The Beach Boys are going for simplicity in a battering ram. A heavy pole, mounted on chains will be swung back and forth. The trick will be getting the ram to hit the wall at the bottom of the swing, providing the maximum amount of force. You also have to consider where to hit the wall. Hit it at the top, where it's the weakest but you get the least amount of swing or hit it at the bottom with the most swing but the strongest brickwork.

The Chaos Crew have their work cut out for them in building a hydraulic "muncher". Remember hydraulics from last series final? To quickly recap, a piston is in a sealed tube that is moved back and forth by hydraulic (fluid) pressure at either end of the tube. They'll need rams, a pump, strong support members and luck. We all know how well complicated machines work, right?

The Chaos Crew l to r: captain Andy, John & Spike Their expert is Steve Garfirth	The Beach Boys clockwise: captain Chris, Jamie & Dan The expert is Peter Cracknel
The (in)famous Scrapheap timer	A collision with the set. That won't be good for the bodywork
Apparently, they aren't worried about the bodywork, they're dumping it.	Going on holiday? Nope, that will be the chassis for the Beach Boys ram
Our judge this week is John Roberts, an engineer	These hydraulic hoses will come in handy if you want the hydraulics to work.
From hydraulic rams to another kind of ram	Cathy! Now look what you've done!
That is some serious cutting	Apparently, the Beach Boys are done
Look out Robert!	Looking like something from King Arthur, the Beach Boys Bodgetastic Batterer
Looking like something from Jurassic Park, the Chaos Crew's muncher