United States Patent [191
`Dolengowski
`
`[11] Patent Number:
`[45] Date of Patent:
`
`4,890,568
`Jan. 2, 1990
`
`[54] STEERABLE TAIL BUOY
`
`_
`_
`[75] Invento? George A- 1301611801751“, Bellaue,
`Tex.
`
`.
`-
`.
`[73] Asslgnee' Exm“ Producm’" Research
`Company, Houston, Tex.
`[21] APPL No_: 236,107
`[22] Filed:
`Aug. 24, 1988
`[5;] gr. cg .................................... 1.1.3.3531}: 42/12/5126
`
`
`
`
`
`
`
`g / n ---------------------------------- n as. [5 ] [58] Field of Search ............. .. 114/162, 163, 242, 244,
`
`
`
`
`
`4,404,664 9/1983 Zachariadis ......................... .. 367/19
`4,463,701 8/1984 Pickett et a1. .... ..
`114/245
`4,506,352 3/1985 Brandsaeter et al.
`367/21
`4,574,723 3/1986 Chiles et al.
`114/253
`4,729,333 3/1988 Kirby et a1. .
`. 114/244
`4,763,126 8/1988 Jawetz ................................. .. 441/16
`
`FOREIGN PATENT DOCUMENTS
`204740613
`/1983 United Kingdom
`Primary Examiner-Sherman D. Basinger
`Assistant Examiner_stephen P_ Avila
`
`'
`
`'
`
`.
`
`9
`
`[57]
`
`
`
`M. ABSTRACT
`
`A remotely controllable tail buoy\ for use in marine
`geophysical prospecting operations is disclosed. The
`tail buoy is attached to the trailing end of one or more
`seismic streamers towed by the vessel. The tail buoy is
`provided with rudders that are controlled by a Steering
`mechanism and communication system. The communi
`cation system collects and processes radio signals emit
`ted from a radio transmitter located on the towing ves
`sel. The processed signals control the steering mecha
`nism which includes a hydraulic pump for directing
`?uid into a hydraulic cylinder. The ?uid ?ow rotates
`the rudders. The tail buoy will travel toward the direc
`tion that the rudders are turned and thus avoid hooking
`or entanglmg of the tail buoy on other like tail buoys or
`
`Structure?
`
`15 Claims, 2 Drawing Sheets
`
`[56]
`
`114/246’ 253
`
`References Cited
`U.S. PATENT DOCUMENTS
`1,717,286
`3,125,980
`3,469,552
`3,560,912
`3,605,674
`3,710,749
`3,774,570
`3,896,756
`4,033,278
`4,063,213
`4,087,780
`4,130,078
`4,290, 124
`4,323,989
`4,350,111
`
`6/1929 Ward ................................. .. 114/ 163
`‘gntdg?on '
`at";
`M1971
`9/1971 weese ____
`1/1973 Dnryea ..
`11/1973 Pearson ...... ..
`7/1975 Pearson et al.
`7/ 1977 wfiters ------- -
`Z: 2}‘ '
`12/1978 Cholet ____ i’
`
`340/
`{@235 B
`114/153
`114/235
`114/235 B
`114/ 245
`
`" ll4/244
`
`9/1981 C016 .................... .. 367/18
`4/1982 Huckabee et al.
