|
|
|
 Developments in Naval Warfare Naval developments in World War II may be divided into four categories: (1) carrier operations, (2) amphibious operations, (3) mobile logistics, and (4) antisubmarine warfare. The development that overshadowed all others was the task force system whereby both carrier and amphibious operations were conducted in the Pacific. Also of major importance was the development of the mobile logistics that enabled the task force system to be employed. In addition, the developments that resulted from the campaign against German submarines may have been particularly significant because of their relation to future naval warfare. Task Force System During World War II the expression "task force used in connection with fast carrier operations in the Pacific caught the imagination of the American people and became part of their language, though with a variety of meanings. In the working language of the United States Navy, however, "task force is one of a group of terms employed in connection with a system of organization which it has evolved for managing its combat ships in order to make the most effective use of sea and air in modern, fast-moving warfare, while at the same time providing for the maintenance, support, and constant replenishment needed by these ships. In naval warfare it is the manned ship that fights, not the man himself. A combat ship functions only at sea, but it must return to port at various intervals to prepare and replenish itself again for sea duty. It is therefore possible to separate in time the tactical employment from the logistics of a ship, its operation from its administration, and this separation is carried over into naval organizational structure in a manner not possible in land warfare. The task force method of conducting naval warfare is a byproduct of what might be called the task-type organization of naval operating forces. In this method of organization a combat ship's captain actually works for two commanders. He is under the operational control of a task commander, who is responsible for completing some task within the Navy's mission; and is under the administrative control of a type commander, who is responsible for the ship's upkeep, supply, discipline, and (within certain limits) training. Broadly speaking, a task commander is concerned with functions of purpose, and he serves as operational commander of a composite force of ships suited to a particular purpose. A type commander is concerned with the functions of support, and he maintains the readiness of his ships, which are usually of one type, such as carriers, cruisers, or destroyers. He is an administrative commander and does his job primarily with such of his ships as are in port. The task force organization of combat ships was best represented during World War II by the carrier task forces, which also included battleships, cruisers, and destroyers. Amphibious task forces were composed of amphibious ships of all types, as well as battleships for gunfire support, small carriers for air support, and destroyer types for antisubmarine protection. Replenishment task forces consisted primarily of tankers, ammunition ships, and salvage tugs, with a cruiser flagship and small carriers and destroyer types for protection. These task forces could be divided into task groups and task units, while the administrative commands retained the older designations of squadron and division. The task concept was expanded to the fleet level in 1944. The two task fleets in the Central Pacific were the Fifth and Third fleets: the Fifth Fleet conducted the operations against the Marianas, Iwo Jima, and Okinawa, while the Third Fleet assisted Gen. (later General of the Army) Douglas MacArthur in the recapture of the Philippines. The units that composed these fleets came from the pool of Central Pacific ships, which were assigned or withdrawn as operations required and the condition of the individual ships warranted. When ships were withdrawn from operational status, they reverted to the control of their type commander, whose headquarters were usually located with that of the commander of the Pacific Fleet. Ships newly commissioned or reverting to operational status after extensive repairs were assigned temporarily by the type commander to training commands, which specialized in preparing ships for combat. Such training was usually conducted outside of operational areas, although Japanese forces on bypassed Pacific islands provided targets for aircraft training. Carrier Operations
The task force
system was most widely exemplified in carrier operations. The destruction
of the battleships at Pearl Harbor in December 1941 made the capital ship
of the United States Navy the carrier, with its main battery of manned striking
aircraft carrying torpedoes and bombs and a defensive system consisting
As a capital ship, the carrier caused a revolution in naval
tactics. As long as the gun remained the major weapon, the standard combat
formation was the battleline, with light forces disposed on the engaged van
and rear. When carriers first operated with the fleet, they took station on
the unengaged side. As the manned airplane with its longer range replaced
the big gun, the battle formation was changed to a circular one, with the
carriers in the center, and other forces disposed around them to give them
protection. United States formations were generally tight, with all the ships
making tactical movements together in a task group that included four carriers.
