By Adam Shergold PUBLISHED: 06:22 EST, 2 August 2012 | UPDATED: 04:02 EST, 3 August 2012 Britain's men’s lightweight four drained themselves of so much energy in their rowing final they literally had to be helped from their boat. The crew lay exhausted on the pontoon at Eton Dorney after winning silver in a thrilling race yesterday. After being pipped to the gold by a quarter of a second, Chris Bartley was too weak to get back in the boat and row up to the podium with his crew mates. Instead he had to walk over, supported by race workers.
@highlight
Total now stands at two golds, four silvers and four bronze medals
@highlight
British quartet pushed South Africa every stroke of the way in thrilling finish to lightweight fours final
and South Africa were left to fend off the @placeholder challenge which