Disclosed is a capping board for use to support anodes and cathodes within adjacent electrolytic cells, which has a plurality of individual seats positioned in spaced apart relationship all along its length to receive and support hanging legs projecting from these anodes and cathodes. This capping board is improved in that it has at least one sheet or wire of electrically conductive material embedded therein. This sheet or wire extends over the length of the board and is shaped and positioned so that part of its extends externally within at least some of the seats so as to allow electrical contact of the legs of either the anodes or the cathodes and to allow fast dissipation of heat in the case of a short circuit.