Abstract: A system for simultaneously extending two storable tubular extendible members, each such member being composed of two elongate strips of elastically deformable material, each strip having been fabricated to normally assume the form of a tube having an axis parallel to the length of the strip and being capable of being coiled about an axis perpendicular to such tube axis and of being flattened in the direction of its width while retaining its ability to assume the form of a tube upon being uncoiled, there being provided two coiling drums each arranged to carry one respective component strip of each tubular member and the drums being arranged to be rotated simultaneously in order to uncoil the strips in a manner to extend the two tubular members, or to coil the strips in a manner to retract the tubular members. The system can be arranged to provide any number of pairs of tubular members by providing a plurality of axially spaced pairs of coiling drums each carrying two such strips.