Giant vacuum cleaner to attack London’s underground

A giant vacuum cleaner is to whisk ballast off the rails of London’s tubes. Tube Lines, the company rebuilding the busiest Underground lines, is investing £1m in a vacuum system one thousand times more powerful than the average domestic Hoover.

The monster machine can consume up to 20 cubic metres of ballast. Six people are needed to operate it. But Tube Lines said that until now the same work was done by people shovelling ballast by hand. “Teams of 12 typically battled to complete a third of the work of the machine each night,” Tube Lines claimed.

The Tubevac is hauled along rails by two locomotives and its suction is powered by some seven diesel engines. Their suction force is directed through a hydraulically driven nozzle operated by a single person via remote control.

Stephen Peat, director of operations at Tube Lines said: "The Tubevac brings track maintenance from the 19th Century into the 21st. It's good news for passengers who benefit from smoother journeys and fewer delays.”

Tubes Line developed the machine jointly with DISAB Vacuum Technology AB in Sweden.