Eddie Paul: How to build a mechanical shark
By now, the scope and breadth of Eddie Paul's achievements as an inventor, automaker, stuntman and hollywood prop builder are just about legendary. He's packed more into one lifetime than most people could into 10. Among hundreds of other credits, he's one of the key guys that Discovery Channel goes to when it needs a mechanical stunt shark built for one of its numerous shark shows. But Paul's first mechanical shark was built more than 20 years ago, as part of a documentary by famed oceanographer Jean-Michel Cousteau.
On an impossible timeline, with the vaguest of instructions, Paul built Alison, a 10-foot mechanical shark powered by compressed air. He then watched as she interacted successfully with a school of live great whites, who eventually attacked her and tore her to pieces. Here, in Paul's own words, is an insight into the process of conceiving, creating, testing and destroying one of his unique creations.
Building a great white shark is not much different than say, building a nuclear powered sub or a supercomputer. It just requires different materials and techniques for its construction. Just like any job, you start with a plan or blueprint, and lacking one, the difficulty factor goes up exponentially. So, for the sake of argument, let's pretend that all you have is a French voice on the phone telling you to "start the shark!"
Let's go back a little. In 1989 I was on the Discovery, a small boat of some 50 feet, with a group of Silver Suits (the Cousteaus') in Alaska. I was in the midst of a light and sobering conversation with a fellow diver on the virtues of quantum electro dynamics as it pertained to the current problem at hand, namely the shortage of bananas on board. Suddenly, Jean-Michel Cousteau interrupted us. He could do this, as he was both French and our boss.
We terminated our in-depth dialogue to see what jewels of wisdom he was about to bestow upon us humble divers. "So, Ed, you have done many things in your life. What would you do or build if you had it to do all over again?" Did he know something I didn't? Were we about to sink or something? Not knowing what he meant, and not wanting to act stupid by asking him to clarify, I quickly reflected back to a previous expedition in which we (the crew) and the Cousteaus waited for days to get a single shot of a small blue shark swimming toward a camera.
I burst out with the answer: "A shark! I never got to build a shark…sir!" This seemed to be the right answer, as he went on to another subject. The rest of the expedition went on without him bringing up the subject again. We finished what we were doing, filming damage caused by the Exxon Valdez, and we all headed home.
I took on other film work and all but forgot the conversation. Then one day, my assistant found me in the machine shop and told me a Cousteau was on the line with some work. It turned out to be none other than Jean-Michel. By the time I got to the phone, though, he had taken another call and was on his way out of town! So his assistant relayed a message to me that he wanted "the shark," and that was all she knew.
How to build a shark
When does he want it? How big? What kind? What shark? Then it came back to me, the conversation we'd had in Glacier Bay over dinner. He was just now granting my humble wish—I was going to get to build the small blue shark! Did this mean we would be plopping ourselves back into the Pacific and redoing the shot we'd needed so many months ago? I had thought editing had been completed, but maybe not. This was great! I was going to build a swimming baby blue.
I must have been leading a boring life, because this project really got me excited…the thought of duplicating one of God's cutest creatures out of…. Oh yeah, I needed to get a list of materials together, and a plan…. Where was I supposed to get a plan? Al Gore had yet to invent the Internet. So, we are back to the start of this story.
I needed a plan and a list of materials. These would actually be simple to make, and I learned a lesson that Isaac Newton once learned from Descartes: when a problem seems too large and complicated, break it down into small problems and solve each of them individually. This became my basic approach to projects. I broke the shark down into basic problems, such as, "First, what will I make it out of?" Well, it would be used in the ocean, so the materials would need to be made of non-corrosives such as stainless steel, plastic, and brass, and anodized aluminum.
Next, I considered weight. Since I didn't want to create an expensive anchor, I was leaning toward plastic materials. I could cast the skin from Skin Flex, a relatively new product, and add microballoons to aid in the differential in buoyancy, to help it float. This would be my control over weight in the water. You see, it wouldn't matter how much the thing weighed out of water but how much it weighed when submerged - which should be nothing! This would be no easy task. So, at the top of my list was a reminder to keep a running tab on each material and its weight and displacement in seawater. This would give me a general ballpark for the total cost of the shark, and the remainder could be trimmed out with foam or a little lead shot.
