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The destroyer of World War II was a fast unarmored
warship
of 1000 to 3000 tons displacement. It was typically armed with
four- to five-inch (10 to 13 cm) guns,
torpedoes,
antisubmarine
weapons, and light antiaircraft
weapons for point
defense.
Destroyers were originally developed to protect
capital
ships from torpedo boats.
This required
rapid-firing weapons and enough speed, range, and sea keeping
ability to
accompany and screen the larger
ships. With the advent of the submarine, the destroyer became the
principal
antisubmarine screening ship, and depth
charges
and sound gear were added to
its
inventory. During the First World War, the
sound gear took the form of sensitive hydrophones, which could
detect
noises
from a nearby submerged submarine. Most of the major powers had
independently developed
sonar, which uses an active
signal to
more precisely locate submarines,
by the
start of the Second World War.
The antisubmarine mission continued through World War II, but destroyers proved to be the workhorses of the fleet. Their main gun armament shifted to dual-purpose weapons useful against aircraft (of which the best was the U.S. 5”/38 gun) and Allied destroyers acquired sophisticated radars. This gave them a significant antiaircraft escort capability. Because of their shallow draft, destroyers were useful for shore bombardment, because they could get in close to shore for accurate gunnery.
The proper role of destroyers was debated vigorously between the world wars. In the U.S. Navy, the younger officers commanding the destroyers favored smaller, faster ships with heavy torpedo armament suitable for an offensive role, while the older officers favored ships that sacrificed some speed for good sea keeping and endurance, making them more suitable for screening the battle line. Destroyers were also needed to act as scouts for the battle fleet, since Congress had provided almost no funding for the light cruisers that usually filled the scouting role in other navies. The British were even more aware of the conflicting requirements for their destroyer forces, since their destroyers were seen both as offensive torpedo craft to wreck an enemy battle line, as screening vessels to protect their own battle line, and as escort vessels for Britain's vast overseas trade.
American destroyers built before the war were almost universally top heavy and very uncomfortable for their crews. Friedman (2004) attributes this to poor coordination between the Bureau of Construction and Repair and the Bureau of Engineering, which shared responsibility for ship design. The two were merged in 1940 into the Bureau of Ships, which seems to have resolved the problem: The Fletchers, built during the war, were stable and very capable ships. Japanese destroyers were also very capable and did not suffer from stability problems, largely because the Japanese had learned this lesson from the Tomozuru Incident, in which a torpedo boat capsized in a typhoon in the 1930s. (Two pre-war American destroyers would capsize in a typhoon late in the war.) American destroyers had powerful antiaircraft armament but miserable torpedoes, while Japanese destroyers were almost the opposite, with poor antiaircraft and the best torpedo in the world — the Long Lance. British destroyers started the war with even worse antiaircraft defenses than the Japanese, but better torpedoes than the Americans, and they excelled at antisubmarine warfare.Much of the difference between American and Japanese destroyers
was a reflection of different naval doctrine. Whereas
the Americans had settled on balanced designs, suitable for
defensive
screening roles as well as torpedo attacks against the enemy, the
Japanese clung to torpedo attack as the primary mission of the
destroyer for much longer. Their role in Decisive Battle Doctrine
was to throw the American battle line into as much confusion as
possible prior to the decisive gun duel with the Japanese battle
line.
American destroyers were designed to have a cruising radius of 5,500 nautical miles (10,200 km) with operations in the Pacific in mind. However, when steaming at their maximum speed of better than 30 knots, destroyers consumed fuel prodigiously. American practice was to maintain an equally lavish fleet train with enough tanker support to keep the destroyers going. The Japanese, with fewer tankers, often refueled their destroyers from the larger warships in the task force, a practice occasionally used by the Americans as well.
The British, faced with both tight naval budgets and the
constraints imposed by the naval
disarmament treaties between the wars, settled on a strategy
of constructing both powerful destroyers to operate with the fleet
and less expensive ships that could be mass produced in the great
numbers needed for commerce protection. The latter were often
rated as corvettes, sloops, or frigates rather than
destroyers. The treaty limits on cruiser construction led to
greater reliance on powerful destroyers to replace cruisers as
protection from enemy surface raiders. Anticipating that their
fleets might have to sail great distances to the theater of
operations (the British already had Japan in mind), the screening
role of destroyers received greater emphasis, and by 1932 all new
British destroyers were being equipped with ASDIC (sonar). British
destroyers were also designed so that they could be equipped at
short notice with Two-Speed Destroyer Sweep (TSDS), a form of minesweeping gear usable
at high speed by destroyers escorting a task force. However, the
British were slow to adopt a main destroyer battery with
significant antiaircraft capability, persuading themselves first
that this was incompatible with good antisurface capability and
then that a maximum gun elevation of less than 40 degrees was
adequate for guns meant to fire at approaching aircraft that were
still some distance away. However, by the time war broke out in
the Pacific, the British were constructing destroyers with
meaningful antiaircraft capability.
