Articulated boom and head for manipulating objects under water

The articulated boom and utility head for manipulating objects underwater of the present invention includes an articulated arm mounted at a first end thereof to a free floating platform, and a remotely operable utility head mountable at a second end of the arm. At least one sensor for relaying sensed information from the sensor to a remote operator or processor is mounted to the articulated arm. The sensed information is transmitted in real time as the arm remotely operated under water.

FIELD OF THE INVENTION 
This invention relates to the field of devices for manipulating objects 
under water and in particular to booms for extending underwater from the 
water surface where the underwater end of the boom has a manipulating 
device mounted thereto, such as a means for gripping objects, for 
manipulating objects by selectively actuable articulation of the boom and 
manipulating device. 
BACKGROUND OF THE INVENTION 
Flooding of forested valleys by reason of natural causes or by reason of 
hydroelectric damming has left submerged forest as unharvested free 
standing trees. A substantial percentage of the submerged free standing 
trees are within depths of approximately 100 feet of water and so are 
available to be harvested given an appropriate log cutting and retrieval 
mechanism. 
As opposed to well understood dry land logging practices, the harvesting of 
submerged free standing trees presents many obstacles. Such obstacles 
include the fact that if manual divers are used to dive to the base of 
such trees, to either cut through the tree trunks using saws or other 
means such as blasting to uproot or free the tree, the diver is faced with 
severe restrictions on the amount of time that may be spent at such 
depths. Further, the difficulty of wielding saws or the like in an 
underwater environment can prove dangerous to the diver. Because a 
majority of the submerged free standing trees are waterlogged, they will 
not rise to the surface of their own accord once uprooted or otherwise 
freed from the bottom and so must be retrieved by means of cables, 
flotation bags or the like. The result is a slow process which does not 
yield many logs harvested in a typical day. In the case of some of the 
larger submerged free standing trees, they are so large, because they form 
part of very old stands of timber, that unassisted manual sawing is very 
difficult and retrieval slow and difficult. 
A further obstacle relates to underwater visibility. It is known in the 
prior art to attempt underwater cutting or sawing of submerged elongate 
objects such as logs or pilings, but what is not addressed is the fact 
that activity at or near the mudline results in stirring up of silt or the 
like which quickly makes seeing underwater difficult if not impossible. 
Such difficulties are in addition to the normal darkness one would 
anticipate at depth. However, the solution to the problem is not merely 
the use of underwater lighting. By way of analogy, the problem is akin to 
the use of driving headlights when set on high beam in a snowstorm. The 
result is merely a whiteout. Thus, because it is desired to saw or cut 
submerged free standing trees near their base so as to maximize the 
recovery of the timber, a means must be provided for clearing, or seeing 
through, the murky water if is it desired to use a remotely actuated 
mechanical device employing a real time imaging system for positioning the 
gripping and sawing or cutting means. 
In the prior art, applicant is aware of U.S. Pat. No. 3,667,515 which 
issued Jun. 6, 1972 to Corey for a Pile Cutting Device. Corey teaches a 
pile cutting device for use in locations remote from the operator. A pile 
cutter suspended on a cable is lowered by means of a crane to a desired 
depth, for example, to the bottom of a water body. The base of the pile 
cutting device is lowered so as to journal the pile in the base as base is 
lowered. The base has a guide across which is swept a selectively actual 
blade. The blade shears the pile at its base. 
Applicant is also aware of U.S. Pat. No. 3,693,676 which issued on Sep. 26, 
1972 to Burch for an Underwater Pile Cutting Saw. Burch discloses a power 
saw capable of being manually manipulated above the surface of a body of 
water for cutting off pilings and the like adjacent to the bottom. A 
locator member engages around the piling or object to the cut and includes 
a post about which a saw swings, so as to swing across the locater member 
to cut off the piling or object. The locator member and saw may be 
manipulated from a boat, barge, dock or the like, it being an object of 
the Burch device to eliminate pilings and other objects adjacent the 
bottom as navigational hazards. 
Applicant is further aware of U.S. Pat. No. 4,168,729 which issued Sep. 25, 
1979 to Tausig et at for an Underwater Self-gripping Pile Cutting Device. 
