Control of undesirable vegetation on roads or permanent ways of railways, (destruction of undesirable vegetation in general A01M7/00 - A01M15/00, A01M21/00; weeding involving working the ballast E01B27/00; mowers for embankments A01D34/86; hedge shearing machines A01G3/04); Applying liquids, e.g. water, weed-killer bitumen, to permanent ways (specially to rails E01H8/10 ; for preserving sleepers E01B31/20)