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In naval architecture
Naval architecture, or naval engineering, is an engineering discipline incorporating elements of mechanical, electrical, electronic, software and safety engineering as applied to the engineering design process, shipbuilding, maintenance, and o ...
, a mack is a structure which combines the radar masts and the exhaust stack of a surface ship, thereby saving the upper deck space used for separate funnels and the increasingly large tripod masts used to carry heavy radar
Radar is a detection system that uses radio waves to determine the distance (''ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, w ...
aerials. The word is a composite (portmanteau
A portmanteau word, or portmanteau (, ) is a blend of wordswarship
A warship or combatant ship is a naval ship that is built and primarily intended for naval warfare. Usually they belong to the armed forces of a state. As well as being armed, warships are designed to withstand damage and are usually faster a ...
s, (e.g. the rebuilt Baltimore class cruiser
The ''Baltimore''-class heavy cruisers were a large class of heavy cruisers in the United States Navy commissioned during and shortly after World War II.The ''Baltimore''-class were the largest cruisers of World War II by tonnage. Fourteen ''B ...
s), and on some cruise ships
Cruise ships are large passenger ships used mainly for vacationing. Unlike ocean liners, which are used for transport, cruise ships typically embark on round-trip voyages to various ports-of-call, where passengers may go on tours known as "s ...
.
The Marine Nationale
The French Navy (french: Marine nationale, lit=National Navy), informally , is the maritime arm of the French Armed Forces and one of the five military service branches of France. It is among the largest and most powerful naval forces in th ...
used a combined exhaust stack and rear director mast on Richelieu class battleship
The ''Richelieu'' class were fast battleships built for the French Navy between the 1930s and 1950s. Initially two ships were ordered in 1935 in response to Italian orders for the s the previous year. The ''Richelieu''s were based on the preced ...
s in the late 1930s. The Royal Navy
The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by English and Scottish kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years' War against F ...
used this design feature on the 1944 Weapon class destroyer
The Weapon class was a class of destroyers built for the British Royal Navy towards the end of World War II. They were the smaller counterpart to the (which followed them) and were the first new destroyer designs for the Royal Navy since the ...
s, and the subsequent ''Daring''s, and in the diesel-engined Type 41 "Cat" class and Type 61 "Cathedral" class frigates of the 1950s. It provided unbalanced and unattractive designs, which led to a reversion to separate masts and funnels in subsequent RN vessels.
The close proximity of exhaust fumes to delicate radio and radar equipment led to corrosion problems, making macks unpopular for later designs.
References
{{Reflist Shipbuilding