1965 – CURV Cable-controlled Underwater Recovery Vehicle – Jack L. Sayer Jr. (American)


1965 – CURV Cable-controlled Underwater Recovery Vehicle by Jack L. Sayer Jr.

NOTS-Pasadena Scientists Develop Recovery Vehicle from Rocketeer, July 9, 1965.
CURV Pays Its Way Recovering Valuable Deep Ocean Ordnance
NOTS Pasadena Laboratory has disclosed a new and unique method of reclaiming small ordnance items from the ocean floor. CURV—which sounds like a bend in the road or a part of the human anatomy, in Navy language means Cable Controlled Underwater Research Vehicle.
It promises to be one of the most useful, capable, and money-saving devices yet discovered for recovering expensive hardware from the bottom of the sea.
Boon to Economy Program
In any missile or torpedo program, hundreds of thousands of dollars are expended for test hardware in dummy form. Every torpedo that can be recovered represents a taxpayer's investment in both effort and money.
First, the hardware can be reused — saving the price of a duplicate. Second, and perhaps the most important, is the ability of the scientists and engineers to study the recovered hardware to determine areas of weakness or malfunction, thus correcting and improving the design in a minimum of time.
In use by NOTS Pasadena Laboratory, CURV is an unmanned vehicle comprised of a tubular aluminum frame 4-ft. high, 4-ft. wide, and 11-ft. long, upon which are mounted four ballast tanks (two on each side), three propulsion motors (port, starboard and vertical) with screws, a hydraulic system, and acoustic instrumentation components; also, a transistorized TV camera with two mercury vapor lights, a deep-sea documentation camera with a strobe light, a recovery claw, and a recovery buoy.
CURV weighs approximately one ton, and operates to a depth of 1000 feet at present. It will operate to a depth of 2000 feet when current modifications are completed.
Tug Supports Operation
The CURV is supported by the YTM 759, a tug, which not only transports it to the designated search and recovery location but also houses the control console from which the five-man CURV crew directs, controls, and monitors recovery operations.
After the general location of the target has been established by range methods and the topside checkout has been accomplished, the CURV is lowered over the side of the anchored support ship and submerged. It is then directed to the required position for recovery of the object on the ocean bottom.
Search and Recovery
Search and recovery procedures using CURV are described by the Navy as follows: (l) Locate target with CURV's high resolution sonar. (2) Classify target with TV camera and document event with Edgerton camera. (3) Position and attach hydraulically-operated recovery claw on target to be recovered. (4) Release recovery buoy with attached line. (5) Eject claw from CURV. (8) Back off CURV, leaving claw attached to target. (7) Surface CURV and secure it aboard the support ship. (8) Surface recovered target.
Recovery from great depths has been, until recently, an impossible job. With the development of CURV, an important milestone has been reached in recovery of research ordinance components. Navy personnel believe that it may be expanded to even broader use in the future.

The original CURV had only two buoyancy tanks.


In 1966, CURV was quickly upgraded to be used in the H-bomb recovery effort. It had and extra pair of buoyancy tanks mounted on top of the existing tanks.


CURV (cable-controlled underwater research vehicle) was developed by the U.S. Naval Ordnance Test Station, Pasadena, California. CURV weighs about one ton and operates to depths of about 2,000 feet. Advanced versions should be able to reach 8,000 feet, however. The vehicle was designed to recover torpedoes and other hardware weighing a maximum of one ton. The CURV vehicle is operated by a five-man crew on the surface. This crew directs, controls, and monitors recovery operation through a closed-circuit television network, supported by acoustic detection and positioning components.

The CURV (Cable-controlled Undersea Remote Vehicle) was developed by Space and Naval Warfare Systems Center San Diego (SPAWAR) in the early 1960s. It was initially designed to recover test ordnance such as torpedoes lost off San Clemente Island at depths as great as 2,000 feet (610 m). CURV was the pioneer for teleoperation. CURV was a prototype for remotely operated underwater vehicles and a pioneer for teleoperation. It became famous in 1966 when CURV-I was used to recover a hydrogen bomb from the floor of the Mediterranean Sea. In 1973, CURV-III performed the deepest underwater rescue in history when it rescued two men 1,575 feet (480 m) from the ocean surface who were stranded 76 hours in the submersible Pisces III with just minutes of air remaining. The CURV-III became known in the Great Lakes region in 1976 when it was used to survey the wreck of the SS Edmund Fitzgerald. CURV-21 is the current generation that replaced CURV-III.

This film is part of the Periscope Film LLC archive, one of the largest historic military, transportation, and aviation stock footage collections in the USA. Entirely film backed, this material is available for licensing in 24p HD. For more information visit http://www.PeriscopeFilm.com

Comment on Youtube  by Jason Pace –
My father was one of the engineers on the CURV project(s).  He's in this video actually … 7:56, the guy standing behind the 2 guys at the consoles.  Based on what he told me, I think your hypothesis is probably quite accurate in that there were any number of politicians and generals all with their pet projects that each wanted to see succeed.  And of those, the CURV was most certainly the ugly baby.  That sure didn't stop those same fellows from slapping each other on the back and celebrating when it proved successful however! 


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Above and below images from Popular Science, June 1966.

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The gripper is holding a grappling hook used to snag the parachute.



Navy CURV Underwater Retrieval Robot

PRESS-3/29/66-PALOMARES,SPAIN:This U.S.Navy undersea robot called CURV may get a chance this week to lift America's missing H-bomb out of the Mediterranean Sea from a depth of 2,500 feet. CURV, which stands for Cable-controlled Underwater Research vehicle, is 6 feet high, 5 feet wide, and 13 feet long. It goes beneath the sea equipped with a television camera to search for objects and a remotely operated claw to lift them to the surface. CURV was designed by the Naval Ordnance Test Station at Pasadena,Calif.,to retrieve such objects as stray torpedoes fired off the Calif. coast.    U.S.NAVY PHOTO VIA UPI TELEPHOTO



Underwater recovery vehicle

Publication number    US3367299 A
Publication date    Feb 6, 1968
Filing date    Aug 1, 1966
Inventors    Jack L Sayre Jr
Original Assignee    Navy USA

This invention relates to improvements in apparatus for the recovery of objects on the floor of the sea and more particularly to an unmanned vehicle, controlled by a surface vessel, which may locate the sunken object, and attach recovery apparatus to it which may then permit raising of the object independent of the vehicle. Such vehicle is commonly known as the CabloControlled Underwater Research Vehicle (CURV).

In the testing of negatively buoyant torpedoes and other underwater ordnance devices the test device is sometimes lost on the floor of the sea after a test run, which, if it be at considerable depth, particularly beyond diver depih, presents serious problems in the recovery of the device, which, in addition to its relatively high cost also contains valuable test data recorded during its run which is invaluable in the determination of the possible malfunction. While manned vehicles are now known which descend to great depths they suffer certain disadvantages such as high initial cost and limited search periods.

One of the objects of this invention is to provide an improved vehicle which may remain submerged indefinitely with which a sunken object may be located, recovery apparatus attached to it, and the recovery apparatus and sunken object raised to the surface of the sea independent of the vehicle.

Another object is to provide a recovery tool on the vehicle which may be oriented to desired positions to attach it to the sunken object and to thereafter eject it from the vehicle on command from a surface vessel, the operations all being visible on a TV screen located on the surface vessel.

Another object is to provide an ejection mechanism for receiving various recovery tools which may be selected in accordance with the shape, size or nature of the sunken object.


Recovery snare
Publication number    US3588161 A
Publication date    28 Jun 1971
Filing date    5 Feb 1969
Inventors    Robert E Pace, Jack L Sayre
Original Assignee    US Navy

ABSTRACT: A recovery snare including a cable, and an elongated element, such as a tube, and a yoke at a snare end of the tube. The yoke may include a pair of hollow longitudinally slanted arms which are pivotally connected to the snare end of the tube. The cable is threaded through the tube and the hollow arms to form a loop at the snare end. The arms of the yoke are provided with means, such as snubbers, for releasably retaining the cable in the arms until such time the cable is looped around and drawn tight on an object to be retrieved.

