The ASW “Six Pack”
By Ensign John W. Skipper, U. S. Navy
The requirement to continuously improve the antisubmarine warfare capability of the U. S. Navy has been well documented, and, with varying degrees of success, several special projects and designs have been explored to fulfill this requirement. The following concept is proposed purely for academic discussion and is not necessarily a design proposal.
The scene takes place in the mid-Atlantic. An ASW ship has been dispatched to investigate a suspected submarine contact which was reported earlier by an aircraft. Arriving at datum at 50 knots, the ship slows to 22 knots, divides herself into six separate units and begins to search a portion of ocean 140 miles wide. How is this possible? This is an ASW barge-train, doing its thing.
The basic unit in the barge-train has a 110 to 120-foot overall length and a 48-foot beam, with an 8-foot draft. It is a true trimaran. Each hull has a 12-foot beam, a 15-foot depth (giving 7-foot freeboard), and there is a 6-foot space between hulls. On a platform across the three hulls is a 7-foot high structure which leaves only 2 feet of deck space on all four sides. She faintly resembles a monitor. Construction is of boron-epoxy, aluminum, and fiber glass. Boron-epoxy is an advanced composite having an approximate 3.5-to-1 strength and a 3.7-to-1 modulus/weight ratio over aluminum.
There is no deck or bulkhead area inside or out that is not covered with fiber glass, so there is no necessity for chipping and painting. Indoor-outdoor carpets are used throughout for cleanliness and sound absorption.
Propulsion is provided by gas turbine engines in the outboard hulls driving hydro-jet pumps. The maximum speed of an individual unit is 65 knots. The barge-train maximum speed is 60 knots.
A CODAG system was not provided, since in the barge-train configuration, only those units required to maintain the desired speed are operated. However, an auxiliary generator is installed to provide electric power and a retractable electric outboard motor is available for emergencies.
Although all units are similar, there are some differences and for extended or special cruises, special units are available.
Type Alfa is the control unit. Its primary mission is to provide space for the command information center and command. Alpha and Alfa-One are lead units and are ten feet longer than the other units. Just as in all units, type Alfa has an advanced sonar mounted in the bow of the center hull. To prevent mutual interference, each sonar in a raft has a different active mode frequency.
Type Alfa contains the target data collection, analysis, and control system. Into this system is fed (via VHF/UHF data link) the sonar and radar data from all units. Feedback channels in the data link are able to control equipment function in the various units. Weapons can be controlled from the individual unit or by the control unit. There are also covered voice channels available in this system.
Type Alfa has a completely enclosed bridge at the 01 level. However, the bridge is not really required as the unit is actually conned in main control. Located inside the center hull, the helmsman sits in a padded chair, wearing a safety belt, and watches not a compass, but four television screens. The closed-circuit TV gives the helmsman 360-degree vision with a 10-degree overlap on each screen. Low light level TV and/or infrared is employed during hours of darkness. Course information appears in digit form just below the horizon on all screens. The conning officer sits directly behind and slightly to the left of the helmsman and controls the closed circuit TV system.
A fifth TV screen, directly to the left, is also controlled by the conning officer. The camera feeding this screen is movable (remotely) through a 1,080-degree arc (three times around from lock to lock) and is fitted with 20-power zoom lens and power magnifiers.
[Figures depicting the external concepts of the “ASW Six-Pack (Racked up),” “Type Alfa and Alfa-One,” “Type Bravo and Charlie,” and “Type Delta.”]
Conning and helmsman facilities are also located on the bridge for use in case of system failures.
Directly behind and slightly to the right of the helmsman is the Basic Control Panel (BCP). The BCP operator controls the propulsion, fuel, water, sanitary, docking, and electric systems of the unit and throughout the other units when they are in the barge-train configuration.
Intra-unit communications, electric distribution, fuel, and water transfers are all accomplished by the BCP operator using a probe and drogue hook-up system. The probe section of this system is mounted on the starboard bow of the superstructure of all units except type Alfa and Alfa-One. The drogue section is mounted on the starboard stern side of all units. The probe and drogue system for connection between type Alfa and Alfa-One units is located on both sides of the stern.
Main communications spaces are located in type Alfa. Communications capabilities include ship-to-ship, ship- to-shore, ship-to-air, and ship-to-underwater. Frequencies used are from DC to EHF, and communications modes include voice, printer, and data. All equipment is solid state, modular construction with self diagnostic read out for modular failure.