`367/181
`9/1982 Boyce, II .......................... .. 114/245
`
`72A
`1
`
`12B
`)
`
`72C
`
`)
`
`20
`i
`
`20
`l
`
`20
`
`20
`/'
`
`2)0
`
`22/1
`/ <7;
`\
`24A
`
`22B
`2 Q
`‘24B
`
`22C
`
`n
`
`:P
`\
`24C
`
`PGS v. WESTERNGECO (IPR2014-00687)
`WESTERNGECO Exhibit 2065, pg. 1
`
`

`

`US. Patent Jan. 2, 1990
`
`Sheet 1 of2
`
`4,890,568
`
`PGS v. WESTERNGECO (IPR2014-00687)
`WESTERNGECO Exhibit 2065, pg. 2
`
`

`

`US. Patent Jan. 2, 1990
`
`Sheet 2 of2
`
`4,890,568
`
`F/G.4
`
`M
`56% '
`70
`III
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`P1
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`/
`56
`
`i
`
`“
`
`a
`
`:
`
`OOj‘
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`70
`
`m '~\
`
`REMOTE
`CONTROLLER
`
`RAD/O
`
`BATTERY l
`
`74
`
`50
`52
`
`S
`
`50
`
`g 2:52
`
`___m
`
`PGS v. WESTERNGECO (IPR2014-00687)
`WESTERNGECO Exhibit 2065, pg. 3
`
`

`

`1
`
`STEERABLE TAIL BUOY
`
`4,890,568
`
`FIELD OF THE INVENTION
`This invention relates generally to marine towing
`operations. More speci?cally, but not by way of limita
`tion, it relates to a steerable tail buoy for use while
`gathering marine seismic data using one or more seismic
`streamers.
`
`25
`
`35
`
`2
`of the streamer. It also serves as a warning device for
`other vessel operators to indicate that a streamer is
`being towed. The tail buoy is usually a catamaran raft
`provided with tubular ?oats, lights and radar re?ectors.
`The rope, which may range in length from 30 to 300
`meters (about 100 to 1000 feet), allows the tail buoy to
`?oat on the surface of the water without raising the
`trailing end of the streamer.
`In recent years, it has become feasible to tow a plural
`ity of streamers, laterally spaced apart, behind a single
`vessel. As a result, a greater survey area may be cov
`ered in a shorter period of time, resulting in a lower
`overall survey cost. When a plurality of streamers are
`towed behind a single vessel, paravanes, being attached
`to the lead end of each streamer, are often used to later
`ally seperate the lead end of each streamer. One exam
`ple of a paravane is described in US. Pat. No. 4,463,701
`- which issued Aug. 7, 1984 to Pickett, et al. A remotely
`controlled paravane is disclosed in US. Pat. No.
`4,729,333 which issued Mar. 8, 1988 to Kirby, et al.
`A particular difficulty has arisen when towing a plu
`rality of streamers. In routine turns, all streamers nor
`mally tow in concentric circles. However during de
`ployment or repair of the streamers or in non-routine
`turns such as slow speed turns or sharp turns, it is ‘com
`mon for the streamers to cross and become tangled. It is
`possible to prevent entanglement of the streamers by
`diving one streamer while surfacing the other with the
`aid of the remotely controllable birds. Although this
`keeps the streamers from tangling, the tail buoys, which
`at all times remain on the water’s surface, are likely to
`cross and become hooked, or the ropes that connect the
`buoys to the streamers may become tangled. Unhooking
`the tail buoys or untangling the ropes requires the use of
`a small auxiliary boat, if available. Otherwise, the
`streamers and ropes must be reeled toward the vessel to
`be untangled by the vessel operators.
`Another difficulty arises when data is being collected
`near an offshore structure. As one or more streamers are
`towed behind a vessel, the wind and water current may
`cause the trailing end of the streamer to feather out
`wardly from the vessel’s path. If data is being collected
`along a path near an offshore structure, the wind and
`current may push the streamer and tail buoy into the
`structure. As a result the buoy or the streamer may
`become damaged or they may become hooked to the
`
`BACKGROUND OF THE INVENTION
`In recent years the search for oil and gas has moved
`offshore. In order to locate potential offshore oil and
`gas reservoirs, it has been necessary to develop new
`devices and techniques for conducting marine geophys
`ical prospecting operations. Due to the hostile environ
`ment in which they are conducted, such operations are
`typically quite dif?cult and costly to perform.
`The primary method for conducting marine geophys
`20
`ical prospecting operations involves the use of towable
`marine seismic sources and seismic receiver cables. The
`basic principles of this prospecting method are well
`known to those skilled in the art. The seismic source(s)
`introduce seismic signals into the body of water. The
`signals travel downwardly through the water, across
`the water-?oor interface, and into the subterranean
`geological formations, and are, to some extent, reflected
`by the interfaces between adjacent formations. The
`re?ected signals travel upwardly through the geologi
`30
`cal formations and the body of water to a seismic re
`ceiver cable located near the surface of the body of
`water. The seismic receiver cable typically contains a
`number of hydrophones spaced along its length which
`record the reflected signals. Analysis of the signals
`recorded by the hydrophones can provide valuable
`information concerning the structure of the subterra
`nean geological formations and possible oil and gas
`accumulation therein.
