Lattice mast

Lattice masts, or cage masts, or basket masts, are a type of observation mast common on United States Navy major warships in the early 20th century. They are a type of hyperboloid structure, whose weight-saving design was invented by the Russian engineer Vladimir Shukhov. They were used most prominently on American dreadnought battleships and armored cruisers of the World War I era. In the age of sail, masts were required to support the sails, and lookouts were posted on them; with the advent of engine-powered warships, masts were retained and used for observation and to spot fall of shot. The purpose of the lattice structure was to make the posts less vulnerable to shells from enemy ships, and to better absorb the shock caused by firing heavy guns, isolating the delicate fire control equipment (rangefinders, etc.) mounted on the mast tops. However, the masts were found to be easily damaged by the inclement weather experienced at sea by naval ships during typhoons and hurricanes: s mast was bent right down to the deck by such a storm in 1918. As the caliber and range of ships' guns increased, heavier rangefinders were required, and the powerful guns and engines created shock and vibrations; lattice masts were eventually phased out in favor of the more rigid tripod masts favoured by the Royal Navy. The s of 1910 were the first class of American battleships to feature lattice masts, which were to become a standard fixture on all American battleships, and many cruiser classes. Older vessels, including the first modern American battleship, , were modernized with lattice masts during the period. During 1912, gunnery tests were carried out by the US Navy Department on a lattice or basket mast specially installed on the San Marcos (formerly ), to see how capable the design was of withstanding sustained gunfire. The mast was prefabricated in the Norfolk navy yard and shipped out for installation.