WHAT IS AN ROV
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WHAT IS AN ROV?
A Remotely Operated Vehicle Vehicle (ROV) is essentially a tethered underwater robot that allows the vehicle's operator to remain in a comfortable environment while the ROV works in the hazardous environment below. he total ROV system is comprised of the vehicle! which is connected to the control van and the operators on the surface by a tether or umbilical " a #roup of cables that carry electrical power! video and data si#nals back and forth between the operator and the vehicle " a handlin# system to control the cable dynamics! a launch system and associated power supplies. $i#h power applications will often use use hydraulics in hydraulics in addition to electrical cablin#. %n many cases! the umbilical includes additional stren#th members to allow recovery of heavy devices or wrecka#e &ost ROVs are euipped with at least a video camera and li#hts. Additional euipment is commonly added to epand the vehicles capabilities. hese may include sonars! ma#netometers! a still camera! a manipulator or cuttin# arm! water samplers! and instruments that measure water clarity! clarit y! li#ht penetration and temperature. ROVs can vary in size from small vehicles with Vs for simple observation up to comple work systems! which can have several deterous manipulators! V's! video cameras! tools and other euipment. he mechanism of the top hat handlin# system! which contains deployable neutrally buoyant cable for local ecursions. *uch handlin# techniues allow the heavy umbilical to remain vertical in the water column while the ROV maneuvers with the smaller cable! free of the surface dynamics! which in many cases! can pull the ROV from its work station. oday! advanced technolo#y is allowin# many ROVs to shed their cable! and thus become free to roam the ocean with out such physical constraints. hese emer#in# systems! which are battery operated! are called autonomous underwater vehicles (A+Vs) and are used for ocean search and oceano#raphic research.
NAMING CONVENTIONS
ROVs that are manufactured followin# a standardized desi#n are commonly named by a brand name followed by a number indicatin# the order of manufacture. ,amples would be Sealion 1 or Scorpio 17 . he desi#n of a series of ROVs may have chan#ed si#nificantly over the life of an ROV series! however an ROV pilot will often be familiar with the idiosyncrasies of a particular vehicle by name. ROVs that are one"off or uniue desi#ns may be #iven a uniue name similar to the style used for ships. ROVs are not normally referred to in the female #ender as ships may be! but by #ender"neutral pronouns or 'neuter words'.
ROV APPLICATIONS - COMMERCIAL OFFSHORE
-y far the #reatest use of ROVs around the #lobe is in their application to the oil and #as industry in the eploration and eploitation of hydrocarbons. *ince the mid"/01s! ROV technolo#y has aided man in his relentless search for ener#y beneath the sea. odays hi#hly sophisticated! capable and reliable work class systems are routinely undertakin# operations in water depths #reater than 0!111 ft (2!34 m). Althou#h re#ulations vary internationally! #enerally saturation divin# techniues are prohibited in water depths #reater than 561 ft (26/ m) of water. As a considerable percenta#e of offshore oil and #as reserves are located in water depths in ecess of diver depths! the importance of ROV technolo#y is si#nificant. &an has adapted several standard means of etractin# hydrocarbons in various water depths from 7ackup drillin# production ri#s in very shallow water to subsea completion! tension le# platforms (89s) and spars in deep and ultra deep water! over 6!111 ft (!624 m). ROV technolo#ies support operations for services such as drillin# and completion! installation:construction! inspection:maintenance and repair and other activities from installations such as that shown above left. Over ;1 percent of the worlds ROV systems supportin# oil and #as eploitation are en#a#ed in drillin# support operations. *ystems are utilized in water depths as shallow as 11 ft (31 m) on 7ackup ri#s and as deep as 1!111 ft (3!145 m) on semi"submersibles and drillships. his means that the full ran#e of ROV systems are en#a#ed worldwide to support these activities. Observation ROV systems are typically used in shallow water and when surface trees are utilized. <ork class ROV systems are used in deeper water! areas of hi#h current! and when intervention tasks reuire the use of manipulators! fluid transfer or load bearin# capabilities. %f drillin# support is a walk in the park for ROV contractors! then installation and construction support is the triathlon of all the support services in the oil and #as ROV industry. hese activities are the most demandin#! reuire the most capable euipment and the #reatest eperience and skill of the ROV crew. %nstallation and construction support is the realm of the work class ROV. Operatin# on the critical path as a key element in the development pro#ram! ROV systems are used before! durin# and after the installation of platforms! subsea production systems and others! and the installation! layin#! hook"up and commissionin# of flowlines! trunklines! eport lines! cables and umbilicals. ROV APPLICATIONS - MILITARY
&ilitary applications for unmanned systems provided the #enesis for unmanned underwater vehicle technolo#y. %nitially! such systems were developed primarily for undersea observation and the recovery of lost devices and weapons. *ince then! the technolo#y has moved steadily forward! brin#in# with it a directly related increase in operational capability. +nfortunately! this increase in capability brin#s with it a hi#her price ta#=especially in the military=a fact that may have initially slowed s lowed the acceptance of such advanced technolo#y. And more recently! the chan#e in the political climate around the world has caused a refocusin# of what the military feels is the primary mission for such systems. &any of the ori#inal applications by the military for unmanned vehicles was in the area of mine countermeasures! where tethered ROVs were much more ependable than a ship or a diver. %n addition! there were many pro#rams
conductin# research into recovery technolo#y and the fled#lin# arena of untethered vehicles used for search. 9rior to the //1s! the +* >avys eyes were focused on the depths of the ocean=the ma#ic number bein# 21!111 ft (;!1/; m)! where /5 percent of the ocean floor could be reached. %n the +* military at that time! there was a need to dominate all aspects of undersea search! work! and recovery to such full ocean depths. %t was a critical need! if for no other reason than to remain one up on the perceived threat from the *oviet +nion.
%n those early days! there was no knowled#e of an obvious undersea vehicle pro#ram on#oin# in the *oviet +nion. hat soon chan#ed as the *oviets concern with the deep ocean and their capability to reach it was unveiled. +nclassified presentations on their pro#rams in unmanned undersea systems! such as those at the %nstitute of &arine echnolo#y echnolo#y 9roblems in Vladivostok! where the MT 88 autonomous autonomous vehicle (see photo to left) was developed! alon# with many others! soon became common at international conferences. Althou#h the +* and *oviet +nion may have led the pack! ,urope was not idle. <ith the transition of ROV technolo#y from the +* to ,urope in the /51s! many other vehicle developers emer#ed! primarily to support >orth *ea oil fields. Alon# with that was the maturation of the technolo#y and subseuent application to mine countermeasures. he once dominant PAP PAP v vehicles ehicles from ?rance (see photo to ri#ht) be#an to see others arrivin# such as 9luto from *witzerland! Pinguin from @ermany! the Eagles from *weden and many others. Althou#h some limited developments were pursued for deeper application! such as the rather unsuccessful owed +n&anned *ubmersible (TUMS) developed for the Royal >avys HMS CHALLENGER ! mine countermeasures (&&) was basically the focus of military applications for some time! not the deep ocean thrust that eisted in the +* and the *oviet +nion. %n recent years! a redirection of future military system reuirements has been caused by two si#nificant eventsB the first was the end of the cold war! and the second is the potential of hostilities with smaller countries that could wreak havoc throu#h terrorism or unconventional warfare techniues. Criven by these chan#es! the +* >avy be#an to rethink its Dat seaD strate#y and a new focus on littoral warfare be#an to dominate. && became critical=not only for surface ships! but also for submarines. %f future battles were to be fou#ht alon# world coastlines! with mobility a key factor! then safe operatin# areas needed to be found or established. hus came one of the bi##est chan#es in military strate#y re#ardin# unmanned systems. <hat had once been discussed only behind closed doors=the use of unmanned vehicles deployed from submarines=was not only out in the open! it was on the <orld <ide <eb. %n the +*! ma7or moves were made to solicit the development of Doffboard sensorsD for use from submarines. ontracts were awarded for the >&R* (>ear erm &ine Reconnaissance *ystem) and the 8&R* (8on# er erm m &ine Reconnaissance *ystem). he threat had chan#ed and the >&R*! 8&R* and other versions of shallower water systems be#an to achieve a foothold in the +* >avy.
%n Russia! where the most si#nificant unmanned undersea systems of the former *oviet +nion were developed! the trend moved from secret military applications to private enterprise! as most of the institutes moved into a financial fi#ht for survival. he cold war had ended=the #ame and the rules had chan#ed. o oday! day! tethered ROVs are available for hire from industry! or industry is contracted to operate navy owned systems. he future thrust in the military will be toward autonomous vehicles that are not only capable! but low cost. he technolo#y bein# developed in academia! and bein# fielded in the offshore oil fields! will soon find its way into military systems of the future! whether for intelli#ence collection! search! reconnaissance! mine countermeasures or various other applications. ROVs and A+Vs will both play a ma7or role in the military in the future. ROV APPLICATIONS - ACADMIC/SCIENTIFIC
echnolo#y has taken deep"sea researchers far into the depths since the early epeditions of the $.&.*. hallen#er durin# the 501s! when the first comprehensive samples of life in the deep ocean were collected. o oday! day! there are several methods to obtain data on benthic communities=from trawls to manned submersiblesE but the technolo#ical sophistication of ROVs and camera sleds has allowed the biolo#y and ecolo#y of deep"sea habitats and or#anisms to be efficiently studied. Althou#h many scientists still prefer manned submersibles! unmanned undersea systems will provide the primary means of obtainin# scientific knowled#e in the future. heir ability to obtain hi#h uality photo#raphic and video documentation of the dive site will allow them to reach previously unobtainable locations. %n particular! they will provide the scientist with access to populations in ru##ed terrain! a topo#raphy where even the a#e old trawl is useless. he first deep ROV in the +nited *tates desi#ned from the outset to support oceano#raphic science missions is the <oods $ope Oceano#raphic %nstitutions Jasonvehicle (see photo to left). his /!;56 ft (;!111"m) system has completed science missions ran#in# from the survey of ancient ship wrecks in the &editerranean to performin# #eolo#ical surveys at hydrothermal vent sites on the Fuan de ?uca Rid#e. Jason uses electric motors for its thrusters! pan:tilt! and manipulator! thus avoidin# the need for a noisy and less efficient hydraulic power system and providin# more precise control capabilities.Jason system has made many si#nificant contributions to deep"sea oceano#raphic research and continues to work all over the #lobe. +R%:%?,'s Hercules ROV is one of the first science ROVs to fully incorporate a hydraulic propulsion system and is uniuely outfitted to survey and ecavate ancient and modern shipwrecks.