`Seismic receiver cables, commonly known as
`“streamers”, are usually towed below the water surface.
`The streamers are preferably of neutral buoyancy and
`can be balanced by ?lling them with a liquid having a
`speci?c gravity less than 1 to add ?otation, or by re
`moving excess liquid or taping lead strips to the outer
`surfaces of the streamers to reduce ?otation. As is well
`known to those skilled in the art, a properly balanced
`streamer should maintain approximately the same depth
`along its entire length while it is being towed. Balancing
`the streamer is often a difficult process as it is possible
`for the streamers to be 6 kilometers (3.7 miles) long or
`more.
`The depth of the streamers during tow is usually
`controlled by winged devices known as “birds” which
`are attached to the streamers typically every 300 to 500
`meters (about 1000 to 1600 feet). The birds are provided
`with remote depth controls which enable them to main
`tain the streamer at a uniform running depth or to raise
`or lower the streamer. A typical bird looks like a tor
`pedo, being about 0.6 meters (2 feet) long, with two
`short winglike ?ns. It usually separates into halves,
`along its length, and is hinged on one side so that it can
`be opened and clamped onto the cable. One example of
`a bird is described in US. Pat. No. 3,605,674 which
`issued on Sept. 20, 1971 to Weese.
`~
`At the trailing end of the streamer, away from the
`vessel, a tail buoy is attached to the streamer, typically
`by a rope. The tail buoy enables the vessel operators to
`determine and mark the approximate location of the end
`
`45
`
`structure.
`
`,
`
`Accordingly, in marine seismic exploration the need
`exists for a remotely controllable tail buoy which can be
`attached to a seismic streamer so as to indicate the ap
`proximate location of the trailing end of the streamer,
`and which can be remotely steered away from other tail
`buoys attached to other streamers or from offshore
`structures and other obstructions in order to prevent
`tangling of the tail buoys or damage to the tail buoys or
`streamers.
`
`SUMMARY OF THE INVENTION
`The present invention is a remotely controllable tail
`buoy that may be directed from a remote location such
`as from a towing vessel to prevent damage to the tail
`buoys, hooking of the tail buoys or tangling of the ropes
`when one or more streamers are being towed by the
`towing vessel. Additionally, the inventive tail buoy may
`be used when towing one or more streamers to direct
`the trailing ends of the streamers away from offshore
`
`55
`
`60
`
`65
`
`PGS v. WESTERNGECO (IPR2014-00687)
`WESTERNGECO Exhibit 2065, pg. 4
`
`

`

`4,890,568
`3
`structures or other obstructions which could damage
`the streamers.
`In a preferred embodiment, the tail buoy is provided
`with two or more rudders, a steering mechanism and a
`communication system. The rudders are adapted to
`rotate substantially simultaneously about generally ver
`tical axes to control the course of the tail buoy. The
`rotation of the rudders are controlled by the steering
`mechanism and the communication system. The steer
`ing mechanism controls the rudder position based on
`signals received by the communication system from a
`remote transmitter on the vessel. The communication
`system includes a two-way radio receiver tuned to the
`same frequency as the remote transmitter for receiving
`radio signals emitted from the remote transmitter. The
`signals are processed by a remote controller which is
`preferably a microprocessor-based controller and data
`acquisition system. The processed signals control the
`steering mechanism which includes a hydraulic pump.
`The pump directs ?ow to a hydraulic cylinder causing
`the rudders to turn. Then, as the vessel continues to
`move, the tail buoy will travel toward the direction that
`the rudders are turned thereby avoiding other tail buoys
`or offshore structures.