CURV II had 4 buoyancy tanks, but mounted in side-by-side pairs.





CURV III had a boxed tank and a new manipulator arm.




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Extract from The Day We Lost The H-Bomb – Barbara Moran 2009.

…….Before leaving for Spain, MacKinnon and Kunz had visited the Naval Ordnance Test Station (NOTS) in  Pasadena. The supervisor of salvage had told MacKinnon about a torpedo recovery device called CURV, which might be useful in Palomares, and asked him to check it out.   MacKinnon visited CURV and realized that the Navy might need this device in Spain. He told the technicians to prepare CURV for the mission and then headed to Palomares himself.

      The engineers and technicians at NOTS had built CURV, which stood for Cable-controlled Underwater Research Vehicle, two years earlier because the Navy needed a better way to recover prototype torpedoes. To test a new torpedo, the Navy used a real weapon but removed the warhead and replaced it with an “exercise head” containing lead weights and pingers. Then it took the modified weapon to the test range off Long Beach and shot it at a target. If all went well, the torpedo completed its full run, using up all its fuel, and then dropped its lead weights. The loss of fuel and weights made the torpedo buoyant. Spent, it floated to the surface, where the Navy could recover it easily.

      But test torpedoes didn’t always work as planned. Often they sputtered before finishing their test run and, carrying their heavy load of fuel, sank to the bottom. With each sunken torpedo costing close to $100,000—and holding important information about the failure — the Navy couldn’t just leave them there and so developed a crude way to recover them. It tracked the torpedo’s pinger and, when it located its resting place, sailed a barge to the site. The barge had a moon pool in the center and four mooring winches, one on each corner. When the barge arrived at the torpedo, searchers moored the ship directly over it with three or four anchors. Then they lowered a rectangular frame containing lights, sonar, a wire noose, and a TV camera and looked for the lost torpedo. To move the dangling frame, the captain had to motor the entire barge back and forth. Eventually, if the searchers were in the right place, they would see the torpedo and try to snare it with the noose. The process was long, slow, and awkward; it could take days to recover one torpedo.

      CURV resembled this old system in some ways. It consisted of a frame of aluminum tubing, which held sonar equipment, lights, cameras, and three propellers. On top rested four oblong buoyancy tanks, and off the front jutted an arm holding a metal hydraulic claw lined with rubber. The whole contraption measured about five feet high, six feet wide, and thirteen feet long.

      To recover a torpedo, the Navy steered a ship to the site and lowered CURV into the water. But CURV didn’t just dangle there as the barge swayed overhead. CURV was remote-controlled, attached to the surface ship with a thick umbilical cord. A surface operator, sitting at a console, could see the bottom through CURV’s TV and sonar and direct its propellers with joysticks. The operator flew CURV to the lost torpedo, grasped it around the middle with CURV’s claw, then carried it to the surface. If the torpedo was too heavy, the operator could jettison the claw and back away. The claw, attached to a lift line, could then be raised to the surface. Early in its career, CURV managed to recover an unheard-of four torpedoes in one day.

      By the time the Air Force dropped four bombs over Palomares, CURV had been operating for about two years and had plucked up fifty-two torpedoes from as deep as 2,000 feet. The CURV team had mastered their job, but the device itself was still a work in progress, and the CURV group remained a small-scale, low-budget operation.

      When the Navy requested CURV’s services in Spain, the team welcomed another opportunity to show off their skills. If they were successful, it would mean more recognition and money for their project. An H-bomb, to them, was just a big torpedo, and they certainly knew how to recover those.

      There was only one problem — the tether was too short.  CURV’s umbilical cord, an inch-and-a-half-diameter cable that fed power and commands to the device, was about 2,000 feet long. But by March 15, when Alvin found the bomb at 2,500 feet, the Navy knew that CURV would have to go deeper. So the CURV team embarked on a crash program to lengthen its lifeline by splicing in an additional 1,000 feet of cable.

      The splicing was tedious work. The cable contained fifty-five separate conductors, each of which had to be spliced individually. The team staggered the splices over about four feet of cable, then covered the wounded area with a gray, pliable goo used for sealing air ducts. (The team dubbed the material “monkey shit.”) Then they wrapped the area in black electrical tape, sealing the splices as well as they could. Larry Brady and George Stephenson, the CURV operators, spent several days on the splicing operation. When they finished, the splice was an ugly black blob. “It looked like a python had swallowed a dog,” said Brady. “Or a couple of dogs.” Dragging the device to a NOTS range, the CURV team ran a few test dives. The ugly splice held.

      The cable now stretched 3,100 feet long — long enough for the job — but they couldn’t go much below 2,800 feet and still maneuver. There were some other bugs as well: CURV’s depth gauge didn’t work well below 2,000 feet, and its altimeter, which measured CURV’s distance from the bottom, didn’t work at all. But on March 24, as soon as Task Force 65’s first lift attempt failed and the bomb fell back into the Mediterranean, Admiral Swanson ordered CURV to Spain. On March 26, the team packed up the CURV system, loaded it onto a cargo plane, and headed to Palomares.

      The CURV team set up shop on the USS Petrel, a submarine rescue ship, on March 29. The Petrel and her commanding officer, Lieutenant Commander Max Harrell, were old hands at Navy salvage, having worked on such operations for years, and the ship proved a good home for CURV. The CURV team set up their gear but had little to do; the bomb was still missing after the failed lift attempt. So for a couple of days, they ran tests. The Navy dropped a dummy bomb into the water with the same dimensions as the missing weapon and sent CURV off to find it.

      The CURV team operated the device from a small control shack on the deck of the Petrel. It took two people to run the device: one to operate the sonar and read the compass, the other to move the switches and levers that spun CURV’s three propellers and sent it swimming. When it came to “flying” CURV, Larry Brady was the undisputed master. He just imagined himself sitting on the device, sailing happily underwater, and the moves came naturally. Once he found the target, Brady grabbed it with the claw, like a kid in an arcade grabbing cheap toys from a bin.

      A couple of days after his arrival on the Petrel, Brady dove CURV to 1,050 feet, found the dummy bomb, and recovered it with a special claw the team had built in California. The next day, CURV dove to 2,400 feet and recovered a pinger hidden inside a barrel. The team could have continued performing ever-more-elaborate circus tricks for weeks, but on April 2, Alvin found the bomb resting on the gray bottom 2,800 feet below the surface, just within CURV’s reach. As the parachute had wrapped itself completely around the weapon, however, CURV couldn’t grab it with its claw. The crew needed another way to snare the bomb.

      Robert Pace, CURV’s project engineer, came up with an idea. Sketching a grapnel that would fit onto CURV’s arm, Pace brought the drawing to the Albany’s tender and asked the men in the machine shop to build it. Pace envisioned a grapnel with softly curving spring-loaded tines that couldn’t accidentally slice the parachute shrouds and wouldn’t let go once they hooked in. The chief who ran the machine shop looked at the drawing skeptically. Another grapnel? They had already made a bunch of these things for Alvin and Aluminaut, all of which had never been used or had ended up somewhere on the bottom of the sea. And his crew had already been at sea ninety days longer than planned, with no end in sight. It was really too much. And now they wanted another grapnel? The chief complained until he ran out of steam. Then, realizing that Pace wasn’t going anywhere without his grapnel, he ordered his men to get to work. In the end, they made him three.

      On April 3, the day after relocating the bomb, Alvin rendezvoused with Aluminaut, and Aluminaut surfaced. Alvin, left alone with the bomb (now code-named “Robert” after Admiral Guest’s stepson), tried to pull the parachute aside to examine the weapon. The parachute and bomb lay tightly tangled, however, and the Alvin crew couldn’t get a good look at it. They attached two pingers to the parachute, placed a transponder nearby, and headed to the surface, leaving the bomb alone.

