USS New Mexico (BB-40) - Construction

Construction

New Mexico was laid down on 14 October 1915 by the New York Navy Yard; launched on 23 April 1917; sponsored by Miss Margaret Cabeza De Baca, daughter of the recently deceased Governor of New Mexico, Ezequiel Cabeza De Baca (he had died on 28 February 1917); and commissioned on 20 May 1918, Captain Ashley Herman Robertson in command.

Unlike the other two battleships of this class which used geared turbines, New Mexico was equipped with a turbo-electric propulsion system, where the high-speed steam turbine drove a set of generators providing electricity to electric motors turning the propeller shafts. General Electric ran an advertisement titled "The "Constitution" of To-day—Electronically Propelled" with a drawing of the New Mexico next to USS Constitution. The ad touted the battleship as "the first of any nation to be electrically propelled". The electrical generating plant was said to put out 28,000 horsepower for a cruising speed of 10 knots. GE called it one of the most important achievements of the scientific age and related it to consumer products noting that "so general are the applications of electricity to the needs of mankind that scarcely a home or individual today need be without the benefits of General Electric products and service." An illustrated booklet titled "The Electric Ship" was offered free of charge upon request.

A comparison of the turbo-electric propulsion with the more conventional direct-drive turbine design used on her sister ships demonstrated that the conventional design generated 2.5x the power per ton of machinery and required 1/3 the floor area although at the cost of 20% greater fuel consumption, always a concern for the US Navy given Pacific distances. The turbo-electric design did allow for the equipment to be split between smaller watertight compartments, which was a potential benefit should parts of the engine space be attacked and flooded. There was a design weakness in that all electrical connections went through a single switch room, which could entirely disable the ship were it to be hit: USS Saratoga, which used a similar propulsion design, lost power for five minutes when it was hit by a torpedo in 1942. The scheme of watertight subdivisions was further weakened by large ventilation trunks passing through bulkheads and glass windows in the generator room bulkhead.

The ship's main armament comprised twelve 14"/50 caliber guns mounted three guns in each of four turrets, each turret weighing 980 tons. The design was compact, but the barrels were so close that there was the possibility of interference between adjacent shells in flight, while the limits on the speed at which the guns could be loaded meant that contemporary British turret designs using two guns would probably be able to fire at the same rate.