In the past month Londoners have faced delays on the Tube because of over-running repairs, cracks on the lines, signal failures and faulty trains.

BBC: London mayor 'must act on Tube chaos', says Livingstone

He rolls his tube over the warm sand-dirt.

NEWYORKER: Getting Closer

To make an oil-collecting caisson, such a pile would be used as a collar around a funnel-topped tube that would sit over the leak.

ECONOMIST: Fixing oil wells