Episode: JAWS Special (Shark Week)

Orignal Air Date: July 17, 2005

Myths:

Run Time: 2 hrs. 

Concept of Special: Deals with the movie original Jaws that came out in 1975. They need to bust or confirm a lot of the details that were seen in the movie.



Myth #1: Shark Strength

Myth: The Great White in Jaws displays super feats of strength: he keeps three flotation barrels submerged for hours and yanks the Orca (the boat in the movie) backwards while the engine is running (examples of Continuous Force). It also demolishes a shark cage and rams a hole in the Orcaís Hull (Examples of Shock Force).

Experts:

- Sean Van Sommeran (Executive Director Pelagic Shark Foundation http://www.pelagic.org/)

- Bimini Biological Research Station (http://www.miami.edu/sharklab/news_mythbusters.html)

- John Callahan (Piano technician)

- Stuart Cove (Stuart Cove's Dive Bahamas http://www.stuartcove.com/)



Memorable Moments/Quotes:

- Kari (with fishhead): "Next on Mythbusters, I get eaten"

- Kari: "I christen thee the Orca V" Swing & Miss with Champaign bottle, whack, whack, whack "How the hell do they do this?"

- Adam (looking at MTVL): "That is foxy. That is a foxy machine."

- Adam to Tory about barrels: "The only we're told we can't do is burn them, blow them up or lose them". Tory to Adam: "Has he watched the show?"



Setup: Adam and Jamie try to determine how much force a human can impart. By using shock force they can exert almost 10 times their body weight; however on a constant pull they only achieve half their body weight.  They then try to see what a shark can do.



Using seal decoys and a 20,000lb force gauge they set up an experiment to determine how much pulling strength a shark might have. They go to the Farallon Islands to deploy. Though a great white's speed has never been clocked, it's estimated that they can achieve 20 -25 miles per hour. Unfortunately the sharks decided to opt out of the testing.



To try to get the data, the Mythbusters head to the Bahamas. They set up another test to measure shock and continuous force. The line is attached to a 150lb force gauge and baited. The measurements are taken and the sharks weighed. The findings are that sharks can pull no more than their own weight on a shock load and about 30% of their weight on a continuous pull. These figures were used as the basis of the future shark strength experiments.



Sub-Myth 1A: Can a real shark destroy a shark cage like it did in the movie?

Setup: It was noted that there have been no historical reports of a shark destroying a dive cage. For the strength tests, the approximate size of a real shark needs to be determined. The great white in Jaws is said to be 25 feet long weighing 6,000 lbs. Science has no record of a shark that big. Based upon research, the team decided to go with an approximate size of between 17 - 19 feet long weighing approximately 3,000 lbs. To replicate this, Adam creates a reproduction shark cage based upon exact specifications from the prop used in the Jaws movie.



The Build Team creates a "shark ram" by casting a shark head which sits at the front of a 3,000 lb length of pipe. The head was made out of a rubber that mimics the shark's skin. The contraption is dubbed "Sharammer" by Kari ("Sharkpedo" by Adam; "Jawpedo" by Rob).



Test: The "Sharammer" is hooked up to the MTVL which will pull it at 25mph The MTVL stops at a point so that the "Sharammer" is carried into the cage under its own speed.

Result:  CONFIRMED! The "Sharammer" went through the cage completely destroying it and taking away part of the cage. It was pointed out that there is no information of this actually happening outside of the movie.



Sub-Myth 1A-1: Can Number 12 piano wire withstand the force of a shark?

Setup: Adam visits a piano store. John Callahan, piano technician, states that the breaking tension of Number 12 piano wire is 300lbs.

Test: Jamie and Adam stress test of the piano wire using a forklift and a force gauge. Based upon their test, the wire broke at exactly 300lbs. This is the same wire that they tried to catch a 6,000lb shark with.

Result: BUSTED!



Sub-Myth 1B: Can a real shark submerge barrels and keep them under?

Setup: Adam was able to procure three of the original barrels used in the movie. The barrels are tethered to a concrete block on the bottom of the channel. A length of rope goes from the barrels through a system of pulleys to the force gauge to the tank.

Test: The MTVL pulls the barrels under and the force gauge measures the amount of force needed to submerge them. According to the test, it took approximately 1,200 lbs to submerge the barrels.

Result: BUSTED! The test showed that the average "real" shark would not have the strength to hold three barrels under the water. They may be able to pull them under briefly, but not keep them under.



Sub-Myth 1C: Can a shark pull a boat backwards??

Setup: Using the Orca 5 (a 38 foot cruiser), the Mythbusters hook up the boat to the tank and have it yanked backwards. The rope is attached to a force gauge to measure the amount of force needed to pull the boat so that waves break over the stern.

Test: The MTVL was clocked at 25mph, the highest estimated speed for a great white shark. The force gauge fluctuates between 4,000 and 8,000 pounds.

Result: BUSTED!  In order to do this, a shark would need to pull more than two times its own weight.



Sub-Myth 1D: Can a real shark ram a boat with enough force to breach it?