As in the Corey device, Tausig et al teach a shearing pile cutter 
lowerable by means of a cable onto a pile. The shear cutter assembly has 
self-gripping teeth or spikes incorporated as part of the cutting blades 
to hold the pile and prevent slipping during cutting operations. As the 
hydraulically operated scissor-type cutter blades close about the pile, 
the spikes bite into the timber and keep the blades from squeezing off the 
pile. 
SUMMARY OF THE INVENTION 
An articulated underwater arm comprises a longitudinally extending array of 
pivotally linked elongate boom sections, adjacent boom sections in the 
array pivotally linked at longitudinally opposed ends and selectively 
actuable so as to rotate the adjacent boom sections relative to each other 
in a plane containing the array, the array extending between a base 
mountable to a floating platform at a base end of the array, and a head 
mounting end of the array at a head end of the array. One such head may 
have a gripping means for gripping submerged elongate objects, or other 
manipulating attachments thereon, mounted to the array at the head end of 
the array and selectively actuably rotatable at least in the plane 
relative to the array and, in one aspect, universally articulatable 
relative to the array. Clear-water purging means are mountable on the head 
or on the array proximate the head end. A vision means is mounted on the 
head or the head end of the array so as to be rotatable with the 
manipulating attachments, such as the gripping means in the plane. The 
vision means communicates visual information to a display on the floating 
platform. The clear water purging means urges clear water, drawn from a 
remote clear water location, through apertures cooperating with means for 
communicating the clear water from the remote clear water location to the 
apertures. Pressurizing means pressurizes the clear water so as to urge 
the clear water through the apertures into a working zone adjacent the 
manipulating attachments or within a field of view of the vision means, 
wherein the field of view includes a working area longitudinally forward 
of the manipulating attachments, the head, and the array. 
In a further aspect of the invention pressure or position sensing means are 
mounted at joints between adjacent boom sections and communicate 
rotational position information, by communicating means, to a processor 
where the water pressure or position information is processed into a 
graphical display of the array relative to the floating platform, 
displayable to an operator, whereby the operator may view the display of 
the visual information and the graphical display of the array and 
selectively actuate the array, the head, and the manipulating attachments 
on the head to manipulate an underwater object. 
In summary, in one aspect, the articulated boom and utility head for 
manipulating objects underwater of the present invention includes an 
articulated arm mounted at a first end thereof to a free floating 
platform, and a remotely operable utility head mountable at a second end 
of the arm. At least one sensor for relaying sensed information from the 
sensor to a remote operator or processor is mounted to the articulated 
arm. The sensed information is transmitted in real time as the arm is 
remotely operated under water. 
In a second aspect, the present invention includes a means for stabilizing 
the second end of the articulated arm so that the utility head, when 
mounted to the second end, maintains a substantially fixed position 
relative to an underwater object, independent of movement of the first end 
of the arm. 
In one embodiment, at least one sensor includes both a position sensor to 
provide boom position information and an imaging sensor to provide 
environmental information from the underwater environment. The imaging 
sensor may be a visual sensor such as a camera mounted on the arm in a 
preferred embodiment, although it may be mounted on the head, in proximity 
to the second end of the arm. The visual sensor is aligned to provide the 
remote operator with a field of view in front of the utility head. The 
location of the imaging sensor, whether a visual sensor or otherwise, is 
not intended to be limiting so long as the field of view may be imaged. 
Advantageously, a means for dispersing suspended detritus is provided for 
use when the detritus would, if not dispersed, occlude the field of view. 
The means for dispersing detritus may be mounted to the arm in proximity 
to the second end, or may be mounted to the utility head. Because it is 
desirable to use interchangeable utility heads, a preferred embodiment 
provides for mounting the means for dispersing detritus on the arm so as 
not to interfere with the operation or interchangeability of the heads. 
Such a design choice is not intended to be limiting. 
Further sensors mounted on the arm may include rotary transducers mounted 
at articulated joints between the boom segments. The rotary transducers 
sense relative rotational movement of the boom segments about the joints 
between the segments, and provide a corresponding signal for transmission 
to a remote location for processing by a computer and for display as 
corresponding arm position information at a graphical interface for use by 
the operator. 
In a preferred embodiment, the means for dispersing detritus comprises a 
clear water manifold. The manifold is supplied with clear water, under 
pressure, by a water conduit from a water source remote from the second 
end, for example, from the water surface. A plurality of nozzles mounted 
on the manifold are aligned to direct the clear water into the field of 
view of the imaging sensor. Advantageously, the clear water manifold is 
pivotally mounted to the boom. A manifold actuator is mounted between the 
manifold and the boom for selective pivoting of the manifold according to 
remote control inputs by the operator. 