&any of the concepts applied to Jason have been adopted by the &onterey -ay Auarium Research %nstitute (&-AR%) in the development of an ROV dedicated to scientific missions=the Tiburon 1!!7"! which cost over G; million +* dollars to develop and is used primarily for midwater and hydrothermal research on the <est oast of the +*. (*hown below) &issions for which it is desi#ned includeH •
%nstrument placement! retrieval and support. •
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#n si$u eperimentation.
,colo#ical studies and observations (midwater and benthic).
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*amplin# and li#ht corin#.
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*urveys of environmental parameters.
he anadian *cientific *ubmersible ?acility R%P%S system is continually used by several leadin# ocean sciences institutions and universities for challen#in# tasks such as deep"sea vents recovery and eploration to the maintenance and deployment of ocean observatories. n line with the academic development of all electric ROVs is the all electric &ues$ ROV ROV was developed by A8*O& Automation Automation *chillin# Robotics in the +*. *uch technolo#y provides a nice match to the academic reuirements of uiet and efficient ROVs. %n Fapan! the Fapan &arine *cience and echnolo#y enter (FA&*,) is developin# a family of 'olp(in ROVs for scientific missions and for recovery of the S(in)ai manned manned submersibles. he 'olp(in 3I! a /!543 ft (3!111"m) ROV! has been used for #eolo#ical and biolo#ical research operations. &ore recently! they have completed the development of the *ai)o! which has reached the deepest part of the ocean=30!111 plus feet (!205 m) in the &ariana rench. he %nstitut ?rancais de Recherche pour l,ploitation de la &er (%?R,&,R)! lon# a developer and user of systems for deep eploration! has developed a /!;56"ft (;!111"m) ROV for scientific missions. alled Victor! the ROV became operational in //5. o oday! day! the #reatest strides bein# made in the academic community revolve around the development of autonomous undersea vehicles (A+Vs)! with test beds eistin# in many universities and research institutions around the world. One of the most well known vehicle is the %+,sse, class class of A+Vs (ri#ht)! built by personnel in the Autonomous +nderwater Vehicle 8aboratory at the &assachusetts %nstitute of e echnolo#y chnolo#y (&%)! throu#h the
support of the Office of >aval Research and the *ea @rant olle#e 9ro#ram. he vehicles are desi#ned for operation to depths of /!;56 ft (;!111 m). At least five vehicles! which have recently become commercially available! have been built to date. Another A+V A+V that has been used effectively in oceano#raphic research is the A Autonomous utonomous -enthic ,plorer ( A-E A-E ) built by <oods $ole Oceano#raphic %nstitution. A-, was desi#ned to address the need for lon# term monitorin# of the seafloor. <hile manned submersibles and ROVs allow intensive study of an area! they can remain on station for only hours! days or weeks. onseuently! a system that can remain in an area #atherin# data to fill the time voids between submersible and ROV visits would provide another level of more detailed information on temporal variations. he academic community! due in part to the limited fundin# available for vehicle development! has become adept at developin# very capable yet low cost vehicles. he A+V shown to the left! bein# developed at ?lorida Atlantic +niversity in the +*! can be mass"produced from non"metallic pressure housin# castin#s and will provide an effective tool in the future for investi#atin# the worlds oceans.
ROV APPLICATIONS - LOCATIONS AROUND THE WORLD
here are several areas around the world where the ma7ority of ROV operations occur. hey are primarily tied! of course! to the production of oil and #as. %t is estimated that nearly 411 work class ROVs are in operation at this time servicin# the oil and #as industry. he followin# para#raphs discuss the level of ROV activity around the world. Europe - he >orth *ea has always been an area of hi#h ROV activity with systems bein# operated in both
the UK and Norwegian Se!or". One of the lar#est concentrations of ROVs is in this re#ion with over 11 systems in operation. he ma7ority of operations in the Nor!# Sea are in water depths of 4/2 ft (61 m) or less. Recently! there has been a move to <est of *hetlands! desi#nated a DfrontierD area where the water is much deeper=!45 to 3!25 ft (361 to !111 m)=and wind and current conditions more severe. >orway has drilled its
deepest well in 4!51 ft (!204 m) of water and they have discovered #as at 2!0/6 ft (3!/11 m) in the Vorin# basin. A"ia - &uch activity stretches from $e"!ern Au"!ra%ia &A"ia Pai'i( !o Ma%a)"ia an* !#e Sou!# C#ina Sea+ ,on&obil and eaco are conductin# seismic studies in the @or#on field of <estern Australia in 2!/63 to
6!24/ ft (/11 to !;11 m) depths in search of additional natural #as reserves. ,penditures in this re#ion in /// may reach 22 percent of the worlds total bein# spent on offshore oil and #as developments. Sou!# A,eria - he ma7ority of ROV operations in *outh America are occurrin# o'' ra.i%! mainly in the oil
rich Ca,po" a"in. 9etrobras continues the race to deeper water in the ampos -asin in depths up to ;!6;2 ft (2!111 m). 9etrobras' &arlim *outh development currently holds the record for the deepest onstream well at 6!032 ft (!040 m) and has another waitin# at a depth of ;!121 ft (!536 m). Nor!# A,eria - Reports indicate 14 deepwater prospects in water deeper than /!543 ft (3!111 m) and 3 ri#s
simultaneously drillin# in these deepwater re#ions. &uch of the activity in the Gu%' o' Me/io is now in deep water! up from a mere 4 percent in //6. -etween /50 and //0! the number of operators in the @ulf has increased from 00 to 60. Over 11 ROVs support work in the @ulf. Ar!i - Russia is openin# up! with ma7or developments offshore about to be eploited. *ome of these prospects
will be in water depths of !32 ft (411 m) and in the icy aren!" Sea and Kara Sea! where the lar#est #as reserves in the world may be located. A'ria - $e"! A'ria is a ma7or hot spot with new leases available in water to 5!353 ft (2!666 m). ?or eample!
,on&obil is drillin# off Nigeria Nigeria in 4!53; ft (!404 m) in the Gu%' o' Guinea and is eplorin# in depths to ;!;1 ft (2!12 m) offshore of !#e !#e Congo. O!#er - Other areas where ROVs are reuired are off New'oun*%an*0 A%a"1a0 A%a"1a0 !#e Ca"pian Sea o'' A.er2ai3an0 Trini*a*0 Trini* a*0 !#e $e"! Coa"! o' Ca%i'ornia0 o'' Au"!ra%ia in the In*ian Oean0 !#e a"" S!rai! in !#e Ta",an Sea and the Me*i!erranean Sea o'' Eg)p!+ ROV APPLICATIONS - DEPTH OF OPERATIONS
asks for ROVs in support of oil eploration and development! deepwater pipelines! and many other areas! continues to increase in both depth and compleity. he eploration water depths in the @ulf of &eico more than doubled between /0; and //;! increasin# from depths of 3!611 ft (!1;0 m) in /0; to 0!;11 ft (2!3; m) in //; " and continue to increase. %n 211/! >ereus! a hybrid remotely oeprated vehicle which can operate either tethered or untethered! made depth history when it dove to 1!/12 meters (;.5 miles) on &ay 3! 211/ into the &ariana ench. Gu%' o' Me/io 4ri%%ing Mi%e"!one"
he move into deep water for oil and #as eploration! development and production has opened up a whole new market for innovative solutions to operatin# systems on the seabed. ,ploration is already bein# carried out in water depths over 1!111 ft (3!145 m)! while production is uickly approachin# this depth. he move into deep water! in the +* @ulf of &eico alone! has created a new re#ulatory problem that is only be#innin# to be addressed by various a#enciesH the safety to personnel and safety of the environment as technolo#y attempts to
keep pace with new discoveries in deeper and deeper water. he need to monitor this activity around the world will be critical in the prevention of a disaster to life or the coastal environment. %n addition to the offshore oil and #as industry! many tasks eist for ROVs in the oceans deepest depths. owed search systems! systems! tethered ROV work systems systems!! and autonomous and autonomous vehicles are vehicles are now routinely used to locate and recover ob7ects around the world. Vehicles such as the CUR. ### and and AT AT. . can can reach beyond ;!111 meter depths and Fapans *A#*% has reached the deepest point in the ocean at 1!/1/ meters. And! with costs comin# down! ROVs are increasin# their support of scientific investi#ations. Vehicles such as Jason at the <oods $ole Auarium Research Re search %nstitutio %nst itution n can support scientific Oceano#raphic %nstitution and and iburon at the &onterey &ontere y -ay Auarium investi#ations to depths of ;!111 meters and 4!111 meters respectively.