The Japanese operated in looser formations, and carriers with their attached
ships conducted flight operations independently.
The primary striking carrier weapons in the United States
Navy were the TBF Grumman Avenger, which could be used as a torpedo plane
or as a level bomber, and the SDB Douglas Dauntless, a scout and dive bomber.
The fighter that finally triumphed over the Japanese Zero was the Grumman
F6F Hellcat. Japanese aircraft were also given identification names by the
Allied forces. The famous Mitsubishi Zero fighters, for example, were called
Zekes, while the long-range, two-engine Mitsubishi bombers were known as Bettys.
All American ships were equipped with aircraft and surface
radar by the end of 1942, but radar did not come into general use in the Japanese
Navy until late in 1943. The Japanese fought such major actions as the battles
of the Coral Sea and Midway without it. United States fighter aircraft in
these and subsequent engagements were directed against oncoming raids by fighter
directors using radar, thereby enabling the fighters to meet enemy aircraft
from 50 to 70 miles out. The extensive use of radar resulted in the establishment
in United States ships of a combat information center (CIC), where all information
received was analyzed and plotted and then relayed to the flag or commanding
officer for his action. In some cases the officer in tactical command took
his station in the CIC. It was surface radar that finally enabled the Americans
to overcome the superiority of the Japanese in night actions.
Antiaircraft fire from United States ships early in the
war was not effective, and enemy planes that were able to elude the United
States fighter planes had good chances of making a successful attack. The
variable-time (VT) or proximity fuze in antiaircraft ammunition, which was
adopted in the Pacific in January 1943, changed this situation. An influence
fuze, the VT was actually a small radar set that triggered the firing mechanism
within 70 feet of the target in its destructive zone. At first it was restricted
to naval actions, since it was feared that its use against land targets would
result in its discovery by the enemy. In 1944, VT fuzes were employed successfully
against V-1 flying bombs, as well as by ground forces in the Battle of the
Bulge, the importance of which was considered to justify the possibility of
discovery. Exploding a short distance above the ground, this fuze made the
foxhole valueless as a safeguard for the foot soldier.
Amphibious Forces
All ground operations
in World War II began with amphibious assaults. The first, made in August
1942 at Guadalcanal, was a defensive operation designed to seize the island
in order to halt the Japanese thrust into the Solomons. It was followed in
November by landings in North Africa. Amphibious operations in Europe included
the assault on Sicily in July 1943, the cross-Channel invasion of Normandy
in June 1944, and the movement into southern France in August. These were
all primarily operations intended to seize beachheads from which large forces
would subsequently break out for land campaigns. In the Pacific, however,
one amphibious operation necessarily followed another. Amphibious operations
in the Southwest Pacific were made at frequent intervals in relatively short
shore-to-shore movements, while in the Central Pacific they involved large
lifts over long distances. The assaulting forces in Europe were Army troops,
whereas in the Central and Southwest Pacific both Marine and Army forces were
employed. A greater amount of improvisation was necessary in the Southwest
Pacific than in the Central Pacific, since naval elements were smaller and
the theater generally received lower priorities for amphibious equipment.
Because of sound doctrine and proper landing equipment,
all United States amphibious operations in World War II were successful. The
doctrine had been developed by the United States Marine Corps in the two decades
before the war, under the shadow of the British failure at Gallipoli in World
War I. It was set forth in a Manual for Landing Operations, which
attempted to define (1) command relationships; (2) naval gunfire support;
(3) air support; (4) ship-to-shore movement; (5) the securing of the beachhead;
and (6) logistics. The basic doctrine outlined in this manual withstood the
long trial by fire in war without fundamental changes.
