
equipment can
include ROCLS drum frames, Instrument platforms and other large and heavy
packages.
Specifically, the winch system allows the operator to hoist or lower other
packages under

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4
underwater craft 12.
[0017] The purposes are:
= to right a tipped over underwater package 30, as shown in FIG. 4,
= to pull underwater craft 12 down to underwater package 30 resting on the
seafloor at an
angle, thus allowing it to latch, as shown in FIG. 3
= to pull underwater package 30 off the seafloor and bring it up to
underwater craft 12 for mid-
water latching, as shown in FIG. 5
= to unlatch and lower package 30 from the underwater craft to the seafloor
[0018] The fact that winch 16 is located on the ROCLS tool skid directly
below center of
mass C of underwater craft 12 allows the operator to lower and raise
underwater package 30
without affecting the pitch or roll of the vehicle. Winch 16 is fitted with
enough lift line 26 to
allow the operator to grip the ROCLS lift interface at the end of lift line 26
with either of
manipulators 28 of underwater craft 12 and not restrict the reach of
manipulators 28 in any
direction while making a connection to underwater package 30. Lift line 26 is
equipped with a
low profile connector that allows winch 16 to pull underwater package 30 snug
up to first
underwater coupling assembly 20. It is preferred that winch 16 is situated on
tool skid 24 to
allow undersea package 30 to be hoisted enough that a coupling can be made
between first
underwater coupling assembly 20 and second underwater coupling assembly 36.
The coupling
components used are, preferably, hydraulically operated latches. The lift
interface is designed to
not interfere with underwater package 30 and tool skid 24 of underwater craft
12 when the two
are in close proximity to each other.
Operational Example 1 ¨ Coupling when conditions are not ideal
[0019] Referring to FIG. 3, as stated in the Background undersea
coupling can be difficult
due to movement communicated through the umbilical connection as the surface
vessel rises and
falls with the heaving of the ocean. There can also be alignment problems in
trying to align first

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underwater coupling assembly 20 on underwater craft 12 with second underwater
coupling
assembly 36 on underwater package 30 to complete the underwater coupling. When
this occurs,
a first step is taken of lowering a lift line 26 from winch 16 of underwater
craft 12 and engaging
lift line receiver 32 of underwater package 30. A second step is then taken of
activating winch 16
5 to draw underwater craft 12 down onto underwater package 30 and bring first
coupling
components 22 of first underwater coupling assembly 20 of underwater craft 12
into coupling
engagement with second coupling components 38 of second underwater coupling
assembly 36 of
underwater package 30.
Operational Example 2- Remotely deployed ROCLS frame tipped over
[0020] Referring to FIG. 4, in many instances, underwater package 30 is
lowered to the
seafloor by the ship's winch via a separate cargo line and remotely released
via acoustic release.
In this particular example, underwater package 30 is either not level or has
fallen over and the
operator must have a method to right underwater package 30. In this situation,
the operator would
spool out enough lift line 26 from belly winch 16 to pick up lift line 26 with
one of manipulotors
28 for underwater craft 12. Lift line 26 would then be attached to lift line
receiver 32 on top of
underwater package 30 and umbilical connection 14 hoisted until both
underwater craft 12 and
underwater package 30 were safely off the seafloor. Underwater package 30
could then be either
placed back on the seafloor in a vertical orientation or hoisted up all the
way to allow the
hydraulic latches to mate.
Major Benefits
[0021] Without the belly winch the operator is far too reliant on
everything being perfect. To
date the belly winch has been called on to work in exactly the way it was
designed and has made
what could be a major problem, a standard operation of little consequence.
[0022] In this patent document, the word "comprising" is used in its non-
limiting sense to
mean that items following the word are included, but items not specifically
mentioned are not

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6
excluded. A reference to an element by the indefmite article "a" does not
exclude the possibility
that more than one of the element is present, unless the context clearly
requires that there be one
and only one of the elements.
[0023] The scope of the claims should not be limited by the illustrated
embodiments set forth
as examples, but should be given the broadest interpretation consistent with a
purposive
construction of the claims in view of the description as a whole.

Representative Drawing