ROV" - A RIEF HISTORY
,actly who to credit with developin# the first ROV will probably remain clouded! however! there are two who deserve credit. he 9+V (9ro#rammed +nderwater Vehicle) was a torpedo developed by 8uppis"<hitehead Automobile in Austria in 5;4! however! however! the first tethered ROV! ROV! named 9OOC8,! was developed by Cimitri Rebikoff in /63. he +nited *tates >avy is credited with advancin# the technolo#y to an operational state in its uest to develop robots to recover underwater ordnance lost durin# at"sea tests. he +* >avy funded most of the early ROV technolo#y development in the /;1s into what was then named a Dable"ontrolled +nderwater Recovery VehicleD (+RV). his created the capability to perform deep"sea rescue operation and recover ob7ects from the ocean floor! such as a nuclear bomb lost in the &editerranean *ea after the /;; 9alomares -"62 crash and then saved the pilots of a sunken submersible off ork! %reland! the 9isces in /03! with only minutes of air remainin#. he net step in advancin# the technolo#y was performed by commercial firms that saw the future in ROV support of offshore oil operations. -uildin# on this technolo#y baseB the offshore oil J #as industry created the work class ROVs to assist in the development of offshore oil fields. wo of the first ROVs developed for offshore work were the RV"226 and the RV"61 developed by $ydro9roducts in the +.*. &any other firms developed a similar line of small inspection vehicles.&ore than a decade after they were first introduced! ROVs became essential in the /51s when much of the new offshore development eceeded the reach of human divers. Curin# the mid /51s the marine ROV industry suffered from serious sta#nation in technolo#ical development caused in part by a drop in the price of oil and a #lobal economic recession. *ince then! technolo#ical development in the ROV industry has accelerated and today ROVs perform numerous tasks in many fields. heir tasks ran#e from simple inspection of subsea structures! pipeline and platforms to connectin# pipelines and placin# underwater manifolds. hey are used etensively both in the initial construction of a sub"sea development and the subseuent repair and maintenance.
<ith ROVs workin# as deep as 1!111 feet in support of offshore oil and other tasks! the technolo#y has reached a level of cost effectiveness that allows or#anizations from police departments to academic institutions to operate vehicles that ran#e from small inspection vehicles to deep ocean research systems. %t was once thou#ht that somethin# thrown into the ocean was lost and #one forever! however! or#anizations such as &itsui and FA&*, in Fapan have ended that vision. <ith the development of their ultra"deep ROV Iaiko (photo at ri#ht)! they have reached the deepest part of the ocean " the hallen#er Ceep in the &ariana rench! at 1!/1/ meters. A record to be tied! but never eceeded. ROV APPLICATIONS - DESIGN
oday! with the aid of advanced computer desi#n techniues! the modern ROV has evolved throu#h many iterations of the desi#n spiral shown previously. odays odays ROVs are relied upon to perform comple operations offshore! in ever increasin# water depths! and have accordin#ly reached a hi#h level of technical desi#n. hese vehicles must also be fleible! that is! they must be capable of bein# confi#ured for many tasks. his holds true for small and lar#e systems! which are used for a variety of inspection and:or work tasks. *ince the #oal of the ROV is to accomplish an often"complicated task! its overall capability is usually driven by two ma7or considerations=work reuirement and operational water depth=both of which drive the considerations of the desi#n spiral.
$owever! the desi#n of the ROV must take into the overall system. here are a lar#e number of considerations that must be made both in the desi#n and in the selection of an ROV system such asH •
ost
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&arket size! reuirements and acceptability
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he operational platform (e.#. ships! ri#s! platforms! etc.)
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urrent technolo#y available
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9ower
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*ize
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<ei#ht
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Ceck space reuired
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&aimum depth
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&aimum sea state
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9ayload capability
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Application
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Versatility (i.e. confi#urability for different tasks)
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*afety
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Reliability
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rack record (if any)
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&aintainability
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?ield support and spares
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<arranty
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*ubsystem interfaces and options available
he photo of 9erry Tri$on vehicle with a top"hat tether mana#ement system and an A"frame style launch and recovery system hi#hli#hts the compleity of the overall system and underscores the point that the ROV is only a small! yet si#nificant! piece of the overall puzzle. / DRAG ROV APPLICATIONS - DESIGN /
he speed a vehicle can attain is a function of the available power and the total dra# imposed by the vehicle and tether. his is characterized by the euationH 4rag 5 678 / " AV8 C*
whereH s K density of sea water:#ravitational acceleration density of seawater K ;4 lb:ft3 (!126 k#:m3) #ravitational acceleration K 32.2 ft:sec2 (/.5 m:sec2) A K haracteristic area on which d is nondimensionalized. ?or vehicles! it is usually the cross sectional area of the front or the volume of the vehicle to the 2:3 power. ?or cables! it is the diameter of the cable in inches divided by 2 times the len#th perpendicular to the flow. ?or ships! it is the wetted surface. V K Velocity in feet per second ( knot) K .;5/ feet:second
K 1.6 meters:second d K >ondimensional dra# coefficient.
d is in the ran#e of 1.5 to based on the cross sectional area for most vehicles. d is in the ran#e of .2 for unfaired cables! 1.6 to 1.; for hair faired cables and 1. to 1.2 for faired cables. NOTEH alculations will be the same usin# metric units provided units are consistent. Co not mi meters and
centimeters. he power absorbed is characterized byB 4rag / V Power 5 99:
where 661 is a constant! which converts feet:pounds:seconds to horsepower. hus! the power is proportional to the velocity cubed (recall that dra# is proportional to velocity suared). *imply stated! because the power absorbed is proportional to the velocity cubed! a vehicle will reuire (3:2)3 K 3.4 times as much power to #o 3 knots as 2 knots. his means that if the power to wei#ht ratio is constant! the propulsion system on a 3"knot vehicle will wei#h 3.4 times that of a 2"knot vehicle. his does not turn out eactly this way because components come in discrete sizes. >onetheless! it is clear that a reuirement for hi#her speed has a dramatic impact on power! which in turn has the same sort of effect on system wei#ht. A rule of thumb is that you can #et about 36 to 41 lb (6./ to 5. k#) of thrust per horsepower available.
he vehicle dra# is only one part of the euation as the tether usually dominates the vehicle"tether combination. his can be best illustrated by an eample for a vehicle cable system. 4rag 5 678 " A; V8 C*; < 678 " Au Vu8 C*u
(v K vehicleB u K umbilical) As an eample! suppose a vehicle is bein# live boated at knot (./ km:hr) in !111 ft (316 m) of water. *uppose further that the cable is han#in# strai#ht down and there is a float on the surface and a wei#ht on the bottom of the umbilical. Assume further that the umbilical dra# from the ship to the float is small and the dra# on the umbilical from the wei#ht to the vehicle is small. Other dataH +mbilical diameter K inch (2.64 cm) he frontal pro7ected area of the vehicle K ; ft2 (.6 m2) henH Vehicle dra# K :2 L ;4:32.2 ; (.;5/)2 1.5 K 3; %b (;.3 k#) +mbilical dra# K :2 ;4:32.2 (:2 111) (.;5/)2 .2 K 254 %b (2/ k#) his simple eample shows why improvements in vehicle #eometry do not make si#nificant chan#es to system performance. / BALLAST, BUOYANCY CONTROL OV APPLICATIONS - DESIGN /
<hen desi#nin# an ROV! it is usual to attempt to use li#ht wei#ht components to keep the overall vehicle wei#ht within practical limits! thus the reason for usin# aluminum and other li#ht wei#ht materials. he wei#ht of the vehicle consists ofH •
*ubsystem components
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8ead mar#in:payload
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-uoyancy reuired to establish the desired operational specific #ravity
%t is conventional operatin# procedure to have vehicles positively buoyant when operatin# so they can be operated anywhere in the water column! and to ensure they will return to the surface if a power failure occurs. his positive buoyancy would be in the ran#e of 6 lb (2.3 k#) for small vehicles and to 6 lb (6.1 to ;.5 k#) for lar#er vehicles! and in some cases! vehicles will be as much as 61 lb (22.0 k#) positive. Another reason for this is to allow for near"bottom maneuverin# without thrustin# up! forcin# water down! thus stirrin# up sediment. %t also obviates the need for continual thrust reversal. Very lar#e vehicles with air"blown ballast tanks that allow for subsurface buoyancy ad7ustments are an eception. he measure of stability of a vehicle is conveyed by the assessment of the moment reuired to chan#e the pitch an#le of the vehicle. %t is characterized by the euationH
, 5 &$ &$(( G G S Sin in 0 w#e w#ere re==
mK moment moment K (w)(d (w)(d)) wK wei#ht of force force wher where e d K moment moment ar arm m <K vehicle vehicle wei# wei#ht ht -@K distance distance between the center center of buoyancy buoyancy and center of #rav #ravity ity
K pit pitch ch an#le! an#le! or roll roll an#le an#le
Obviously! the selection of units must be consistent. hat is! if D<D is in pounds and D-@D is in inches! DmD will have to be in inch"pounds. -y inspection! it is clear that a lar#e -@! which can be readily produced by havin# wei#ht low and buoyancy hi#h! produces an intrinsically stable vehicle. ,ternal forces do! however! act on the vehicle when it is in the water! which can produce apparent reductions in the -@. ?or eample! the force of the vertical thruster when thrustin# down appears to the vehicle as an added wei#ht hi#h on the vehicle and! in turn! makes the center of #ravity appear to rise and hence destabilizes the vehicle in pitch and roll. he center of buoyancy and center of #ravity can be calculated by takin# moments about some arbitrarily selected point. &ost ROVs are desi#ned to be as stable as practical (i.e.! stiff in roll and pitch). <hen desi#nin# an ROV! stability may be kept hi#h by placin# heavy wei#ht components such as electric motors low on the vehicle and buoyant components (@R9 chambers and syntactic foam) hi#h on the vehicle. -allast may be classified as fied ballast or variable ballast (V-). ?ied ballast may be syntactic foam! closed chambers! and lead. Variable ballast may be provided by open! air"blown tanks called Dsoft tanksD or pumped or blown sealed tanks that can take full divin# pressure called Dhard tanksD. Fixed Baa!"