Test: The Mythbusters position the Orca V so that the "Sharammer" will hit the flattest side of the hull. Once again the "Sharammer" is towed at 25 mph by the MTVL.

Result: PLAUSIBLE! The side of the Orca V is damaged. Given the right circumstances, a 3,000 lbs shark could do damage to a boat.



Myth 2: If you are attacked by a shark and you punch it in the nose or jab it in the gills youíll frighten it away.

Myth: It is a commonly held belief that if you are attacked by a shark, "offence is the best defense". There are historical instances where this method has been attributed to survival. In 1963, Rodney Fox was spear fishing of the South Australian coast when he was attacked by a great white shark. He fought it off and believes that's why the shark released him and he survived.



Experts:

- Rodney Fox (Shark Attack Survivor)

- Stuart Cove (Stuart Coveís Dive Bahamas http://www.stuartcove.com/)



Memorable Moments/Quotes:

- Kari: "I got Jamie's approval! <<giggle>>"

- Adam: "If Buster were a real boy, he'd be absolutely terrified right now"

- Adam: "We leave no man behind on Mythbusters, man!"

- Adam: "Jamie, you look really hot in that chain mail."

- Adam: "This is more fun than should be allowed."

- Rob Lee (about Buster): "The conquering hero returns bearing the scars of battle."

- Kari: "If I see a shark coming up with a beret, I'm going to be mad at you."

- Jamie (in chain mail): "Hurt Me! Go Ahead! <<laugh>>"



Setup: To ensure that no sharks would be harmed during the experiment, Jamie and Adam test the force of the human punch. Adam punches Jamie, who is protected in the "Red Suit". Adam's fastest punch was clocked at 20 MPH. A second test was conducted using Buster's thigh. The object of the test was to determine the amount of force behind the punch. [Force = Mass * Acceleration] Buster's thigh weighs 10lbs. Jamie's punch moved it 37 inches in 1/3 of a minute.



Test1: Buster is modified to have a pair of aluminum arms with fists (one punching / one jabbing) powered by compressed air using the pneumatic rotary actuators from the "Breakstep Bridge" episode. Buster's wet suit is filled with chum (fish waste) to attract the sharks. The difference between Jamie's test punch and Buster's was only 2 inches. This variance was determined to be acceptable.

The team packs up to take Boxing-Buster to the Bahamas so that he can do battle with Caribbean reef sharks.

Result: The reef sharks so go away when punched or poked, but they don't go away for long.



Test2: Jamie dons chain mail to punch the sharks to determine if punching helps fend them off or makes them more aggressive. They move to a new location, further out than the original test. The sharks were more aggressive than the original spot causing concern in the Mythbuster Crew. Jamie dives to the bottom with a full bait box and attempts to defend it from the sharks. Adam, unable to dive, takes a bubble sub to observe. Jamie strikes in the areas specified in the myth (using very little force) making the observation that striking them is like hitting bone.

Result: PLAUSIBLE! The sharks didn't respond to punching in the nose however punching in the soft tissue, like gills, seemed to have an impact. It was observed that the punches did not make the sharks more aggressive.



Myth #3: Exploding a Scuba Tank

Myth: Is the end of the movie JAWS actually feasible. If you fire a bullet at the end of a scuba tank will it explode with enough force to destroy a shark?

Experts:

- Sal Zimmitti (Owner, Bamboo Reef http://www.bambooreef.com/)

- Frank Doyle Jr. (Retired FBI Crime Scene Investigator)



Memorable Moments/Quotes:

- Rob Lee: "Adam's Muppet Man-eater is nearing completion. It's just like the real thing... only cuddly"

- Kari (after FBI yells "Fire in the hole"): "I didn't know they really said that"

- Adam (hold Fred): "Anybody up for sushi?"



Setup: In order to maximize safety, Jamie indicates that the tank should be placed into a shipping container with a remote firing rig. It's estimated that a tank carries 1.3 million pounds of explosive force. According to Sal Zimmitti, the aluminum tanks are filled to 3,000psi, which makes the tank a "walking bomb". However the tanks are very safe. They won't explode unless you do something "extremely radical" to them. Adam was able to obtain one of the actual scuba tanks used in Jaws, which Jamie identifies as "aluminum 80". Adam creates a mock-up of a shark's head (Fred) using a technique called "additive foam buildup". Jamie chooses a .30-06 M1 Garand Rifle to shoot the tank as it appears to be the same type used in the movie.

Test 1: A baseline test is completed to see if the myth can be busted outright. An empty scuba tank is shot to see if a bullet can pierce the bottom of the aluminum tank. The bullet was able to pierce the bottom of the tank.

Test 2: The test is repeated with a tank filled with 80cf of compressed air at 3,000psi. The tank did not rupture but was propelled like a rocket around the container.

Test 3: The test is repeated however rather than shooting at the end of the tank, the side of the tank is shot. The tank ricochet around the container but did not explode.

Result: BUSTED!  The metal is strong enough to withhold the pressure without completely rupturing.


Appendix:

MTVL:  Mobile tactical vehicle light. (http://www.uniteddefense.com/www.m113.com/mtvll.html)