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MythBusters Episode 115: Demolition Derby

Air Date: April 8, 2009

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While a city bus is turning sharply at 50 miles per hour (80 km/h), all the passengers need to move to the inside of the turn to prevent the bus from flipping over. (This myth is inspired by a scene in the movie Speed.)

busted

In their initial test, Adam and Jamie placed several water-filled barrels inside a bus to match the weight of the nineteen passengers seen in the film. They first placed all of the barrels on the right side of the bus and performed a right hand turn at 50 miles per hour. The bus struggled to make the turn but did not flip over. Next, they performed a second turn with the weight evenly distributed, and the bus still did not flip, busting the myth. In order to flip the bus, Adam and Jamie distributed all of the weight to the outside of the bus to shift its center of gravity, added steel weights to the roof to make it top heavy, and deflated the left side air-suspension to further shift the weight of the vehicle.

As seen in Hollywood movies, a car can be driven into a fruit stand and continue to drive away afterward.

busted

The car completely demolished the fruit stand, and was no longer drivable because the of a crushed front end.

As seen in Hollywood movies, a car can be driven through a locked chain link gate and continue to drive away afterward.

plausible

The car successfully crashed through the gate. Despite suffered severe damage, the car was still drivable, prompting the Build Team to declare this myth plausible.

As seen in Hollywood movies, a car can be driven through a camper trailer and continue to drive away afterward.

busted

The car completely demolished the trailer, rather than making the clean hole seen in movies. The car itself was also completely destroyed in the crash.

As seen in Hollywood movies, a car can be driven through the cavity between the ground and a big rig trailer, ripping off the roof, and continue to drive away afterward.

plausible

The trailer tore the roof off of the car, making it an instant convertible. However, the car’s braking system failed and it continued on, uncontrollably driving off an earthen berm and going airborne. Based on video playback, the car looked as if it was still in drivable condition after driving under the trailer, prompting a plausible result.

A car driving at 142 miles per hour (229 km/h) can beat an identical car falling at terminal velocity in a race at a distance of 4,000 feet (1,200 m). (Based on a car advertisement.)

busted

The Build Team first dropped a car from a crane to see how it would behave in freefall. However, they found that unlike the commercial, the car would not fall upright and would instead hit the ground front-first. They solved this problem by evenly distributing the weight of the car. For the actual test, the Build Team dropped a car from a helicopter while a remote controlled car drove at 140 miles per hour (225 km/h) in an attempt to beat it. However, because the car on the ground could only achieve a top speed of 105 miles per hour (169 km/h), the Build Team had to shorten the ground distance to 2,950 feet (900 m) to compensate. Despite this, the falling car still managed to beat the ground car. These factors prompted the Build Team to declare the myth busted.

Two big rigs that collide head on can fuse together and completely flatten a compact car between them. (Revisited from Episode 41: Compact Compact.)

busted

In their first attempt several years ago, the MythBusters had technical difficulties testing this myth. This time, the MythBusters rebuilt the entire crash rig. The test was successful, with both trucks crashing head on and simultaneously with the compact car. However, the compact car was pushed out of the collision zone rather than staying between the trucks, and the trucks were not fused together as stated in the myth. In order to see what it would take to pancake and fuse a compact, the MythBusters decided to ram a compact car with a rocket sled. The rocket sled struck the compact car at a speed of 648 miles per hour (1,043 km/h), completely disintegrating it. Nonetheless, the impact didn’t achieve the fusion they were looking for. In order to see what it would take to fuse two pieces of metal together, the MythBusters demonstrated explosion welding where metal could be fused by using high explosives. Since trucks cannot travel faster than sound, nor can high explosives be easily found on a highway, the myth was ultimately busted.

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12 Comments

  1. Xomeron:

    In the myth for tearing through a caravan, it’s inaccurate, as I believe the car in question had been reinforced, and more importantly, because the car was in the air during the impact, and would only have to tear through the walls of the trailer.