In a further aspect of the present invention, the boom is a longitudinally 
extending array of elongate, pivotally linked, rigid boom segments. The 
boom segments are pivotally linked at their ends by articulated elbow 
joints. Boom segment actuators cooperate between adjacent boom segments to 
selectively fold and unfold, i.e. retract or extend, the array of boom 
segments. The boom segment actuators are in a preferred embodiment 
hydraulic rams remotely actuable by the operator. 
The boom segments are rotated relative to one another by actuation of the 
hydraulic rams. The hydraulic rams are actuated by means of a primary 
hydraulic circuit. Advantageously, the means for stabilizing the second 
end includes a hydraulic float circuit cooperating with the primary 
hydraulic circuit. 
The interchangeable utility heads may include, without intending to be 
limiting, the following types of heads: selectively operable claws; a 
selectively operable clam shell rake; a selectively operable overpack; a 
selectively operable suction dredge; a selectively articulatable viewing 
arm; a selectively operable core sampling head; an extraction head; a 
selectively operable vibrator head; a selectively operable grout 
application head; and, a selectively operable surface cleaning head. 
The boom segment actuators are alternatively referred to herein as first 
actuators mounted between the adjacent boom segments for selective 
relative rotation of the adjacent boom segments relative to each other. 
Second actuators are provided, which cooperate with the second end of the 
boom and the utility bead when mounted thereon, for selective actuation, 
that is, rotation or extension of the utility head relative to the second 
end of the boom. The first and second actuators are of course remotely 
actuable by control inputs from the operator. In the preferred embodiment, 
the water manifold is a rigid container pivotally mounted to the boom. A 
third actuator is mounted between the rigid container and the boom for 
selective pivoting of the at least one water nozzle so as to direct a 
stream of water from the nozzle into the field of view of the visual 
sensor. 
Advantageously, the boom is maintained in a neutral buoyancy state by 
hollow, air filled tanks mounted near the second end of the boom.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
As seen in FIGS. 1-5, in articulated boom 10 has a longitudinal array of 
pivotally linked elongate boom sections 12a, 12b, 12c and 12d pivotally 
linked at their ends by means of hinge pins 14. Adjacent boom sections are 
selectively articulated in a single plane. Hinge pins 14 are parallel and 
boom sections 12 are selectively rotated about hinge pins 14 by selective 
actuation of hydraulic rams 16 acting on the hinged elbows or joints 
between boom sections. FIGS. 8-10 illustrate in enlarged detail, one 
embodiment of the hinge mechanism between boom sections 12b and 12c. 
Hydraulic lines 20 and purge water lines 22 are mounted along the length 
of the boom sections and looped at the elbows or joints between boom 
sections to allow relative movement between the boom sections. 
The joints between the boom sections of articulated boom 10 can be 
independently opened or closed by the remote actuation of hydraulic rams 
16. Rams 16 are pivotally connected to adjacent boom sections, for 
example, section 12c and 12d as seen in FIG. 2, by means of pins 24 which 
are journalled in webs 28. 
The joints between boom sections may, as seen in FIGS. 8-10, have hinge 
pins 14 offset from the ends of the boom sections on opposed pairs of 
mounting flanges 30 rigidly mounted to one end of a boom sections 12. The 
cantilevered ends of the opposed pair of mounting flanges 30 have hinge 
pin 14 journalled therethrough. Hinge pin 14 pivotally mounts nose 30a 
between flanges 30. 
Extension of hydraulic ram 16 in direction A acts through cantilevered ends 
of mounting flanges 30 at the end of boom sections 12 so as to rotate 
adjacent boom sections 12 about hinge pin 14. Rotation of boom sections 12 
about hinge pins 14 causes articulated boom 10 to either unfold so as to 
extend head 32 away from barge 34 or so as to fold articulated boom 10 up 
to, and in one embodiment depicted in FIG. 5 on top of, barge 34. 