`The tail buoy design preferably includes a single
`tubular ?oat and an anti-roll weight. The tubular ?oat
`provides all necessary buoyancy for the tail buoy while
`the anti-roll weight keeps the buoy in an upright or
`vertical position. This design lessens the probability that
`the tail buoys will hook if one buoy ?oats into another’s
`path.
`The steerable tail buoy of the present invention may
`include additional peripheral equipment such as rudder
`position sensors, relative positioning instrumentation
`and navigational instrumentation. The navigational in
`stnimentation may be acoustic based, radio based or
`optical based instrumentation. Data from these sensors
`and instruments may be continuously transmitted to the
`vessel and fed into a computer located on board the
`vessel. The computer would continuously monitor the
`precise location of the tail buoy and initiate any neces
`sary actions to adjust the course of the tail buoy.
`
`35
`
`DESCRIPTION OF THE DRAWINGS
`The actual operation and advantages of the present
`invention will be better understood by referring to the
`following detailed description and the attached draw
`ings in which:
`FIG. 1 is a plan view of a vessel towing three stream
`ers with the inventive tail buoys attached to ends of the
`streamers.
`FIG. 2 is a side view of a vessel towing two stream
`ers, illustrating that one streamer has been lowered to
`avoid entanglement with the other streamer during a
`repair operation and the other streamer has been raised
`to the surface of the water.
`FIG. 3 is a perspective view of the inventive tail
`buoy.
`FIG. 4 is an internal diagram along line 4-4 of FIG.
`3 which illustrates a preferred embodiment of the tail
`buoy’s steering mechanism, communication system and
`power source.
`While the invention will be described in connection
`with the preferred embodiments, it will be understood
`that the invention is not limited thereto. On the con
`trary, it is intended to cover all alternatives, modi?ca
`tions, and equivalents which may be included within the
`spirit and scope of the invention.
`
`45
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`55
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`65
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`5
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`25
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`30
`
`4
`DESCRIPTION OF THE PREFERRED
`EMBODIMENT
`FIG. 1 illustrates a plan view of vessel 10 which is
`moving in the direction of the arrow and is towing three
`streamers 12A, 12B, and 12C in a body of water 14. In
`normal operation, streamers 12A, 12B, and 12C are
`towed at a constant depth of approximately 3 to 15
`meters (10-50 feet) below the surface of water 14. Outer
`streamers 12A and 12C are maintained separated later
`ally from streamer 12B by paravanes 16. The total dis
`tance between streamers 12A, 12B, and 12C can be
`varied from approximately 50-300 meters (160-1000
`feet). For illustration purposes only, seismic source 18 is
`shown directly behind vessel 10. The most common
`seismic source used today is an air gun array. Other
`seismic sources include water guns, explosive gas guns,
`steam, small explosives and marine vibrators. Spaced
`along the length of each streamer 12A, 12B, and 12C are
`remotely controllable birds 20. Birds 20 are typically
`used to control the depth of streamers 12A, 12B, and
`12C. However, as illustrated in US. Pat. No. 3,605,675
`to Weese, birds 20 also have been designed to control,
`although to a limited extent, lateral movement of
`streamers 12A, 12B, and 12C. At the far end of stream—
`ers 12A, 12B, and 12C, attached by ropes 22A, 22B, and
`22C, are the inventive tail buoys 24A, 24B, and 24C
`disclosed herein. Tail buoys 24A, 24B, and 24C are used
`to indicate the approximate location of the ends of
`streamers 12A, 12B, and 12C and warn boat operators
`and others that one or more streamers are being towed.
`FIG. 2 illustrates the particular problem to be solved
`by steerable tail buoy 24 of the present invention. For
`purposes of simpli?cation, streamer 12B and seismic
`source 18 are not included in FIG. 2. During a repair
`operation using an auxiliary boat (not shown), to avoid
`tangling of streamers 12A and 12C, streamer 12A is
`raised to or near the surface of water 14 and streamer
`12C is lowered by about 18 to 30 meters (60400 feet) by
`birds 20. As the repairs are being made, streamers 12A
`and 12C may cross paths due to wind or surface cur
`rents but they will not tangle due to vertical separation.
