To improve the efficiency of dust removal in the tube tunnel, Transport for London developed a Tunnel Cleaning Train for the Underground. The dust, created by rail-wheel contact and braking, is removed using suction. The project has discarded in recent years due to technical and cost issues. The carriages seen at Acton Town siding was part of the motive power units for the train, modified from 1967/72 Stock, and they have now scrapped.