?ied ballast (positive fied buoyancy) of a vehicle is achieved by pressure resistant buoyancy chambers! syntactic foam and lead to brin# the vehicle to the desired specific #ravity. &ost vehicles use a syntactic foam block near the top of the vehicle to #ain positive buoyancy. here are currently two types of syntactic foam. One is a matri of plastic macrospheres and #lass microspheres in a binder! the other has microspheres only. %n #eneral! the micro:macro material is used for shallower water depth capability and microsphere material for #reater depths. Obviously! the smaller the microsphere! the hi#her pressure it can take! thus the density of the foam increases! alon# with the cost! as the depth of application increases. he trade off is based on cost! wei#ht and pressure ratin#. Vehicles that use sealed tubular frame members to #ain buoyancy may be sub7ect to operational dama#e. herefore! it is conventional to use multiple compartments in the frames to prevent si#nificant loss of buoyancy in the event of impact dama#e. ?illin# the frame with foam can also maintain buoyancy in the event of impact dama#e.
Cependin# on the depth reuirement! it may be desirable to use a pressure vessel as buoyancy! however! this techniue has found limited use in commercial ROVs. %t is more common in A+Vs where the primary structure is often a lar#e pressure vessel. ?ied payload on the vehicle is usually in the form of several lead blocks. his lead may be echan#ed for euipment without ad7ustin# the vehicle's foam packa#e.
Va#ia$e Baa!"
Variable ballast permits pickin# ob7ects up from the sea floor and maneuverin# them without thrustin# downward. %t also allows the ROV to be heavy when divin# in hi#h current situations. A typical soft ballast subsystem could include one or more 3111 psi scuba bottles! a pressure reduction re#ulator! a surface controlled solenoid valve! and a thin wall tank with a lar#e openin# at the bottom. he soft tank approach has the disadvanta#e that air in the tank chan#es volume as the vehicle chan#es depth. Variable payload may also be obtained by floodin# or deballastin# hard (i.e.! pressure resistant) buoyancy chambers. ?loodin# a hard buoyancy chamber when a wei#ht is released from a submer#ed vehicle is a simple! effective techniue. Ceballastin# the hard chamber may be accomplished by forcin# the water out with air when valves are opened or by pumpin#. Variable buoyancy is uncommon in most ROVs but is widely used in hybrid vehicles where the vehicle must be neutrally buoyant for some operations and then become heavy for operations on the seafloor (e.#. cable and pipeline burial! repair! etc.). ROV APPLICATIONS - DESIGN / / CABLE
&ost ROVs reuire a cable to transfer the mechanical loads! power! and communications to and from the vehicle. Alternatives to this are vehicles under autonomous or semi"autonomous control (such as an acoustic link)! or vehicles with ependable cables such as fiber optic microcables. he vehicle size! wei#ht and operatin# depth! as well as the vehicle motors! subsystems! and payload! all combine to determine the ROVs cable desi#n. ?or the standard ROV! which uses an electro"mechanical cable! there are two #eneral cate#ories for cableH umbilical cable (ship to the ROV or tether mana#ement system (&*)) and tether cable (&* to the ROV). %nitial cable desi#n considerations include! power! si#nal and stren#th reuirements Power Re>uire,en!"
he power reuirements translate into amperes. ?or each ampere it is necessary to have enou#h material to conduct the power to the far end. &ost conductors have resistance to electrical ener#y flow! which creates a volta#e drop. herefore! it is necessary to use material with as low a resistance as possible such as copper! which is the most common.
Another consideration is insulation on the conductors to contain the electrical ener#y. ROV cables usually use thermoplastic materials for insulation such as ,?8O>M. $owever! because thermoplastics soften or melt with heat! it is important to know both the operatin# environment and the current reuirements. he operatin# volta#e is another consideration in the cable desi#n. %t is important to limit volta#e stress on the insulation. %f this is too hi#h it can cause the insulation to fail and the electrical ener#y to eit the conductor before it reaches its ob7ective! which can create a hazardous condition. herefore! it is important for the cable desi#n to address the insulation volta#e stress. Also! a separate conductor for an emer#ency #round is common as a safe#uard in case there is a breakdown in the insulation. Signa% Re>uire,en!"
he si#nal reuirements translate to attenuation losses. he si#nal! whether electrical or optical! attenuates throu#h both the conductor and the insulator. his loss varies with both the si#nal transmission media and freuency. *i#nal transmission can be either analo# or di#ital! and either electrical or optical. opper conductors with thermoplastic insulation are also common for electrical si#nals. *i#nal transmission wires freuently reuire a shield from electro"ma#netic interference (,&%) and radio"freuency interference (R?%). Also! it is common to #roup the si#nal transmission wires separate from the power conductors. here are both balanced and unbalanced electrical transmission schemes! and the system determines this reuirement. ypical balanced lines are twisted"pairs! and unbalanced lines are coaial. Other parameters to consider for si#nal transmission include impedance! capacitance and freuency. Nou can also transmit si#nals over multi"mode and sin#le mode optical fibers. *ome parameters to consider in any type fiber optic areH attenuation! bandwidth and wavelen#th S!reng!# Re>uire,en!"
he stren#th"member provides the mechanical link to the ROV. %t usually has to support the cable wei#ht! the ROV and any additional payload! and handle any dynamic"loads. Also! the cable size can influence the load on the cable due to dra#. herefore! there are many variables to consider when choosin# the cable stren#th. *teel is the most common stren#th"member material for umbilical cablesB usually a carbon steel wire with a #alvanizin# coatin# on the outside to protect the steel from corrosion. his materials tensile stren#th! modulus! and abrasion"resistance protect the cable from dama#e in service. *ynthetic fibers! such as I,V8ARM from Cu9ont! can reduce wei#ht. *ynthetic fibers are freuently necessary in tether cables! and also in umbilical cables for deep"water systems. *ynthetic fiber stren#th"members usually reuire an overall 7acket for abrasion resistance. A synthetic stren#th"member is #enerally more epensive than steel! but the wei#ht difference can be si#nificant. ?or ultra deep systems! usin# synthetic fiber is the only way to #et to the necessary depth. Overall! the desi#n of an ROV umbilical or tether is critical to the successful operation of the system. $owever! the technolo#y has advanced to the point that it is indeed a desi#n problem and ecellent cables are available for
virtually any application! whether for a low cost ROV inspectin# a dam or the IA%IO! searchin# the bottom of the &ariana rench. ROV APPLICATIONS - 4ESIGN " PROPULSION
9ropulsion systems are currently classified as either ,lectro"hydraulic or ,lectric. @enerally! the wei#ht and relatively lower efficiency of an electro"hydraulic system effectively eliminates this system from consideration in vehicles wei#hin# much less than 611 %b (220 k#). %n lar#er vehicles! however! it has the advanta#e of simplicity! ease of packa#in#! versatility! reliability! and low electrical noise. Althou#h not a practical limitation in commercial operations! the hi#her acoustic noise inherent in the electro"hydraulic system may be important when considerin# the mission of the ROV! especially in the military mission of mine countermeasures. ypical direct drive electric propulsion systems use a separate electric motor for each propellor! althou#h a multiple output #earbo can be driven by a sin#le motor. ,lectrical propulsion has wei#ht advanta#es in small ROVs. 9ropulsion unit styles includeH •
ontinuous pitch propellors with constant speed motors (61:;1 $z)
•
Variable Variable freuency A driven
•
+niversal motors with double reduction #ear
•
-rushless C motors
•
9ermanent ma#net brush type motors
he ROV can be characterized as a small tu#boat! with the conseuence that the thrusters must be pitched to obtain #ood bollard pull=essentially the thrusters maimum static thrust. -ut one must be careful usin# bollard pull to determine thruster reuirements. *ystem efficiency must be taken into consideration alon# with the fact that most thruster output will decrease as velocity increases. he optimum pitch is also a function of vehicle speed. herefore! the wise en#ineer will use the desi#n curves available on the candidate thrusters to determine the proper size and location of thrusters based on epected vehicle speed. *ince the velocity of the water surroundin# the thruster! essentially the inlet velocity! effects the output of the thruster! the location of the thruster is very important. Accordin#ly! the location of the thruster in the vehicle frame or body is not 7ust a matter of strappin# on a thruster. hruster size and location should be considered within the overall system! includin# the balance of power used by the thruster and other subsystems! ensurin# that one doesnt rob the other of needed output in a critical situation. hrusters come in several sizes and confi#urations and may be powered electrically or hydraulically! throu#h direct or #ear drives! with or without shrouds or ducts. @enerally! most thrusters will have a ducted shroud or a Iort nozzle to increase the output efficiency such as the %nnerspace hi#h performance thrusters shown below +
&arketin# brochures advertise output thrust ran#in# from 31 to 11 pounds per shaft horsepower input. Obviously! the results will be put in the best li#ht for the company! so the thrusters desi#n curves should be