      As Alvin worked beneath the sea, the CURV team prepared for their first dive on the bomb. With the weapon resting at 2,800 feet and CURV’s cable just 300 feet longer, the device would practically be hanging on the end of the line, with little room to maneuver. CURV would literally be at the end of its tether.

      To give CURV as much freedom as possible, the commander of the Petrel, Max Harrell, had to hold his ship almost directly over the bomb each time it dove. And he couldn’t use the Petrel’s own power: the CURV lines dangled dangerously near the Petrel’s propeller, and Harrell couldn’t risk turning it on. Instead, he decided to position the ship with two Mike boats, one attached to the bow and one to the stern. By directing them with walkie-talkies, he would try to keep his ship over the bomb, with only 50 yards of leeway in any direction. The first time they tried the maneuver, both Mike boats got tangled in their own tow lines and had to be untangled by divers and boat crews.

      Harrell would have to keep them untangled — and in position — for at least ten hours each dive.

      While Harrell ironed out the positioning, the CURV team prepped their lift line. The machine shop had finished Bob Pace’s grapnel, strength-tested it to 10,000 pounds, and found it could hold the weight. The grapnel was attached to one end of a braided nylon line that stretched 3,200 feet, well over half a mile. The other end of the line was hooked to a buoy. The rest of the lift line — the entire midsection — was attached to CURV’s umbilical cable with masking tape at regular intervals. The tape would keep the line in place until CURV ejected the grapnel and pulled away.

      On April 4, just before 9 a.m., CURV dropped into the water and headed down to the bomb. Air Force experts had told Larry Brady that the apex was the strongest point of the parachute; if Brady could hook the grapnel in there, he was home free.

      Around noon, CURV reached the bomb, guided by the pingers that Alvin had left behind. Brady sailed CURV around the bomb, looking at the tangled chute through the video monitors. He found the apex and, with his usual dexterity, dug three tines of the grapnel in through the hole and out through the chute. Sure that the grapnel was firmly attached, Brady ejected it from CURV and backed away. The masking tape binding the nylon line to the cable snapped, piece by piece, and the lift line buoyed off. The operation had gone exactly as planned.

      Larry Brady and the rest of the CURV crew had been cocky since their arrival in Spain. After all, they retrieved lost bombs for a living. They had heard about the first attempt to retrieve the bomb and thought that the men involved, while certainly earnest, had been amateurs. It was as if, said Brady, two guys flipped their car into a ditch, tried to tow it out on their own, and burned up the clutch before finally calling a tow truck. CURV, said Brady, was the tow truck. With one line solidly attached, Brady considered his job done. He was surprised to learn that it wasn’t.

      The CURV crew expected that the Navy would now lift the bomb. Instead, they learned that Admiral Guest wanted two more lines attached. Guest had been burned the first time around; it wouldn’t happen again. Bob Pace tried to talk Guest out of it. “Admiral,” he said, “you got that parachute ballooning in the water now. It’s going to be difficult enough to get another grapnel into it without tangling it.” Guest shook his head. “I can’t help that,” he said.

      On April 5, Mac McCamis and Val Wilson dove Alvin down to the bomb to assess the situation with human eyes. When they arrived, they saw the chute, supported by the buoyed line, floating in the water column. The parachute danced in the water like a giant jellyfish, the bomb still tangled in its tentacles. Dragged by the bobbing buoy on the surface, the bomb and chute had moved several hundred feet west and now rested a bit deeper, at about 2,850 feet. Trying to get a better look, McCamis carefully nudged the sub toward the dangling mess. “This sixty-four-foot cargo chute was billowing up like you was under a Barnum and Bailey circus tent,” said Mac. “My biggest worry was getting tangled.”

      Approaching cautiously, Mac stopped just short of the parachute. But Wilson, looking out the side window, panicked. The curvature of the window made it appear that the parachute was reaching over them, threatening to engulf the sub. “Scared him dead,” said McCamis. “So he yelled topside to Rainnie that we’re in the parachute, which we weren’t, and I couldn’t shut him up quick enough. So I moved off to the side, to get him back in his seat.” Worried by Wilson’s report, Rainnie ordered the sub back to the surface.

      Both Mac and Wilson had been spooked by the close call. If Alvin got trapped or tangled, the pilot could jettison various parts of the ship — the batteries, the mechanical arm — with explosive bolts, hopefully allowing the sub to surface. If that didn’t work, he could lift a panel on the floor, exposing a stout metal cylinder: the sphere release. If the pilot turned the cylinder 90 degrees, Alvin would release the personnel sphere, and it would rocket, spinning, to the surface. The sphere separation could save the inhabitants from death at the bottom of the sea, but it would be a rough and terrifying ride to safety.

      Just before midnight on April 5, CURV dove to attach a second line. In the early-morning hours, Larry Brady twisted CURV’s second grapnel into the parachute, snaring at least six lines. Then he ejected the grapnel, and the line was buoyed off. Alvin, diving to check on CURV’s progress (but now keeping a safe distance from the chute), reported that the bomb had shimmied farther downslope, dragged by the two buoyed lines. The news injected new urgency into the operation.

      Admiral Guest and his staff feared that the bomb might slip out of CURV’s reach. They had to get that third line attached as soon as possible.

      But just as the Navy got the second line to the surface on the morning of April 6, the weather turned sour. Twenty-two-knot winds whipped the sea into five-foot waves, conditions too dangerous to operate CURV. Admiral Guest looked at the recovery crews. Most of the men had been awake for more than thirty hours and looked like zombies. Since the seas were too rough to dive anyway, Guest stood them down until that evening.

      Just before 9 p.m., sensing that a recovery attempt was near, Admiral Guest and his staff boarded the Petrel. Bad weather grounded CURV until after midnight. Around 1 a.m., CURV dove to attach the third and final line. The control shack was crowded. Members of Guest’s staff, including the admiral himself, watched over Brady’s shoulder as he flew CURV toward the target. Guest asked him to pull closer to the chute, to try to see the bomb. Since Admiral Guest was paying the bill, Brady indulged him. “We might get stuck,” he told Guest, “but we’ll sure give it a try.” Brady steered CURV back and forth around the dangling bomb, trying to give Admiral Guest a clear view of the weapon. Suddenly he noticed that a switch on the control panel had flipped. It was the circuit breaker for the starboard thruster. Brady reached up, flipped it on, and tried to run the thruster. The circuit breaker popped again. Brady panned the underwater TV camera around, looking back over CURV’s shoulder. The parachute had tangled in the starboard thruster. CURV was stuck.

      Brady pointed at the TV and said, “We’re fouled.”

      Guest and his staff stared at the image on the screen. Then they stood up and walked out. Guest thanked his lucky stars that CURV was an unmanned machine, rather than a manned sub. Then he climbed the steps to the wardroom and gathered his staff. He had to make a decision.

      The CURV crew waited in the control shack, killing time by playing cards. Eventually, a member of the CURV team came down from the wardroom, looking grim. You’re not going to believe this, he told his colleagues. The admiral wants to cut CURV’s umbilical cord, tie it off to a buoy, and retrieve the bomb later. The men in the control shack were shocked. They had two lift lines solidly in place; why not just raise the bomb?

      The same argument flew about the wardroom. The atmosphere grew so tense that Howard Tarkington, the CURV division head, fainted from the stress. Guest had vowed not to make another lift attempt without three lines attached. Yet if they strained to free CURV, the only vehicle that could attach a third line, the bomb might be dragged out of reach. Guest wanted to cut CURV loose.

      He turned to each member of his staff and asked his opinion. Red Moody and Brad Mooney argued against cutting CURV free. CURV, in a way, was the third line they were looking for. They should lift the bomb now.