Head 32 may take the form of many interchangeable attachments such as 
those, better illustrated by way of example in FIGS. 16 to 24, which will 
permit remote underwater visual inspection, core sampling, concrete 
grouting, drilling, venturi dredging and the placement and removal of 
objects. An example, but not intended so as to be limiting, is head 32, as 
better seen in FIGS. 1, 6 and 7, which is adapted to grip elongate 
objects. The frame 40 of head 32 is removably secured to flange 39 which 
is rotatable by remotely operable hydraulic motor 38. Motor 38 is in turn 
connected to the distal free end of boom section 12d through a hinge 
connection 36. In this manner, the gripping head 32 may be readily 
detached from motor 38 so as to be interchanged with another head. 
The frame 40 of head 32 provides structural support for claw hinges 42 upon 
which are pivotally mounted claws 44. Claws 44 are selectively actuable by 
claw hydraulic rams 46. 
A vision system may advantageously be mounted proximate head 32, for 
example on the distal free end of boom 12d. The vision system enables an 
operator to monitor positioning and operation of claws 44 remotely in real 
time. In one embodiment, without intending to be limiting, the vision 
system incorporates a video camera and, advantageously, a water purge 
device. The water purge device has as its function pumping clear water 
from a remote location, such as the surface of the body of water within 
which the device is operating, along the articulated boom, to head 32 
where the clear water is injected under pressure into the field of view of 
the video camera. The clear water displaces murky water stirred up by the 
operation of the boom and head so as to avoid white-out conditions which 
would otherwise render visual monitoring difficult if not impossible. The 
field of view of video camera 48 encompasses an area including the area 
between claws 44 and in a forward direction along claws 44 ahead of head 
32. Clear water is collected from a remote location such as through a 
clear water intake 50 on barge 34 and pumped through purge water line 52 
by water pump 54, along purge water lines 22 and thereby alone articulated 
boom 10. As also seen in FIG. 6b, purge water lines 22 feed clear water 
purging manifold 37, in one embodiment through flexible tube or pipe. The 
pressurized purge water from manifold 37 is then injected into the field 
of view of video camera 48 through nozzles 56 as also seen in FIG. 6a. 
Video camera 48 may be enclosed in a protective housing. In alternative 
embodiments, other vision systems may be employed as would be known to 
those skilled in the submariner arts, for example, acoustic or solar 
systems, or other sensors employing radiation of other wavelengths. 
Clear water purging manifold 37 is journalled on boom 12d for rotation 
about a generally horizontal axis on pins 38. Rotational movement about 
pins 38 is accomplished by a hydraulic ram 58 connected between manifold 
37 and boom 12d or, alternatively, by mechanical linkage which directly 
connects the purging manifold 37 to frame 40 of head 32 (not shown). 
Neutral buoyancy tanks 64, as seen in FIGS. 2-5 and FIG. 6b, assist in 
maintaining the neutral buoyancy of head 32 and boom 12d. 
As can be seen in FIGS. 1, 6 and 7, a V-shaped bracket 66 for cradling 
therein an elongate object gripped between claws 44 is mounted to frame 
40. V-shaped bracket 66 holds an elongate object centered within the "V" 
and helps to stabilize the elongate object during movement of the boom. 
FIGS. 1 and 7 show head 32 in operation. Head 32 is shown in close 
proximity to submerged elongate object 68. The gripping operation of claws 
44 is actuated by hydraulic rams 46. Head frame 40 and claws 44 are held 
against elongate object 68 by actuation of boom Section 12d. Head frame 40 
is oriented so as to engage V-shaped bracket 66 against the surface of 
submerged elongate object 68 by the operation of hydraulic cylinder 41 
which pivots head 38 about a generally horizontal axis on hinge 36. 
Hydraulic motor 38 rotates head 32 about the longitudinal axis of shaft 
38a. 
As seen in FIG. 15, a remote operator 70, who may be situated on barge 34, 
controls the articulation of articulated boom 10 and head 32 by means of 
remote controls 72, which, as illustrated, may be an opposed pair of 
articulated pistol grips. Remote operator 70 monitors a real time display 
(not shown) of the video image captured by video camera 48. Remote 
operator 70 may also monitor a real time computer simulation 74 of the 
deployment status of articulated boom 10 deployed beneath barge 34. Such 
spacial orientation status information about the deployment of articulated 
boom 10, combined with the video real time image from video camera 48, 
provides the information which is of assistance to the remote operator 70. 
