Sep 16

Cruisers: Interwar Roles and Limitations

Wednesday, September 16, 2015 11:52 AM

By

An excerpt from “The Fleet’s Ambiguous, Versatile Warships,” by Norman Friedman, in the October issue of Naval History magazine

The 1922 Washington Naval Treaty's restrictions on capital-ship construction also signaled the start of a race to build cruisers, which the pact limited to 10,000 tons and 8-inch guns. Above: The Pensacola (CA-24) was the first of these U.S. "treaty cruisers."

The 1922 Washington Naval Treaty’s restrictions on capital-ship construction also signaled the start of a race to build cruisers, which the pact limited to 10,000 tons and 8-inch guns. Above: The Pensacola (CA-24) was the first of these U.S. “treaty cruisers.”

With the end of World War I, U.S. naval policy turned from concentration on Europe to concentration on the Far East and Japan. Even so, supporters of continued U.S. naval construction exploited widespread anti-British feeling in the United States by suggesting there was a U.S.-British naval rivalry. This was despite the fact that the United States and Great Britain were given naval parity in the 1922 Washington Naval Treaty while the far more likely enemy, Japan, was given the short end of the 5:5:3 capital-ship tonnage ratio. The U.S. Navy adopted a politically inspired policy of demanding parity in cruiser strength, even though the U.S. and Royal navies had radically different cruiser requirements. For the U.S. Navy, cruisers were almost exclusively part of the battle fleet. For the British, they were insurance against future commerce raiding as well as members of the battle fleet.

That demand extracted a large cruiser program from Congress and eventually led to a drastic reduction in British cruiser strength. In retrospect, both navies apparently found their supposed rivalry a valuable way of ensuring a degree of superiority over Japan. But the Depression led to cuts in U.S. and British naval spending, and Japan pulled ahead of its intended naval ratio.

As envisaged during the interwar years, cruisers had several roles in a fight between fleets. As before, some served as scouts that would make the engagement possible in the first place. Other cruisers working directly with the fleet would beat off enemy destroyers trying to fire torpedoes at the capital ships. Yet others might support their fleet’s own destroyers against the enemy’s protective cruisers. All of these ships would contribute to the fleet’s antiaircraft firepower, but by the late 1930s the U.S. Navy had concluded that fleet air defense would depend mostly on fighters, not surface ships.

Cruisers were also essential to attacks on enemy trade. Even though the World War I German U-boat campaign had proven extremely effective, it seemed unlikely that the U.S. Navy would conduct a similar campaign against Japan. The fear was that, just as the indiscriminate deaths of Americans and sinking of American ships during U-boat attacks had brought the United States into the Great War, a U.S. submarine campaign against Japan might similarly draw Britain, Tokyo’s one-time ally and the greatest shipping power in the world, into a war. That left the classic type of trade warfare, in which cruisers stopped individual merchant ships and seized or sank those belonging to the enemy or carrying contraband. In such a campaign, numbers mattered.

Perhaps the most important effect of the horror of World War I was to encourage postwar attempts to limit naval armaments. The first wave of limitations, in the form of the Washington Naval Treaty, killed the U.S. battle-cruiser program, leaving only Britain and Japan with these type ships. An attempt to limit total cruiser numbers failed, but the treaty did restrict future cruisers to 10,000 tons and 8-inch guns.

The U.S. Navy saw such large, or heavy, cruisers as the closest it could get to battle cruisers and as one of several ways the service could accomplish long-range scouting in the western Pacific. For example, scouts could spot a deploying Japanese battle fleet in time to cue a U.S. fleet to engage. The Navy considered this mission so important it also pursued using large submarines and rigid airships as scouts. It might be argued that the slow-firing 8-inch gun was hardly best suited to the cruiser role inside the battle fleet, but the weapon offered sufficient range to perhaps enable a lightly armored scout to beat off Japanese battle cruisers.

Through the 1920s the British rebuffed the U.S. government’s attempts to convince them to accept parity in cruisers with the argument that the Royal Navy needed many more such ships to protect the empire’s global trade against the threat of various kinds of raiders, including converted merchant ships. By 1929 Great Britain’s finances were sufficiently strained that agreement was possible, partly because the British realized they could never build as many cruisers as they thought they needed. They extracted an agreement—the 1930 London Naval Treaty—drastically limiting construction of cruisers with 8-inch guns, their theory being that any rational navy would build smaller and much more affordable 6-inch gun cruisers. (They favored the 7,000-ton Leander design.)

The 10,000-ton USS Brooklyn (above) and her sisters featured 15 6-inch guns.

The 10,000-ton USS Brooklyn (above) and her sisters featured 15 6-inch guns.

 

The United States signed the treaty but went on to build 10,000-ton ships armed with 6-inch guns (the Brooklyn class of light cruisers), much to the horror of the British. The Brooklyns were envisaged in the anti-destroyer role, their very high rate of fire being particularly attractive. The 8-inch heavy cruisers served prewar as fleet scouts, in concentrated formations. Strategic scouting in the western Pacific became a role for submarines and, it was hoped, would become one for airships.

Planning for War

Most of the American cruisers remembered from World War II were built under programs framed in 1939 to 1941, before the United States entered the conflict. They were conceived with the interwar ideas of fleet battle and trade warfare in mind, not the lessons of Guadalcanal or the big carrier battles. The fact that aircraft carriers offered decisive advantages in terms of mobile firepower was already understood, though observers probably had not yet accepted carrier planes’ ability to sink battleships at sea.

Whether carriers should be integrated with battleships was not clear. The great argument against integration was based on the premise that carriers were fragile. Whichever side found the enemy’s carriers first would destroy them—as at Midway. The battle line was relatively easy to find from the air, hence any nearby carriers would be located quickly. Yet carriers could not operate without surface escorts because enemy battleships finding carriers could quickly sink them, just as the German Scharnhorst and Gniesenau had done to HMS Glorious in 1940. Before fast battleships joined the U.S. fleet, fast cruisers were the only available carrier escorts. Moreover, if the battle line was to play a major role, any fast battleships might best be used as its fast wing, not assigned to completely different duty.

Prewar U.S. strategy against Japan envisaged a campaign culminating in a decisive fleet battle, after which a blockade would be mounted to squeeze the enemy into surrender. Prior to the battle, cruisers could conduct antishipping sweeps, both to force the enemy to dissipate its own energies and to run down its merchant fleet. Cruisers were essential in this role because they could operate independently. Not surprisingly, the building programs included large numbers of cruisers armed with 6-inch guns (the Clevelands) and smaller numbers of larger cruisers armed with 8-inch guns.

These programs also included two outliers, the small Atlantas and the huge Alaskas. The former were conceived in 1937 to support destroyers attacking an enemy battle line, a role previously avoided because it had lower priority than either strategic scouting or protecting against Japanese torpedo attacks. That is why the Atlantas had 5-inch/38-caliber destroyer guns and torpedo tubes.

Japanese heavy cruisers posed a serious threat to an American campaign across the western Pacific. The U.S. fleet’s lines of communications would need to be protected from raids and its carriers screened. Consequently, the Alaskas were conceived as heavy-cruiser killers. Armed with 12-inch guns, these huge cruisers were often described as battle cruisers or light battleships.

 

To read Dr. Friedman’s article in its entirety, go to: http://www.usni.org/magazines/navalhistory/2015-10/fleets-ambiguous-versatile-warships