The reason for this success was without doubt the provision
of adequate craft for the landing of assault units and for logistic support
over the beaches until proper port facilities could be built. The landing
craft were of two basic types: (1) ships and boats that had the ability to
beach without swamping, and also to withdraw; and (2) amphibians. Hulls of
the first type were designed so that the craft grounded on only a small area
forward. In withdrawing, the slipstream from the protected propeller washed
away sand in the grounded area, thus releasing the craft from the beach. A
ramp forward facilitated the rapid discharge of passengers and cargo. The
smaller types, which were carried aboard transports, were designed by Andrew
J. Higgins, a New Orleans boatbuilder. These were the LCVP (landing craft,
vehicle and personnel) and the LCM (landing craft, medium), which were capable
of transporting a tank. A larger type, designed to proceed under its own power
to the designated area, was of British design; it included the LST (landing
ship, tank) and the LCI (landing craft, infantry). The LCI subsequently evolved
into a close-support gunboat type, while the LST with its ample tank deck
became one of the most useful crafts in the war, employed in a range of logistic
services far beyond those originally intended. LST's were employed as hospital
The second basic type of landing vehicle, the amphibian,
could be propelled both in water and on land. The caterpillar type, invented
by Donald Roebling, was able to cross the shoals and beaches of the Pacific.
Two models were employed: the personnel carrier, LVT (landing vehicle, tracked),
with a ramp in the rear, which allowed troops to debark quickly under some
cover; and the LVT (A), or armored amphibian, which was actually an amphibious
tank. The Army developed a vehicle of its own, code named the DUKW, an amphibious
truck with a propeller drive in the water and a wheeled drive on land.
Special types of large amphibious ships also were built,
mainly for the transport and support of landing craft, such as the LSD (landing
ship, dock) and the LSV (landing ship, vehicle), an amphibian carrier. The
assault transport or cargo ship carried as many as 9 LCM's and 26 LCVP's.
An important element in an amphibious operation was the
shore party, which included the labor for quick unloading under difficult
conditions. In the Central Pacific, where troop space in large overwater movements
was limited, such labor was performed by a small number of specialized service
troops augmented by reserves, although the latter were often called into combat
when the unloading phase was at its most critical stage. In the Southwest
Pacific the engineer special brigade was employed; it had regiments consisting
of a boat battalion and a shore battalion, ably officered and with needed
service troops attached.
Mobile Logistics
The major carrier
and amphibious operations in the Pacific could not have been carried out without
a highly developed system of mobile logistics. By means of this system ships
of the Pacific Fleet were able not only to remain indefinitely in forward
areas adjacent to enemy territory, but also to cruise at sea for long periods
in readiness for combat. Such mobile logistics enabled combat ships to receive
fuel and other needs from service ships either while under way or at anchorages
near operating areas. Advanced base facilities were maintained afloat at all
times, and techniques were developed for transferring fuel, ammunition, stores,
and personnel at sea, thus freeing combat ships from the necessity of returning
to port at frequent intervals.
The maintenance of logistics afloat had two advantages in
addition to keeping combat ships at sea: (1) Service craft could move forward
relatively easily either under their own power or by towing. (2) Better storage
and handling facilities and more accurate inventory control were available
than in primitive shore areas. The disadvantage was the great demand for ships.
The primary requirement of a floating base is a large anchorage
affording good holding ground and capable of being protected from submarine
attack. Adjacent land is required only for fighter strips, recreation areas,
and those naval facilities that can perform their functions better on shore.
The atolls and islands of the Central Pacific provided such areas, and in
the advance across the ocean United States naval forces used the anchorages
at Majuro, Eniwetok, and Ulithi. Earlier in the war floating bases were established
in conjunction with shore facilities at Noumea in New Caledonia, Espiritu
Santo in the New Hebrides, and Manus in the Admiralty Islands. Afloat bases
were later located at Samar in the Philippines and the Kerama-retto near Okinawa.
From its beginning the United States Navy had a tradition
of operating with afloat logistics, since historically it was a navy without
proper bases even in its own country. Nevertheless, the immensity of the logistic
problem in a cross-Pacific war had not been realized in prewar planning. Various
reasons may be advanced for this failure, the most logical being the discontinuance
of the study of logistics at the Naval War College and the fact that fleet
problems could not be made broad enough for the impact of logistics to be
felt. As a result, major problems had to be solved just before or during the
war. A logistic structure had to be improvised, and the reason that it was
done so quickly and so well was that abundance could cover mistakes.