`However, since tail buoys 24A and 24C remain on the
`surface of water, they may hit one another, become
`hooked, or ropes 22A and 22C may tangle.
`FIG. 3 illustrates a perspective view of a preferred
`embodiment of steerable tail buoy 24. The major com
`ponents shown include tubular ?oat 26, frame 28, anti
`roll weight 34, actuator housing 36, rudders 38, mast 40
`with light 42 and radar re?ector 44, tow bridle 46 and
`solar panel 48, if desired. Float 26 provides sufficient
`buoyancy to maintain tail buoy 24 on the surface of
`body of water 14 during operation. Preferably the buoy
`ancy is provided by one tubular ?oat 26, rather than a
`plurality of ?oats in order to reduce the possibility of
`one tail buoy getting hooked to another by reducing the
`number of components on the tail buoy. Float 26 should
`be designed to provide low drag when towed while
`maintaining adequate hydrodynamic stability. Many
`designs are feasible, however a cylindrical ?oat with
`hemispherical ends may be preferred. Frame 28 is at
`tached to the bottom of ?oat 26 by one or more support
`legs 30. Support legs 30 extend downwardly from ?oat
`26 and attach to base plate 32. Attached to base plate 32
`is anti-roll weight 34 which reduces rolling of tail buoy
`24 due to rudder lift or sea state. Anti-roll weight 34 can
`be a lead pipe or any other object of sufficient weight to
`reduce rolling of tail buoy 24. The weight tends to
`
`PGS v. WESTERNGECO (IPR2014-00687)
`WESTERNGECO Exhibit 2065, pg. 5
`
`

`

`5
`
`25
`
`20
`
`4,890,568
`6
`5
`simultaneously rotate rudder shafts 50, thereby causing
`lower the center of gravity, reducing rolling in a man
`rudders 38 to rotate simultaneously.
`ner similar to ballast in a ship’s keel. If a plurality of
`Connecting rod 66 may be moved in a number of
`?oats are used, anti-roll weight 34 may not be needed.
`Actuator housing 36, being attached to the bottom of
`ways. In a preferred embodiment, as illustrated in FIG.
`?oat 26, contains the tail buoy steering mechanism and
`4, hydraulics are used. Receiving electrical power from
`battery 78, motor 56 powers hydraulic pump 58. Hy
`communication system which will be further described
`draulic pump 58 directs hydraulic ?uid (not shown)
`in connection with FIG. 4. Rudders 38 are substantially
`through one of the ?uid conduits 60 into hydraulic
`vertical, wing-shaped plates of either uniform or varied
`size and shape. Although any number of rudders may be
`cylinder 62 which is pivotally mounted on one end 64 to
`actuator housing 36. The pressure of the hydraulic ?uid
`used, a preferred embodiment has at least two rudders
`to allow tail buoy 24 to move laterally while continuing
`in cylinder 62 causes piston rod 68 to move. Piston rod
`to face the general towing direction of vessel 10. Rud
`68 is pivotally attached to extension 54 on one of the
`tiller arms 52 opposite the connection to connecting rod
`ders 38 are connected to tail buoy 24 by rudder shafts
`50. In a preferred embodiment rudder shafts 50 extend
`66. As piston rod 68 moves, it causes tiller arm 52 to
`vertically through rudders 38 and upwardly into actua
`rotate about the axis of rudder shaft 50 and move con
`tor housing 36, where they are ?xedly attached to tiller
`necting rod 66. This results in simultaneous rotation of
`arms 52 (see FIG. 4). In a preferred embodiment, the
`rudder shafts 50 and rudders 38. Fluid conduits 60 are
`constructed using a ?exible material or joints 70.
`lower end of rudders shafts 50 are rotatably attached to
`base plate 32 of frame 28 for added strength to prevent
`Motor 56 is preferably a low voltage (12 volt for
`example) reversible DC motor. Battery 78 may be sup
`shafts 50 from twisting or bending. Rudders 38 are ?xed
`plemented or recharged by solar panel 48 (see FIG. 3).
