MythBusters Episode 120: Exploding Bumper
Air Date: May 13, 2009
A car bumper can explode in a car fire and fly across 50 feet (15 m) to knee-cap a person.
busted
Adam and Jamie set fire to a car with gasoline and measured the temperature with a thermographic camera, eventually determining that the blaze reached 1,400 °C (2,600 °F), enough to melt the aluminum bumper but surprisingly unable to make the bumper shock explode. Suspecting that unfocused flames might have caused the explosion to fail, back in the shop they subjected several bumper shocks to directional heat from an oxyacetylene torch at various spots. However, all shocks lost pressure in one way or another before they could explode. During the episode, the MythBusters interviewed an Oakland firewoman who indeed suffered bumper knee-capping. But in her accident, the bumper flew only 15 feet (4.6 m) instead of 50 feet as alleged in the myth. Finally, Adam and Jamie simulated a 50-foot bumper blast using a delicately engineered rig consisting of two pistons packed with gunpowder and wet sand and an electric ignition system, which demonstrated the improbability of such a blast under normal conditions.
Hungarian archers got twice the penetration shooting a bow from a galloping horse than from shooting stationary.
busted
The Build Team first attempted to test the myth by having trained horse archers firing at a foam target at varying speeds. However, they were unable to get consistent data because the three archers they tested all rode at different speeds, fired their arrows at different distances, and had varying arrow velocities. For a more conclusive test, the Build Team obtained a Jeep and mounted a crossbow on the top. They then fired arrows at a large foam target while stationary and then while the Jeep was driving at 40 miles per hour (64 km/h), in both cases from a fixed distance of 60 feet (18 m). While the arrows fired while the Jeep was moving did penetrate deeper into the target, they did not penetrate twice the distance of the arrows fired while stationary, busting the myth.
Newer: Episode 121: Seesaw Saga
why didn’t they seal the safety valve in the bumper piston and heat it homogeneously or at least slowly, of course its gonna cut it its a torch
July 2, 2009 at 5:07 AMWatching the episode the Lady Fireman.(Excuse the political incorrectness) Did she not say she turned the nozzel onto the wheelwells before it exploded? Now if there was water thrown on to the bumper struts when extremely hot would it maybe cause some kind of kaboom? Just curious.
September 7, 2009 at 1:02 AMGood point Parry.
I didn’t agree with them busting this myth. We know it can happen, it happened to that firefighter. Just because they could not make it happen, does not mean it is busted.
They should have said plausible really. I think they need to revisit the myth, but it was kind of a boring one so I don’t really care.
September 10, 2009 at 3:01 PMBusting it was probably premature…plausible, but highly unlikely has been used before…the situation for this one, however, was incredibly slim…almost no chance, since the bumpers are designed not to fail.
September 14, 2009 at 2:45 PMI was just watching this episode and realized that most car fires are due to an accident so use a perfectly good bumper and not a damaged one would create a different result. If there is no damage to the bumper then the safety mechanisms would work but may not work properly if damaged. so i agree it should have been plausible not busted
October 27, 2009 at 2:57 AM