reviewed and appropriate ad7ustments made based on system inte#ration. A rule of thumb that has been used for some time to estimate thrust or power reuirements is 36 to 41 pounds of thrust per horsepower! however! it appears that technolo#y is makin# the Dmodern thumbD a bit lar#er. ROV APPLICATIONS - 4ESIGN " CAMERAS
here is no universal underwater vehicle system E nor is there an optimal underwater viewin# system. Cependin# on the application! one viewin# or inspection techniue will out perform the other. 8ow li#ht V provides lon# distance viewin# whereas color provides contrast! but reuires hi#h illumination! which results in hi#h back scatter! however! the camera produces #ood close in resolution. Accordin#ly! lar#er systems will have a combination of several types of underwater viewin# and documentation subsystems! and smaller vehicles will carry what they can! but what they do carry must be matched to the task at hand. amera location and movement is critical. he main V cameras should have the capability to move E rotate (pan) and pitch (tilt) to aim the lens in the desired direction. he operators cameras should have a full field of view in the direction of travel to avoid hittin# obstacles! in addition to a full view of the workin# area (includin# the manipulators' area of reach). Additionally! the V cameras should have overlappin# fields of view where possible to allow cameras to operate as backups systems. he ability to view behind the ROV to watch the umbilical or tether cable for foulin# or sna#s! and to inspect the ROV itself (to check for dama#e or problems) is desirable. Aimin# the camera reuires that you know where the camera is pointin#. he best method of showin# the pan and tilt information is to overlay it on the V screen with the actual picture so that the viewer does not have to look away from the picture. An important part of navi#atin# an ROV is seein# where the vehicle is #oin#. V cameras have problems similar to human vision=a lack of sensitivity at low li#ht levels. +nless a stereo camera system is used! depth perception is non"eistent. herefore! a dual perspective camera system is almost mandatory for any comple work tasks &odern ROV systems have the capability of carryin# 1 V cameras and operatin# 6 or more simultaneously. <ith the advent of components such as ?ocal echnolo#ies' fiber optic video and data multipleer! up to 5 uncompressed video channels and 6 bi"directional data channels may be transmitted on one sin#le"mode optical fiber. ROV umbilicals may carry up to 2 fibers! of which several are desi#nated as spares in case of breaka#e. losed circuit television:video systems! unlike film type photo#raphic euipment! provide real time feedback and documentation to the operator=an absolute necessity for direct operator control of the system. Althou#h the ima#es acuired do not have the very hi#h resolution available with hard copy photo#raphic ima#es! the operator has the warm feelin# that he does have #ood documentation of the ob7ect bein# investi#ated without the concern of returnin# to the site because of a problem with the photo#raphic camera. And! new frame #rab technolo#y can #ive the operator a hard copy of the video ima#e! albeit at a lower resolution than other techniues. ameras in use include *ilicon %ntensified a ar#et r#et (*%)! *ilicon Ciode Array (*CA)! and har#e oupled Cevice (C). 8ow"li#ht"level (888) cameras! which operate with illumination levels hundreds and even thousands of times less than conventional tube or C cameras! have been used in the underwater environment for more than 26 years! with the *% the most commonly used. >ew ima#e intensifiers with up#raded features are now available for use with %C (intensified C) assemblies and are likely to become the sensors of choice in the
future. hese intensifiers can si#nificantly improve low"li#ht performance! and provide a lar#er variety of spectral response. here are several benefits of 888 cameras. 8i#htin# is a ma7or item in the power bud#et for many television systems! thus 888 cameras can si#nificantly reduce this bud#et. his is an especially important consideration in battery powered vehicle desi#n! and also for interconnectin# cables! where their size and wei#ht can be reduced. 888 cameras include si#nificant reductions in size! wei#ht! and power consumption and improvements in reliability! stability and repeatability. %t was only a matter of time before the 888 cameras became inte#rated with the computer. %nsite *ystems! in its @emini camera (shown left)! has combined advances in computer and surface mount technolo#y throu#h the use of an onboard microprocessor that enables the user to control virtually all of the cameras internal settin#s to optimize performance under any li#htin# condition. he operator can uickly ad7ust the video level! hi#h freuency compensation! A@! iris settin#! or return the unit to factory settin#s. rouble shootin# is performed by built in dia#nostics that monitor the camera! which can be linked via modem directly to the factory for on"line dia#nostic assistance. Obviously! such technolo#y will really sprin#board underwater cameras into the computer a#e. Ceep*ea 9ower and 8i#ht (C*98)! in addition to their line of underwater li#hts! offers underwater ima#in# solutions with its ecellent line of cameras. he miniature &ulti"*eaam (shown ri#ht)! is desi#ned as an inepensive! small! fied focus! monochrome and color camera with depth ratin#s to ;!111 m. ROV operators find the miniature camera particularly useful as a manipulator or tether"monitorin# camera. An additional benefit as a manipulator camera is the sapphire port! which is nearly impervious to scratchin# (ecept with a diamond)! and holds up etremely well in the hi#h"impact workin# environment of a manipulator. Re#ardless of the type of camera chosen! todays advanced desi#ns are allowin# compact and efficient systems that provide an ecellent end product. OV APPLICATIONS - 4ESIGN " LIGHTING
+nderwater li#htin# is driven by the viewin# system! which is made up of one or more television! video or still cameras. o properly desi#n an underwater viewin# system! the understandin# of several relationships is essential. -oth absorption and scatterin# present difficulties when optical observations are made over appreciable distances in water. Cissolved matter increases the absorption! and suspended matter increases scatterin#. *catterin# is the more troublesome! as it not only removes useful li#ht from the beam! but also adds back#round illumination. ompensation for the loss of li#ht by absorption can be made by the use of stron#er li#hts! but in some circumstances! additional li#hts can be de#radin# to a system because of the increase in backscatter. hese circumstances are analo#ous to drivin# in
fo#B the use of Dhi#h beamD headli#hts in most cases causes worse viewin# conditions than Dlow beamD headli#hts. Ieepin# unnecessary li#ht out of the water between the ob7ect bein# photo#raphed and the camera can reduce the back#round illumination caused by scatterin#. his can be accomplished by separatin# the li#ht and camera! and in very turbid water usin# two or three lower powered li#hts positioned efficiently instead of one hi#her" powered li#ht helps the situation. Ob7ects a few meters from a camera can be clearly ima#ed in ocean water! but unlike air! even in the best ocean water the clarity is sharply reduced for distances even as small as 6 to 1 m. %n some coastal water the effect of backscatter can reduce visibility or useful photo ran#e to only a meter or two. Ieepin# the li#ht source away from the front of the camera helps the situation. %n addition to the basic effect of li#ht intensity reduction in water due to absorption! the matter is further complicated by the fact that absorption is a function of color. Red li#ht is absorbed approimately si times faster than blue"#reen li#ht in water. his is why lon# distance underwater photo#raphs are simply a blue tint without much color. he #raph shows the severe attenuation of red li#ht (0111 A) compared to that of blue"#reen and violet. ,ven in the clearest surface water! reds are virtually non"eistent in ambient li#ht beyond 4 to 6 m depth. his situation is #reatly improved in underwater photo#raphy by usin# powerful strobe li#hts with the camera to #et more DredD li#ht to the sub7ect and thus yieldin# a more color balanced photo#raph. he color temperature of a lamp is measured in de#rees Ielvin (I). &ost underwater li#hts use tun#sten halo#en incandescent lamps with a color temperature of 2!511" 3!411 de#rees I. he dominant wavelen#ths at this color temperature are red and li#ht at this color temperature comprises primarily red wavelen#ths. As previously discussed! red is rapidly absorbed in water! reducin# penetration of the li#ht and also the ran#e at which true color ima#in# is achieved. his is fine for some ROV applications where the intent is merely to navi#ate or produce videotape of close"in work for documentation. $i#her color temperature li#ht also reduces backscatter! particularly at lon#er distances underwater as the ratio of near scattered li#ht (more red) is lower relative to li#ht comin# in from the ob7ect of interest farther away. ?or professional video ima#in# applications! lamps such as Ceep*ea 9ower and 8i#hts $&% lamps provide the ecellent illumination. C*98s 411 < $&% *eaArc2 (shown on the left) is an arc dischar#e lamp in which the luminous arc burns in a dense vapor atmosphere comprisin# mercury and the rare earth halides. $&%s have a ''dayli#ht'' color temperature around 6!;11 de#rees I! similar to natural sunli#ht. 8i#ht produced by $&%s has a hi#her color temperature (lon#er li#ht wavelen#ths)! and thus penetrates further! providin# #reater true"color illumination over a wide area! makin# them an ideal illumination source for filmin# wrecks.