Inputs required to produce the real time computer simulation 74 may be 
provided by rotary position transducers known in the art. They may be 
mounted on the boom tower, at the tower to boom joint, and at boom joints 
76a, 76b, 76c, and 76d (see FIGS. 3 and 15), and at the rotation, tilt and 
grip articulation locations 36 (see FIG. 6), 62 for head 32 (see FIG. 7). 
The position transducers provide a signal which is proportional to 
relative movement, both between 0 and 10 volts, to an analog-to-digital 
converter, and thence to a remote computing device, as for example a 
computer located on barge 34. The operation of the boom tower is better 
described below. 
Rotary position transducers 87 as shown in FIG. 10 are mounted at the boom 
joints and may comprise a rotatable gear at the transducer on one boom 
section and a non-rotatable sprocket mounted to the hinge pin 14 
connecting the two boom sections. Pin 14 rotates with one boom section, 
while the other pinned section of boom is freely rotatable on the hinge 
pin. The gear and sprocket are connected by a drive chain which rotates 
cooperatively as the hinge pin is rotated during relative movement of the 
boom sections. 
The enabling software of the present invention, based upon software 
provided by Wonderware of Irvine, Calif., version 5.6, provides a 
man/machine interface in the dynamic data exchange (DDE) open 
architecture. The software is a custom DDE server to display the graphics 
representing the position in real time of articulated boom 10, and to 
refresh same in real time. The software, interpolates the position of the 
boom sections by determining the degrees of rotation of the longitudinal 
axes of boom sections 12 from a zero point. The software, in the preferred 
embodiment, computes the position of all boom and head components based on 
the boom geometry and rotational position at each joint as provided by 
position transducers, such as position transducers 87, each of which have 
been previously calibrated throughout the full range of joint motion. 
Tables 1 and 2, are function flow charts for the Wonderware application 
software and for the software forming part of the present invention 
respectively. 
In one alternative embodiment pressure transducers provide real time analog 
inputs to the software so that, once the first pressure transducer at boom 
joint 76a is calibrated on a particular day, then the inputs from the 
remaining pressure transducers provide differential pressure information 
indicative of depth relative to boom joint 76a. This provides the 
advantage that the depth information is independent of surface conditions 
such as swells, as the pressure increases at a known rate relative to 
depth underwater. Assuming the length of boom sections 12 remains 
constant, the differential pressure measurements indicate the positions of 
the boom joints relative to the calibrated position and may be thereby 
converted by the software into degree of rotation information. 
In a preferred embodiment, and as better explained below, a float circuit 
such as depicted in FIG. 15 is incorporated into the hydraulics and 
actuating software whereby the free end of boom section 12d is translated 
to compensate for wave action at the water surface and the corresponding 
motion of barge 34, so as to prevent head 32 being driven into the mud as 
barge 34 drops between swells. 
As seen in FIGS. 11-14 boom tower 78 may be secured to the deck of barge 34 
by hinged struts 80. Struts 80 cooperate with hydraulic cylinder 92 to 
permit tower 78 to be pivoted about a generally horizontal axis relative 
to the deck of barge 34. Sleeve 82 has upper and lower annular supporting 
collars 86a and 86b respectively. Inner shaft 84 is journalled within 
outer sleeve 82. Inner shaft 84 is by a top bearing plate 87a supported to 
allow rotational motion of inner shaft 84 relative to outer sleeve 82. 
Bottom bearing plate 87b is removably fastened (for example by means of 
the bolts illustrated) to the bottom of inner shaft 84. Lugs 88 are 
rigidly mounted to upper bearing plate 87a. Lugs 88 pivotally mount tail 
89 of boom 10 to tower 78. Hydraulic cylinder 90 is mounted between tail 
89 and outer sleeve 82 of boom tower 78. Cylinder 90 raises tail portion 
89 when retracting boom 10. A second hydraulic cylinder 92 is mounted 
between the deck of barge 34 and outer sleeve 82 of boom tower 78. 
Cylinder 92 may rotate tower 78 between an upright position as 
illustrated, and an off-vertical position in an are lying in a vertical 
plane. That is, tower 78 may be rotated in direction B as seen in FIG. 4. 
It is advantageous to rotate boom 10 in a horizontal radial are in 
direction C as seen in FIG. 11 and 14 relative to barge 34, for example in 
a horizontal 60 degree arc. Arm 96 is mounted to the outer sleeve 82 of 
tower 78. Rotator lug 98 is mounted to the underside of bottom bearing 
plate 87b. Hydraulic cylinder 94 is mounted between arm 96 and lug 98, as 
seen in FIG. 14. Actuation of cylinder 94 rotates the bottom bearing plate 
relative to the outer sleeve thereby rotating the boom in direction C. 
