Radio masts and towers Radio masts and towers Radio masts and towers are, typically, tall structures designed to support antennas (also known as aerials) for telecommunications and broadcasting, including television. There are two main types: guyed and self-supporting structures. They are among the tallest man-made structures. Masts are often named after the broadcasting organizations that originally built them or currently use them. In the case of a mast radiator or radiating tower, the whole mast or tower is itself the transmitting antenna. The terms "mast" and "tower" are often used interchangeably. However, in structural engineering terms, a tower is a self-supporting or cantilevered structure,
Ketch than the Bermuda rig. In strong winds a ketch's mainsail can be dropped altogether (rather being reefed), thereby reducing sail and leaving a balanced sail-plan with just jib and mizzen set. When sailing with just mizzen and jib set, there is no excessive lee helm, and some claim that the additional sail allows a better balance; and in an emergency the ketch may be steered without use of the rudder. When running before the wind or reaching across the wind, a ketch may set extra sails such as a spinnaker or mizzen staysail on the mizzen mast, as well as