A frame system for supporting two wheels of an associated vehicle for transport within an existing transportable structure such as a standard ISO container which has longitudinally extending side structures 5, 6. The frame system comprising a transverse wheel supporting frame 41, 43 supported by two vertical posts 40, 42 located one at each end of the wheel supporting frame. Each post is provided with attachment means 44, 48a for securing the top and bottom of the post at a plurality of locations along the length of the associated side structure independent of the shape of the side structure. The wheel supporting frame 41, 43 is raiseable with or without a vehicle loaded thereon and once raised is fixable 49, 50, 51 to the posts 40, 42 at a chosen location for transport within the transportable structure. The attachment means may comprise ties 44 of adjustable length which pull each post in the fore and aft direction relative to the side structure 5, 6 to locate each post.