      Cliff Page, the admiral’s chief of staff, agreed. Knowing that Mooney enjoyed a strong rapport with Admiral Guest and had excellent diplomatic skills — one Navy man called Mooney “the snake charmer”—Page took charge. He cleared out the wardroom, leaving the lieutenant and the admiral to slug it out. They stayed there, behind a closed door, for hours. “I tried to be as respectful as I could, but I was saying, ‘Admiral, this is dumb as hell to cut this thing loose,’” recalled Mooney. “‘It’s totally enmeshed in there, and they can’t help but lift it now.’” By early morning, Mooney had beaten the admiral down. At 5:02 a.m. on Thursday, April 7, Guest sent a message to General Wilson. The message said that Admiral Guest had a broken leg, code that the lift would soon begin.

      Red Moody and Max Harrell, the commanding officer of the Petrel, had already started preparations. The two men went over every detail: they didn’t want any lift lines snapping this time around. Harrell designed a system of blocks and pulleys that would haul the two lines up, distributing the load equally between them. He attached a dynamometer to measure the total lifting stress.

      Both lines were wound around one capstan, ensuring that the ship would hoist both at the same speed. Moody made sure that the capstan was smooth, free from any imperfections that might cut the lines. A second capstan would wind CURV’s umbilical cable. CURV, though hopelessly tangled in the chute, was slightly buoyant and didn’t pose much of a lifting problem. But to keep it neutral during the lift, it had to be raised at the same speed as the weapon.

      Harrell positioned the Mike boats that would hold Petrel steady for the lift. Looking at the weather, he knew that today would prove particularly difficult. April 7 dawned with little breeze and a calm sea, beautiful for a spring picnic but less than ideal for ship control. It was easiest to judge and hold position when a breeze or surface current offered a force to work against. With neither of these, Harrell’s difficult job would be that much harder.

      Guest and his staff gathered in the wardroom to watch the lift on CURV’s video monitor.

      Meanwhile, Moody cleared all nonessential personnel—“tourists,” he called them — off the Petrel’s stern, or fan-tail. The only people allowed on deck were those actually recovering CURV or the bomb. Moody wanted to give the recovery team space to work, not necessarily protect the men who hustled belowdecks. Moody was certain the bomb wouldn’t explode. But if it somehow did, it wouldn’t matter if a man were abovedecks or below. As one EOD diver put it, there’d be nothing left but a greasy stain.

      At 5:50 a.m., the Petrel began to raise the weapon. Guest worried most about the bomb lifting off the bottom. He had been told that when the bomb was within 100 feet of the bottom and 100 feet of the surface, vibrations in the nylon line could reduce its strength by as much as 75 percent. The admiral was not the only man in the wardroom worried about this possibility; one scientist paced back and forth with such a scowl that Red Moody and Herman Kunz had to take him outside and tell him to cheer up. Guest, powerless to do anything but wait, looked sick to his stomach. He turned to the man next to him and said, “I’d prefer combat any day to this.” As it turned out, the weapon came up so smoothly that they hardly noticed it leaving the bottom. For an hour and forty-five minutes, the capstans turned slowly, gently raising the weapon. Finally, the top of the parachute broke the surface. Two of Red Moody’s divers jumped into the water to inspect the bomb. The weapon, they found, wasn’t dangling below the chute but remained tangled about a third of the way up. The fact that they saw the weapon was a huge relief; for the first time, Guest knew he really, truly had the bomb.

      The divers attached metal straps and hoisting lines to the bomb. Boatswain mates rigged the lines to the cargo boom on the Petrel’s fantail. Then the divers cut CURV free from the chute, and the signal was given to lift. The Petrel hoisted the weapon clear of the water and swung it inboard.

      Immediately, the EOD team swarmed the waterlogged weapon with radiation monitors. The readings were negative. The boom swung the bomb over the back of the ship and set it down. It was 8:46 a.m………….

See other early Underwater Robots here.

1965 – Telenaute ROV – (French)


The Telenaute Remote Operated Vehicle.


Manipulator arm of the Telenaute.


Movietone Newsreel Clip – hereTelenaute preparing for an underwater cave exploration.

A commercial French company, the Compagnie Generale pour le Developpement Operationel des Recherches Sousmarines, own a similar craft [to CURV] known as the Telenaute. This is capable of movement in any direction at depths up to about 1,000 m. The arm fitted to the Telenaute can handle a load of 50kg at a distance of 1.1 m. The Telenaute has a very open structure, since there is no need for an unmanned device to have a large and pressurised body. Source: Robotics – John Frederick Young – 1973.

The French Petroleum Institute (IFP -l’Institut Français de Recherches Pétrolières) built the "TELENAUTE", which is available for chartering. The "Telenaute" is a cable controlled, self propelled vehicle monitored from a control vessel on the surface. It is used for underwater search, making observations, filming and performing simple underwater operations.

See other early Underwater Robots here.

1965 – General Purpose Underwater Manipulating System Patent – Ralph K Crooks et al (American)


Publication number US3381485
Publication date 7 May 1968
Filing date 23 Oct 1965

Original Assignee Battelle Development Corp


General purpose underwater manipulating system

ABSTRACT OF THE DISCLOSURE A cable-suspended, remote-controlled manipulating device for operation underwater. The apparatus includes propulsion means, TV camera, clamping devices, manipulating arm, support feet and other devices necessary to underwater operation. Numerous components of the apparatus are preferably hydraulically actuated by a system, having a plurality of capacity or power levels. Various sensor devices are included to obtain information about underwater environment and to inform the above-water operator of the condition and activity of the apparatus. The apparatus is constructed in modules to facilitate re placement and substitution of various working devices. The command system of the device includes partial multiplexing where signals are originated by an operator and released to the underwater apparatus on a priority system with lag time within the area of human reaction time. Sensor signals and command signals are sent along common channels.

This invention relates to apparatus for underwater exploration, research, and remote controlled manipulation of various devices and tools. More particularly, it concerns a fully controlled, uninhabited apparatus provided with television and operated by a cornmand station that is preferably situated on a craft above water.

Much of the Worlds wealth and resources lie on or beneath the floor of the ocean. Under present engineering capabilities, these resources are largely inaccessible. Interest is developing, and some experiments have been conducted, in mining, farming the ocean floor, and under sea dwellings; also, there has been very active development of off-shore oil reserves throughout the world. Under to 300 fathoms of ocean water lie broad continental shelves which in themselves constitute nearly fifteen percent of the earths total surface. When these continental shelves come within the reach of man, the total area that mankind can utilize for its benefit will more than double. High pressure, the corrosive nature of sea water, and many other factors combine to make the ocean a hostile environment in which man has, to date, operated only in a limited way.

In the past, deep-sea exploration and research has been limited by mans inability to reach deep enough into the ocean and remain there long enough to accomplish given tasks. Two principal concepts of deep-sea penetration are: (1) attempts to put man deep into the ocean by scuba apparatus, hard helmets or aboard submersibles, and (2) unmanned dredges and trawls or programmed machine systems.

Recently, especially with development of improved television devices, interest has increased in remote controlled manipulators. Considerable success is being achieved in increasing the economic productivity of divers at depths exceeding 100 feet or so; nevertheless, an expanding need for remote controlled equipment to complement or supplement the work of divers is still needed. The apparatus of this invention is intended for use in the growing underwater science, to increase the knowledge in that science and for application in present common underwater operations such as general underwater observations, search, repair, salvage and other tasks requiring manipulatory functions.

A variety of remote controlled craft have been proposed and a smaller number built. In general, these have been very complex in structure but limited in function. The present invention is directed to the need for a structurally simple, but reasonably versatile, device that can operate at continental shelf depths, and deeper, and perform a variety of manual tasks. To accomplish this, a vehicle suspended by a cable from a floating vessel is preferred since cable suspension eliminates a number of complex problems inherent in a freely swimming vehicle.