Then, power. How could I power this little bag of cartilage? The choices were endless: electric power, hydraulic power, spring power, remote power through linkage or cables…. I wanted it to be self-contained, so I ultimately chose air. It's water-friendly, and the environment likes it, too. Divers always have it handy, which means a supply of compressed air is never farther away than the nearest compressor, and it can be stored in small bottles under high pressure. Besides, it's not a good idea to mix water with electricity, anyway - as many can attest, God rest their souls.
For the mechanics, I looked to nature. I had materials and a power source, so I needed to turn it from potential to kinetic energy and still keep it simple, compact, and, above all else, on budget. Which brings up a point—what was the budget? We had never discussed it! So, armed with ignorance and an abundant bundle of energy, I marched over to the drawing board and proceeded to put pen to paper and dream of how I would have created the shark if I were God. I looked at all my books on ichthyology and shark anatomy, and what I came up with was plagiarized from the system already in existence: the shark itself.
One small, short, cylindrical shark vertebra, made up not of bone but cartilage (like the rest of its skeleton), can move only a few degrees by itself. When all of them work together, though, it allows the shark to bend in half, almost able to eat its own tail. So, I constructed my little guy this way, with a series of flat discs representing a narrow slice of the real-life shark I used as a model. I spaced these slices about a 1/2-inch apart and glued them to the perpendicular pieces of 1/8-inch-thick Lexan plastic that made up the shark's silhouette. The flat discs were notched and glued at their respective locations, filling in the shape of the body. Once covered with a rubberized skin, my carnivore would look even more like its living counterpart. This arrangement of spaced discs would allow a limited amount of movement resembling the motion of a real shark.
I gave my creature a long cable running down its side toward its tail and ending at the caudal keel, simulating one of the shark's main tendons. The artificial tail could move from side to side but not up and down. Whereas the shark uses a simple system of muscle contraction to pull its tendon, I used an air cylinder to mimic the muscles' pull. The air cylinder was connected to one end of a horizontally mounted bell crank that was allowed to pivot at its midpoint. Each end of the bell crank would reach the span of the shark so that cables would run down both sides and connect to each side of the tail.
I found that simply tilting the bell crank would pull one cable and slacken the other. The tail would then flex to that side and the other cable would relax, allowing the tail to bend away from that cable. This mimicked the motion of the shark so well that it scared my cat out of the shop.
Finishing and testing
Finally, size. This was a tough call, as the sharks we had tried to film were about 5 to 6 feet long. My assumption was that since the background of the expected shot was to be blue water, I could cheat the shot and use a smaller shark. This would save time and money, as there would be no reference for size. I decided to make the shark 18 inches, small enough to handle but large enough to showcase some detail.
The shark was complete within a few weeks and ready to skin, and then out of the clear blue ocean, Jean-Michel showed up, film crew in tow. I proudly showed him my little work of art and then was a bit set back by his response: "This looks wonderful. When will ours be done?" At this point, I was in total confusion. "Yours?" I asked. He responded with, "Yes, the shark we need for Australia, the great white!" "Oh…" I returned, not letting on that I was still not up to speed. Then I asked, "And what size did you want that again?" He said, "How about 10 feet? We don't want it too large!"
I calmly told him it was not a problem, but the data processor in my head buzzed away, calculating the mass and mess that this would now create for me. He was just leaving as I was just coming to the end of my tally - which concluded that the work just thrust on me would be cubed as the length doubled and a multiple of the function of the delta length. In layman's terms, a truckload of plastic and Skin Flex would be required. This would not be something I could even start to complete alone, so the calls went out for help.
Back to the drawing board
Craftsmen and noncraftsmen alike were called for the challenge and many responded. But I picked Cindy, a friend's girlfriend - not for her experience but for her drive. So, armed with an unskilled craftsgirl, a bunch of plastic, and a pad of paper, we set off to build a shark. I was drawing as fast as I could as Cindy made coffee and got the shop ready for the deadly intruder that would make me the talk of the town. As the sketches neared completion, the coffee was ready and the shop was clean. Cindy turned to me and said, "Where do we start?" I pointed to one end of the shop and said, "There, at the head." Pretending to understand, she placed a large block of rigid foam on the floor. I sat down next to it and started to sculpt, using the many photos and books I had collected for reference. Cindy busied herself by reading up on the different materials and answering the frequent phone calls.
I then drew a full set of drawings for templates and transferred them to plastic, with the help of anyone who ventured in to visit. They enjoyed it, and it did help a great deal. The Lexan silhouette was now cut out and had the profile of a great white without its head, as I was still adding detail to it. A few days passed, and it began to look good.
