The semi-final pits the Hairy Hogs - Con, Alistair,
and Darrell - against the Thirsty Knights - Roo, Frog, and Pete. They won
the jetboat and propellor car heats, respectively. Their challenge is to
build a landing craft. It must carry a car and all three team members across
a lake, powered by the car's engine, rescue the expert, and drive back
on shore.
The Knights are with Bill Rutland, a professional
boat designer. They're going for something to do with paddles, like the
boats on the Mississippi. Put those on the sides of a floation tank, pop
a light car on top, and go like the clappers.
The Hogs have the help of Simian Oakley, who lives
on a boat. Floatation - perhaps a pontoon of oil barrells. "Propulsion
is the easy bit" says Sim. They'll do something clever with the rear wheels,
for values of "clever" yet to be determined. They'll split the chassis
of a four-wheel car into a front-wheel car for land drive, and a rear-wheel
car to power the boat. They need a contraption that will engage with the
rear wheels, and one that will disengage the front wheels. That's "clever."
The Knights have a couple of rusty and holed pontoons,
though they could yet be repaired. That's Scrapheap for you. They've also
got a small beetle, while the Hogs do strange things with a jeep, an old
truck flat-bed, and a large collection of oil cans. The Knights, meanwhile,
are having terrible trouble finding their rollers. Eventually, they go
for some eight-inch pipe - that'll do to make an axle, but they now need
to make a steering mechanism.
Trouble for the Hogs, too, their jeep isn't starting.
They have managed to get the top frame just resting on their floating barrels
- fewer holes means fewer chances for water to come in. The semi-submersible
strikes the judges as a little low.
With a single roller, and a rudder for steering,
the Knights might be onto a nifty little runner. Especially as the Hogs
are still without a working engine. Two hours later, the engine finally
splutters into life, and the Hogs are cooking on gas. Driveshaft, rudder,
even some little rails to get the jeep up onto the platform. But they've
got a lot of joining together of things to do before they can get going.
The Knights can just drive in and go, but will their steering be up to
it?
The race day dawns, and it's an all-or-nothing
race. First back with the expert is the winner. The Knights' drive-on-and-go
system gives them a real advantage, though they're splashing out a lot
of water. The Hogs forgot to bring up their drive-on ramps, and end up
turning on a very large sixpence to drive forwards. When they go, these
Hogs go like greased pigs. Er. The Knights try to spin the paddles quickly,
thus reducing surface area in contact with the water. But they've still
got to drive back on to shore, and the ramp is securely tied. Too securely
tied, almost, but the Hogs manage to come ashore and take the win. The
Knights expert was last seen floating off back to his start point...