WO2001021479A1 - Underwater power and data relay - Google Patents

Abstract

An underwater apparatus for performing subsurface operations adapted to be operated from a remote location (50) above the surface of a body of water (8) is disclosed. The apparatus includes a linelatch system (10) that is made up of a tether management system (12) connected to a flying latch vehicle (20) by a tether (40). The tether management system controls the amount of free tether between itself and the flying latch vehicle. The flying latch vehicle interfaces with various underwater structures (60, 70). Also disclosed are methods of transferring power and/or data between two or more underwater devices using the linelatch system of the invention.

Description

UNDERWATER POWER AND DATA RELAY

Field Of The Invention

The invention relates to the field of systems for deployment, recovery,

servicing, and operation of equipment in deep water and methods for utilizing

such systems. More particularly, the invention relates to devices having a tether

management system and a detachable flying latch vehicle for use in deep water.

Background Of The Invention

Vehicles that operate underwater are useful for performing tasks below the

sea surface in such fields as deep water salvage, the underwater telecommunica¬

tions industry, the offshore petroleum industry, offshore mining, and

oceanographic research. (See, e.g. , U.S. Patent Nos. 3,099,31 6 and

4,502,407) . Conventional unmanned subsurface vehicles can be broadly

classified according to how they are controlled. Autonomous underwater

vehicles (AUVs) are subsurface vehicles that are not physically connected to a

support platform such as a land-based platform, an offshore platform, or a sea-

going vessel. In comparison, remotely operated vehicle (ROVs) are those subsea

vehicles that are physically connected to a support platform.

The typical physical connection between an ROV and a support platform is

referred to as an "umbilical. " The umbilical is usually an armored or unarmored

cable containing an electrical and/or hydraulic conduit for providing power to an

ROV and a data communications conduit for transmitting signals between an

ROV and a support platform. An umbilical thus provides a means for remotely

controlling an ROV during underwater operation. ROVs are commonly equipped with on-board propulsion systems,

navigation systems, communication systems, video systems, lights, and

mechanical manipulators so that they can move to an underwater work site and

perform a particular task. For example, after being lowered to a subsurface

position, a remotely-located technician or pilot can utilize an ROVs on-board

navigation and communications systems to "fly" the craft to a worksite. The

technician or pilot can then operate the mechanical manipulators or other tools on

the ROV to perform a particular job. In this manner, ROVs can used to perform

relatively complex tasks including those involved in drill support, construction

support, platform cleaning and inspection, subsurface cable burial and

maintenance, deep water salvage, remote tool deployment, subsurface pipeline

completion, subsurface pile suction, etc. Although they are quite flexible in that

they can be adapted to perform a wide variety of tasks, ROVs are also fairly

expensive to operate as they require a significant amount of support, including,

for example, a pilot, technicians, and a surface support platform.

ROVs and other subsurface vehicles that are connected to a surface vessel

by a physical linkage are subject to heave-induced damage. Heave is the up and

down motion of an object produced by waves on the surface of a body of water.

Underwater vehicles physically attached to a floating surface platform therefore

move in accord with the surface platform. Therefore, when an underwater

vehicle is located near a fixed object such as the sea bed, a pipeline, or a

wellhead, heave-induced movement can damage both the vehicle and the fixed

object. To alleviate this problem, devices such as heave-induced motion

compensators and tether management systems have been employed to reduce the transfer of heave to underwater vehicles.

In contrast to ROVs, while underwater, AUVs are not subject to heave-

mediated damage because they are not usually physically connected to a support

platform. Like ROVs, AUVs are useful for performing a variety of underwater

operations. Common AUVs are essentially unmanned submarines that contain an

on-board power supply, propulsion system, and a pre-programmed control

system. In a typical operation, after being placed in the water from a surface

platform, an AUV will carry out a pre-programmed mission, then automatically

surface for recovery. In this fashion, AUVs can perform subsurface tasks

without requiring constant attention from a technician. AUVs are also

substantially less expensive to operate than ROVs because they do not require an

umbilical connection to an attached surface support platform.

AUVs, however, have practical limitations rendering them unsuitable for

certain underwater operations. For example, power in an AUV typically comes

from an on-board power supply such as a battery. Because this on-board power

supply has a limited capacity, tasks requiring a substantial amount of power such

as cutting and drilling are not practically performed by AUVs. In addition, the

amount of time that an AUV can operate underwater is limited by its on-board

power supply. Thus, AUVs must surface, be recovered, and be recharged

between missions- a procedure which risks damage to the AUV and mandates

the expense of a recovery vessel (e.g., a boat) .

Another drawback of AUVs is that, without a physical link to a surface

vessel, communication between an AUV and a remote operator (e.g., a

technician) is limited. For example, AUVs conventionally employ an acoustic modem for communicating with a remote operator. Because such underwater

acoustic communications do not convey data as rapidly or accurately as electrical

wires or fiber optics, transfer of data encoding real time video signals or real time

instructions from a remote operator is not efficient given current technology. As

such, AUVs are often not able to perform unanticipated tasks or jobs requiring a

great deal of operator input.

Other underwater vehicles having characteristics similar to AUVs and/or

ROVs are known. These vehicles also suffer drawbacks such as subjection to

heave, need for expensive support, poor suitability for some applications, lack of

a continuous power supply, poor communications, poor capabilities, etc.

Therefore, a need exists for a device to help overcome these limitations.