`to rudder shafts 50 so that rotation of the rudder shafts
`50 will rotate the rudders 38. Alternatively, rudder
`Pump 58 may be a bidirectional pump which works in
`combination with an internally piloted, double check
`shafts 50 and rudders 38 may be integrated into single
`valve (not shown). Pump 58 is capable of pumping the
`components, each component forming one shaft 50 and
`hydraulic ?uid into either side of hydraulic cylinder 62
`one rudder 38. The angular position of rudders 38 is
`controlled by the steering mechanism (see FIG. 4)
`through ?uid conduits 60. The double check valve
`hydraulically locks rudders 38 into place when pump 58
`which is in actuator housing 36. Connected to mast 40 is
`light 42, radar reflector 44 and radio antenna 76. Light
`is turned off. When pump 58 is turned on, cracking
`42 aids in visual detection of tail buoy 24; radar re?ector
`pressures of the check valve are overcome allowing
`?uid to ?ow, thereby affecting rotation of rudders 38.
`44- aids in radar detection of tail buoy 24; and radio
`antenna 76 (further described with FIG. 4) receives and
`As an alternative, pump 58 may be a non-reversable
`pump where hydraulic ?uid ?ow may be directed into
`transmits signals from vessel 10 or from another remote
`either side of hydraulic cylinder 62 by using a solenoid
`location. Tow bridle 46 is the connection on which to
`operated, normally closed, 4-way, 3-position control
`tie rope 22. In a preferred embodiment as illustrated in
`valve (not shown). As a second alternative, rotation of
`FIG. 3, one end of tow bridle 46 is attached to frame 28
`rudders 38 could be achieved by using an electro
`near actuator housing 36 and the other end is attached
`mechanical push-pull actuator (not shown). If used, the
`near anti-roll weight 29. This connection will provide
`electric actuator would replace hydraulic cylinder 62,
`towing stability particularly when tail buoy 24 is pro
`the control valve (if used), and pump 58. However, due
`vided with a single tubular ?oat 26. Tow bridle 46 may
`to low mechanical efficiency, the electric push-pull
`be made of any suitable shape and material, including
`actuator will result in high power consumption. Other
`?exible material such as a rope or chain, having suffi
`cient strength to tow buoy 24 without breaking. Solar
`methods for actuating the rudders will be apparent to
`panel 48 is an optional device intended to supplement
`those skilled in the art.
`‘
`battery 78 (see FIG. 4) through the utilization of solar
`The tail buoy communication system includes radio
`72, remote controller 74 and antenna 76 (see FIG. 3). In
`energy. The output of solar panel 48 is related to avail
`45
`able sunlight and therefore is dependent on the time of
`a preferred embodiment radio 72 is a two-way radio
`capable of sending and receiving signals transmitted
`day and weather. Marine worthy solar panels are com
`mercially well known and will not be further described.
`through antenna 76 over radio waves. Remote control
`Actuator housing 36 is sealed against water penetra
`ler 74 is a microprocessor-based controller and data
`acquisition system, such as Motorola's microprocessor,
`tion. Within actuator housing 36 is the steering mecha
`nism for turning rudders 38, the communication system
`Model 6805. It decodes and executes commands trans
`which provides a communication link between opera
`mitted to radio 72 over radio waves from a two-way
`tors on vessel 10 and tail buoy 24, and battery 78 which
`radio (not shown) by a master controller (not shown),
`each being on vessel 10. In addition, remote controller
`supplies the necessary power to run the communication
`74 regulates the average charge rate of battery 78 by
`system and the steering mechanism. FIG. 4 illustrates a
`automatically switching solar panel 48 (see FIG. 3) on
`preferred embodiment of the elements within actuator
`housing 36.
`or off as needed. Typically the communication system is
`Referring to FIG. 4, the steering mechanism in a
`contained within actuator housing 36, however antenna
`76 may extend outside actuator housing 36 (see FIG. 3)
`preferred embodiment includes tiller arms 52, connect
`for improved reception.