I decided that the cost, as well as the weight, of the many discs I needed for the vertebrae could be replaced at a reduced effort if I redesigned them into flat, 1-inch-wide strips of Lexan. These were fastened to the top and bottom of the silhouette's center spar with brackets allowing them to bow outward. (If a shark had ribs, these would resemble the ribs of the shark.) This cut the weight and allowed more space inside the big guy for whatever I needed to use the space for. This part went without a hitch.
The "ribs" were attached within a few days, and the body looked like a real shark body, although minus the head. As soon as the head was complete, it was attached with angle brackets. The hollowed-out fiberglass head allowed room for the cylinder and bell crank. The head was rough-sculpted from foam and then coated with fiberglass and a layer of body putty. The detail was carved and sanded into the body filler, this was greased, and then a mold was cast from this "plug." The mold was sprayed with mold release, and a fiberglass head was cast inside this detailed mold.
When the new head was pulled out for the first time, it was a serial moment. It was then set aside for painting and detail: eyes, teeth, gums, and airbrushing. Neither my dad nor my then-girlfriend (now-wife) Renée escaped the great white's vengeance. They were both drafted on sight into the hard labor of shaping and sanding the body and cutting the thousands of feet of Lexan sheet that went into making the monster. Everything went very well on the mechanical end of things. It wasn't until we started the skin that life took an evil turn.
Shark skin: no easy matter
While we were building the shark, a second "beauty shark" was constructed to serve as a plug for the mold of the body. This mold was to be the female mold for the skin, which had to be cast from Skin Flex. As I mentioned before, this was a new product. This meant little was known about it and that I was pretty much on my own. There was a castable brand and a brushable brand, so I took about 40 gallons of each. Mixing was no easy chore: the stuff had to be mixed in 5- to 6-gallon lots for there to be enough to paint large-enough sections to make it all worthwhile.
This was the turning point of the project. The stuff just didn't want to do as it was told. When I needed it to be stiff, it was flexible; when I wanted it flexible, it was rigid. The first skin was so flexible that we pulled it out to a 30-foot length and it would still stretch more. This skin was a $2,000 experiment gone bad. The second and third skins were better but not right, and the trash collector hated me on trash day for the added weight in the cans. Alas, rubber shark skins could not be recycled. The fourth skin was the one I used, as time and money were running out. The rest of the crew was already in Australia, and the chumming (luring live sharks with fish parts, bone and blood) had begun.
I grabbed a chance to test the skeletal shark at Dive and Surf, a dive shop near my house, to see if it would even swim. With the help of Joko, an old friend, I put the shark into the water, hooked the umbilical to a spare scuba tank, and moved the little pneumatic control lever to the right side. The tail slowly moved to the right. I then moved the control to the left, and the tail mimicked the motion. The mass moved forward a little, and as I continued the motion, the shark did the same, moving even faster. Well, I'll be, the darn thing worked.
Once the fabric-reinforced skin was complete and painted, it was finally installed on the skeleton. We christened the shark "Alison," placed her in a giant wooden crate, and locked her in. The crate was picked up just as I was running into the house to pack for the trip. My flight was the following day, and I hadn't had a good night's sleep in over a month.
Straight to Australia for filming
Upon my arrival in Adelaide, I was met by the Cousteaus' chief diver, Steve Arrington. I asked to be briefed immediately on which side of the street the cars come from, so I wouldn't be killed before the shark was even set up.
Steve drove me to Port Lincoln and the awaiting Alcyon, where I met the crew and was assigned a bunk below deck. We all went to town and got each other up to speed on both the shark and the expedition. I found out that Alison had not yet arrived, so we all decided to have a few beers while we finished the conversation. We got back at about 2:00 a.m. to a lit-up ship readying for sea. It appears that while we had been in town getting a bit blurry, the boat that had been chumming at Dangerous Reef had seen its first shark, a great white of some 16 feet in length.
The captain told us that we should get aboard, as we were off to Dangerous Reef and would be arriving in about 3 hours. This would give me some time to check out the shark, which had been loaded earlier in the day on the mid-deck. At dawn, the captain told us that if we needed to practice with her, this would be a good place. We dropped anchor, carried Alison to the rear swim step, and slid her into the cold, murky water. I suited up, slipped in behind the shark, and moved her a little way from the wooden swim platform that spanned the stern of the ship.