Summary of the Invention

The present application is directed to a remotely operable underwater

apparatus for interfacing with, transferring power to, and sharing data with other

underwater devices. The apparatus includes a linelatch system for servicing and

operating various subsurface devices such as toolskids, ROVs, AUVs, pipeline

sections (spool pieces), seabed anchors, suction anchors, oil field production

packages, and other equipment such as lifting frames, etc. The linelatch system

includes a flying latch vehicle connected to a tether management system by a

tether.

The flying latch vehicle is a highly maneuverable, remotely-operable

underwater vehicle that has a connector adapted to "latch" on to or physically

engage a receptor on a subsurface device. In addition to stabilizing the interaction of the flying latch vehicle and the subsurface device, the connector-

receptor engagement can also be utilized to transfer power and data. In this

aspect, the flying latch vehicle is therefore essentially a flying power outlet

and/or a flying data modem. The flying latch vehicle is unlike conventional ROVs

or other underwater vehicles in that its primary purpose is to bridge power and

data between two devices, rather to perform a manual task such as switching a

valve or drilling a hole.

The tether management system of the linelatch system regulates the

quantity of free tether between itself and the flying latch vehicle. It thereby

permits the linelatch system to switch between two different configurations: a

"closed configuration" in which the tether management system physically abuts

the flying latch vehicle; and an "open configuration" in which the tether

management system and flying latch vehicle are separated by a length of tether.

In the open configuration, slack in the tether allows the flying latch vehicle to

move independently of the tether management system. Transmission of heave-

induced movement between the two components is thereby removed or reduced .

The advantages of the linelatch system over conventional underwater

vehicles allow it to be used in a number of ways to facilitate subsurface

operations. For example, the linelatch system can be used for deploying and

recovering loads to and from a subsurface location (e.g., the seabed) . In

comparison to the use of fixed rigging to deliver a load to the seabed, the

linelatch system's ability to uncouple a load from vertical heave prevents heave-

related damage from occurring to the load. Moreover, the maneuverability and

remote operability of the flying latch vehicle facilitate accurate deployment, and faster and less risky recovery of subsurface loads.

The flexibility of the linelatch system allows it be used for various other

undersea operations. Among these, for example, the linelatch system can be

used to power and control underwater tools such as cleaners, cutters, and

jetters. As another example, the linelatch system can be utilized for subsurface

battery charging of underwater devices such as AUVs and battery-powered

underwater tools. Further demonstrating its flexibility, the linelatch system can

be used to convey power and data between a subsurface power and control

module and a subsurface tool or vehicle.

According to one aspect, the invention includes a submersible system for

transferring power from a subsurface power supply module to a subsurface

device. The system includes a tether management system having an umbilical

connector with an umbilical cable releasably attached thereto for deploying the

tether management system from a surface vessel to a seabed, a jumper cable

extendible from the tether management system configured for receiving power

and/or data from an external subsurface module. The tether management system

further includes a submersible vehicle provided as part of the tether management

system and releasably docked thereto. The submersible vehicle has a tether

receiving at least one of data and power from the tether management system. A

transfer system is provided for selectively transferring the data and/or power to

the submersible vehicle from a deployment vessel attached to the umbilical cable

and from the external subsurface module.

The submersible vehicle of the invention is preferably self-propelled to

move between the tether management system and a subsurface device for performing a task. The submersible vehicle has a connector which automatically

engages a corresponding mating connector on the subsurface device when the

submersible vehicle is propelled to a mating position adjacent to the subsurface

device. According to one aspect, the connector is a power connector and about

50% and 1 00% of the power received by the submersible vehicle from the

transfer system is transferred to the subsurface device. According to an

alternative embodiment, an auxiliary onboard power supply can be integrated

within either the tether management system or the submersible vehicle for

powering the submersible vehicle and or tether management system.

According to another aspect of the invention, the submersible vehicle is

operable for extending the jumper cable from the tether management system to

the subsurface module to form a data and/or power connection between the

subsurface module and the tether management system.

The submersible system also preferably includes suitable command and

control circuitry and actuators for automatically remotely detaching the umbilical

cable from the submersible system in response to a control command. In this

regard, a shock absorber system on a lower portion of the tether management

system for absorbing impact with a seabed resulting from positioning the

submersible system.

According to yet another aspect, the invention can include a method for

establishing a power and control connection from a subsurface power supply

module to a subsurface device, comprising the steps of: deploying a tether

management system to a subsea location; in response to a control command,

extending a jumper cable from the tether management system to the subsurface power supply module for transferring at least one of data and power from the

subsurface power supply module to the tether management system; and flying a

power connector from the tether management system to the subsurface device

to establish a power and/or data transfer circuit between the tether management

system and the subsurface device.

The deploying step according to the method can further include the step of

lowering the tether management system to the subsea location using a cable, and

subsequently detaching the cable from the tether management system.

According to one embodiment, the detaching step is performed before the jumper

cable extending step. However, the detaching step can also be performed after

the jumper cable extending step. In a preferred embodiment, the cable which is

used to lower the system to a subsea location can be an umbilical cable for

providing at least one of data, power and materials to the tether management

system.

According to another aspect of the invention, a method is provided for

deploying a submersible system and connecting the submersible system to a

subsurface module. This method includes the step of deploying a submersible

system to the bottom of a body of water, the submersible system having a tether

management system that includes a jumper cable for receiving data, power,

and/or material from the subsurface module, a submersible vehicle releasably

docked to the tether management system, and a tether providing a power and/or

data link between the submersible vehicle to the tether management system.

The method further includes the step of undocking the submersible vehicle from

the tether management system; and the step of connecting the jumper cable to the subsurface module.