That is, since outer sleeve 82 is prevented from rotational movement by 
the rigid mounting of struts 80 to the deck of barge 34, force applied to 
rotator lug 98 is transmitted from bearing plate 87b through inner shaft 
84 to upper plate 87a and then to the tail 89 of the boom. 
Chromium plating of the outer surface of inner shaft 84 and the use of 
ultrahigh molecular weight plastic inserts 100 between inner sleeve 84 and 
outer sleeve 82 and between upper supporting collar 86a and top plate 87a, 
provide low friction bearing surfaces. 
The accurate placement and operation of head 32 when mounted to the end of 
articulated boom 10 can be difficult since the boom is mounted on a 
floating barge 34 which is subjected to rolling and to vertical and 
horizontal displacement by wave action. Thus it is advantageous to provide 
a means for compensating for erratic movement of the boom and head caused 
by waves or swells on the water surface. In one embodiment of the present 
invention, this is accomplished by a hydraulic float circuit. The float 
circuit, as seen in FIG. 25, is incorporated into the regular hydraulic 
operating circuit for the boom. Also, to maintain lateral stability of the 
boom, a further float circuit may be incorporated into the operating 
circuit of the hydraulic ram 94 as seen in FIG. 14, which moves the tail 
89 of articulated boom 10 in horizontal are C relative to barge 34. 
The float circuit of FIG. 25 translates the water resistance on boom 12d, 
as it is moved through the water due to wave action on the barge, into at 
hydraulic fluid pressure differential on each side of the piston within 
the hydraulic rams 16. Rams 16 control movement or boom 12d. This pressure 
differential between the two sides of the ram plungers is detected by one 
of the preset pressure reducing valves. Which of the pressure reducing 
valves is dependent on which side of the plunger the pressure increase is 
on. This is dependent on which way boom 12d is being moved through the 
water, i.e. either up or down. 
The float circuit is in operation when power switch 266 is in the "on" 
position and the operator is not engaging boom 12d, that is, when the boom 
is expected to be stationary relative to boom section 12c. 
As can be seen illustrated in FIG. 25, pump 250, located on the barge 34, 
supplies pressurized hydraulic fluid to the system. Flow control valve 252 
is operated by electrical solenoids 252a and regulates fluid flow to the 
normal operating hydraulic drive circuit 254. The solenoids 252a are 
driven solely by the operator joystick 258, supplying power to either 
solenoid depending on the direction that the operator desires the boom 12d 
to be moved. Solenoids 255 control flow control valves 256a and 256b of 
the float circuit 260. Solenoids 255 are driven solely by the operator 
on/off power switch 266. With switch 266 in the "on" position, electrical 
power is supplied to valves 256a and 256b through a set of normally closed 
contacts of a contact relay 268, better seen in FIG. 25a. It is important 
to note that the signal lines providing electrical power to the normal 
hydraulic circuit control valve 252 also control the switching coil of the 
contact relay 268. The result of this connection is that even with the 
float circuit switch 266 in the "on" position, the activation of the 
normal circuit flow control valve 252 fires the control switch of the 
relay opening the normally closed contacts. This disables the float 
circuit flow control valves 256a and 256b effectively shutting off the 
reduced fluid pressure to rams 16 while the boom 12d is being operated. 
Also note, with respect to coupled rams 16, float circuit 260 is connected 
in parallel to both rams 16 in order to avoid duplication of the float 
circuit. 
An example of float circuit operation is as follows: 
Pressure from the pump 250 is supplied to the pressure reducing valves 270a 
and 270b at all times. With switch 266 in the "on" position the state of 
the system is as follows: 
(a) electrical power is supplied to the float circuit flow control valves 
256a and 256b through switch 266 and the normally closed contacts of 
contact relay 268; 
(b) reduced pressure from the pressure reducing valves 270a and 270b is 
delivered to both sides of ram 16 through the flow control valves 256a and 
256b; 
(c) wave action occurs moving the vessel and arm in the upward direction; 
(d) water restriction causes increase in fluid pressure on one side of rain 
plunger 262; 
(e) pressure reducing valve 270a shunts excess fluid pressure to the 
reservoir 272; 
(f) flow from pressure reducing valve 270b allows nominal pressure to 
increase fluid displacement on the other side of plunger 262, within 
cavity 264, causing the ram plunger to move opposite the original force of 
the water restriction. 