Conventional remote-controlled underwater craft have usually emphasized certain functions while neglecting others. Most conventional devices have been impractical in the area of ability to orient and maintain orientation of the device with respect to tasks to be performed. Other conventional devices provide great mobility with seemingly ample controls but neglect to consider cable requirements for the large number of communication lines involved. In order to operate at increased depths, the suspension and control cables must be kept to a minimum size; otherwise, the cable weight becomes a problem, and, if the command craft is towing the underwater craft or, if the underwater craft is exposed to significant currents, cable drag becomes a prohibiting factor as depth increases.

It is accordingly an object of this invention to provide a cable suspended general purpose underwater manipulating system capable of being towed and capable of maneuvering without towing.

Another object of this invention is to provide apparatus that approaches human dexterity in manipulation while underwater and in many instances surpassing human capabilities underwater.

Another object of this invention is to provide a control system that provides communication to and from the underwater craft with a balance between the number of communication channels and the complexity of the electronic circuitry.

A further object of this invention is to provide an underwater craft that can attach itself to underwater objects and also maneuver without requiring forward motion of the craft to perform operations on objects where attachment to the underwater object is impractical.

A still further object of this invention is to provide an apparatus that requires a minimum amount of sealing from the pressure and corrosive effects of sea water.

Another object of this invention is to provide a manipulating arm so proportioned as to maximize the volume in which it can approach objects from several angles.

A further object of this invention is to provide means for moving the manipulatory elements that substantially maintain the elements in selected or set positions without the use of complicated feedback or servomechanisms.

A further object of this invention is to provide a system capable of using tools; sufficient versatility in the manipulating arm, and capacity in the command system to permit the efficient use of tools are provided without excessive weight or complexity.

A still further object of this invention is to provide, in part, a modular arrangement whereby modules may be quickly replaced or modules having varied functions may be substituted.

Still another object of this invention is to provide a propulsion means with particular attention to form,
mounting, and location so as to be ideally suited for a cable suspended craft and especially useful for the varied functions the craft is intended to perform.

Still another object of this invention is to provide an apparatus having holding and support means for attaching to and stabilizing on a work piece or work area for operation either in a horizontal or vertical position.

Another object of this invention is to provide a source of power that supplies energy to various elements at different energy levels providing for both fast-slow speed and high-low power operations.






See other early Underwater Robots here.

1964 – UNUMO UNiversal Underwater MObot – Hughes Aircraft (American)


Source: The Advanced Handbook of Robotics, Safford.



Source: Popular Mechanics, Aug, 1963.


Source: Teleoperator Operations.


The MOBOT (MObile roBOT) was developed by Hughes Aircraft Company and is used by Shell Oil Company of California as an underwater wellhead manipulator. MOBOT, which is shown in Figure 16, consists of an electro-hydraulic vehicle designed to be lowered into the ocean, land on a track, and operated to insert or break out screws arranged in a horizontal axis. The MOBOT's operations are directed from the surface by means of a closed-circuit television network supported by acoustic sensors. MOBOT, because of the nature of the work it must perform, is very specialized and therefore is limited with respect to the underwater work it can perform. A more advanced version of MOBOT has been proposed but to date has not been constructed. This advanced vehicle called UNUMO is also shown In Figure 16.

Related Patents:


Underwater manipulator with suction support device

Publication number    US3165899
Publication type    Grant
Publication date    19 Jan 1965
Filing date    11 Sep 1963
Inventor    Howard L. Shatto Jr.
Original Assignee    Shell Oil Co

This invention relates to apparatus for carrying out operations at underwater installations and pertains more particularly to a method and apparatus for manipulating equipment in the vicinity of, or which are components on, an underwater installation, such for example as an underwater wellhead, an underwater oil and gas production facility, storage facilities, etc.

A recent development at offshore locations is the installation of large amounts of underwater equipment used in producing oil fields and gas fields situated many miles from shore. Many of the wells are being drilled in water up to 600 feet deep, a depth greater than divers can safely work. Thus, in drilling wells, producing wells, installing underwater equipment on the ocean floor, and carrying out work over operations underwater at any of the various ocean floor installations, use has been made of what is known as an underwater manipulator. One such manipulator is described in US. Patent 3,099,316, which manipulator makes use of a track secured to the underwater installation on which the manipulator is designed to be seated and moved thereon. However, many underwater structures may not be provided with a manipulator track at the time they are installed or positioned at an underwater installation so that in the event that it is necessary to make repairs at a later date, a manipulator of the above-mentioned type cannot be readily employed.

Consideration has been given to the use of magnets or electromagnets carried by a manipulator device by which the manipulator device could be secured to an underwater installation during the time it is carrying out a particular operation thereon. However, in order to combat sea water corrosion, there has been a tendency to make more of the underwater equipment of stainless steel on which electro-magnets cannot be used to mount a manipulator device.

It is therefore a primary object of the present invention to provide a manipulator device provided with suitable connector means for securing it to any underwater installation whether made of magnetic or nonmagnetic materials.

A further object of the present invention is to provide a manipulator apparatus for use on component parts of underwater installations, which parts are so large or smooth that it is impossible to engage it by a mechanical gripping device such as a claw arm, hook, etc.

Another object of the present invention is to provide an underwater manipulator device having means for supporting it on the smooth outer wall of a large diameter storage tank or other vessel position on the ocean floor or at enormous depths below the surface of the ocean.

A still further object of the present invention is to provide a remotely controlled manipulator device adapted to move through a body of water and be temporarily secured to a smooth surface of an underwater installation for carrying out the various operations of setting, adjusting, connecting or disconnecting component parts of the underwater installation.

Related patent by Shatto:

Ship Control Apparatus: Publication number  US3154854.


Publication number    US3105453
Publication type    Grant
Publication date    1 Oct 1963
Filing date    24 Nov 1961
Inventors    William J. Hayes
Original Assignee    Shell Oil Co

Ship control system

This invention pertains to a method of ship control and more particularly to a method for positioning a mother ship with relation to a submarine vehicle or operator.

In many marine operations it is necessary to have a submarine vehicle or robot operator operating below the surface of a body of water or moving along the floor of a body of Water to perform various operations. These submarine vehicles are free-moving vehicles that are controlled and operated from a mother ship floating on the surface. While the submarine vehicles are controlled from the surface, it is desirable that they be moved without regard to the position of the mother ship. The mother ship is then positioned with relation to the submarine vehicle in order to maintain the proper relationship between the mother ship and the submarine vehicle.

In the past it has been the practice to manually control the mother ship to follow the movements of the submarine vehicle. This method requires skilled personnel to observe the movements of the submarine vehicle and operate the controls of the mother ship so that it can follow these movements. Even with the use of skilled personnel it is very difficult to follow a freely moving submarine vehicle. This results in curtailment of the sub marine vehicles movements in order to permit the operating personnel to properly position the mother ship.

Accordingly, it is the principal object of this invention to provide a novel method of control to permit the mother ship to accurately follow the movements of a submarine vehicle.

A further object of this invention is to provide a novel method for positioning a mother ship to follow the course of a submarine vessel within certain preset limits.

A still further object of this invention is to provide a unique automatic control system for a mother ship to permit it to follow the movements of a submarine vessel wherein the angular deflection of a control line between the mother ship and the submarine vessel is determined, the angular deflection then being used to control the movements of the mother ship.

The above objects and advantages of this invention are achieved by providing a control line between the submarine vehicle and the mother ship. The angular deflection of this control line is then measured in two fixed planes that are oriented with the longitudinal and athwartships axes of the mother ship. These angular deflections are then compared with preset values in order to obtain error signals. The preset values are adjusted to provide the required freedom of movement of the submarine vehicle within a limited radius of the mother ship. The error signals are then vectorially combined and used to operate the thrust producing devices of the mother ship.