The deploying step featured in this method can further include the step of

lowering the submersible system with an umbilical cable from a vessel to the

bottom of the body of water, and subsequently detaching the umbilical cable

from the submersible system. It can also include the step of powering the

submersible vehicle from a power source in the submersible system before the

detaching step.

The connecting step of this method can additionally include the steps of

maneuvering the submersible vehicle to the jumper cable, retrieving the jumper

cable with the submersible vehicle, and maneuvering the submersible vehicle and

jumper cable to the subsurface module; all occurring before the detaching step.

The method can also include the step of powering the submersible vehicle

from the jumper cable before the detaching step. The connecting step of this

method can further include the steps of maneuvering the submersible vehicle to

the jumper cable, retrieving the cable with the submersible vehicle, and

maneuvering the submersible vehicle and jumper cable to the subsurface module;

all before the detaching step.

Unless otherwise defined, all technical terms used herein have the same

meaning as commonly understood by one of ordinary skill in the art to which this

invention belongs. Although methods and materials similar or equivalent to those

described herein can be used in the practice or testing of the present invention,

suitable methods and materials are described below. All publications, patent

applications, patents, and other references mentioned herein are incorporated by

reference in their entirety. In the case of conflict, the present specification, including definitions will control. In addition, the particular embodiments

discussed below are illustrative only and not intended to be limiting.

Brief Description Of The Drawings

The invention is pointed out with particularity in the appended claims. The

above and further advantages of this invention may be better understood by

referring to the following description taken in conjunction with the accompanying

drawings, in which:

FIG . 1 A is a schematic view of a linelatch system of the invention shown

in the open configuration.

FIG. 1 B is a schematic view of a linelatch system of the invention shown

in the closed configuration.

FIG. 2 is a schematic view of a flying latch vehicle of the invention.

FIGs. 3A-F are schematic views showing the use of a linelatch system for

providing power to an undersea device.

FIG. 4 is a schematic view of an underwater operation performed by a

linelatch system of the invention.

Detailed Description

The invention encompasses underwater devices including a linelatch

system adapted to be operated from a remote location above the surface of a

body of water and utilized for servicing and/or operating various subsurface

devices such as toolskids, ROVs, AUVs, pipeline sections (spool pieces), seabed

anchors, suction anchors, oil field production packages, and other equipment such as lifting frames, etc. The below described preferred embodiments illustrate

various adaptations of the invention. Nonetheless, from the description of these

embodiments, other aspects of the invention can be readily fashioned by making

slight adjustments or modifications to the components discussed below.

Referring now to FIGs. 1 A and 1 B of the drawings, the presently preferred

embodiment of the invention features a linelatch system 1 0 including a tether

management system 1 2 connected to a flying latch vehicle 20 by a tether 40. In

FIG. 1 A, linelatch system 1 0 is shown positioned on the seabed of a body of

water 8 connected to a subsurface module 70 by a jumper cable 24. From a

surface support vessel 50 floating on the surface of the body of water 8 depends

an umbilical 45 used to place linelatch system 1 0 on the seabed.

Tether management system 1 2 can be any device that can reel in or pay

out tether 40. Tether management systems suitable for use as tether

management system 1 2 are well known in the art and can be purchased from

several sources (e.g., from Slingsby Engineering, United Kingdom; All Oceans,

United Kingdom; and Perry Tritech, Inc., Jupiter, Florida). In preferred

embodiments, however, tether management system 1 2 includes an external

frame 1 5 which houses a spool 1 4, a spool control switch 1 6, a spool motor 1 8,

and jumper cable 74.

Frame 1 5 forms the body of tether management system 1 2. It can be any

device that can house and/or attach system 1 2 components such as spool 1 4,

spool control switch 1 6, and spool motor 1 8. For example, frame 1 5 can take

the form of a rigid shell or skeleton-like framework. In the presently preferred

embodiment, frame 1 5 is a metal cage. A metal cage is preferred because it moves easily through water, and also provides areas for mounting other

components of tether management system 1 2.

Spool 1 4 is a component of tether management system 1 2 that controls

the length of tether 40 dispensed from system 1 2. It can any device that can

reel in, store, and pay out tether 40. For example, pool 1 4 can take the form of

a winch about which tether 40 can be wound and unwound. In preferred

embodiments, spool 14 is a rotatable cable drum, where rotation of the drum in

one direction causes tether 40 to be payed out of tether management system 1 2

by unreeling it from around the drum, and rotation of the drum in the other

direction causes tether 40 to be taken up by tether management system 1 2 by

reeling it up around the drum.

Spool motor 1 8 provides power to operate spool 1 4. Spool motor 1 8 can

be any device that is suitable for providing power to spool 1 4 such that spool 1 4

can reel in or pay out tether 40 from tether management system 1 2. For

example, spool motor 1 8 can be a motor that causes spool 1 4 to rotate

clockwise or counterclockwise to reel in or pay out tether 40. In preferred

embodiments, spool motor 1 8 is an electrically or hydraulically-driven motor.

Spool control switch 1 6 is a device that controls the action of spool motor

1 8. It can be any type of switch which allows an operator of linelatch system 1 0

to control spool motor 1 8. In a preferred from, it is a remotely-operable electrical

switch that can be controlled by a technician or pilot on surface support vessel

50 so that motor 1 8 can power spool 1 4 operation.

Tether management system 1 2 can also include a power and data transfer

unit 75 between umbilical 45 or jumper cable 74 and tether 40. Unit 75 can be any apparatus that can convey power and data between umbilical 45 or jumper

cable 74 and tether 40. In preferred embodiments of the invention, unit 75

takes the form of electrical, hydraulic and/or fiber optic lines connected at one

end to umbilical 45 and/or jumper cable 74, and at the other end to tether 40.