There are living and airline-type emergency messing spaces in type Alfa for the watch-standers as well as for the commanding officer, operations officer, and communications officer.
The ASW weapons capability of type Alfa is limited to two active/passive ASW homing torpedoes, mounted in non-trainable tubes recessed into the outer hulls at their highest outboard point.
Self-defense weapons in type Alfa consist of one four-tube rack containing small surface-to-surface missiles similar to the French SS-12M. This rack is mounted on the center line, aft, atop the superstructure. Hand weapons are also available.
Contact on a suspected submarine has been acquired by type Alfa-One and this information has been automatically relayed via the data link to the target data collection, analysis, and control system, as well as the weapons control system on type Alfa-One.
Type Alfa-One, externally, is a twin of type Alfa. Internally, Alfa-One is conned in the same manner, but there is no BCP. This function for this unit is performed by the helmsman’s assistant at the conning station. There is a small target data collection, analysis, and control system which can be operated in emergencies.
The main mission of this unit after ASW is to provide space for a ships’ office, executive officer’s office, electronic countermeasures (ECM), all messing spaces, and berthing for the personnel assigned to the unit. The ASW and self-defense systems of Alfa-One are the same as type Alfa.
The orders from Commander Antisubmarine Warfare Force, Atlantic (ComASWForLant) for this barge-train for this mission are “track, trail, and report.” The barge-train commanding officer now orders all units into passive sonar mode and directs them into a large “U-shaped” formation behind and up both sides of the contact. Range from contact is set at five miles.
The two type Bravo units are in position at the base of the “U.” The construction of type Bravo is the same as the basic unit, except there is no bridge. Instead, all units other than type Alpha and Alpha-One, have visual observation bubbles fore and aft to supplement the video system normally used by the helmsman.
In addition to the sonar mounted in the bow of the center hull, type Bravo is also fitted with variable depth sonar (VDS), which is operated through a well in the stern section of the center hull. The VDS streamed at different depths makes it possible for the two type Bravo units to detect any change in depth or direction of the contact.
By using two type Bravo units in each barge-train or raft, even in waters that are not good sonar seas, a good target locating and tracking system is available to the barge-train commanding officer.
The ASW weapons system of type Bravo is composed of two twin ASW torpedo mounts. These mounts are located amidship, recessed into the superstructure and are trainable through a 90-degree arc. There are no reloads normally on board.
Self-defense against surface and air threats is concentrated in one Basic Point Defense Missile System. The mount for this system is located on the center line aft.
Type Charlie has now moved into position on the port point of the “U.” With the exception of armament and VDS, type Charlie is the same basic unit as type Bravo.
The long-range ASW striking power for the whole barge-train is mounted on type Charlie in the form of two twin antisubmarine rockets (AsRoc) mounts. There are normally no reloads carried on board. The mounts are positioned athwartships, one facing each side, thus negating the requirement for a trainable platform. The front of each mount can be hydraulically raised to 50 degrees. A water-cooled blast deflector shield is located behind each mount.
A fully-automatic, remotely-controlled, medium-caliber gun mount is located on the center line forward for self-defense.
By positioning type Charlie on the port point of the “U”, two AsRocs are continually trained on the contact. The starboard point would also be a good position[;] however, Charlie was already on the port side of the contact.
Type Delta, on the starboard side of the contact, is now in the starboard point position of the “U”. The construction and ASW system on type Delta are the same as type Bravo. The large bore, conventional defense system for the barge-train is located on type Delta in the form of one center line, 5-inch, 50 caliber gun mount amidship.
This unit is a small, fast, very-maneuverable, and hard-hitting platform. Several of the type Delta units are sometimes used together for shore bombardment.
The “U” formation is completed by positioning Alfa midway between Charlie and the port Bravo, and Alfa-One between Delta and the starboard Bravo.
Tracking a contact can be a tedious and sometimes frustrating task. But, with eight sonar sets on six platforms (all of which are within five miles of the contact), it is almost impossible for a submarine to break free. With all units in passive sonar mode, there is a very good chance that the submarine is unaware that she is under surveillance.
After 18 hours of tracking, word is received from ComASWForLant to “break contact” as the submarine is following a “homeward bound” track. The barge-train commanding officer now maneuvers the units into docking position.