$&%s are also more efficient than incandescent lamps! producin# 3"4 times more lumens per watt. *ince there is no filament to break! they are less sensitive to shock and vibration. A separate electronic ballast re#ulates power input. 9rimarily used for documentary epeditions (such as the movie Ti$anic )! )! $&% li#hts are #ainin# acceptance in the #eneral ROV market. omplementin# $&% li#hts are metal halide hi#h intensity dischar#e ($%C) li#hts. $%C lamps are arc lamps! 7ust like $&%s! but use a ma#netic ballast instead of an electronic one. $%C lamps can also be doped to produce different colors of the spectrum. Ceep*ea offers a choice of Cayli#ht! hallium"%odide (%)! and ultra"violet. Cayli#ht lamps produce a color temperature essentially the same as $&%s! 6!111";!111 de#rees I. % lamps produce #reen li#ht! which penetrates the furthest underwater! and are the best lamp for lon#"ran#e pilotin#. +ltra"violet (+V) lamps used in con7unction with +V filters are useful for findin# oil leaks. $%C li#hts are useful for applications where lon# lamp life is important! or lamps are left on continuously without off:on cyclin#. Ceepow photo survey vehicles! lon# duration ROVs and tourist submarines are eamples. ROV APPLICATIONS - 4ESIGN " LASER LINE SCANNERS
One of the newest tools on the market is the laser line scanner! a device that works eceptionally well from a towed or movin# platform for underwater search and:or surveys (see fi#ure). he 8aser 8ine *canner (88*)! in its simplest form! is a sensor that takes advanta#e of a laser to concentrate intense li#ht over a small area in order to illuminate distant tar#ets and etend underwater ima#ery beyond that offered by more conventional means. he 88* builds up an optical ima#e from a rapidly acuired series of spots on the seafloor! each seuentially illuminated by a pencil sized diameter laser beam that scans the bottom perpendicular to the direction of the sensor support platform. his techniue minimizes the effects of forward scattered and back"scattered li#ht. he resultant data are displayed as a continuous DwaterfallD ima#e that can be recorded on a standard video cassette recorder. Cistinct frames can also be captured and used to #enerate mosaic ima#es of seafloor features. he optical sensor consists of subassemblies for the imbedded sensor control electronics! the laser! a scanner and a detector. hese four subassemblies are inte#rated into a sin#le physical unit and installed inside a waterti#ht pressure housin#. he scanner subassembly is composed of two rotatin#! four"faceted mirrors! ri#idly attached to a common rotatin# shaft. he illumination laser is oriented such that its output beam is incident on the smaller of the mirrors! deflectin# the beam downward to the seafloor. he receiver views the seafloor reflected li#ht! incident on the lar#er mirror such that it is actually trackin# the output laser spot as it scans. he unscattered! unabsorbed li#ht that mana#es to reach the bottom illuminates a small! localized area that is called the primary scan spot. As the mirrors rotate! the scan spot traces a continuous line across the bottom. <hen there is relative motion between the scanner and the tar#et! perpendicular to the scan direction! then seuential scan lines will be displaced sli#htly and the tar#et will be
scanned in two dimensions. -y synchronizin# the scan rate with the forward velocity of the sensor! it is possible to control the spacin# between the scan lines! ensurin# that true ima#e aspect ratios are preserved. -y samplin# the output of the photo"multiplier tube within the receiver with mirror rotation! it is possible to build up a 2"dimensional reflectance map of the scanned area. <hen each new scan line is introduced at the top of the operator console display screen! it automatically displaces the last one at the bottom and a DwaterfallD display is created. his #ives the operator a realistic downward view of passin# over the bottom in real time. A computer system eecutes the functional al#orithms that control the process. ypical size for a 88* system is about 3.5 in (36 cm) diameter by 6. ft (.; m) lon#! with an in"air wei#ht of 311 lb (3; k#). -y usin# folded optics! it may be possible to shorten the len#th with a lar#er diameter to achieve better form factor for certain applications. he niche where the 88* system seems to fit best is between sidescan sonar and video camera for search or survey operations. he #ood optical resolution offered by these systems makes them an ideal tool for applications such as limited area search! corridor surveys (e.#.! pipelines and cable routes)! and hi#h resolution environmental surveys. As such! they have been historically transported on tow bodies such as the *cience Applications %nternational orporation! *an Cie#o! alifornia system shown in the concept. owed owed systems have inherent lon# line stability with hi#h data rate tethers to a topside processin# and display console. 9erhaps one of the best"known uses of the 8aser *canner was the search for wrecka#e of the ill"fated <A ?li#ht 511 off 8on# %sland. he etent of the -oein# 040 debris field was enormous! with most of the pieces relatively small. Visibility was mar#inal and! althou#h a #reat number of divers were used to recover such wrecka#e! their time on bottom under a no"decompression schedule was etremely limited. *idescan sonar was of limited use! due to the soft bottom and lar#e number of small aluminum pieces. An eample of the ima#in# ability is provided in the ima#e of a seat section located durin# the <A search (shown ri#ht). As with most tools! the 8aser 8ine *canner has distinct limitations as well as specific advanta#es. ?or eample! one drawback to 88* is that it typically reuires motion in order to #enerate an ima#e. his precludes stationary ima#ery. ,fforts to Ddither' the scan while the sensor is stationary have been eperimented with! but such a procedure is not yet available for common use. ?inally! the cost of 88* systems is substantial. Cependin# on a host of factors! a price ta# of about G011!111 would not be uncommon. Cay rates will vary! but a typical at"sea cost mi#ht be in the area of G2!611 to G3!111 per day! includin# two operators. he 88* systems can be readily inte#rated with ROVs and! sub7ect to the reuirements for stable fli#ht! used to #ood advanta#e to au#ment common video cameras. &aimum depths are currently limited to about ;!6;2 ft (2!111 m)! primarily due to laser window structural limitations. ?uture trends include color ima#ery (Ocean >ews J echnolo#y! echnolo#y! Fune:Fuly //0) and improved resolution.
/ AU%ILIARY AU%ILIARY WOR& PAC&AG PAC&AGES ES ROV APPLICATIONS - DESIGN /
he addition of auiliary work packa#es! or toolin# skids! to ROVs has provided the net step in lo#ical system inte#ration. here is no vehicle that can do all thin#s=contrary to the #oal of early ROV developers who failed miserably in tryin# to produce such beasties. he removable skid allows the primary vehicle to be reconfi#urable for various operations! alon# with bein# a simpler system when only performin# visual inspection or other less comple tasks. Vehicles have been desi#ned to allow the toolin# skid to be as simple as an auiliary hydraulic power supply or as comple as an underwater trencher. he primary consideration is that the new skid must follow the same system inte#ration considerations that the ROV had to follow earlier. he interface between the ROV and the skid must be taken into consideration when the ROV is developed! and the interface between the skid and the system it will work with is 7ust as critical. An eample of a removable auiliary work packa#e is shown in the followin# fi#ure.
Auiliary work packa#es are often the most efficient and sometimes the only method of providin# comple and varied intervention services for field operators and installation contractors. he interface reuirements for the skid can be specified to ensure the skid can be fitted to and inte#rated with any work class ROV of opportunity. <ith the capability of todays lar#e and powerful work class ROVs! it was only a matter of time until a system such as *onsub %nternationals (*aipem's) Civerless ?lowline onnection *ystem (C?*) was developed. he C?* was developed for the Amoco 8iuhau " field for 3.6"in (34"cm) and ;"in (6"cm) fleible flowline tie"in operations. *ome of the C?* components! which dwarf the ROV! are shown in the photo to the left. he C?R* is an ecellent eample of an ROV desi#ned to perform a comple task without repeated trips back to the surface. *ome of the key elements includeH o
wo specially desi#ned $"frames used to elevate the dama#ed pipeline from the seabed.
o
wo water"inflatable pipeline support trestles inserted under the pipeline usin# ROV operated winches.
o
wo 9ipemate #eneral"purpose universal pipeline tools! which can be interfaced to both the ool ool Rotation &odule and the *pool Cockin# &odule.
o
A pipeline replacement spool euipped with subsea buoyancy systems! to allow easy maneuverin# of the spool by the ROV without dependence on surface lift.
o
A ool ool Rotation &odule! which interfaces with the 9ipemate and can be installed or removed subsea.
o
he 9ipe"end 9reparation ool ool (99) used to suare the pipeline end and prepare it for the L" 8oc seal! which was desi#ned to allow installation! activation and seal testin# by an ROV. A 9ipeline *cissor lamp used to remove debris.
o
An ROV"deployed ROV"deployed dred#in# system.
One should not underestimate the ma#nitude of the overall pipeline repair operation. he section of pipeline about to be inserted must be suspended by the underwater buoyancy system. *ubsea acuired toolsEeuipment or toolin# that is placed on the seafloor ahead of timeEreduces the number of trips to the surface that an ROV must make. hese modules! or tools! which must also be desi#ned with ROV interface in mind! may add several benefits to the ROV desi#n. <ithout havin# to carry the tool or skid as part of
the ROV system! the overall size! wei#ht and compleity of that system can be reduced. %f the tool is put in place while the ROV is operatin#! then an additional deployment system may be reuired. *uch eamples underscore the compleity of the tasks that can be performed by an ROV offshore when the vehicle and toolin# are inte#rated with the overall system desi#n prior to installation. ROV CATEGORIES - SUMMARY
&odern ROV systems can be cate#orized by size! depth capability! onboard horsepower! and whether they are all"electric or electro"hydraulic. %n #eneral! ROVs can be #rouped as followsH •
Miro " typically &icro class ROVs are very small in size and wei#ht. odays &icro lass ROVs can
wei#h less than 3 k#. hese ROVs are used as an alternative to a diver! specifically in places where a diver mi#ht not be able to physically enter such as a sewer! pipeline or small cavity. •
Mini " typically &ini lass ROVs wei#h in around 6 k#. &ini lass ROVs are also used as a diver
alternative. One person may be able to transport the complete ROV system out with them on a small boat! deploy it and complete the 7ob without outside help. Occasionally both &icro and &ini classes are referred to as DeyeballD class to differentiate them from ROVs that may be able to perform intervention tasks. •
Genera% " typically less than 6 $9 $9 (propulsion)B occasionally small three fin#er manipulators #rippers
have been installed! such as on the very early RV 226. hese ROV+s may be able to carry unit and are usually used on li#ht survey applications. ypically the maimum workin# depth is a sonar unit less than !111 metres thou#h one has been developed to #o as deep as 0!111 m. •
Lig#! $or1%a"" " typically less than 61 hp (propulsion). hese ROVs may be able to carry some
manipulators. heir chassis may be made from polymers such as polyethylene polyethylene rather rather than the conventional stainless steel or aluminium alloys. hey typically have a maimum workin# depth less than 2111 m. •
Hea;) $or1%a"" " typically less than 221 hp (propulsion) with an ability to carry at least two
manipulators. hey have a workin# depth up to 3611 m. •
Tren#ing7uria% " typically more than 211 hp (propulsion) and not usually #reater than 611 hp (while
some do eceed that) with an ability to carry a cable layin# sled and work at depths up to ;111 m in some cases. •
Au!ono,ou" un*erwa!er ;e#i%e &AUV( " a a robot which robot which travels underwater without reuirin# input
from an operator. A+Vs constitute part of a lar#er #roup of undersea systems known as unmanned underwater vehicles! vehicles! a classification that includes non"autonomous non"autonomous remotely operated underwater vehicles (ROVs) E controlled and powered from the surface by an operator:pilot via an umbilical or usin# vehicles remote control. %n military applications A+Vs more often referred to simply as un,anne* un*er"ea ;e#i%e" &UUV"(.
