Tripod mast

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.

The idea dates at least as far back as the French Terrible-class ironclads, built in the late 1870s, which used a pair of tripod masts.

The United States Navy preferred the lightweight lattice mast, which used an array of thin columns at angles, crossing each other in a double helical spiral configuration in a form of hyperboloid structure.

Beginning in the 1930s, the US Navy started refitting their battleships and other capital ships with the more robust tripod mast design.

[citation needed] 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 HMS Salisbury in 1962.