Early Hughes Underwater MOBOT concepts







Tyler Priest – University of Iowa

Shatto and other Pacific Coast engineers also developed an experimental underwater completion system that addressed the perceived need for diverless operations in a unique way. Code-named MO, for "manipulator operated," the system featured the use of a free-swimming remote-controlled robot "diver" designed by Hughes Tool, which had a mechanical arm capable of turning lock screws, operating valves, and attaching control hoses and guidelines. Driven by propellers and guided by sonar and a television camera, the so-called "Mobot" could be lowered by a wire cable and attached to the wellhead equipment. It then rode around the wellhead on a circular track to perform its tasks. Source: here.

Partial Transcript of Oral History of Howard Shatto


Title     Shatto, Howard
Creator (LCNAF)      University of Houston : Houston History Project

    Pratt, Joseph A., interviewer
    Priest, Tyler, interviewer

Date     October 2, 1999

TP: We are conducting this interview of the Offshore Hall of Fame 1999 inductees. ……………..
TP: …….. Let's go back and talk about wellheads.
HS: In January, 1960, I moved to the Marine Division and started the highly secret development of underwater completions for drilling and production. The whole effort was based on the idea that we didn't need and didn't want guidelines. We wanted a guideline-less system. We didn't want to have to use divers because we expected to go to water depths a great deal deeper than divers were able to go, at least at that time. But we needed something like divers. So Bill Bates and Glen Johnson had squirreled up some schemes and sold Ned Clark, who was the executive vice-president of E&P in New York, on the idea of running a parallel development to the one that was going on at the lab in Houston. And I was the Division Engineer for that project starting in January, 1960. What we did was based on some work that Hughes Aircraft had done. They were doing work in atomic energy plants with remotely operated arms, and they had developed some electrically operated arms. So we contacted them and they were willing to work with us under great wraps of secrecy. So we started working on two efforts for underwater vehicles. One was heavy and meant to operate with little railroad wheels around a circular track made around the wellhead, so we could land it on this track using propellers to swim it into position and a television camera to see where we were going.
TP: Is this what you would call Mobot?
HS: That was called Mobot, which was a Hughes Aircraft name for Mobile Robot. That first vehicle also had a scanning sonar that could see where a wellhead was. We could see a wellhead from 1,000 feet away. So we could lower whatever we got out to a wellhead. If we had the leave one, we could lower the Mobot, turn on the scanning sonar, pick up the wellhead, move the ship in that direction, pick it up on television, land the Mobot on the wellhead and use it to operate all kinds of things. Most of it at the start was to lock down or unlock the wellheads, or to lock the blowout preventer onto the wellhead or to unlock it, to override the rams on the blowout preventer, and to operate lock down screws to hold down the blowout protection sleeve. It had a lot of functions. And we even developed ways that it could be used to attach a flowline to the wellhead.
TP: You were working on this in New Orleans or in California?
HS: This was in California. This was an effort that was really in competition with the one going on.
TP: So the marine division in California, you say?
HS: Right, the marine division in California. I was Division Engineer for that. My boss was the division manager, Bill Bates. I had four guys working for me. Ron Dozier was looking at building the ship that became the first dynamically positioned ship. Bruce Watkins was working for me. He was developing the blowout preventer and some of the wellhead equipment. I think he is an honoree tonight. Bill Peterson came to work for us. He was interviewed here just a bit ago. Who else? Ben Gethfort was one. A couple of others.
TP: You were in competition with what shell …
HS: We were in competition with the group that was working in Houston at the Shell lab at Bellaire Research, which was developing underwater completions and had started maybe a year before we did, maybe less. We actually had a wellhead on the ocean floor before they did. It was supposed to be a diverless system. There was a lot of money made by divers working on diverless underwater completions. Ours was meant to work with the robot instead of divers. The system in Houston had guidelines and we were trying to get rid of guidelines.
TP: Was Shell pushing these two developments just to hedge itself, because they saw the technology could possibly be going in two different directions? You had to deal with the fact that the E&P organization on the west coast and east of the Rockies were really distinct entities in some
HS: Very. The people in the Gulf Coast, the ones in Houston said we have to use guidelines. We can't use a robot or anything that depends on television to see or even divers because the water is so muddy from the Mississippi that people can't see out there. We were drilling in the Gulf of Mexico in very deep water and the television worked just fine with ROVs. We were right there working on that development. The old diverless systems are no more. They all worked with ROVs.
TP: To follow up a little bit on Mobot, how was it deployed?
HS: We actually had two of them we developed. One was the wellhead Mobot, and it was the heavy one that landed on a track and went around. It had no arms but it had a hydraulically-operated screw drive with an-inch-and-an­eighth hex head wrench socket, which we could put over the nuts on the wellhead and turn them right or left to operate valves or whatever it was we wanted to do. It had a telescopic extension. It could raise or lower the head which included the television cameras. That was the wellhead Mobot. At the same time, we began development of what they called the Unimo, or universal mobot, and its purpose was, more than the wellhead mobot, to take the place of divers to do the kinds of unexpected things that divers could do that the wellhead mobot was really not going to be able to do with just a simple socket wrench. It could do the heavy stuff that you could plan for well ahead of time, but the UNUMO was equipped with arms and was nearly neutrally buoyant. So the idea with it was very much like present day ROVs to be able to swim to where it needed to be to work on something, and then with its arms, to get a hold of it and do what it needed to do -­untangle something, tie something, or cut cables or lines, pick up something and then drop or loss, whatever. Things a diver might be able to do.
TP: It seems ahead of its time.
HS: It was. It was in a couple of ways. One was that the reliability of both the systems was very poor. They used vacuum tubes. You are probably too young to remember how often you had to replace those in radios! But they were not very reliable. Our development got superseded when the man in charge of the effort in Houston was promoted to take Ed Clark's place in New York as Executive Vice­President of Production.
TP: McAdams?
HS: No, it was Bert Easton.
TP: McAdams was exploration, right?
HS: Right. They decided that they wanted to combine these two very different systems into one, and in the process, they did away with the robots and mobots and just went to a guideline operated system. It was rather like the one being developed in Houston. That is when I went to licensing and head office and Ron Geer came to be the manager of the group that developed a combined system. He had come out of the Houston effort, so the system ended up looking like the Houston effort. And the ROVs got superseded.
TP: It was ahead of its time, but it still was a precedent. Can you maybe talk about how the industry went from Shell's development of the mobot back in the early 1960s to what they are using today in deep water and the ROVs?
HS: ROVs had just begun to be used for drilling support. A couple of people have used them in shallow water. In 1981, when Shell wanted to drill in deep water on the east coast, we took a contract then with the offshore company who had The Discover Seven Seas. We modified it to go to deeper water — high currents, rough seas, off the Atlantic coast. Up until that time, they had been using a little two-man submarine to find their wellheads if they lost them, and they were their only contact with the ocean floor and on the way down. I thought that could be done much better with ROVs. In the meantime, people had begun development of ROVs for the Navy. Not Honeywell but an outfit in La Jolla.
TP: Lockheed?
HS: No. A little company in Sorrento Valley there developed a little flying eyeball ROV for the Navy. Hydroproducts. I found out about that and decided that Shell ought to be able to use something like that. So we contacted what is now Oceaneering. I saw you talking to Mike Hughes. Mike bought Solis. Solis was the company with Dick Brisby, whom you also ought to interview. Dick Brisby was working on ROVs. They had used them for drilling support for shallower water. They were ready to build one for 7,500 foot water depths, which more than doubled what their capability at that time. They said they could, and I worked with them on developing that system. We put fiberoptics on it, which turned out to be a real boon in the ROV business and was very successful. In fact, we built two of them just for reliability's sake and had both of them aboard. We used one to cannibalize to keep the other one outfitted properly. We put that to work and got rid of the submarine after a lot of haggling. Some people didn't want to see the submarine leave and an ROV come into operation. There were some people who said ROVs had no place in the drilling business, and that there were some companies that said that for many years. But now, they all are happy to use ROVs in their operations.
TP: What was the bias against them? They didn't think they could work?
HS: They thought guidelines would work O.K., and they could use divers if they had to. Of course, we are drilling up where divers can't possibly go now. Citgo held out for many years. I remember I got a call one day from Earl Shanks who was with Citgo at that time. They were drilling in the Gulf of Mexico and had dynamic positioning of one of their rigs. It moved off location and had stretched the riser. They couldn't get loose from the wellhead. He asked me if there was any place I knew of that they could get hold of an ROV in a hurry. They weren't using them at the time. They do now on all their rigs.
TP: You developed something 40 years ago but only really saw it come into use on a widespread basis within the last 10 or 15 years?
HS: Yes. We started that work with dynamic positioning and ROVs in 1960. Dynamic positioning wasn't used on a drilling rig until we did it with the Citgo 445 10 years later. It was another 10 years later or more, in 1981, when we took the Seven Seas to go to very deep water using ROVs. I have been working for the past 12 years. Since I have retired from Shell, I have been working on almost all of the new rigs, doing a lot for the oil companies, some for Shell, BP, Amoco, Chevron, Global Explorer and several others such as Exxon. Vastar has a new rig coming up. And for several of the drilling contractors .
TP: You are working mostly with drill ship dynamic positionings on deep water drill ships?
HS: Dynamic positioning on deep water drill ships, and the use of ROVs and ROV interfacing. I mentioned to you that some of the work I had done with that mechanical resonant energy research outfit in La Jolla turned out to be useful. One of the problems with running ROVs in deep water is that the cages run as a heavy thing on a long cable. Then the ROV comes out of the cage on a tether to do a tour. A heavy cage is used to keep it under the ship so it doesn't drift away in the current. It doesn't give the ROV such a heavy, long thing to work with, I guess. But if you are working with a small vessel and the vessel is going up and down with the wave action and heave, you can get into a resonant condition between the ship and gets too active, then the cable can go slack. And then when the ROV comes down, it will jerk against the plot cable when it becomes taut. The question is how much are the forces induced in the cable and can the cable stand that kind of a beating? The work I had done with the resonance systems seemed to fit in perfectly. I could analyze that kind of stuff. Piece of cake!
TP: Looking back at all the innovative things that you have been involved in, what was the source of your inspiration for coming up with a new concept, or applying things to certain areas that no one had thought of before?
HS: The need was almost always there, and it seemed when we started in 1960, everything we wanted to do was new. Nobody had done it before. So we got a lot of patents. I ended up with 35 patents in the U.S. and Canada, and a lot of them are also filed overseas in various countries. So the need is there. Once the need is there, if you can just keep thinking, a solution somehow or other will come to you. Sometimes, a lot of ways arise that it could be done. The concept for dynamic positioning control, to solve the vectors that needed to be solved so you could direct each of two positioning thrusters, came while I was on the freeway. I had been thinking about it. I had thought up all kinds of wrong ways to do it — ways that would not be right. All of a sudden, driving down the freeway one sunny afternoon, the answer just suddenly was there. And it makes goose bumps stand up when it happens.
TP: It seemed like Shell was very good at both the theoretical side in basic research and communication between the people who were doing pure research and the operating side — being able to get this feedback from what is happening in the field and developing things they need for the field.
HS: It was an exceptional time when everything we thought of was brand new. Communication, in a way, was shut down because . . .
TP: Because of the secrecy?
HS: They had taken us out of the telephone book. People thought we had died or gone away. But we did communicate with our competitors in the research group in Houston. We were reasonably free to do that, although the systems that we were developing were very much in competition. We did communicate among each other pretty well. ……….