The first conception for providing logistics for the fleet
was the establishment of advanced base units on shore. Such units were specially
organized in the United States with equipment packaged for erection in forward
areas. Designated as Lions (major bases), Cubs (minor bases), and Acorns (aviation bases), they included construction battalions,
boat pools, harbor defense units, repair facilities, and other functional
components. These had to be set up in advanced areas and could not readily
be moved forward as the war advanced. Cubs were established at Espiritu Santo
and Guadalcanal, and a Lion was set up at Manus. As the war moved closer and
more rapidly toward Japan, this conception was largely abandoned.
With the capture of the Marshall Islands in February 1944,
the practice of afloat logistics came into its own. Most of the service ships
at Pearl Harbor were transferred to Majuro to form Service Squadron 10. This
force was a medley of floating equipment, including repair ships, floating
dry docks, tenders, provision ships, ammunition ships, hospital ships, station
tankers, lighters, tugs, floating cranes, distilling ships, survey ships,
cold storage ships, and floating barracks. The largest piece of floating equipment
used during the war was the ABSD (advanced base sectional dock), capable of
lifting 90,000 tons and docking any ship in the Pacific. Any of its sections
(a maximum of 10) could be towed forward separately and be docked by the others.
The second element in mobile logistics during the war was
afloat replenishment, which enabled ships to remain at sea longer than steam
vessels had ever done before. The continuing requirement was fuel oil, of
which a combat ship always required sufficient for battle. The practice in
the Pacific therefore was to fuel at sea every three to five days. The technique
of such fueling, which had been developed in the United States Navy before
World War I, did not change essentially thereafter. Two ships would steam
alongside each other, one at a slightly greater speed so as barely to tow
the other, and both under rudder control. Fuel would be delivered through
flexible hoses that were kept suspended and out of the water between the two
ships by booms and running gear. The British Navy, having operated through
two world wars largely in the North Sea and with bases elsewhere in the world,
had not developed an efficient technique of fueling at sea, and the Royal
Navy carrier force that joined the Pacific Fleet in 1945 had to fuel by the
slow method of towing in tandem with a floating hose between the two ships.
The major replenishment need after fuel was ammunition, for magazine space
in combat ships was limited. In the later stages of the war provisions and
special stores, replacement aircraft, and even personnel also were transferred
at sea.
The replenishment force operated as Service Squadron 6 during
the Iwo Jima and Okinawa campaigns. While its composition varied with conditions,
it was generally composed of a light cruiser flagship, about 16 tankers, 4
ammunition ships, 4 fleet tugs or salvage ships for towing crippled ships
from the battle area, 2 aircraft transports, provision ships as required,
and protective escort carriers and destroyer types.
The realization of the importance of mobile logistics was
illustrated in the Okinawa campaign by the seizure before the assault landing
date of the Kerama-retto, an island group west of Okinawa that had a good
anchorage. Mobile logistics was not nearly as essential for ground forces
and land-based forces in the Pacific as for naval forces, but it was found
that, where sufficient shipping was available, it was preferable to retain
supplies afloat until they were needed ashore. The transfer forward of army
bases from the New Guinea coast after the recapture of the Philippines necessitated
the withdrawal of a large number of LST's from combat operations.
To move men and materials across two oceans required a complete
reorganization of the American merchant marine and a tremendous shipbuilding
program. In February 1942, the War Shipping Administration (WSA) was established
to provide shipping needs for the war economy and the armed services. Two
standard types of cargo ships were built rapidly and in quantity by the American
shipbuilding industry: the 10-knot Liberty ship and, later, the 15-knot Victory
ship. These ships were then outfitted and manned by shipping companies but
were operated by the WSA.