The docking and securing system is made of four subsystems. The positioning subsystem includes radar transponders and distance-measuring (DME) devices, which are used to align properly the units in the docking process. With the exception of type Alfa and Alfa-One units, there are eight devices on each unit (i.e., two on each side). Type Alfa and Alfa-One are fitted with only six devices, as they are lead units. Additionally, an infrared/visual system is installed for use during periods of emission control.
The securing subsystem is composed of connectors similar to those used with railroad cars. However, there is only five degrees of horizontal or vertical movement possible. There are three positions available for the couplings: (1) extended six feet from the hull (initial docking position), (2) extended one-and-a-half feet from the hull (cruising position in the barge-train configuration), and (3) fully retracted inside the hull (independent operations position).
After the radar transponders/DME have guided the units into position, the couplings have made contact, locked, and then drawn the units into position three feet apart, the third subsystem, an air inflatable collar, is inflated between the units to prevent the sea from coming up between them. The fourth subsystem is now activated. This subsystem consists of covered expandable walkways which extend from unit-to-unit to provide weatherproof access throughout the barge-train. The walkways (six per unit) are stored in the first three and last three feet of the superstructure in all units, except for the lead units which have only three walkways.
The basic barge-train configuration is one Alfa in the forward port position, one Alfa-One in the forward starboard position, followed by two Bravo units, and then one Charlie and Delta units. This arrangement gives the barge-train the following weapons: (for ASW) 16 ASW active/passive homing torpedoes and four AsRoc missiles/torpedoes; (for self-defense) one 5-inch, 54-caliber dual purpose gun, one medium-caliber mount, two Basic Point Defense Missile Systems, and two quad-tube, short-range, surface-to-surface missile systems.
Having completed docking, the barge train now turns back towards her Norfolk homeport, accelerates to 50 knots and, setting the normal underway watch, follows her own “homeward bound” track.
There are several special-purpose type units which are attached to the barge-train as required. All of these units are constructed on the same basic trimaran and have the same bow-mounted sonar in the center hull. The various units include, but are not limited to: type Echo, which is a tanker; type Foxtrot, a repair shop; type Golf, an antiair warfare unit; type Hotel, a messing and berthing unit, and type India, a squadron commander unit.
A barge-train tender is made up of one Alfa, one Alfa-One, two Echos, two Foxtrots, a Hotel, and an India. These units are in the barge-train configuration while underway, but in port, they are separated and moved to where their services are required.
This author feels that if one compares the ASW, AAW, and self-defense capabilities of a barge-train with that of ships having the same basic mission, the barge-train will show a definite edge over the other conventional units.
Japan’s Naval Air Strength
By Lieutenant General Masataka Okumiya, Japan Air Self-Defense Force (Retired)
Japan—an island country located in the northwest Pacific with a total area of only 142,728 square miles—is larger than the Philippines, smaller than the state of California, and two thirds as big as France.
With a population of nearly 110 million and limited arable land, the country is handicapped in supplying itself with food. It relies on foreign countries for many vital raw materials. For example, 99% of both crude oil and iron ores and 100% of both nickel ores and bauxite are imported. In addition, as the world’s second largest fishing country, Japan must send its fishing fleets to the Atlantic as well as the Pacific and the Indian Oceans. Consequently, Japan has had to trade with almost all the countries of the world in order to support her economy.
These facts clearly show how closely Japan’s safety is associated with world peace and how great a role its naval air strength plays in national safety. Needless to say, one half of Japan’s present Maritime Defense Force consists of the maritime air force.
One of Japan’s most important defense policies is to secure its safety with the existing defensive setup under the American nuclear umbrella. For this purpose, Japan set up the Ground Self-Defense Force in 1950, the Maritime Self-Defense Force in 1952, and the Air Self-Defense Force in 1954. As these three Self-Defense Forces were fostered by the assistance of the U. S. Army, Navy, and Air Force, they have their respective air units.
Japan’s naval air strength is not only the air force of the Maritime Self-Defense Force, but also includes all air units operational over the seas. Unlike other nations’ naval air strength, however, the operational area is limited, by the Constitution and other regulations, to the Japan mainland and its adjacent waters.
The Fleet Air Force consists of four air wings of fixed-wing antisubmarine aircraft and one air wing of antisubmarine helicopters. The Air Training Command is responsible for training pilots and other aircraft specialists. The Maritime Self-Defense Force has a total of 270 aircraft—166 antisubmarine fixed-wing and helicopters and 104 trainer, transport, and liaison aircraft. A breakdown of the antisubmarine type shows it to consist of 55 S-2F, 55 P-2V-7, 12 P-2J, and two PS-1 aircraft, and 40 HSS and two V-107 helicopters.
