New 'shoe' safety checks on trains

Safety checks on Northern line Tube trains increased today.

Problems with train power shoes breaking free are still causing concern.

The shoes collect traction current from the tracks, and at one stage Tube Lines - the private sector consortium responsible for maintaining the line - considered halting the entire fleet.

The problems were revealed by the Evening Standard two weeks ago.

New inspections checking all the shoes have now been started.

Tests will be carried out this week to find out why the shoes are breaking free. The Jubilee line uses identical stock but does not have the same problem - which suggests a fault with the Northern line track.

A Tube Lines spokesman said five shoe beams had been found to be showing "earlier signs of fatigue" as a result of last week's inspection. These, he said, were "not near to failure".

He said inspections had been changed and increased. "We are confident that these measures will pick up any potential (of the shoe beam) for failure in the future. We are confident the fleet is safe."