See other Hughes Mobot-related posts here.

See other early Underwater Robots here.

1962 – Underwater MOBOT – Hughes Aircraft (American)


Source: Meccano Magazine, Feb, 1963.
….. I am introducing you to a machine known as Mobot, pictured above. Developed by the Shell Oil Company in the U.S.A., Mobot can work on oil wells 1,000 feet down on the ocean bed. It can swim, see, hear, and has a "nose" that can turn screws, work valves, and grip pipes and hoses. It can also wield a wire brush and other tools.
Mobot's first job was to complete a well off the coast of Santa Barbara, California. As you probably know, because most of the promising areas on land have already been explored, drilling in the open sea has become the oil companies' biggest hope of finding new oil and gas fields. Since, however, exploration at great depths rules out the use of conventional well-head equipment, placed on a platform projecting above the water, the necessary components have to be assembled on the floor of the ocean itself, and the well put into production by remote methods. Mobot can carry out these tasks at greater depths, and for longer periods, than any human deep-sea diver could cope with. Electro-hydraulically operated from a master control centre aboard the drilling vessel, Mobot swims down to its work, using two adjustable propellers. A gyroscope gives it a sense of equilibrium. The device can see up to 30 feet by means of self-contained lighting and a TV camera, which transmits its field of view to a screen in the control centre. Sonar acoustic equipment, possessing a bat-like squeak, is used to locate well-head or other metal objects at greater distances. A sensitive microphone enables the robot to listen to the various operations it performs. THE EDITOR



In this application, referred to as 'Welmo'. Image source: The Complete Handbook of Robotics, Safford.


Caption: SHIPBOARD control panel, television screen, and other devices used to monitor and guide the robot's underwater activities are shown above. Shell Oil Company uses the robot to perform work on submerged wellheads, but it could be used for other deep-sea jobs.

Undersea-robots-SMaug63_0005 - Copy - Copy-x640

Caption: MOBOT'S powerful claw is adjusted by workmen prior to lowering the robot into the sea for routine task.

Undersea-robots-SMaug63_0003 - Copy-x640

Undersea-robots-SMaug63_0003 - Copy (2)-x640
Caption: MOBOT'S electronic "brain" components are sealed in a pod (below) at the bottom of robot. Principal parts (left) of the 7000-lb. monster are: (1) cord protector (2) mercury vapor lights (3) TV camera (4) sound microphone (5) hydraulic arm with socket wrench attachment (6) hydraulic lift to raise arm, TV, lights up to 8 ft. height (7) motor-driven wheels (8) propellers (9) pressurized tank for hydraulic lift (10) bumper wheels to ride on wellhead (11) compressed gas tanks to pressurize electronic pod (12) electronic pod.

Source: Science and Mechanics, August 1963.

MAN now knows more about the vast reaches of space than he does about the comparatively minute and mysterious submerged ocean world. He has a greater knowledge of Venus, which revolves about our sun at a mean distance of 67,200,000 miles, than of the mysteries hidden by the greatest known ocean depths of the 35,400- ft. Mindanao Deeps. Now Shell Oil Company has developed a mechanical robot who is at home in the sea. Named "MOBOT," it is knocking on the door beyond which lies the world of the secretive sea.

Mobot is a true mechanical giant. He stands a towering 14 feet high, is five feet in diameter, and weighs a solid 7,000 pounds on land. In the sea for which he was created his weight is reduced to 3,800 pounds. At present he is at home at depths down to 1,000 feet, where he is a hardworking counterpart of a human diver.