    June 11, 2009 at 5:17 PM
  2. Diane Sorensen:

    In the myth of the two semis traveling on the highway fusing together with a compact between them may have a flaw in the experament. If I were driving on a highway I would have fuel in my gas tank as well as both the semis. I think that upon inpact the little car could explode perhaps creating a fusion of the two semis.

    July 11, 2009 at 9:10 PM
  3. Michael Day:

    In the Myth car going 142 mph vs the falling car… you kinda forgot about terminal velocity… what is it for the car falling at 400 feet… by dropping the hight and speed you did not fairly test the claim. people have a terminal velocity of 125 mph so if I ran 142 I would beat it… the same could go with the car.

    August 14, 2009 at 4:39 PM
  4. Terry Spivey:

    I love your show keep up the good work

    August 26, 2009 at 10:43 PM
  5. Don:

    Some friends of mine tried the “driven through a locked chain link gate” trick. The gate broke and one of the tubes went through the windshield. One less friend.

    September 6, 2009 at 3:37 AM
  6. coleman:

    Have your friends not seen the do not attempt what you are about to see warnings?

    September 12, 2009 at 8:48 PM
  7. Dragonfyre:

    To Diane: indeed, cars do have gas in their tanks, as well as semis. That would not, however, result in an explosion, per-say. They would burned, but not at a high enough temperature to fuse together. An explosion is something completely different from the combustion of gasoline, as the Mythbusters have said on occasion.
    I don’t know the exact amount of explosives they used to fuse the pieces of metal together, but it would be extremely unlikely that any sort of explosion could happen on a highway…the only way it MIGHT happen is if both trucks were carrying the explosives to begin with…even then, it’s unlikely to happen, since everything would probably just disintegrate around them.

    September 14, 2009 at 2:29 PM
  8. SG:

    the myth with the semis is no longer a myth. A similiar event actually took place with two semis and a compact car, and the driver of the compact escaped unharmed while his car was crushed (but not accordioned). So MB got it right.

    September 18, 2009 at 3:06 PM
  9. Craig:

    There was an instance just outside Walden Ontario Canada where a transport truck carrying 18,000 Kg’s of High power mining explosives had caught fire and exploded leaving a creator 50 feet deep and 100 feet across. It obliterated the entire west bound side of the divided highway and took out the bed rock dividing the two roads and still managed to take half of the second road away. Just wondering if this would be enough explosives to fuse metal like in the episode of the two transport trucks crashing head on? If anyone wants to search it look for “Walden Transport Truck Explosion” on Aug 5th of 1998 and you’ll see the official release of report.

    January 1, 2010 at 8:40 PM
  10. Paul Malley:

    Re City Bus

    You were always too rich in America, but in the Uk
    up until the fifties, that’s 1950 Yank, a motor cycle and side car was common transport.
    Naturally they used to race them.
    The “passenger” was a ” trapeze artist” who used
    his body weight to keep the outfit on the road.
    Rather than following the rules for the prevention
    of collision at sea( pass port to port) in the UK
    and in various Successful ex Colonies and Japan they pass “strong side to strong side”.
    That means the side car is on the left so turning
    right is okay,but turning left the side car lifts.
    The passenger has to get a much weight as possible to that side, his head usually end up only a couple of inches above the road.

    January 3, 2010 at 3:36 AM
  11. Peterbilt Driver:

    As a professional driver I have seen my share of car/car, car/truck, and truck/truck accidents to last me a lifetime. Never have i seen one fuse together. I would like however for the mythbusters to test if a car door can be ripped off by another car passing it hits the door as it is being opened as we so often see in the movies.

    January 29, 2010 at 10:59 AM
  12. GetStopGo:

    My dad drove under a semi that cut him off the day he got his liscense, if my aunt hadn’t seen it coming and passed out in the back seat she would have died. It totally took the top of the car off, like a convertible. Because of the angle he hit it at, acute rather than perpendicular he did not go all the way through.
    I would also like to thank mr. Frye up there for his valuable insights that well nigh guarantee no one will ever read this comment.

    February 18, 2010 at 11:24 PM

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