This process is exactly reversed when the wave action is in the opposite 
direction. 
It is anticipated that boom 10 and head 32 may be utilized to perform a 
variety of tasks in an underwater environment, for example, in situations 
that might pose a safety hazard to divers or submersible watercraft. Such 
tasks may require a variety of different heads 32 which can be readily 
secured to the end of articulated boom 10. One form of head, as 
illustrated in FIGS. 16 and 16a is a clam-shell rake 110. Rake 110 has a 
frame 112 to which are rotatably connected opposed jaws 114 and 116. The 
jaws have a series of arcuately shaped fingers 118 which are operable by 
hydraulic cylinders 120. Fingers 118 on jaw 114 are offset relative to the 
fingers on the other jaw 116 so as to allow meshing as illustrated by 
broken lines in FIG. 16a. Rake 110 may be secured to the articulated boom 
10 by flange 122. 
Another form of head, as illustrated in FIGS. 17 and 17a, is an overpack 
126. Overpack 126 has a frame 128 to which are pivotally connected opposed 
scoops 130 and 132. Scoops 130 and 132 are rotated on flame 128 by 
hydraulic cylinders 134. The opposing perimeter edges of the open faces of 
scoops 130 and 132 are provided with a flexible strip 136 which, when 
scoops 130 and 132 are rotated to a closed position by hydraulic cylinders 
134, seal the perimeter edges to prevent contents escaping from inside the 
overpack. This overpack can be utilized to retrieve cylindrical shaped 
objects such as drum 137 front an underwater environment. It is 
anticipated that the overpack can also be used for munitions retrieval, 
and in this application, the interior of the scoops would be lined with 
cushioning material or an inflatable liner to prevent jarring of the 
retrieved munitions. The construction or the overpack would be 
sufficiently explosion resistant to provide protection for the end of the 
articulated boom 10. Connecting flange 138 may be provided with a quick 
release mechanism, or may be fabricated from deformable material which 
will prevent vibrations from an explosion being transmitted to boom 10. 
Another form of head, as illustrated in FIGS. 18 and 18a, is suction dredge 
140. Suction dredge 140 has a rigid tubular body 142. Water inlet lines 
144 supply pressurized water into body 142 directed into discharge hose 
146. A venturi effect within body 142 causes a vacuum within body 142, in 
particular at the vacuum orifice or inlet 150. Dredge 140 can be connected 
to articulated boom 10 by a connecting flange 148. Water lines on boom 10 
utilized to supply purge manifold 37 can be used to supply water to inlet 
lines 144. A vacuum at nozzle inlet 150 may be used to clean underwater 
objects. 
Another form of head, as illustrated in FIG. 19 is an articulated viewing 
arm 152. Arm 152 has a camera 154 or the like mounted at its outer end. 
Flange 156 at the other end provides for mounting to boom 10. Independent 
articulation of the segments of arm 152 is accomplished by gear motors. 
Motor 158 provides articulation in direction D, while motors 160 provide 
articulation in direction E. This viewing arm, when mounted to articulated 
boom 10, permits minute adjustments to both arms 152 and camera 150 for 
viewing within confined situations. 
Another form of head, as illustrated in FIG. 20, is a core sampling head 
162. A coring drill 164, which is operated by a hydraulic motor, is 
extended or retracted relative to a working surface by hydraulic cylinder 
166. Cylinder 166 is mounted within housing 170. Housing 170 has at one 
end a rigid base 172 which contains a perimeter seal 174 and at the other 
end has hose connector 176. Flange 117 provides connection to articulated 
boom 10. 
In operation articulated boom 10 positions core sampling head 162 at the 
location at which a core sample is to be taken. Hose connection 176 is 
connected to either the purge water line 22 on boom 10 or a separate hose 
on boom 10 which is connected to a water pump on the barge. When the pump 
is operated to pump water out of core sampling head 162, the vacuum 
created by seal 174 holds the head 162 tightly against the workplace as 
coring drill 164 cuts the core sample. The core sample is held within 
drill 164 until head is raised to the surface by boom 10. 