Transfer unit 75 also preferably includes suitable switching circuitry for

connecting tether 40 to umbilical 45 or jumper cable 74.

Jumper cable 74 is also attached to tether management system 1 2.

Jumper 74 is a flexible rope-like device that can be extended lengthwise from

system 1 2 and attached to subsurface module 70 ( a subsurface apparatus that

can supply power and/or data) via power and data connection 80 (a power and

data output socket) . It can take the form of any device that can transfer power

and/or data between module 70 and tether management system 1 2. For

example, it can be a simple insulated copper wire. In preferred embodiments,

however, it is a flexible waterproof cable that houses a conduit for both power

(e.g., a copper electrical wire and/or a hydraulic hose) and data communication

(e.g., fiber optic cables for receipt and transmission of data) .

Shock absorber 1 7 is attached to the bottom portion of tether

management system 1 2. It can be any device that can that can absorb or

cushion the impact resulting from positioning tether management system 1 2 on a

hard surface (e.g., the sea bed) . Shock absorber 1 7 can, for example, be a

synthetic rubber pad. In preferred embodiments, it takes the form of a plurality

of springs or like compression-resisting devices encased within a rugged cover.

Detachably connectable to tether management system 1 2 is umbilical 45,

a long cable-like device used to move linelatch system 1 0 between a surface platform such as surface support vessel 50 and various subsurface locations via

launching and recovery device 48 (e.g., a crane or winch) . Umbilical 45 can be

any device that can physically connect linelatch system 1 0 and a surface

platform. Preferably, it is long enough so that linelatch system 1 0 can be moved

between the surface of a body of water and a subsurface location such as the

sea bed. In preferred embodiments, umbilical 45 is negatively buoyant, fairly

rigid, and includes an umbilical port 46 capable of transferring power and/or data

between tether management system 1 2 and umbilical 45 (i.e. for conveyance to

surface support vessel 50). In some embodiments, the umbilical port 46 includes

two ports. The first port for communicating power tether management system

1 2 and umbilical 45. The second port for communicating data between tether

management system 1 2 and umbilical 45 More preferably, umbilical 45 is a

waterproof steel armored cable that houses a conduit for both power (e.g., a

copper electrical wire and/or a hydraulic hose) and data communication (e.g.,

fiber optic cables for receipt and transmission of data) . Umbilicals suitable for

use in the invention are commercially available from several sources (e.g., NSW,

Rochester, and Alcatel) . An umbilical connector 49 is provided on tether

management system 1 2 for mating with umbilical port 46.

Also attached to tether management system 1 2 is tether 40. It has two

ends or termini, one end being securely attached to tether management system

1 2, the other end being securely attached to tether fastener 21 of flying latch

vehicle 20. While tether 40 can be any device that can physically connect tether

management system 1 2 and flying latch vehicle 20, it preferably takes the form

of a flexible, neutrally buoyant rope-like cable that permits objects attached to it to move relatively freely. In particularly preferred embodiments, tether 40 also

includes a power and data communications conduit (e.g ., electricity-conducting

wire, hydraulic hose, and fiber optic cable) so that power and data can be

transferred through it. Tethers suitable for use in the invention are known in the

art and are commercially available (e.g., Perry Tritech, Inc.; Southbay; Alcatel;

NSW; and JAQUES) .

Attached to the terminus of tether 40 opposite tether management system

1 2 is flying latch vehicle 20. Flying latch vehicle 20 is a remotely-operated

underwater craft designed to mate with an undersea device for the purpose of

transferring power to and/or exchanging data with the undersea device. In

preferred embodiments, flying latch vehicle 20 includes tether fastener 21 ,

chassis 25, connector 22, a manipulator 27, and propulsion system 28.

Chassis 25 is a rigid structure that forms the body and/or frame of vehicle

20. Chassis 25 can be any device to which various components of vehicle 20

can be attached. For example, chassis 25 can take the form of a metal skeleton.

In preferred embodiments, chassis 25 is a hollow metal or plastic shell to which

the various components of vehicle 20 are attached. In the latter form, the

interior of chassis 25 can be sealed from the external environment so that

components included therein can be isolated from exposure to water and

pressure. In the preferred embodiment shown in FIGs. 1 A and 1 B, components

shown affixed to or integrated with chassis 25 include tether fastener 21 ,

connector 22, manipulator 27, propulsion system 28, andmale alignment guides

1 9.

Tether fastener 21 connects tether 40 to flying latch vehicle 20. Tether fastener 21 can be any suitable device for attaching tether 40 to flying latch

vehicle 20. For example, it can take the form of a mechanical connector adapted

to be fastened to a mechanical receptor on the terminus of tether 40. In preferred

embodiments, tether fastener 21 is the male or female end of bullet-type

mechanical fastener (the terminus of tether 40 having the corresponding type of

fastener) . In other embodiments, tether fastener 21 can also be part of a

magnetic or electromagnetic connection system. For embodiments within the

invention that require a power and/or data conduit between tether 40 and flying

latch vehicle 20, tether fastener 21 is preferably includes a tether port for

conveying power and/or data between tether 40 and flying latch vehicle 20 (e.g.,

by means of integrated fiber optic and electrical or hydraulic connectors).

Mounted on or integrated with chassis 25 is connector 22, a structure

adapted for detachably connecting receptor 62 of subsurface device 60 so that

flying latch vehicle 20 can be securely but reversibly attached to device 60.

