Testing an Aircraft Carrier Catapult | Outrageous Acts of Science
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Testing an Aircraft Carrier Catapult | Outrageous Acts of Science


Narrator: EVER WONDERED
HOW THE U.S. NAVY MAKES SURE THEIR CARRIERS
CAN FLING FIGHTERS LIKE THIS? ♪♪ WELL, THEY SLING
8,000-POUND SLEDS OUT TO SEA… LIKE THIS. ♪♪ WHOA. THAT SLED SKIPPED! I WASN’T EXPECTING THAT. I LIKE SKIPPING STONES, BUT THIS IS
A WHOLE NOTHER LEVEL. ♪♪ Narrator: WE WENT TO
THE NAVAL AIR WARFARE CENTER TO ASK CHIEF TECHNOLOGIST
MIKE DOYLE WHY HE’S DRIVING SLEDS, ALSO
KNOWN AS DEAD LOADS, OVERBOARD. ♪♪ SO, A DEAD LOAD IS BASICALLY A
HUNK OF STEEL WITH WHEELS ON IT. AND IT’S MEANT TO REPLICATE
THE WEIGHT OF AN AIRCRAFT. DEAD LOADS ARE CHEAP. IF ANYTHING GOES HORRIBLY WRONG, ALL YOU’VE LOST
IS A BUNCH OF STEEL. ♪♪ THE DEAD LOAD
IS NOT DESIGNED TO SKIP, ‘CAUSE IT ACTUALLY CAUSES DAMAGE
TO THE DEAD LOAD WHEN IT HITS. SO, THE TIRES GET RIPPED OFF, AND THERE’S DAMAGE
TO ALL THE INSTRUMENTATION. Narrator: SO, THIS WAS
A BIT OF A DISASTER. WHY DID THE SLED,
THAT’S DESIGNED TO SINK, SKIP? ♪♪ TO GET THIS SLED TO BOUNCE,
YOU NEED A LOT OF SPEED. WHEN IT LEAVES
THE AIRCRAFT CARRIER, IT’S MOVING AT A SPEED
OF 150 MILES PER HOUR, OR 240 KILOMETERS PER HOUR. WHEN THE SLED
MAKES CONTACT WITH THE WATER, IT’S EXERTING A HUGE FORCE OVER A LARGE SURFACE AREA
VERY QUICKLY. AND IT DOESN’T GIVE TIME
FOR THE WATER TO GET OUT OF THE WAY
AND ABSORB THAT FORCE. SO, INSTEAD, IT PUSHES BACK. Oluseyi: THE SLED COMES IN
AT A VERY SHALLOW ANGLE. AND AS A CONSEQUENCE,
MOST OF THE SLED’S MOMENTUM IS IN THE FORWARD DIRECTION
RATHER THAN DOWNWARDS, SO ONCE THE WATER
PUSHES THE SLED IN THE AIR, IT CONTINUES FORWARD. AND, THUS, IT’S SKIPPING
ACROSS THE WATER. THE SYSTEM THAT HAS THE POWER
TO THROW THIS HEAVY SLED SO FAST IS CALLED EMALS — ELECTROMAGNETIC AIRCRAFT
LAUNCH SYSTEM. THIS TRACK IS MADE UP OF AN
ARRAY OF ELECTROMAGNETIC COILS. EACH COIL IS TURNED ON
OR TURNED OFF IN SEQUENCE, MAKING SURE THAT
THE COIL IN FRONT IS PULLING THE SLED FORWARD WHILE THE COIL BEHIND
IS PUSHING IT FORWARD, ALLOWING THE SLED
TO ACCELERATE RAPIDLY. THERE IS
AN INCREDIBLE FUN FACTOR WHEN YOU’RE DEALING WITH THIS. IT IS BASICALLY A HUGE TOY. IT IS JUST TREMENDOUS TO WATCH
THESE HUGE VEHICLES — UP TO 100,000 POUNDS — AND, IN THREE SECONDS,
IT’S JUST GONE. SO, IT’S JUST TREMENDOUS. ♪♪ [ APPLAUSE ]

31 thoughts on “Testing an Aircraft Carrier Catapult | Outrageous Acts of Science

  1. Here’s my theory:
    Water is incompressible. Build up enough speed and water will resist an incoming force. Since water is incompressible a fast moving object with a large, flat surface area will have its forward momentum redirected back upwards. It’s the same principle as skipping stones.

    Any thoughts?

  2. did this with an oldsmobile delta 88 off of the USS Coral Sea as we crossed the atlantic… it did not skip.

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