`ing rod 66, hydraulic cylinder 62 with piston rod 68,
`hydraulic pump 58 with ?exible ?uid conduits 60, and
`The communication equipment (not shown) on vessel
`motor 56. FIG. 4 illustrates four tiller arms for purposes
`10 includes a two-way radio, an antenna, a master con
`of illustration; however, it will be understood that there
`troller, a CRT screen and a power source. The two-way
`radio on vessel 10 is preferably capable of transmitting
`is one tiller arm for each rudder 38. Tiller arms 52 are
`and receiving signals through the vessel antenna to and
`generally elongated and are connected to rudder shafts
`from radio 72 on tail buoy 24. The signals received by
`50. Opposite the connection to rudder shafts 50, tiller
`arms 52 are pivotally attached to connecting rod 66 in
`the vessel radio on vessel 10 are input to the master
`controller which analyzes the signals received and dis
`series. As connecting rod 66 moves, tiller arms 52 will
`
`55
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`65
`
`PGS v. WESTERNGECO (IPR2014-00687)
`WESTERNGECO Exhibit 2065, pg. 6
`
`

`

`4,890,568
`7
`8
`erally positioned below said buoyant ?oat in said body
`plays the status of tail buoy 24 on the CRT screen. In a
`preferred embodiment, the master controller is a porta
`of water, said anti-roll weight having sufficient weight
`ble personal computer.
`to reduce rolling of said buoy.
`To summarize, if the vessel operator determines that
`3. The tail buoy of claim 1 further comprising a
`the location of tail buoy 24 relative to other buoys or
`power source capable of providing sufficient electrical
`offshore structures is not acceptable, the vessel operator
`power to operate said communication system and said
`initiates a rudder change command by requesting a new
`steering mechanism, said power source being electri
`rudder setting through signals transmitted from the
`cally connected to said communication system and said
`vessel radio to radio 72 on tail buoy 24. When a rudder
`steering mechanism.
`change command is received by radio 72, such com
`4. The tail buoy of claim 1 wherein said steering
`mands are electronically input to remote controller 74.
`mechanism shifts said angular orientation of said rud
`Remote controller 74 executes the command by turning
`ders hydraulically.
`on motor 56. Motor 56 supplies operating power to
`5. A remotely controllable tail buoy for use in marine
`hydraulic pump 58. Pump 58 directs hydraulic ?uid into
`towing operations to indicate the approximate location
`hydraulic cylinder 62 causing piston rod 68 to move,
`of an object being towed in a body of water by a vessel
`thereby moving rod 66 from side to side. Such move
`having a vessel communication system, said tail buoy
`ment causes tiller arms 52 to turn rudders 38. Changing
`being attached to said object by a rope, said tail buoy
`the direction of rudders 38 will cause tail buoy 24 to
`comprising:
`move in a new direction, thereby changing the location
`of tail buoy 24 relative to other tail buoys or offshore
`20
`structures. A feed-back system (not shown) capable of
`reading the rudder position, measured in degrees, pro
`vides rudder position data to remote controller 74
`which turns motor 56 off after the new rudder setting is
`reached. Remote controller 74 con?rms that all rudder
`changes are executed by signaling back through radio
`72 and the vessel radio to the master controller a con?r
`mation after the change is complete. In addition, remote
`controller 74 may periodically update the vessel opera
`tors through the master controller and the CRT screen
`on the following data regarding tail buoy 24: rudder
`position, battery voltage, battery current, solar panel
`voltage, solar panel current, motor current, electronic
`reference voltage, sea water intrusion, and hydraulic
`line pressures from pressure transducers (not shown).
`The present invention and the best modes contem
`plated for practicing the invention have been described.
`It should be understood that the invention is not to be
`unduly limited to the foregoing which has been set forth
`for illustrative purposes. Various modi?cations and
`alternatives of the invention will be apparent to those
`skilled in the art without departing from the true scope
`of the invention. Accordingly, the invention is to be
`limited only by the scope of the appended claims.