Correspondingly, receptor 62 is a structure on subsurface device 60 that is

detachably connectable to connector 22. Although, in preferred embodiments,

connector 22 and receptor 62 usually form a mechanical coupling, they may also

connect one another through any other suitable means known in the art (e.g.,

magnetic or electromagnetic) . As most clearly illustrated in FIG. 2, in a

particularly preferred embodiment connector 22 is a bullet-shaped male-type

connector. This type of connector is designed to mechanically mate with a

funnel-shaped receptacle such as receptor 62 shown in FIG. 2. The large

diameter opening of the funnel-shaped receptor 62 depicted in FIG. 2 facilitates

alignment of a bullet-shaped connector 22 during the mating process. That is, in this embodiment, if connector 22 was slightly out of alignment with receptor 62

as flying latch vehicle 20 approached subsurface device 60 for mating, the funnel

of receptor 62 would automatically align the bullet-shaped portion of connector

22 so that vehicle 20's motion towards receptor 62 would automatically center

connector 22 for proper engagement.

Connector 22 and receptor 62 can also take other forms so long as they

are detachably connectable to each other. For example, connector 22 can take

the form of a plurality of prongs arranged in an irregular pattern when receptor 62

takes the form of a plurality of sockets arranged in the same irregular pattern so

that connector 22 can connect with receptor 22 in one orientation only. As

another example, connector 22 can be a funnel-shaped female type receptacle

where receptor 62 is a bullet-shaped male type connector. In addition to

providing a mechanical coupling, in preferred embodiments, the interaction of

connector 22 and receptor 62 is utilized to transfer power and data between

flying latch vehicle 20 and subsurface device 60. (See below) .

Manipulator 27 is attached to chassis 25. In FIGs. 1 A, 1 B, and 2,

manipulator 27 is shown as a mechanical arm for grasping subsurface objects.

While it can take this form, manipulator 27 is any device that can interface with

an underwater object. Preferably, manipulator 27 is adapted to grasp jumper

cable 74 and insert it into power and data connection 80 on module 70.

Also attached to chassis 25 is propulsion system 28. Propulsion system

28 can be any force-producing apparatus that causes undersea movement of

flying latch vehicle 20 (i.e., "flying" of vehicle 20) . Preferred devices for use as

propulsion system 28 are electrically or hydraulically-powered thrusters. Such devices are widely available from commercial suppliers (e.g., Hydrovision Ltd.,

Aberdeen, Scotland; Innerspace, California; and others) .

Referring now to FIG. 2, in preferred embodiments, flying latch vehicle 20

further includes an output port 24 and/or a communications port 26; and position

control system 30 which may include compass 32, depth indicator 34, velocity

indicator 36, and/or video camera 38.

Power output port 24 can be any device that mediates the underwater

transfer of power from flying latch vehicle 20 to another underwater apparatus

such as subsurface device 60. In preferred embodiments, port 24 physically

engages power inlet 64 on subsurface device 60 such that power exits flying

latch vehicle 20 from port 24 and enters device 60 through power inlet 64.

Preferably, the power conveyed from power output port 24 to power inlet 64 is

electrical current or hydraulic power (derived, e.g., from surface support vehicle

50) to subsurface device 60) . In particularly preferred embodiments, power

output port 24 and power inlet 64 form a "wet-mate"-type connector (i.e., an

electrical, hydraulic, and/or optical connector designed for mating and demating

underwater). In the embodiment shown in FIG. 2, port 24 is integrated into

connector 22 and power inlet 64 is integrated with receptor 62. In other

embodiments, however, port 24 is not integrated with connector 22 but attached

at another location on flying latch vehicle 20, and inlet 64 is located on device 60

such that it can engage port 26 when vehicle 20 and device 60 connect.

The components of flying latch vehicle 20 can function together as a

power transmitter for conveying power from tether 40 (e.g., supplied from

module 70 through jumper cable 74 and tether management system 1 2) to an underwater apparatus such as subsurface device 60. For example, power can

enter vehicle 20 from tether 40 through tether fastener 21 . This power can then

be conveyed from fastener 21 through a power conducting apparatus such as an

electricity-conducting wire or a hydraulic hose attached to or housed within

chassis 25 into power output port 24. Power output port 24 can then transfer

the power to the underwater apparatus as described above. In preferred

embodiments of the flying latch vehicle of the invention, the power transmitter

has the capacity to transfer more than about 50% (e.g., approximately 50%,

55%, 60%, 65%, 70%, 75%, 80%, 85 %, 90%, 95 %, 1 00%) of the power

provided to it from an external power source such as surface support vessel 50

(i.e., via umbilical 45 and tether 40) to subsurface device 60. Power not

conveyed to subsurface device 60 from the external power source cah be used to

operate various components on flying latch vehicle 20 (e.g., propulsion system

28 and position control system 30) . As one example, of 1 00 bhp of force

transferred to vehicle 20 from vessel 50, 20 bhp is used by flying latch vehicle

20, and 80 bhp used by subsurface device 60.

Communications port 26 is a device that physically engages

communications acceptor 63 on subsurface device 60. Port 26 and acceptor 63

mediate the transfer of data between flying latch vehicle 20 and device 60. For

example, in the preferred configuration shown in FIG .2, communications port 26

is a fiber optic cable connector integrated into connector 22, and acceptor 63 is

another fiber optic connector integrated with receptor 62 in on device 60. The

port 26-acceptor 63 connection can also be an electrical connection (e.g.,

telephone wire) or other type of connection (e.g., magnetic or acoustic) . In particularly preferred embodiments, the communications port 26-communications

acceptor 63 connection and the power output port 24-power inlet 64 connection

are integrated into one "wet-mate"-type connector. In other embodiments,

communications port 26 is not integrated with connector 22 but attached at

another location on flying latch vehicle 20, and acceptor 63 is located on device

60 such that it can engage port 26 when vehicle 20 and device 60 connect.

