An endless elongate structure adapted to circulate around a path. The endless elongate structure comprises a central longitudinal portion and two lateral longitudinal portions on opposed sides of the central longitudinal portion for supporting the central longitudinal portion therebetween. The central longitudinal portion and two lateral longitudinal portions are connected together by joiners. The central longitudinal portion is adapted to be assembled into a movable tubular formation which is adapted to be continuously assembled at one end thereof and continuously disassembled at another end thereof during movement of the elongate structure along the path. The central longitudinal portion has two longitudinal edge sections adapted to be releasably connected together for assembling the tubular formation by a slidably interlocking connector. The slidably interlocking connector is integrated with the two longitudinal edge sections by joiners.