Engineers are attempting to winch a stranded narrowboat out of the River Thames after several previous methods to remove it have failed. The Environment Agency has tried pumping water and towing it with a tractor after it came adrift in Oxford. It is one of two boats that came loose on Monday. It has crashed into Botley Bridge causing an obstruction. Russell Robson, waterway operations team leader, said he was "optimistic" the latest attempt would work.