Communications port 26 is preferably a two-way communications port that can

mediate the transfer of data both from flying latch vehicle 20 to device 60 and

from device 60 to vehicle 20.

Communications port 26 and acceptor 63 can be used to transfer

information (e.g., video output, depth, current speed, location information, etc.)

from subsurface device 60 to a remotely-located operator (e.g, on surface vessel

50) via linelatch 1 0 and umbilical 45. Similarly, port 26 and acceptor 63 can be

used to transfer information (e.g., mission instructions, data for controlling the

location and movement of subsurface device 60, data for controlling mechanical

arms and like manipulators on subsurface device 60, etc.) between a remote

location (e.g., from module 70) and subsurface device 60.

Position control system 30 is any system or compilation of components

that controls underwater movement of flying latch vehicle 20, and/or provides

telemetry data from vehicle 20 to a remotely-located operator. Such telemetry

data can be any data that indicates the location and/or movement of flying latch

vehicle 20 (e.g., depth, longitude, latitude, depth, speed, direction), and any

related data such as sonar information, pattern recognition information, video

output, temperature, current direction and speed, etc. Thus, position control system 30 can include such components as sonar systems, bathymetry devices,

thermometers, current sensors, compass 32, depth indicator 34, velocity

indicator 36, video camera 38, etc. These components may be any of those

used in conventional underwater vehicles or may specifically designed for use

with linelatch system 1 0. Suitable such components are available from several

commercial sources.

The components of position control system 30 for controlling movement of

flying latch vehicle 20 are preferably those that control propulsion system 28 so

that vehicle 20 can be directed to move eastward, westward, northward,

southward, up, down, etc. These can, for example, take the form of remotely-

operated servos for controlling the direction of thrust produced by propulsion

system 28. Other components for controlling movement of flying latch vehicle 20

may include buoyancy compensators for controlling the underwater depth of

flying latch vehicle 20 and heave compensators (e.g., interposed between tether

management system 1 2 and umbilical 45) for reducing wave-induced motion of

flying latch vehicle 20. A remotely-positioned operator can receive output signals

(e.g., telemetry data) and send instruction signals (e.g., data to control propulsion

system 28) to position control system 30 through the data communication

conduit included within umbilical 45 and/or jumper cable 74 (via module 70 and

module pipe 47) via the data communications conduits within tether management

system 1 2 and tether 40.

One or more of the components comprising position control system 30 can

be used as a guidance system for docking flying latch vehicle 20 to subsurface

device 60 or inserting jumper cable 74 into connector 80. For example, the guidance system could provide a remotely-located pilot of vehicle 20 with the

aforementioned telemetry data and a video image of receptor 62 on subsurface

device 60 such that the pilot could precisely control the movement of vehicle 20

into the docked position with subsurface device 60 using the components of

system 30 that control movement of vehicle 20. As another example, for

computer-controlled docking, the guidance system could use data such as pattern

recognition data to align vehicle 20 with subsurface device 60 and the

components of system 30 that control movement of vehicle 20 to automatically

maneuver vehicle 20 into the docked position with subsurface device 60.

As shown in FIGs. 1 A and 1 B, linelatch system 1 0 can be configured in an

open position or in a closed configuration. In FIG. 1 A, linelatch system 1 0 is

shown in the open position where tether management system 1 2 is separated

from flying latch vehicle 20 and tether 40 is slack. In this position, to the extent

of slack in tether 40, tether management system 1 2 and flying latch vehicle 20

are independently moveable from each other. In comparison, in FIG. 1 B,

linelatch system 1 0 is shown in the closed position. In this configuration, tether

management system 1 2 physically abuts flying latch vehicle 20 and tether 40 is

tautly withdrawn and mechanically locked into tether management system 1 2 in

a docked or closed configuration. In order to prevent movement of tether

management system 1 2 and flying latch vehicle 20 when linelatch system 1 0 is

in the closed configuration, male alignment guides 1 9 can be affixed to tether

management system 1 2 so that they interlock the female alignment guides 29

affixed to flying latch vehicle 20. Male alignment guides 1 9 can be any type of

connector that securely engages female alignment guides 29 such that movement of system 1 2 is restricted with respect to vehicle 20, and vice versa.

Several other components known in the art of underwater vehicles can be

included on linelatch system 1 0. One skilled in this art, could select these

components based on the particular intended application of linelatch system 1 0.

For example, for applications where umbilical 45 becomes detached from

linelatch system 1 0, an on-board auxiliary power supply (e.g., batteries, fuel

cells, and the like) can be included on linelatch system 1 0. Likewise, an acoustic

modem could be included within linelatch system 1 0 to provide an additional

communications link among, for example, linelatch system 1 0, attached

subsurface device 60, and surface support vessel 50.

Methods of using linelatch system 1 0 are also within the invention. For

example, as illustrated in FIGs. 3A-F, linelatch system 1 0 can also be used in a

method for conveying power and/or data between subsurface module 70 and

subsurface device 60. In preferred embodiments this method includes the steps

of: deploying linelatch system 1 0 to the bottom of body of water 8 (i.e., the

seabed), placing system 1 0 in the open configuration by undocking flying latch

vehicle 20 from tether management system 1 2; and connecting jumper cable to

subsurface module 70. Subsurface module 70 can be any subsurface apparatus

that can provide power and/or data to another subsurface device (e.g., a manifold

of a well head) . Power and data can be transferred between surface platform 52

and subsurface module 70 via module pipe 47 (see FIGs. 1 A and 1 B).