The Japanese began the war with 110 destroyers while the Americans had 68 destroyers in the Pacific, the British had just 8 in the Far East, the Dutch had 7, and the Australians had 2. However, while the Japanese constructed an additional 33 destroyers during the war, the Americans alone deployed an additional 302 destroyers to the Pacific before the surrender. Japanese destroyer losses were relatively heavy during the Solomons campaign, and Allied intelligence was quick to appreciate that the Japanese were suffering from a serious destroyer shortage in early 1943. This prompted Nimitz to issue an order on 13 April that destroyers be given higher target priority by submarines (second only to capital ships) in order to aggravate the Japanese destroyer shortage.
Destroyer Missions. American destroyers found themselves employed in four main roles during the war. As anticipated in prewar planning, they screened task forces, but primarily in an antiaircraft role rather than against light surface forces. They played a major role in shore bombardment, a mission also anticipated in prewar planning, but not nearly to the extent that actually took place. Antisubmarine operations were also far more important than anticipated. Finally, destroyers were a major part of what we would now call surface action groups in the Solomons and elsewhere, employing their torpedoes, not against the enemy battle line, but against enemy light surface forces. This mission was almost completely unanticipated.
One aspect of antiaircraft screening that became increasingly prominent under the kamikaze threat was radar picket duty. Fighter director teams had begun working from destroyers as early as late 1943. During the battle of Okinawa, destroyers were stationed 75 miles (120 km) from the fleet and close enough to each other to allow fighter directors to "hand off" control of fighters to neighboring destroyers as needed. However, the destroyers were not close enough for mutual support against either air or surface attack, and, as casualties mounted, picket destroyers began to be paired and to be supported by landing craft armed with antiaircraft weapons. Eventually each picket group was assigned a section of 12 fighters for local combat air patrol. Even this could not always prevent casualties, and consideration was given to converting submarines to radar pickets that could submerge after reporting incoming strikes. A better idea was Cadillac, a sophisticated (for its day) airborne early warning radar, which was not deployed in time to see combat operations, but was part of the plan for an invasion of Kyushu.
American destroyers were somewhat weak on antisubmarine armament
prior to the war. The standard QC
sonar could not
be produced in sufficient quantity to equip the destroyers with
two
sets, as originally planned, and most had a single QC set
throughout
the war. The standard antisubmarine armament in 1941 was just two
depth
charge tracks with five Mark 7 depth charges each. As war
approached
and the need for a stronger antisubmarine armament became clearer,
many
of the older destroyers gave up a bank of torpedo tubes or a 5"
gun
mount (or both) in order to ship up to eight depth charge throwers
and
many more depth charges. Atlantic destroyers had priority, and few
of
the prewar Pacific destroyers shipped more than four depth charge
throwers.
By the time the Pacific War was underway, most U.S. Navy officers had concluded from British experience in the Mediterranean that "... as carriers of torpedoes, destroyers now were secondary to submarines and torpedo planes" (Friedman 2004). As a result, dual-purpose gun armament was given higher priority than torpedo armament on the Allen M. Sumners and subsequent classes. By the time units of these classes were deployed, the Japanese Navy had been so whittled down that aircraft and submarines were indeed the major threat; but, in the meanwhile, there had been numerous torpedo actions in the Solomons and elsewhere. This played a role in the decision to continue arming destroyers with torpedoes in the postwar era.
The rule of thumb at the start of the Pacific War
was that destroyers should have a top speed about 70 percent
greater
than the battle line. By the time the war ended, the fast
battleships
and carriers making
up
the core of the fleet were capable of better than 30 knots, and
destroyers were barely keeping a 5-knot speed advantage. Cruising
range
was also a serious concern. One solution was nuclear propulsion,
but it
was the helicopter that
would restore tactical mobility to the screen
of surface groups.
References
Roscoe
(1953)
Wildenberg (1996)
Worth (2001)
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