Mobot can see by means of a television camera with an underwater range of 30 feet. Beyond this range he depends on sonar search equipment to locate metallic objects at ranges up to 1,400 feet. He can automatically scan a full 180° which gives him great range. An "umbilical cord," consisting of a 52-conductor electrical element, secures him to a master control board situated on a ship stationed overhead. There an operator guides him, electronically, to perform various underwater duties with human-like dexterity.
A gyrocompass gives Mobot a sense of direction. He "swims" in the water by means of two adjustable propellers, one on each side. His electronic heart and brain are neatly contained in a pressurized pod at the bottom of his giant frame. Darkness is of no consequence, for he has his own lights in the form of two 800-watt mercury vapor lamps mounted on the TV camera housing.
For work, he has a hydraulic arm to which a socket wrench is generally attached. Other hydraulically operated tools, such as grippers, may also be used in place of the socket wrench. The socket rotates at a speed of 20 rpm at a torque of 1,000 foot-pounds. Mobot is a formidable mechanical man indeed.
For what exact purpose did Shell Oil Company develop this explorer of the depths? That is simply answered: to replace the limited human deep-sea diver and to perform all necessary underwater operations. Mobot can go deeper and stay longer than a human diver. He is an extremely effective means for locating and facilitating reentry into an existing oil well on the floor of the ocean. He can tighten or loosen bolts or nuts on the undersea oil wellhead, operate valves, use a wire brush, and grip pipe and hoses with the proper amount of pressure. Unlike humans, he takes no coffee or lunch breaks.
Just how does Mobot manage to stay in close contact with the wellhead on which he is working despite deep-sea currents which might tend to make him drift away? A circular track on the underwater well-head entables him to run his motor-driven wheels on the rail. He rides the rail while he performs the jobs of changing vertical flange bolts, horizontal lock screws, or turning valves.
Dr. J. W. Clark, of Hughes Aircraft Company which cooperated in the building of Shell's Mobot, foresees a rewarding future in the use of deep-sea robots. In addition to underwater petroleum drilling, we can flatly predict that exciting underwater exploration, mining, farming, and salvage operations are now possible.
A great adventure befell Mobot one day. Scientists still have not come up with a satisfactory answer for it. Aboard ship, seated before the television screen which monitored the robot's undersea actions, was Forrest Adrian. Mobot was busily checking a complex of oil equipment with his mighty, sensitive arm.
Suddenly Adrian caught his breath in unbelief at what appeared on the screen. From his throat rose an amazed cry. First to respond was a drilling foreman, Paul Martin. "Look!", Adrian yelled, pointing at the screen with a shaking finger. Martin sucked in his breath at what the screen revealed. Cavorting like a corkscrew gone haywire before the eyes of the startled men was a snake-like creature about 15 feet long. A rough and bumpy ridge encircled its wriggling form like a crude spiral, and it swam with the brisk boring action of a corkscrew.
The deep-sea divers among the amazed crewmen stared at the sea denizen with utter unbelief. They had all seen many strange forms of sea life, but nothing like this creature had ever been seen by any of them. Undisturbed by the nearness of his strange visitor, Mobot continued with his duties 180 feet beneath the surface of the sea.
The living corkscrew appeared and disappeared at intervals. It seemed to become either larger or smaller whenever it reappeared. This led the spectators to believe there were several of the nightmarish beasts in range of the underwater television camera with which Mobot was equipped. Yet only a single creature appeared on the screen in each instance.
At the time of this writing the strange creature still remains unidentified. Shell officials are anxious to learn what the creature is. They want to know if it is capable of endangering human divers or damaging undersea equipment. Scientists on marine life have been consulted, but as yet no positive identification has been made. But all this means nothing to Mobot, and, on the next appearance of this strange creature, he may be directed to capture it in his mighty claw.
Whether it will prove to be friend or foe is still to be determined. But the hopeful Shell people have christened it "Marvin," because the name means "sea friend." States John Prescott, curator of fish at Marineland: "About the only way we'll be able to make a sure identification is to actually have a specimen to examine." Lets hope that Marvin proves to be a friend!"


The MOBOT (MObile roBOT) was developed by Hughes Aircraft Company and is used by Shell Oil Company of California as an underwater wellhead manipulator. MOBOT, which is shown in Figure 16, consists of an electro-hydraulic vehicle designed to be lowered into the ocean, land on a track, and operated to insert or break out screws arranged in a horizontal axis. The MOBOT's operations are directed from the surface by means of a closed-circuit television network supported by acoustic sensors. MOBOT, because of the nature of the work it must perform, is very specialized and therefore is limited with respect to the underwater work it can perform. A more advanced version of MOBOT has been proposed but to date has not been constructed. This advanced vehicle called UNUMO is also shown In Figure 16.


Press Release: PORT HUENEME, Calif., Oct. 31–ROBOT GOES TO SEA–Workmen stand by as Shell Oil Company's underwater robot is lowered into the ocean at Port Hueneme, Calif. yesterday. It was the first public showing for the mechanical roustabout, a remote-controlled quarter-million-dollar gadget that swims, sees hears and has an arm to turn valves and wield tools. The robot in designed to help in drilling and maintenance of oil fields hundreds of feet below the surface of the ocean. The robot is equipped …



Underwater wellhead apparatus and method
Publication number    US3099316
Publication date    30 Jul 1963
Filing date    25 Apr 1960
Inventor:    Johnson Glenn D
Original Assignee    Shell Oil Co

 This invention relates to offshore wells drilled in earth formations lying below a body of water, wherein the wellhead equipment of the well is positioned below the surface of the water. The invention pertains more particularly to a method and apparatus for manipulating equipment in the vicinity of, or which are components on, an underwater wellhead.

At present, offshore wells are drilled either from stationary platforms anchored to the ocean floor, movable barges temporarily positioned on the ocean floor or from movable barges floating on the body of water in which drilling operations are being carried out. Regardless of the manner in which the wells are drilled, most wells are completed in a manner such that the outermost tubular member of the well extend upwardly from the ocean floor to a point above the surface of the water where a wellhead assembly or Christmas tree is mounted thereon for controlling the production of the well.

Wellheads extending above the surface of the water constitute a hazard to the navigation of vessels in the area as well as constituting a structure which is readily attacked by wave action, it being well known that the corrosive action of seawater and the air readily attack the normal steel platforms unless they are protected in a suitable manner by corrosive-resistant material. However, with the wellhead and/or casing head extending above the surface of the water, the flow controlling components of the wellhead may be readily adjusted by an operator working from a platform adjacent the wellhead structure above the surface of the water. Additionally, any workover or reconditioning operations carried out on the well may be readily accomplished as all of the portions of the wellhead structure which must be disassembled order to carry out these operations, are above the surface of the water where they may be reached by maintenance crews.

Recently, however, methods and apparatus have been developed for drilling and completing oil and gas wells in the ocean floor in a manner such that after completion of the well, the wellhead assembly, including various components, such as flow control valves, is positioned beneath the surface of the water, preferably on the ocean floor. These facilities are often positioned in water depths greater than the depth at which a diver can safely and readily work. it may therefore be seen that the adjustment of any of the wellhead components from time to time, or the re-entry of a well to carry out maintenance or reconditioning work, presents a considerable problem when the wellhead assembly is positioned below the sur face of the water.

It is therefore a puimary object of the present invention to provide a method and apparatus for manipulating equipment in the vicinity of, or components on, a wellhead assembly positioned below the surface of the water.

A further object of the present invention is to provide a remotely-controlled manipulator device adapted to move through the body of water and be temporarily secured to an underwater wellhead while being movable therearound for carrying out any of the various operations of setting, adjusting, connecting or the disconnecting of a wellhead assembly, components or associated equipment thereof.

A further object of the present invention is to provide a device adapted to be movably-positioned temporarily on a track adjacent an underwater wellhead, said device being provided with a rotatable object-engaging arm which is movable in any direction in a vertical or horizontal plane within the vicinity of the wellhead assembly.

Another object of the present invention is to provide a wellhead apparatus adapted to be positioned underwater for receiving on said apparatus and movable thereon a manipulator device adapted to engage the various components of the wellhead assembly.

Still another object of the present invention is to provide a method and apparatus for remotely adjusting the flow of fluid from an underwater wellhead assembly from a remote location.



mobot-shell-undersea-hughes-ad - Copy-x640

Underwater MOBOT

See pdf

Dr. John W. Clark, Manager of the Nuclear Electronics Laboratory at Hughes Aircraft Corporation, headed the Mobot group.

See other Hughes' Mobot-related posts here.

See other early Underwater Robots here.