One example of this is illustrated in FIGs. 3A-3F. As shown in FIG.3A

linelatch system 1 0 is deployed from vessel 50 and lowered towards the seabed

by umbilical 45. System 1 0 can be deployed from vessel 50 by any method known in the art. For example, linelatch system 1 0 can be lowered into body of

water 8 using a winch. Preferably, to prevent damage, linelatch system 1 0 is

gently lowered from vessel 50 using launching and recovery device 48 (e.g., a

crane) and umbilical 45.

In FIG. 3B, tether management system 1 2 is shown suspended at a

location just above the seabed (i.e., so that heave-induced motion will not cause

system 1 2 to crash against the seabed) . As shown in FIG. 3C, from this

location, flying latch vehicle 20 then flies away from its docking point on tether

management system 1 2 (i.e., linelatch system 1 0 is placed in the open

configuration) to jumper cable 74 also on tether management system 1 2.

Propulsion system 28 on flying latch vehicle 20 can be used to move vehicle 20

to facilitate this process. When positioned adjacent to jumper cable 74,

manipulator 27 of flying latch vehicle 20 securely grasps the end of jumper cable

74 and gradually extends it from tether management system 1 2. As indicated in

FIG. 3D, in the next step, vehicle 20 and manipulator 27 attach jumper cable 74

to subsurface module 70 by connecting the end of jumper cable 74 into power

and data connection 80 (a power and data output socket) on module 70. This

step permits power and data to be transferred from module 70 to linelatch

system 1 0.

At this point umbilical 45 is no longer needed to supply power to linelatch

system 1 2, so it can disconnect system 1 2 and be recovered to surface vessel

50. With the umbilical disconnected from tether management system 1 2,

linelatch system 1 0 is no longer subject to any heave-induced motion transmitted

through umbilical 45. Therefore, as shown in FIG. 3E, tether management system can then be positioned on the seabed by, for example, by dropping after

being released from umbilical 45. Shock absorber 1 7 on the bottom of tether

management system 1 2 can cushion the impact of system 1 2 landing on the

seabed.

As shown in FIG . 3E, flying latch vehicle 20 then flies (e.g., using power

derived from module 70 to operate propulsion system 28) to a location near

subsurface device 60. After proper alignment of flying latch vehicle 20 with

subsurface device 60, vehicle 20 is moved (e.g., using propulsion system 28) a

short distance toward device 60 so that connector 22 securely engages (i.e.,

docks) receptor 62. FIG. 3F shows flying latch vehicle 20 physically engaging

(i.e., docking) subsurface device 60. In this manner, power and data can be

transferred between module 70 and device 60. For example, where module 70

is connected to a surface structure such as surface platform 52 (see FIG. 1 A for

example), the power and data bridge between module 70 and device 60 made by

linelatch system 1 0 allows subsurface device 60 to be remotely operated by a

pilot located on the surface structure via module pipe 47.

In a variation of the foregoing, umbilical 45 is not required as a power or

data conduit. Rather, linelatch system 1 0 can be deployed and recovered from

the sea bed using a simple lift line such as a cable, and an on board power means

and preprogrammed position control system on linelatch system 1 0 used to fly

vehicle 20 so that it can attach jumper cable 74 to module 70 (thereby providing

power to linelatch system 1 0 from an external source) . In addition to the

foregoing, several other variations on the use of linelatch system 1 0 are within

the invention. For example, two or more linelatch systems 1 0 can be lowered to subsurface locations to link several underwater devices 60 and/or modules 70

and/or vessels 50 to create a network of power and data connections for

operating the underwater devices 60.

Referring now to FIG. 4, linelatch system 1 0 can also be used to service

(e.g., transfer power and/or data between) an underwater device (e.g.,

subsurface module 70) and a underwater vehicle (e.g., an AUV or a submarine)

such as subsurface craft 90. In this method, linelatch system 1 0 serves as a

power and communications bridge (as well as a mechanical link) between surface

support vessel 50 and craft 90. In preferred embodiments, this method includes

the steps of deploying linelatch system 1 0 from surface vessel 50 into body of

water 8; placing linelatch system 1 0 in the open position; connecting jumper

cable 74 to module 70, maneuvering flying latch vehicle 20 to craft 90; aligning

and mating vehicle 20 with craft 90; transferring power and/or data between

module 70 and craft 90 (via flying latch vehicle 20), and undocking vehicle 20

from craft 90.

As shown in FIG . 4, linelatch system 1 0 can be lowered to a subsurface

location to interface, provide power to, and exchange data with craft 90 at a

subsurface (shown) . Similarly to the operation shown in FIGs. 3A-3E, linelatch

system 1 0 is lowered by umbilical 45 from surface support vehicle 50 using

launching and recovery device 48. Linelatch system 1 0 is lowered until it

reaches a location just above the seabed. Flying latch vehicle 20 then flies away

from its attachment point on tether management system 1 2 to jumper cable 74

also on tether management system 1 2. When positioned adjacent to jumper cable

74, manipulator 27 of flying latch vehicle 20 securely grasps the end of jumper cable 74 and gradually extends it from tether management system 1 2. Vehicle

20 and manipulator 27 then attach jumper cable 74 to subsurface module 70 by

connecting the end of subsurface module 70 into power and data connection 80.