Another diver slipped in right behind me without a word. His name was Mark Blessington, and he was one of the Cousteaus' best divers. He made fish look unwieldy in the water. It was very comforting to have him help me on the fine-tuning I had to accomplish. It would've been difficult alone because I needed to take the shark down to about 30 feet and balance her out by adding weight through the mouth. The weights were hung onto a cable that would allow me to pull her weight forward or rearward with a simple pulley system. Mark helped by holding Alison still as I moved the weights around. The whole process took about 45 minutes, and the shark was balanced perfectly.
We swam up to the rear of the ship and met the rest of the crew with questions about the job. Mark and I assured them that the shark was ready to be taken to Dangerous Reef and the waiting great whites. I looked around expecting some type of response and met a bunch of silent grins as the captain spoke out. "We are at Dangerous Reef," he said. "What?" I yelled. "Where are the sharks?" Next to me in the water, Mark spoke up: "All around us."
I jumped out of the water and got out of my suit, trying to look as if I hadn't heard them and hoping to hide my trembling hands. They could have eaten us at any time, and I hadn't even looked around for them. Well, why should I have, I had had no idea they were there!
Alice meets her doom: live great white sharks
The next morning, we put Alison back into the water and started filming the whites interacting with her. I had her set up so that I could operate her from a shark cage in the water. This way, I had a clear view of the area and could steer her around. Her range was limited only by the 50-foot umbilical that carried her air and allowed her motion. She looked right at home as about five or six sharks joined in to swim along with her.
Alison was the shorty of the group, and I remembered back to how large she seemed when I was asked to build her. Now, smack dab in the midst of the great whites, she was noticeably short at 10 feet long. Most of the surrounding sharks were about 12 to 17 feet long, so I had the feeling she would be eaten as a snack just for fun and was amazed to find her accepted by the girls' club. From there on out, Alison performed her job as instructed and became a film star - turning, diving, and circling as the controls were operated, translating this motion into the tail motion propelling the shark, just as in nature.
Jean-Michel decided we needed more action for the film, as the sharks were just cruising by Alison without being threatening. I put a small weight onto one of the pectorals and moved the control stick in an erratic motion to simulate a dying shark. It was as if someone had turned on a switch and ran high voltage through the ocean. The sharks took on a different air, one of danger. We had been, up to this point, somewhat relaxed with the residents of Dangerous Reef, but it was now suddenly different. Each diver felt it, all of us moving a step away from the cage doors and starting to look around more.
It was evident that there was danger in the water. The sharks that we had become comfortable with were now strange to us, moving erratically and unpredictably. The sharks would sometimes hit the cage we were in, knocking us around. People have asked me what it was like to be bumped by a shark while in a cage, and the answer I always give is this: Set a shark cage in the street and get in with dive gear on. Now have a white Volkswagen drive at and hit the cage at 25 miles per hour. A small car has about the same mass as a great white.
The only way I could control the fear that was building was to concentrate immediately on my job and swim the shark as instructed, ignoring my surroundings. It didn't take long for the first attack on Alison to take place by the biggest of the sharks, who we had named Peaches for the peach tag in her dorsal. She went head-on toward Alison, nose-to-nose, rubbing full length as she passed, and then turned and swam out into the dirty water, out of sight.
I next saw her swim directly at Allison's right-side gill area and slowly but steadily take a large bite out of the plastic and rubber shark. She did this four more times, and then the robot was reduced to a gutted toy. But the most important thing of all was that we had got the shot with my reputation intact.
The mood on board was celebratory, and stories were passed around of the views from respective angles. We all agreed that the mission had been a total success. This was a great ending to the saga, and so I knew the time had come to get back to my life in California. After all, I had a swimming barracuda to build for Rescue 911 and another great white for an IMAX film, etc etc.
(Check out Alice's demise in this YouTube video at around 27:20)
Next step: the Shark Sub
Since this time I have built many sharks, fish, turtles, and a variety of other aquatic sea creatures. The latest is a fish-tailed submarine that allows people to study sharks in relative safety while also not harming the sharks. We're naming it the Shark Sub-1 and it should be completed for a production company soon. It will be air-powered and use the air from a standard scuba tank before the diver breathes it then go the diver's air supply, effectively providing "free power" to the sub. It can be recharged as soon as the air tanks are exchanged with new ones.