Extraction head 180, as illustrated in FIG. 21 is an adaptation of head 162 
which can be attached to articulated boom 10 and positioned against the 
surface of a submerged container, such as an oil tanker or the like, to 
initially effect a permanent sealed attachment to the container, secondly 
to gain access to the inside of the container and thirdly to extract by 
suction the contents of the container. Drill 164a, operated by a hydraulic 
motor, is extended or retracted relative to the surface to be drilled by a 
hydraulic cylinder 166a supported within a housing 170a. Housing 170a has 
at one end, a rigid base 172a containing a perimeter seal 174a and at the 
opposite end has a hose connection 176a. Connection to articulated boom 10 
is provided by flange 178a. Also positioned within housing 170a are 
hydraulically operated motors 182 that when operated rotate to drive 
lagbolts 184, into the outer surface of the container. 
When articulated boom 10 of this invention positions the extraction head 
180 against the side of a submerged container water is pumped out of 
housing 170a through hose connection 176a. The resulting vacuum causes 
seal 174a to isolate the inside of housing 170a from the surrounding water 
environment. Motors 182 are activated and lagbolts 184 are screwed into 
the container to permanently attach extraction head 180 to the container. 
Once extraction head 180 is securely fastened to the container, 
articulated boom 10 may be released. Drill 164a is positioned by hydraulic 
cylinder 166a to cut through the container and the contents of the 
container can then be pumped to the surface through a hose connected to 
hose connection 176a. 
A vibrator head 188 as illustrated in FIGS. 22 and 22a can be attached to 
articulated boom 10 by means of connecting flange 190. Head 188 is 
vibrated by shaft 192 which has eccentric lobes 194 formed thereon, and 
which is connected through bearings 196 to the frame of head 188. Shaft 
192 is rotated by hydraulic motor 198 tapered projections 200 extending 
from the underside of the housing of vibrating head 188 can be utilized to 
position hollow steel pilings or the like during vibrating placement. A 
gasket 202 which is designed to reduce the transmission of vibrations is 
secured between connecting flange 190 and articulated boom 10. 
Illustrated in FIG. 23 is a sectional view of a grout application head 206 
which has a frame 208, a water hose connection 210 and a grout hose 
connection 212. Flange 214 allows the head 206 to be connected to 
articulated boom 10. Head 206 is supported by rollers 216 which are 
slidably mounted to the inside of frame 208, at the end opposite 
connecting flange 214. A perimeter seal 218 is secured to the outside of 
frame 208. A viewer 220 and a grout application head 222 are also mounted 
within head 206. 
The grout application head is placed on a surface by articulated boom 10 of 
this invention and can be moved over the surface with rollers 216 in 
contact with the surface. During movement over the surface the integrity 
of the surface can be inspected through viewer 220. When grout application 
is required, the articulated boom 10 of the present invention holds the 
grout application head against the surface as sufficient pressure is 
applied to head 206 the rollers, which may be spring loaded or similarly 
forced to normally extend outwardly of the lower edge of frame 208 are 
depressed, inwardly permitting seal 218 to contact the surface to which 
grout is to be applied. Water can then be pumped from the inside of frame 
208 through hose connection 210 to enable head 206 to adhere to the 
surface by vacuum. Grouting material can then be injected through grout 
application head 222. 
As can be seen in FIG. 24, a surface cleaning head 226 is illustrated in a 
sectional view. Head 226 has a frame 228, internally mounted and inwardly 
depressible rollers 229, a perimeter seal 230 and hose connection 232 
which operate in an identical manner to the same components previously 
described in the operation of grout application head 206. A wire brush 234 
or other abrasive tool, which is rotated by a hydraulic motor (not shown), 
is pivotally mounted to frame 228 and brought into contact with a surface 
by hydraulic cylinder 236. Pumping water out of head 226 through hose 
connection 232 permits head 226 to be positioned against a surface to be 
cleaned by vacuum pressure. During the cleaning of a surface, or the 
removal of contaminants from a surface, water flow may be reversed through 
hose connection 231 to break the vacuum scat against the surface. When 
seals are free of the surface being cleaned water may again be pumped out 
of head 226 thereby removing contaminants along will the water. 
As will be apparent to those skilled in the art in the light of the 
foregoing disclosure, many alterations and modifications are possible in 
the practice of this invention without departing from the spirit or scope 
thereof. Accordingly, the scope of the invention is to be construed in 
accordance with the substance defined by the following claims.