This step transfers power and data from module 70 to linelatch system 1 0.

Umbilical 45 then disconnects tether management system 1 2, which is then

positioned on the seabed. Flying latch vehicle 20 then flies to and then docks

with craft 90.

Linelatch system 1 0 thereby physically connects craft 90 and module 70.

Through this connection, power and data can be transferred between module 70

and craft 90. The power thus transferred to craft 90 can be used to recharge a

power source (e.g., a battery) on craft 90 or run the power-consuming

components of craft 90 independent of its on-board power supply. In a like

fashion, data recorded from craft 90's previous mission can be uploaded to

module 70 and new mission instructions downloaded to craft 90 from module

70. Using this method, craft 90 can be repeatedly serviced so that it can

perform several missions in a row without having to surface.

Myriad variations on the foregoing methods can be made for interfacing

subsurface devices. For example, rather than using a subsurface power supply

(e.g., module 70), power can be supplied for these methods from an underwater

vehicle such as a submarine. From the foregoing, it can be appreciated that the

linelatch system of the invention facilitates many undersea operations.

While the above specification contains many specifics, these should not be

construed as limitations on the scope of the invention, but rather as examples of

preferred embodiments thereof. Many other variations are possible. For example, a manned linelatch system and undersea vehicles having a linelatch

system incorporated therein are included within the invention. Accordingly, the

scope of the invention should be determined not by the embodiments illustrated,

but by the appended claims and their legal equivalents.

Claims

What is claimed is:

1 . A submersible system for transferring power from a subsurface power supply

module to a subsurface device, comprising:

a tether management system having an umbilical connector configured for

deploying said tether management system from a surface vessel to a seabed, a

jumper cable extendible from said tether management system configured for

receiving at least one of power and data from an external subsurface module;

a submersible vehicle releasably docked to said tether management

system, said submersible vehicle having a tether receiving at least one of data

and power from said tether management system

a transfer system for selectively transferring at least one of said data and

power to said submersible vehicle from said external subsurface module and said

umbilical connector.

2. The submersible system according to claim 1 wherein said

submersible vehicle is self-propelled to move between said tether management

system and a subsurface device.

3. The submersible system according to claim 2 wherein said

submersible vehicle has a vehicle connector which automatically engages a

corresponding mating connector on said subsurface device when said

submersible vehicle is propelled to a mating position adjacent to said subsurface

device.

4. The submersible system according to claim 3 wherein said vehicle

connector is a power connector and about 50% and 1 00% of the power received

by said submersible vehicle from said transfer system is transferred to said

subsurface device.

5. The submersible system according to claim 4 wherein said

submersible vehicle is operable for extending said jumper cable from said tether

management system to said subsurface module to form at least one of a data

and power connection between said subsurface module and said tether

management system.

6. The submersible system according to claim 2, further comprising

means for automatically remotely detaching said umbilical connector from an

umbilical cable in response to a control command.

7. The submersible system according to claim 1 , further comprising a

power supply integrated within at least one of said tether management system

and said submersible vehicle for powering the submersible vehicle.

8. The submersible system according to claim 6 further comprising a shock

absorber system on a lower portion of said tether management system for

absorbing impact with a seabed resulting from positioning said submersible

system.

9. A method for establishing a power and control connection from a

subsurface power supply module to a subsurface device, comprising the steps of:

deploying a tether management system to a subsea location;

in response to a control command, extending a jumper cable from said

tether management system to said subsurface power supply module for

transferring at least one of data and power from said subsurface power supply

module to said tether management system; and

flying a power connector from said tether management system to said

subsurface device to establish at least one of a power and data transfer circuit

between said tether management system and said subsurface device.

1 0. The method according to claim 9 wherein said deploying step further

includes the step of lowering said tether management system to said subsea

location using a cable, and subsequently detaching the cable from said tether

management system.

1 1 . The method according to claim 1 0 wherein said cable is an umbilical

cable and provides at least one of data, power and materials to said tether

management system.

1 2. The method according to claim 1 0 wherein said detaching step is

performed before said extending step.

1 3. The method according to claim 1 0 wherein said detaching step is

performed after said extending step.

1 4. A method of deploying a submersible system and connecting the

submersible system to an subsurface module, said method comprising the steps

of:

deploying a submersible system to the bottom of a body of water, the

submersible system including:

a tether management system having a cable for receiving at least one of

data, power, and material from the subsurface module,

a submersible vehicle detachably connected to the tether management

system, and

a tether attaching the submersible vehicle to the tether management

system;

detaching the submersible vehicle from the tether management system;

and,

connecting the cable to the subsurface module.

1 5. The method as recited in claim 1 4, wherein said deploying step

further includes the step of lowering the submersible system with a cable from a

vessel to the bottom, and subsequently detaching the cable from the submersible

system.

1 6. The method as recited in claim 1 5, further comprising the step of powering the submersible vehicle from a power source in the submersible system

before said detaching step.

1 7. The method as recited in claim 1 6, wherein before said detaching

step, said connecting step further includes the steps of:

maneuvering the submersible vehicle to the cable,

retrieving the cable with the submersible vehicle, and

maneuvering the submersible vehicle and cable to the subsurface

module.

1 8. The method as recited in claim 1 5, further comprising the step of

powering the submersible vehicle from the cable before said detaching step.

1 9. The method as recited in claim 1 8, wherein before said detaching

step, said connecting step further includes the steps of:

maneuvering the submersible vehicle to the cable,

retrieving the cable with the submersible vehicle, and

maneuvering the submersible vehicle and cable to the subsurface

module.