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,
Norda steel keel is added under the wooden keel, to provide more counterweight in order to add higher masts and more sail. Its sail plan is wishbone ketch. Norda Norda is a wooden sailing vessel that was commissioned in 1928, originally used as a research vessel in Poland. It served as research vessel, fishing vessel and is now a yacht. The vessel was commissioned in 1928 by MIR (Polish Fishing Institute). It was built in 1928 to order of in the Andersen Shipyard in Frederikssunde, Denmark. It was christened "Ewa", inspired by the names of daughters of both Professor Michał Siedlecki