2 minus u201c the length of a station u201d i e the beam is about 20 shorter than the total path length in the illustrated case in which the stations are five in number mounted beneath the lifting beam 71 are three vertical second hydraulic lifting cylinders 72 in stations 6 8 and 10 the cylinders 72 are mounted on the stand 52 and each cylinder has a piston rod 73 connected to the underside of the beam 71 the walking beam 62 is also provided with a pair of vertical end supports 74 for each station so as to centre the plate in respective treatment station 6 10 when necessary and to prevent the plates 4 from moving in their longitudinal directions when resting on the movable support 67 and being stepped forwards by the cyclically repeated feeding movements which can require relatively powerful acceleration and retardation with each feeding step depending on the operating speed of the plant as a whole extending along part of the walking beam 62 within the regions of the stations 9 and 10 and spaced from said beam 62 is a horizontal rack 64 with outwardly facing teeth the rear side of the rack 64 is joined.