This semi-final contest pits previous winners the Super Chargers against the High Flyers. All they have to do is launch Tyler's shorts the farthest. Simple, right? Very simple except Tyler's shorts are inside a 150 pound washing machine. Each team gets three tries to throw the washing machine the farthest. No engines are allowed so they will have to figure out a way to store the energy then fling the washer forward. Whoever gets it the farthest advances to the finals.
 

The Super Chargers want to build a catapult. With a truck frame for a base and a large steel arm attached to a winch to pull it back, they will fling their washer forward. By twisting steel wire around the base of the arm, that will store the power to fling the washer. It's a simple design but finding enough steel wire (that is in solid condition) could be tricky. Also, the welds will have to be super strong because the forces will be massive when the arm is winched back.

Initially the High Flyers were going with a massive slingshot. By attaching cord to the leaf springs on a car (all attached to uprights on a solid base) a lot of power could be stored and let go. The team didn't think they could find big enough leaf springs so they're going with a trebuchet. We've seen many trebuchets before, but a quick run down anyway. Two a-frames support an arm with a big weight on one end and the washer hooked to the other end. The weight swings down and the washer is flung over the top and forward. It's gonna be big and it's gonna have to be strong.
 
 

Super Chargers expert  Antoni Feldon	High Flyers expert  Rob Ballantine
The Super Chargers want to  build a washer catapult	The High Flyers' expert wants to  ping the washer
But the team would rather  fling the washer	By cutting and stretching this cart, it  will hold the washer in the catapult
These poles will make a great arm	And this trailer will work as a base
The High Flyers clear some junk away  from this truck so they can use...	...it's heavy chassis for the base of  their trebuchet, which is their plan
Judge Tony Swatton	Reams of cable will will put the  fling into their catapult
This winch will wind that massive arm  back into position	By using a car axle, the High Flyers  have a pre-built pivot
By using these hubs, it will be easier to  wind the cable into a torsion spring	The weld holding the arm to the pivot  is critical and must be done with care
Supports are necessary for the  High Flyers trebuchet	By filling this tank with sand, the catapult  should keep from flipping over