A tall fixed scaffold framework on a launch pad that is used to assemble and service a rocket on its launch pad. It supplies the rocket with fuel, electricity, and other reserves. The structure includes cranes, lifts, girders, ladders, cables, and floodlights. Booms, or swing arms, are used by technicians to service various parts of the launch vehicle. These arms swing away at lift-off. The umbilical tower of the Saturn V rocket was 116 m high, and its width was 18 × 34 m at the base, tapering to 12 × 12 m.