A rotational moulding machine including three mould manipulator arrangements (10) and a rotatable carrousel (44) on which the manipulators (10) are mounted for indexed rotation between heating (62), cooling (64) and mould loading stations (66). The manipulators (10) each include a rectangular frame (18), stub axles (28, 30) on the frame (18) which are rotatable in supports on the carousel on a first axis (A), mould locating means (42) in the frame (18) which is rotatable on a second axis (B) normal to the first and means (20, 22) for manipulating a mould (40) in the frame (18) on both axes. The machine includes a crane beam (58) over the carrousel which overlies the heating and cooling station positions on the carrousel, a heating chamber, a wall enclosure, and crane means for lowering the heating chamber (68) and wall enclosure over manipulators on the carrousel at the heating and cooling stations and for lifting them clear of the manipulators to enable them to be indexed to the next station.