C%a""
&icro Observation (P11 meters)
&ini Observation (P 311 meters) 8i#ht:&edium <ork lass (P2!111 meters) Observation:8i#ht <ork lass (P 3!111 meters)
$eavy <ork lass :8ar#e 9ayload (P3!111 meters)
Observation:Cata ollection (3!111 meters)
$eavy <ork lass :8ar#e 9ayload (3!111 meters)
T)pe
Power &#p(
8ow ost *mall ,lectric ROV
P6
&ini (*mall J Q/B(,lectric))
P1
&edium (,lectro:$yd)
P11
$i#h apacity ,lectric
P21
$i#h apacity (,lectro:$yd)
P311
+ltra"Ceep (,lectric)
P26
+ltra"Ceep (,lectro:$yd)
P21
renchin# and -urial
-ottom rawlers and 9lows
owed *ystems
owed *ystems
Autonomous +nderwater Vehicles Vehicles
+ntethered A+Vs
ROV CATEGORIES - SMALL VEHICLES
*mall vehicles includes the ma7ority of Dlow"costD ROVs (8ROV)! most of which are typically all electric and nominally operate to water depths of /54 feet (311 meters). hese vehicles are used primarily for inspection and observation tasks. here has been a recent sur#e in the development of small vehicles! due primarily to the improvement in technolo#y for electrically powered systems. hese improvements have resulted in an increase of capability! performance and depth not previously achieved.
D8ow costD is relative and vehicles in this class sell in the G1!111 to over G11!111 ran#e! however! vehicles like the &ues$ 8ROV 8ROV (ri#ht) and $ydrovisions H,-all (below) (below) are cheap when compared to lar#er work class ROVs. oday's oday's 8ROVs are used widely for many tasks includin# science! marine recreation! search and rescueB dam! waterway and port inspectionB trainin#! shippin#! nuclear inspection and coastal offshore inspection and observation tasks. he 8ow ost ROV (8ROV) first appeared on the market in /5 with %nternational *ubmarine ,n#ineerin#'s RASCL! which cost about G46!111. %n /54 the MiniR%.ER ! built by Ceep *ea *ystems %nternational was introduced at a price of G25!;11. %n /56 Ceep Ocean ,n#ineerin# offered the P(an$o0 at about G31!111. -y //1! 36 versions of 8ROVs could be counted! bein# built by 20 different manufacturers with over 611 systems delivered. oday they account for appro. 22S of all ROVs.
ROV CATEGORIES - HIGH CAPACITY ELECTRIC VEHICLES
Althou#h ROVs like the 9erry REC%N vehicle vehicle (shown left) have been around for some time (over 61 produced)! their technolo#y limited them in both depth and performance. A new class of ROV was born less than five years a#o! which althou#h small and electric! is not necessarily low cost and can approach the G611!111 mark. hese new vehicles feature the latest in technolo#y from -rushless C motors (thrusters) to 9"based control systems and fiber optic telemetry systems. ,lectrically operated vehicles can be made to #o 21!111 feet (;!1/; meters) with much less power reuired to operate them at depth. he ability to do heavy work is still not possible with the electric ROVs! primarily limited by the needed electro"hydraulic desi#n nature of modern manipulator and work systems! but they can still perform many tasks at a much lower cost. Vehicles Vehicles like the 9erry ritech .o,ager (ri#ht) (ri#ht) are very capable inspection systems usin# the state"of"the"art in fiber optic telemetry and control systems. ROVs like the Ceep *ea *ystems %nternational MaR%.ER (below) (below) offer increased power and moderate work capabilities to depths of /!542 feet (3!111 meters) at a fraction of the cost of electro"hydraulic systems.
,lectric vehicles have #ained popularity with the military and science markets due primarily to their uiet operation. %n addition! the work reuirements for military and science are! in most cases! not as comple when compared to ROVs used for oil and #as operations. he future should see a dramatic increase in the work capability of such all"electric systems.
ROV CATEGORIES - ME4IUM VEHICLES
his medium size class of ROV refers to electro"hydraulic vehicles ran#in# from 21"11 horsepower typically! which can only carry moderate payloads and have limited throu#h"frame lift capability. hese ROVs ran#e in wei#ht from 2!216"4!41 lbs (!111"2!211 k#) with typical payload capacities in the 221"441 lb (11"211 k#) ran#e. hey usually carry a sin#le manipulator but the lar#er of the class can carry two. *ome have the capability of throu#h"frame lift of over //2 lbs (461 k#). hese vehicles comprise the most widely used ROV class! which evolved from the early Deye ballD systems that were used to observe divers workin# or to perform routine inspections. his class was developed to perform work! carryin# one or two manipulators! in hi#h current conditions. he early ROVs developed! like 9erry ritechs (ori#inally A&,,Is) Scorpio(left) and %nternational *ubmarine ,n#ineerin#s H,+ra vehicles! are still in operation around the world today. ypical tasks for this class are drillin# support! construction support! pipeline inspection and #eneral Dcall outD work. &odern systems like the 9erry ritech .iper ! Super Scorpio and Scorpio Cobra reflect the latest technolo#y
applied to vehicles with the same horsepower as their predecessors! but with much #reater reliability and efficiency. &ost of these systems fall into the 3!25"foot (!111"meter) depth capability ran#e due to the fact that until recently! the ma7ority of drillin# support work has occurred within this depth.
Vehicles like the 9erry ritechs .iper (ri#ht)! (ri#ht)! wei#hin# in at 2!216 lbs (!111 k#)! replaced the REC%N providin# providin# a more powerful! hi#h thrust! electro"hydraulic platform capable of workin# in 3"knot or #reater currents. he lar#er ROVs such as the Scorpion and Cobra feature 06 hp. and a much"increased work and payload capability while still workin# at the 3!251 foot (!111 meter) mark. ROV CATEGORIES - LARGE $ORK CLASS VEHICLES
his class of vehicle can be broken down by depth capability and horsepower and represents the class of ROVs bein# used for current deepwater operations to 5!212 feet (2!611 meters) ran#in# from 11"261 horsepower and havin# throu#h"frame lift capabilities to !126 lbs (6!111 k#)! the distin#uishin# feature between medium and lar#e ROVs. <ork class vehicles such as 9erry ritech's TR#T%N 2L (left) ran#e in wei#ht (without work packa#es) from about 4!41"4!333 lbs (2!111";!611 k#). <ith new reuirements to perform subsea tie"in operations on deep"water installations and to carry very lar#e diverless intervention systems! this class of ROV has become very lar#e! powerful and capable of carryin# and liftin# lar#e loadsEthus the term Dheavy work class vehicleD has been adopted by the industry. hese vehicles may stand over 5 ft (2.4 m) tall when a tool packa#e has been installed underneath the ROV. A whole new #eneration of lar#e work work class ROVs is bein# developed for the oil and #as industry! with the capability to perform work tasks to /!542 ft (3!111 m). hese vehicles are retainin# the power and lift capabilities of the lar#e systems! but are bein# built into smaller frames while usin# more advanced technolo#y aimed at keepin# the umbilical size to a minimum. <hat distin#uishes these ROVs form the Dultra"deepD systems is that! unlike the deep divin# ROVs that carry only minimal power to minimize umbilical size! this new class carries between 06"11 hp aboard. his is a work class of vehicles that must have the power to perform heavy work at #reat depths. As eploration is bein# carried out in depths to 2!111 feet (3!;65 meters) and production in depths of over ;!111 feet (!52/ meters)! the need for new and advanced technolo#y eists. Only a few of these vehicles have been completed! specifically for oil field applications! and include 9erry ritech's Tri$on ST ! $itec's S$eal$(! HiR%.3444 and and HiR%. 3544 ! *tolt ome *eaway's SC./3444 ! *lin#sbys %l,0pian! and Oceaneerin#'s Magnu0. ROV CATEGORIES - ULTRA 4EEP VEHICLES his class of vehicle is represented by those special"built ROVs with depth capabilities of 3!23 feet (4!111 meters) and beyond. hese vehicles tend to be lower in power to keep umbilical sizes small and are used primarily for deep ocean research! search and salva#e missions. ?or such missions! ultra"deep ROVs do not reuire much power to observe or attach a salva#e line. &any of the ultra"deep systems are desi#ned for science! such as &onterey -ay Auarium Research %nstitute's (&-AR%s " Tiburon (left). A scientist can observe life in the very deep ocean for etended periods of time with the use of the ROV.
