H-drive H-drive An H-drive drivetrain is a system used for heavy off-road vehicles with 6×6 or 8×8 drive to supply power to each wheel station. H-drives do not use axles but rather individual wheel stations, usually carried on a punt chassis. A single differential splits the drive into separate left and right drive shafts, which each run fore and aft inside the bottom corners of the chassis. At each wheel station a bevel box drives the half shaft out to the wheel. H-drive is not commonly used for 4 wheel vehicles, as it is relatively complicated for small vehicles. It has
Level crossings in the United Kingdom signed on 14 March 1957, and automatic and automated crossings came into use, with the first automatically operated level crossing commencing operation at Spath near Uttoxeter in Staffordshire in May 1961. Automatic half-barrier crossings later came into being after another enquiry abroad in 1963, consisting of a single arm each side of the road, which block only oncoming traffic leaving the exits clear for trapped occupants. Half barriers were considered to have an advantage as they have a lesser closure time and do not require to be interlocked with signals, but cases where impatient motorists have driven around the barriers