`What I claim is:
`1. A remotely controllable tail buoy for use in marine
`towing operations, said tail buoy being attached to an
`object being towed by a vessel in a body of water so as
`to indicate the approximate location of said object, said
`tail buoy comprising:
`a buoyant float;
`at least two substantially vertical and substantially
`parallel rudders each rotatably attached by a shaft
`to said buoyant ?oat and extending generally
`downwardly into said body of water;
`a communication system adapted to receive and de
`code signals transmitted from said vessel; and
`a steering mechanism being electrically attached to
`said communication system and operatively at
`tached to said shafts so that said steering mecha
`nism will respond to said signals that are received
`and decoded by said communication system by
`simultaneously rotating said shafts, thereby shifting
`the angular orientation of said rudders relative to
`the course of said vessel causing said tail buoy to
`change directions.
`2. The tail buoy of claim 1 further comprising an
`anti-roll weight attached to said buoyant ?oat and gen
`
`at least two substantially vertical and substantially
`parallel rudders each rotatably attached by a shaft
`to said buoyant ?oat and extending generally
`downwardly into said body of water in such a
`manner that said rudders will control the course of
`said tail buoy, said rudders being adapted to be
`simultaneously rotatable about said shafts;
`a buoy communication system capable of receiving
`and decoding signals transmitted from said vessel
`communication system;
`a steering mechanism being electrically attached to
`said buoy communication system and operatively
`attached to said shafts so that said steering mecha
`nism will respond to said signals received and de
`coded from said vessel communication system by
`simultaneously rotating said shafts, thereby shifting
`the angular orientation of said rudders relative to
`the course of said vessel causing said tail buoy to
`change directions; and
`a power source capable of providing suf?cient elec
`trical power to operate said communication system
`and said steering mechanism, said power source
`being electrically connected to said communica
`tion system and said steering mechanism.
`6. The tail buoy of claim 5 wherein said steering
`mechanism controls said rotation of said rudders hy
`draulically.
`7. The tail buoy of claim 5 wherein said power source
`comprises a battery.
`8. The tail buoy of claim 7 wherein said power source
`further comprises a solar panel mounted on the upper
`surface of said buoyant ?oat and adapted to supplement
`the electrical power provided by said battery.
`9. The tail buoy of claim 5 wherein said buoy commu
`nication system comprises:
`a radio receiver adapted to receive signals over radio
`waves transmitted from said vessel communication
`system; and
`a microprocessor-based controller electrically at
`tached to said radio receiver, said microprocessor
`based controller being capable of decoding said
`signals received by said radio receiver into com
`mands and causing said commands to be executed
`by said steering mechanism to control and adjust
`the angular position of said rudders.
`10. The tail buoy of claim 5 further comprising an
`anti-roll weight attached to said buoyant ?oat and gen
`erally positioned below said buoyant ?oat in said body
`
`55
`
`65
`
`25
`
`40
`
`45
`
`PGS v. WESTERNGECO (IPR2014-00687)
`WESTERNGECO Exhibit 2065, pg. 7
`
`

`

`5
`
`10
`
`20
`
`25
`
`4,890,568
`10
`of water, said anti-roll weight having suf?cient weight
`that said steering mechanism is capable of simulta
`neously controlling said rotation of said shafts
`to reduce rolling of said buoyant buoy.
`thereby simultaneously controlling the rotation of
`11. A remotely controllable tail buoy for use in ma
`rine towing operations, said tail buoy being attached by
`said rudders;
`a power source capable of providing suf?cient elec
`a rope to an object being towed by a vessel in a body of
`trical power to operate said communication system
`water so as to indicate the approximate location of said
`object, said tail buoy comprising:
`and said steering mechanism, said power source
`being electrically connected to said communica
`a singular buoyant ?oat having a bottom side;
`tion system and said steering mechanism; and
`an actuator housing sealed against water penetration
`an anti-roll weight attached to said bottom of said
`and attached to said bottom side of said singular
`singular buoyant ?oat and having suf?cient weight
`?oat;
`to reduce rolling of said tail buoy.
`a communication system located within said actuator
`housing for receiving and decoding radio signals
`12. The remotely controllable tail buoy of claim 11
`wherein said steering mechanism controls said plurality
`transmitted from a remote location,