A tower mounting apparatus consists of tower mounting brackets, track members, a roller assembly, platform mounting brackets, and platform members. The tower mounting brackets are attached to a tower at a first interface, and are attached to the track members at a second interface. The roller assemblies are attached to the platform mounting brackets at a first interface, while the platform members are attached to the platform mounting brackets at a second interface. The roller assemblies are designed to rotate freely over the track members. One or more devices—such as a wind turbine, a cellular communication system, a transmitter/receiver for radio or television signals, or solar arrays—may be mounted onto the platform. The apparatus may further comprise a slip-ring assembly that provides a continuous electrical connection to such devices. The platform mounting apparatus may be installed on a variety of different towers.