THE PROBLEM: wheelchairs simply do not work well, if at all, in sand. That stops millions of disabled people from the enjoying beachs all over the world. The challenge was to design and build a lightweight, portable wheelchair adaptation to overcome this difficulty.
THE SOLUTION: for each wheel, two half shells, 5" wide, were rolled to the diameter of the wheels ( in this case 24" ). these were made from 1/4" aluminum but a lexan plastic would also do. One end of each shell has a lip overlap to assure the two halfs line up and fit snugly. Each half shell has four 1" sq. brackets to grip the tire snugly and the two halfs are held together with heavy duty clamps ( see photo ). This effectively increases the bearing surface on the sand about 10 fold and keeps the wheels from bogging down. The front wheels are kept off the sand using a "rigshaw" pull handle as shown that fits to the chair where the footrests would normally go and the persons feet are held up by a simple canvas strap. The handle also breaks into two halfs for easy storage. The whole device can be assembled and disassembled with the person in the chair.