New Mexico-class battleship

The New Mexico-class battleships of the United States Navy, all three of whose construction began in 1915, were improvements on the design introduced three years earlier with the.

The twelve-gun main battery of the preceding was retained, but with longer 14 in 50 caliber guns in improved triple turrets. Hull design was also upgraded with a 'clipper' bow for better seakeeping and a sleeker look. One ship, the USS New Mexico (BB-40), was fitted with turbo-electric propulsion.

Though eight secondary batteries were located in extremely wet bow and stern positions and were soon removed, the rest of the ships' 5 in guns were mounted in the superstructure, a great improvement over earlier U.S. Navy battleships' arrangements.

Class history
Completed during and soon after World War I, the New Mexicos were active members of the Battle Fleet during the decades between the World Wars. All were rebuilt between 1931 and 1934, receiving entirely new superstructures, modern controls for their guns, new engines and improved protection against air and surface attack. Anti-torpedo bulges increased their width to 106 ft and displacement went up by a thousand tons or more.

The New Mexico class was part of the standard-type battleship concept of the U.S. Navy, a design concept which gave the Navy a homogeneous line of battle (it allowed planning maneuvers for the whole line of battle rather than detaching "fast" and "slow" wings). The standard-type battleship concept included long-range gunnery, moderate speed of 21 kn, a tight tactical radius of 700 yd and improved damage control. The other standard-type battleships were the, , , and es.

In order to counter the German threat, these ships—operating together as Battleship Division 3—were transferred from the Pacific to the Atlantic in 1941, leaving the U.S. Pacific Fleet inferior in battleship strength to the Japanese Navy. Sent back to the Pacific after the Pearl Harbor raid devastated the Pacific Fleet's powerful battle line, they were active in the war with Japan until final victory was achieved in August 1945. Their heavy guns provided vital assistance to the many amphibious invasions that marked the Pacific conflict, and Mississippi took part in the Battle of Surigao Strait, the last time in history that battleships fought each other. New Mexico and Idaho were disposed of soon after the war ended, but Mississippi was converted to a training and weapons trials ship and served for another decade. The U.S. Navy's first generation of ship-launched guided missiles went to sea aboard this old former battleship.

Design history
Designated as Battleship 1916, the design history is marked by the incipient test firing of the 16" U.S. naval gun. The gun promised to deliver twice the energy of a 12" gun and 1.5 times the energy of a 14" gun. The problem was that the 16" gun was not tested. If the gun failed then the design would have to wait for new 14" turrets to be fabricated. The first design offered to C&R was no less than 10 16" guns and 8 torpedos. The design also included upgrading the armor as well as extending it. A secondary battery of 6" guns was incorporated into the design. The General Board arguing that the increasing range of torpedos required the increase of caliber. In August 1914 the 16" gun was successfully test fired silencing that question but that would happen after the design was in front of SecNav. The rise in displacement and the rise in the cost of the new design presented issues. The General board pushed for the advancement with C&R wanting to repeat the Pennsylvania Class. Both the Secretary of the Navy Josephus Daniels and the House of Representatives rose up against the cost. The General Board was convinced that the major sea powers would jump to 15" or 16" naval guns as a main armament and asked for designs based on the 16" gun. A series of designs was laid out with the last being a design with 8 16" guns on the 31,000 ton design of the earlier Pennsylvania design. No one reviewing the design was at all happy with it. Strangely enough, it would except in small details, become the blueprint of the Maryland Class Battleships. On July 30th, the Secretary of the Navy ordered that, except for the inclusion of individual slides for the main guns,the Tennessee Class would be a reproduction of the preceding Pennsylvania Class.

Ships in class

 * USS New Mexico (BB-40)
 * USS Mississippi (BB-41)
 * USS Idaho (BB-42)