Other ultra"deep"water systems have been developed by the military to perform various missions includin# the salva#e of important assets. %nitially! the +* >avy had the missions that reuired unmanned vehicles! and accordin#ly! provided the financial backin# to break down some of the technolo#ical barriers. +ltimately! throu#h technolo#y developed in the >avys RJC centers and throu#h cooperation with industry! >avy financed vehicles broke the ;!1/;"meter barrier in //1=not once! but twice. he first tethered ROV to reach the depth was theCUR. ### vehicle. vehicle. Operated by ,astport %nternational (now Oceaneerin# echnolo#ies %nc.) for the +* >avy's >av y's *upervisor of *alva#e! CUR. ### reached reached a depth of ;!25 meters. hen! less than a week later! that lon# sou#ht record was a#ain broken by the Advanced e ethered thered Vehicle's (AVs) (AVs) record dive to ;!20/ meters. he A AV! V! developed by the *pace and >aval <arfare *ystems enter! *an Cie#o! is now operated by the >avys *ubmarine Cevelopment *uadron ?ive! +nmanned Vehicle Cetachment! also in *an Cie#o.
he celebration of the depth records achieved by the +* was short lived! however! as Fapan stormed onto center sta#e with a series of ecellent vehicles topped by the *A#*%. he *A#*% not only took over the record for the deepest dive! but obliterated it! reachin# the deepest point on ,arth in the &ariana rench=1!/.4 meters=in //6. A record that can be tied! but never eceeded (at least not without a shovel). &any countries have developed ROV systems for etremely deep work includin# .ic$or 6444 (%?R,&,R! (%?R,&,R! ?rance)! R%P%S (%*,! anada)! RTM 6444 (Okean#eofizika!Russia)! (Okean#eofizika!Russia)! H#R%. 3544 ($itec ($itec *ubsea A*! >orway). Other +* vehicles include Magellan 026 and 526! Ge0ini ! Magnu0! andMillenniu0 (Oceaneerin# echnolo#ies echnolo#ies %nternational)! Ha00er(ea+ (*ubsea (*ubsea %nternational %nc.) SuperMa (Ceep (Ceep *ea *ystems %nternational) andJasonMe+ea (<oods $ole Oceano#raphic %nstitution). ROV CATEGORIES - TO$E4
his class represents an overwhelmin# number of systems that have been towed behind ships and boats to perform many different types of work. he primary method of operation for towed systems is to launch the usually heavy vehicle (very heavy for deep applications) and then tow it at the desired depth by varyin# the len#th of the stron# electromechanical cable. <hereas Ievlar has provided the breakthrou#h for lon# len#th cables for free flyin# ROVs! where the tether needs to remain essentially neutral in the water column! steel cables are uite acceptable for towed systems. &odern tow cables now include fiber optic communications that provide ecellent bandwidth for the transmission of data from multiple sensors and Vs.
One application for towed vehicles is oceano#raphic data collection. &any of the smaller vehicles are desi#ned to undulate throu#h the water column in order to provide profiles (e.#. plankton! etc.). ypical sensors used aboard these vehicles are Cs! transmissometers! flourometers! nephelometers! bioluminescence and irradiance meters! optical plankton recorders! dissolved oy#en! p$! chlorophyll and others. &any towed vehicles are specifically desi#ned to locate cables or pipeline either buried or unburied on the seabed. he vehicles are normally either a conventional towed body! or a sled! which can carry either a ma#netometer or flu#ate #radiometer for locatin# metallic ob7ects. A very uniue desi#n by *eatec (see fi#ure at ri#ht) incorporates spinnin# rotors on the tow body that allow the vehicle to be steered alon# a pipeline.
One of the most prominent uses of towed vehicles is for search and survey. hese systems ran#e in size and wei#ht from very small! shallow water bodies to lar#e full ocean depth systems. *uch systems can survey the sea floor for many purposes includin# mappin#! search and salva#e! route survey! pipeline survey! environmental survey! etc. hey can carry a variety of survey sensors includin# V cameras! film cameras! di#ital cameras! laser ima#in# systems! side scan sonars! swath bathymetry sonars! multibeam sonars! sub"bottom profilers and ma#netometers. +nderwater search vehicles! such as *cripps %nstitution of Oceano#raphys Ceep owEone of the first such systemsEhave been used to locate everythin# from lost torpedoes and aircraft up to lon# lost ships. One of the most famous finds was by the <oods $old Oceano#raphic %nstitutions AR@O vehicle which lays claim to the discovery of the HMS Ti$anic . ROV CATEGORIES - OTTOM CRA$LERS ? PLO$S
-ottom crawlers are usually tracked vehicles! althou#h in some cases an Archimedes screw has been used instead. he primary use of tracked vehicles has been for cable layin# and burial. able burial vehicles! such as 9erry ritechs Ga$or (left)! (left)! carry one of four tools for buryin# purposesB water 7ets! chain trencher! wheel trencher or plow! which are normally chan#ed out dependin# upon soil conditions. *ome systems can be operated remotely or from a diver station onboard the crawler. Other uses for crawlers are sediment preparation! pipeline trenchin# and dred#in# operations.
9lows represent another lar#e class of vehicles that have! over the years! become very sophisticated. 9lows come in all sizes and confi#urations! wei#hin# up to 51 tons (5!251 k#)! resistin# tow forces to 261 tons (264!111 k#) and capable of shallow water work to depths of 4!/2 ft (!611 m). here are as many different plow desi#ns as there are different soil conditions around the world. he fi#ure below of one of *oil &achine Cynamics (*&C) 8td.'s line of plou#hs illustrates the size of such systems. he primary cause of dama#e to telecommunication cables is fishin#. Ceepwater fishin# to ;!6;2 ft (2!111 m) is conducted! therefore! burial 7ust beyond that depth may be desirable or reuired in the future. *ome plows combine a plowshare and water 7ettin# capability. he primary tools used for di##in# trenches with plows are the share or the disc. >ot all plows are used to di# trenchesB some specialty plows are built 7ust as back"fill systems for fillin# in trenches du# by other plows. ROV CATEGORIES - UNTETHERE4 AUTONOMOUS UN4ER$ATER VEHICLES &AUV"(
he first A+V was developed at the Applied 9hysics 8aboratory at the the +niversity of <ashin#ton <ashin#ton as early as /60 by *tan &urphy! -ob ?rancois and later on! e erry rry ,wart. he D*pecial 9urpose +nderwater Research VehicleD! or *9+RV! *9+RV! was used to study diffusion! acoustic transmission! and submarine wakes. echnolo#y chnolo#y in in the /01s. One of these is on Other early A+Vs were developed at the the &assachusetts %nstitute of e display in the $art >autical @allery @alleryin in &%. At the same time! A+Vs were also developed in the *oviet +nion (althou#h this was not commonly known until much later). +nion Autonomous +nderwater Vehicle Vehicle (A+V) development be#an in the early ;1s with vehicles such as Rebikoffs SEA SP%%* ! and the Applied 9hysics 8aboratory! +niversity of <ashin#tons SPUR. (*elf"9ropelled +nderwater Research Vehicle). hey were followed by b y many others! unfortunately! most of these early A+Vs were either lar#e! inefficient! epensive! or a combination of all three. <hile the ROVs were be#innin# to #ain in maturity in the early /51s! A+V technolo#y was essentially in its infancy. ROVs have the attributes of a brain (the human operator) attached via a lon# nervous system (the umbilical) and brawn (hydraulic power)! which is provided by heavy duty electro"hydraulic power systems to thrusters! tools and manipulators. onversely! A+Vs are reuired to carry their brain and brawn with them! a reuirement that! in the early /51s! left them waitin# for advances in computer technolo#y and ener#y stora#e. he #ood news is that durin# the last twenty"odd years of continued development! the brains and brawn have be#un to arrive. o oday! day! a minimum of ;; different A+Vs are under development developm ent or are operational in at least 2 different countries! althou#h some countries are purchasin# an initial capability. ?or eample! hina and Iorea (see
Caewoo $eavy %ndustrys %*P% A+V to the left) have purchased their A+Vs from Russias %nstitute of &arine e echnolo#y chnolo#y 9roblems (%&9). %n ,urope! consortia such as &A* and >,R are underwritin# the costs of A+Vs AUT%SU-. And in the +.*.! the most si#nificant developments have been undertaken by the like S#RENE and and AUT%SU
military! where overall investments will reach hundreds of millions of dollars once the >ear"e >ear"erm rm &ine Reconnaissance *ystem (>&R*) and 8on#"erm 8on#"erm &ine Reconnaissance *ystem (8&R*) reach operational status. Vehicles have been developed that ran#e from Robo/Lobs$er and and Robo/Tuna up to the mammoth CAR9A (Cefense Advanced Research 9ro7ects A#ency! +.*.) ++Vs. he offshore oil industry is lookin# at A+Vs! such as the Hugin bein# used by >orways *tatoil! to lower the cost of operations in many areas. Fapan is plannin# an A+V to reach the depths of the &ariana rench and F98 (Fet 9ropulsion 8aboratory! +.*.) is developin# A+Vs to bore throu#h the ice and investi#ate the seas of other planets and moons. And! critical breakthrou#hs are comin# out of academia at institutions such as ?lorida Atlantic +niversity! &assachusetts %nstitute of echnolo#y echnolo#y and <oods $ole Oceano#raphic %nstitution where the hi#h cost barriers of A+V development are bein# broken down. he future will undoubtedly see vast networks of Dinnerspace satellitesD that autonomously roam the ocean #atherin# data in a wide variety of applications.
