Richard Hammond's Crazy Contraptions

A team of physics-obsessed students from Leeds take on three Spanish-born brothers, in a bid to build a machine that allows Richard Hammond to water the plants without getting up from watching the TV. With surprise challenges involving buoyancy and garden shears thrown in, the teams need to think extra hard to devise a winning machine - with some spectacular, and occasionally disastrous, results.

The Fieldhouse Brothers, from Somerset, take on the Bueno Brothers, originally from Spain, in a closely fought first semi-final to build jaw-dropping chain reaction machines that will allow Richard to dust his ornaments without leaving bed. With a place in the final at stake and a challenge that requires delicacy and creativity, the contraptions need to be extra special. Chain reaction machine guru Zach Umperovitch is the expert judge and Shini Somara fills in the science behind the teams' eccentric contraptions.

Two winners from the heats go head-to-head for a place in the final. The challenge this time is to create an ingenious chain reaction machine that allows Richard to cook sausages in the kitchen, without leaving his desk in the study. Zach Umperovitch is the expert judge and Shini Somara fills in the science behind the teams' eccentric contraptions.

Engineering enthusiasts from around the UK competing to create the best chain-reaction machines from everyday objects. Each episode sees the contestants' efforts scored by judges based on the contraption's ingenuity and quality. One team is then voted off, with a winner crowed in the final episode of the series.