The tripod mast is a type of mast used on warships from the

Edwardian era In the United Kingdom, the Edwardian era was a period in the early 20th century that spanned the reign of King Edward VII from 1901 to 1910. It is commonly extended to the start of the First World War in 1914, during the early reign of King Ge ...

onwards, replacing the pole mast. Tripod masts are distinctive using two large (usually cylindrical) support

column A column or pillar in architecture and structural engineering is a structural element that transmits, through compression, the weight of the structure above to other structural elements below. In other words, a column is a compression member ...

s spread out at angles to brace another (usually vertical) column.

History

The masts were intended to provide a raised platform for visual observers and for fire control equipment, elevated up above the main hull for visibility and to reduce the risk of shell damage to the gear and crews. These masts used three large cylindrical tubes or columns to form the mast. The tubes provided structural cross-bracing and a stiff structure, but were still structurally efficient and reasonably lightweight. Tripod masts were predated by pole masts. The idea dates at least as far back as the French s, built in the late 1870s, which used a pair of tripod masts. The

Royal Navy The Royal Navy (RN) is the naval warfare force of the United Kingdom. It is a component of His Majesty's Naval Service, and its officers hold their commissions from the King of the United Kingdom, King. Although warships were used by Kingdom ...

moved to the tripod mast from pole masts with their last

pre-dreadnought Pre-dreadnought battleships were sea-going battleships built from the mid- to late- 1880s to the early 1900s. Their designs were conceived before the appearance of in 1906 and their classification as "pre-dreadnought" is retrospectively appl ...

( ''Lord Nelson'' class) and the first

dreadnought battleship The dreadnought was the predominant type of battleship in the early 20th century. The first of the kind, the Royal Navy's , had such an effect when launched in 1906 that similar battleships built after her were referred to as "dreadnoughts", ...

, HMS ''Dreadnought'' (launched in 1906) and thereafter in their later battleships and battlecruisers. The

United States Navy The United States Navy (USN) is the naval warfare, maritime military branch, service branch of the United States Department of Defense. It is the world's most powerful navy with the largest Displacement (ship), displacement, at 4.5 millio ...

preferred the lightweight

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 Russia ...

, which used an array of thin columns at angles, crossing each other in a double helical spiral configuration in a form of hyperboloid structure. These were used on their first dreadnought battleships launched in 1908. The US were the only significant users of lattice masts. Eventually, these structures proved less structurally sound than intended. On January 15, 1918, had a lattice mast collapse in an intense storm. Beginning in the 1930s, the US Navy started refitting their battleships and other capital ships with the more robust tripod mast design. The tripod mast structure continued in use until stealth designs started to move away from open masts entirely in the 2000s. The Royal Navy began using plated-in masts or "macks" in the early 1960s, either as new construction or by refit, such as that of in 1962.Marriott, Leo. ''Royal Navy Frigates, 1945–1983'', Ian Allan Ltd. p. 50. File:Arizona (BB39) Port Bow, Underway - NARA - 5900075 - 1930.jpg, 's original 1923 lattice masts File:USS_Arizona_after_1931_modernization_NARA_19-LC-19B-1.jpg, USS ''Arizona''s 1931 tripod mast refit File:USS Arleigh Burke (DDG 51) steams through the Mediterranean Sea.jpg, The s have a modern form of tripod mast

References

{{Reflist Nautical terminology Watercraft components

History

See also

References