Abstract: A collapsible access tower has a chassis 10 supporting a pair of road wheels 11 and outriggers 16,17 to impart stability when in use, and a pair of extensible multi-section columns 26,50 carrying a platform 35. A section 27 of one column 26 is rigidly connected to the chassis and another section 33 of that column to the platform 35. The other column is configured as an extendible ladder 50 one section 51 of which is hinged to the chassis 10 and another section 52 of which is hinged to the platform 35. When the platform is in its lowermost setting, the hinged connections of the two sections 51,52 of the ladder 50 are co-axial so that the ladder may be pivoted to a transit setting. A winch arrangement 39 is associated with column 26 to allow raising and lowering of the platform 35.