Antisubmarine Operations
Insofar as
future warfare was concerned, the most important naval developments of World
War II may have occurred in the North Atlantic, where the struggle for survival
of Great Britain was won before the United States offensive in the Pacific
began. The victory over the German submarine was mainly the result of British
efforts, the United States contribution consisting primarily of mass production
processes.
Karl Doenitz (Donitz), the German admiral in command
of submarines, was one of the toughest naval antagonists that the Allies met
during the war. He believed that Germany could win only by sinking an average
of 750,000 tons of Allied shipping monthly, and his strategy was to keep his
submarines moving to areas where sinkings were easiest to obtain. Against
convoys he preferred to use heavy concentrations of U-boats known as wolf
packs in continuous attacks, directing them individually from his headquarters
ashore. The weakness in this method of control was the amount of two-way radio
traffic required: Allied high frequency direction finders were able to locate
German submarines with considerable accuracy. Wider convoy routing and better
antisubmarine precautions in distant areas forced Doenitz to return to the
shipping lanes of the North Atlantic, and it was there that the battle was
finally settled in the summer of 1943.
The German submarines were defeated by the Royal Navy's
battle-scarred escorts and by aircraft of the Royal Air Force (RAF) Coastal
Command under the operational control of the Admiralty. British scientists
also made contributions to this victory, two of them major: microwave radar
and operational research on antisubmarine warfare methods. The British success
can be attributed to radar; sonar (asdic in British terminology), high frequency
direction finding; the escort carrier; antisubmarine support groups of destroyers,
which reinforced the escorts of convoys under attack; and the extension of
land-based airpower across the Atlantic by the employment of B-24 Liberators.
The principal United States contribution was the escort carrier, used to cover
the areas in the mid-Atlantic that land-based aircraft did not reach. Escort
groups, consisting of a small carrier and about 4 destroyer types, began operating
in June 1943. They were especially successful in locating submarine refueling
rendezvous. Hunter-killer groups of this type are still retained in the operating
forces of the United States Navy.
The technological advance that proved most fruitful for the British in the antisubmarine campaign was
microwave radar. German submarines while on the surface were able to detect
enemy use of long-wave radar and could submerge in time to avoid attack. They
failed, however, to discover that microwave radar was being employed against
them until 1944, with the result that surface vessels were able to approach
close enough to a submarine before it submerged to get it on the sonar. Coastal
Command aircraft were eventually fitted with this type of radar. Used in conjunction
with the Leigh light, a powerful searchlight controlled by the radar set,
it was able to surprise surfaced submarines, which could be attacked before
they submerged.
Late in the war antisubmarine ordnance was radically improved
by the introduction of a projectile to augment the depth charge. The mount,
called a hedgehog, threw 24 missiles over the bow of the attacking ship. Since
the missiles exploded only after one of them had struck the submarine, there
was no explosion in an unsuccessful attack to disturb the sonar search and
give the submarine time to escape.
Because sailing in convoys delayed shipping, vessels capable
of making 15 knots and over sailed singly, with the expectation that faster
turnarounds would compensate for submarine losses. Pressure was brought on
the Admiralty to sail 13-knot ships singly as well, but this change proved
a mistake, and the 13-knot convoys were reestablished in May 1941.
Improved convoy efficiency was finally attained through
operational research. By analytical studies of attacks, British scientists
discovered that the number of sinkings bore no relation to the size of the
convoy and depended only on the number of attacking U-boats, on whether the
convoy had air escort, and, when it did not, on the number of surface escorts.
Convoys were therefore increased in size from 32 to 54 ships, providing both
better protection and faster delivery of cargoes. Air escort during daylight
was found to decrease losses by an additional 64 percent, making sinkings
negligible.
Late in the war the Germans developed the snorkel, by which
a submarine could both cruise and charge batteries underwater with only the
extension of this breather pipe exposed. It was perfected too late to affect
the German submarine effort and require antisubmarine methods to counter it.
But the problem of countermeasures remained with the postwar nuclear-powered
submarine, a true submersible able to remain underwater constantly and cruise
at great depths with high speed.
John D. Hayes
|