A rigid rail assembly for a fall protection system comprises a rigid rail segment and a hanger. The rail segment comprises an upper portion defining an elongate slot and a lower portion. The hanger includes a hanger body adapted to be connected to a support member and a hanger coupling member extending downwardly from said hanger body and which is adapted to be received in the rail segment slot. The rail segment lower portion has opposed elongate side walls extending downwardly and outwardly and a flange extending inwardly from each of said side walls. The flanges define a track for the wheels of a trolley.