Des Moines class cruisers

 The last heavy cruisers ships built by the United States, the Des Moines class cruisers were among the most formidable vessels of their type ever built, by any nation. Finished too late for participation in the war, the class would nonetheless be retained by the US Navy longer than any other wartime combatant ships, save for the Iowa-class battleships.

Early wartime experience with 8-inch gunned heavy cruisers showed that the main batteries of these ships did not have a sufficiently high rate of fire. There was a school of thought that the “smothering” effect of rapid-fire 6-inch shell hits was more effective than the slow-firing 8-inchers, but the USN aimed to develop an entirely new 8-inch weapon that combined heavy hitting power with a faster rate of fire.

The Mk.XVI gun was an 8-inch 55-caliber weapon, designed to fire shells at the rate of one every six seconds. This was on the order of five times faster than earlier guns, although in service a more modest sustained rate would be the norm. This advance was achieved by using of cased powder charges instead of individual powder bags, and improved power loading equipment. The guns could also be reloaded from any elevation.

Although the main armament of the Des Moines class was of new design, the basic layout of the ships themselves was an extrapolation of the 1942-vintage Baltimore class. The Baltimore design :had been involved into the Oregon City class., with a revised superstructure and a single funnel to improve the arc of fire of the AA armament. This basic configuration would be used again for the Des Moines, but the hull was lengthened and broadened to allow the larger magazines that were necessary to supply the Mk.XVIs.  At 21,000 tons displacement the new cruisers would be heavier than many early dreadnought battleships, and at 718 feet in length were longer than any US BB prior to the North Carolina class.

No fewer than twelve Des Moines were projected, but only the first two, Des Moines and Salem, had their keels laid prior to V-J Day. Eight others were cancelled, some of these well before the end of the war. Work on two others, Dallas and Newport News, was started in the fall of 1945. Dallas was broken up prior to launching, but the remaining three ships were launched in 1946-47 and completed in 1948-49.

Wartime experience had shown that the 40mm Bofors had become ineffective, so the class was fitted from the outset with twenty of the more capable 3-inch/50-caliber weapons. Since the ships’ design had originated in the 1943 timeframe, a pair of aircraft catapults were to be mounted on the fantail along with a handling crane, as was typical on surface combatants of that period. Such installations were obsolete by 1945, but Des Moines was completed with this equipment, and all three ships kept the crane to launch and retrieve boats.

In the early 1970s, the USN began ridding itself of most of its remaining wartime combatants, some of which had been inactive for decades. These included most of the remaining gun cruisers, with the exception of the Des Moines class. The nameship and Salem had been in reserve since 1959 and 1961 respectively, but were kept on the Naval Vessels Register as potential gunfire support ships. Indeed, Newport News, which remained in commission, saw much use in this role off Vietnam. She had also seen service as a flagship, receiving additional electronics and accommodation spaces, at the expense of some of the 3-inch mounts. The other 3-inch weapons were gradually reduced in number, although the last mounts were not landed until very late in the vessel’s career. On October 1, 1972 the ship suffered a major casualty when an 8-inch round exploded in the center gun barrel of B turret. The accident killed the turret crew, and had the fire progressed down to the magazine, the entire ship might well have been lost.

Newport News was finally decommissioned in 1975, being the last active USN all-gun cruiser. Since her damaged turret had never been repaired, and with several decades of service on her machinery, she was stricken in 1978. Des Moines and Salem were still seen as having potential for reactivation, so Newport News was kept on as a spares hulk to support her sisters if necessary. During the early 1980s, it was proposed to bring the two back into service as an alternative or complement to the Iowas, but they remained in mothballs. Striking finally occurred in 1991, and Newport News was broken up two years later. Salem became a museum ship in Massachusetts, but efforts to preserve Des Moines fell through, and she was finally towed to Texas for scrapping in 2006.

Scale Models:

Yankee Modelworks makes a 1/350th scale Des Moines kit.

Bibliography

"Heaviest Heavy Cruiser"   All Hands April 1947.  Includes a photos of USS Newport News under construction, and of an 8-inch turret firing.

Photo: Launching of USS Newport News.  All Hands  June 1947  p.52

Photo: Newport News berthed next to mothballed Bennington.  All Hands  March 1949  p.35

"USS Salem, newest heavy cruiser, joins fleet"  All Hands  July 1949  p.4

Photo: USS Salem on her shakedown cruise, anchored at Port-au-Prince.  All Hands November 1949  p.34

Photo: Des Moines steaming with French cruiser Montcalm during Operation Longstep in the Med. All Hands January 1953  p.21 

Photo: Salem is relieved as 6th Fleet flagship by Des Moines.  All Hands  January 1955  p.38

Photo: Newport News at anchor in Guantanamo Bay.  All Hands  April 1955  p.37

Photo: close-up of the bow 3'50" mount on Des Moines.  All Hands  January 1959

Photo: Newport News berthed alongside USS Boston at Norfolk.  All Hands  March 1967  inside front cover.