Heavy cruisers were a part of the U.S. Navy for about 50 years, until the late 1970s. Almost all of them were armed with nine 8-inch/55-caliber guns of several different types whose projectiles were fired using bagged powder charges. With the outbreak of World War II in Europe, four cruisers of the Baltimore (CA-68) class were immediately ordered. A total of 24 ultimately would be ordered, with 14 entering service. Combat experience resulted in modifications, which were reflected in the Oregon City (CA-122) class, whose superstructure was more concentrated to widen the antiaircraft batteries’ arcs of fire. Three of the ten cruisers ordered were completed and commissioned.
Shortly after the Oregon Citys were ordered, a startlingly different 8-inch/55 gun became available, one that used semi-fixed ammunition and could repeat firing cycles without human assistance. This was the Mark 16, which required an expansion of the Oregon City design. Twelve ships were programmed, but with the war’s end, only the three hulls well underway were completed: the Des Moines (CA-134), Salem (CA-139), and Newport News (CA-148). These would be the last 8-inch-gun cruisers built by any navy.
Continuing a U.S. practice, the ships’ Mark 16s were mounted in three triple turrets. Beneath each turret, six ammunition hoists hung like tree roots deep into the ship to magazines, where projectiles and metal powder cartridges were arranged in carousels that could feed them directly into separate hoists. A hoist sensor would recognize the presence of a projectile or cartridge, which automatically would be passed upward. A projectile hoist delivered its cargo to a transfer tube on the left side of a gun, while the cartridge arrived in a similar tube on the right side. Once again, sensors detected the arrivals and caused the tubes to swing to the gun’s axis, in precise alignment with each other and the gun’s bore.
At this point, a segmented rammer below the rear end of the gun flicked up and forward to push the now-combined round into the gun. A lip on the powder cartridge’s base released the vertical breechblock, which swiftly rose into position. When the gun was fired, its recoil caused the breechblock to drop, and the powder cartridge was sent out of the turret. And unlike many of the older bag guns, the Mark 16 could perform this evolution at any elevation up to its maximum of 41 degrees. By holding down the trigger, this cycle could be repeated ten times a minute—reportedly three times the rate of previous 8-inch guns—to send 335-pound superheavy projectiles out more than 30,000 yards. Moreover, the new guns had upgraded fire-control computers to give them stunning accuracy.
The three Des Moines sisters were commissioned between late 1948 and the spring of 1949 and soon settled into a peacetime routine of NATO and national exercises, midshipman summer cruises, and short-term deployments. The Des Moines and Salem would appear in two Hollywood productions. The former can be seen at the beginning and end of the 1959 film John Paul Jones, and the latter starred as the German pocket battleship Admiral Graf Spee in the 1956 movie The Battle of the River Plate.
The ships also would have chances to show off their big guns’ incredible accuracy. One of the cruisers had occasion to demonstrate her capabilities to British Royal Navy observers in the Mediterranean. Closing from over the horizon, she acquired the towed target and opened fire at 25,000 yards with six three-gun salvos (using one gun in each turret) in full automatic. The observers reported 17 hits.
On another occasion, the Des Moines was conducting a night shore-bombardment exercise using her newly developed bombardment computer, which permitted her to maneuver at will while firing. The first illuminating round ordered by the shore spotter, fired by one of the cruiser’s six 5-inch/38-caliber mounts, burst exactly where it was wanted. The initial round of 8-inch destructive fire hit the target. In those heydays of battle-efficiency competition, the Des Moines–class ships’ gunnery installations were festooned with Es; some had hashmarks marking consecutive winning years, and a few even had gold Es, marking five consecutive successes.
Between 1956 and 1961, the Salem and Des Moines were homeported in southern France, successively serving as flagship of the Sixth Fleet in the Mediterranean. As each completed a three-year tour, in 1958 and 1961, she returned to the United States and was mothballed. As it turned out, their active service lives were at an end, and both were stricken in July 1991. The latter was scrapped in 2007. The Salem became a museum ship moored at her birthplace, the Fore River Shipyard in Quincy, Massachusetts, where she remains.
The Newport News served mainly as a cruiser-division flagship during these years. But as the Des Moines was decommissioning, the Newport News was given expanded berthing and communications spaces prior to her assignment as flagship for the international staff of the dual-hatted Commander, U.S. Second Fleet/Commander, NATO Strike Fleet Atlantic. During the early and mid-1960s, she participated in NATO exercises, was flagship of deployed forces during the Cuban Missile Crisis, and was active in routine operations in the western Atlantic and in the Caribbean.
Just as flagship duties in the Mediterranean had been taken over by one of the hybrid guided-missile cruisers, in late 1967 the Newport News was relieved of her flagship assignment by another of that type and sent on a six-month deployment to Vietnamese waters in response to repeated Marine requests for “big gun” naval gunfire support. She fired her main battery “in anger” for the first time on 9 October 1967, and in the following two months conducted repeated strikes against enemy targets in South Vietnam as well as against North Vietnamese coastal defense sites. Enemy responses were all misses.
The big cruiser made additional war cruises in 1968–69 and 1972–73. During the latter, a faulty base fuse exploded as the center gun of Number 2 turret was fired, destroying the weapon. As the shooting war stopped at about that time, the gun was not replaced. Training cruises and port calls occupied the ship until she was decommissioned in June 1975. She was stricken in 1978 and sold for scrap in February 1993.
Even as the heavy cruiser era was ending, the Navy recognized the Marine Corps’ continuing requirement for support ashore and sought to find a way to provide it other than with costly guided missiles. One proposal was to adapt the 8-inch/55-caliber rapid-fire gun to a smaller installation, as in a destroyer. The result was the development of the Mark 71 major caliber lightweight gun system—a single 8-inch/55-caliber gun capable of replacing the 5-inch/54 mount then in wide use in destroyers.
The prototype was installed in the Hull (DD-945) and given at-sea technical and operational evaluations in 1975–76. The gun could fire 10–12 rounds per minute from a 75-round carousel operated by only one man. But the Operational Test and Evaluation Force found that the system had accuracy problems and was no more effective than the 5-inch/54 it might replace. The project was terminated in 1978.
Commander Martin, a Golden Life member of the U.S. Naval Institute, served as assistant gunnery officer in both the Des Moines and Salem.