The Fleet Air Force, it can be seen, is equipped and trained mainly for antisubmarine operation. It has little capacity for other operations and air activities and cooperation from other Self-Defense Forces and American forces is vital.
The Air Self-Defense Force has about 210 F-104J and F-104DJ fighters, about 300 F-86F and RF-86F fighters, about 50 YS-11 and C-46 transport aircraft, about 350 trainers, seven small MU-2 twin-engined rescue aircraft, and about 40 rescue helicopters. Because of the type aircraft in the Air Self-Defense Force, it has very little capacity for naval operations.
The Ground Self-Defense Force has a total of about 350 planes—130 small propeller aircraft and about 220 medium and small helicopters. Their maritime activities are also almost nonexistent.
The naval air strength, up until the present time, could counter possible emergencies, since air units of the U. S. Navy, Marine Corps, and Air Force were in Japan in accordance with the Japan-U. S. Security Treaty. However, most of the American air units, except for the Marine Corps air wing, withdrew from Japan in early 1971 under provisions of the Nixon Doctrine. The comprehensive capabilities of the naval air strength of the Self-Defense Forces should now be restudied. Its main problems are as follows.
Maritime Air Reconnaissance—The Maritime Self-Defense Force aircraft have the desired capability in terms of performance and numbers for reconnaissance and search for submarines and unarmed ships, but they are almost powerless against warships equipped with modem anti-aircraft guns and missiles.
The Air Self-Defense Force has a Reconnaissance Squadron, composed of RF-86F planes, which is trained to be used largely against ground targets and not against warships and other vessels. Therefore, even if they take pictures of these vessels, the Air Self-Defense Force is not equipped to identify them. Obviously, there remains a great need for improvement of cooperation in maritime operation between the Maritime and the Air Self-Defense Forces.
Antisubmarine Operations—The antisubmarine component of the Maritime Self-Defense Force has the capacity to support the functions assigned its aircraft and helicopters. Yet, there exist the problems of insufficient numbers and performance of aircraft necessary to cover the seas. The Maritime Self-Defense force has no aircraft carriers and operates only a few vessels that can accommodate helicopters. The development of helicopter carriers is in the research stage.
Because of the domestic situation, it is not easy to obtain increases in the number of the present aircraft, to develop high-performance aircraft, or to purchase them from other countries. Consequently, there is no other way except to improve the present airborne equipment and increase the capabilities of the present aircraft, and then develop new aircraft and airborne equipment.
Anti-aircraft—The Maritime Self-Defense Force has no jet fighters, and those of the Air Self-Defense Force are not accustomed to maritime operations and have not been trained for this type of duty. Neither force has airborne early warning (AEW) aircraft, so air defense for the fleet and merchant ships at sea must rely mainly on radar, anti-aircraft guns, and such surface-to-air missiles as are available on board Force vessels.
Anti-warship—The Maritime Self-Defense Force has two squadrons of F-86F fighter-bombers, whose training is intended mainly for fixed ground targets. To make matters worse, Japan is very short of ranges for the training in gunnery, bombing, and rocket firing, and has little equipment and few targets suitable for training at sea. There are also problems regarding weapons, such as bombs, rockets, and torpedos.
Marine Air Transportation—Neither the Maritime Self-Defense Force nor the Air Self-Defense Force has aircraft capable of non-stop flying between Tokyo and Hawaii. This includes the twin-engined jet XC-1 now under development for the Air Self-Defense Force. Transportation between Tokyo and Iwo Jima Island is also difficult, and therefore, the only available way to transport small numbers of personnel and material is to use antisubmarine aircraft with long flying range.
Weather Reconnaissance—Japan is vulnerable to unusual climatic conditions—typhoons in summer, heavy snow in winter, and heavy rain in spring. Consequently, meteorological observation by means of aircraft is very important. For the past 25 years, Japan has relied upon weather observation by U. S. Air Force aircraft based in Japan and the U. S. Navy aircraft in Guam. Neither the Self-Defense Force nor the Meteorological Agency has yet made plans for weather observation aircraft, and so in the future, Japan will continue to rely on American aircraft. The role played by weather observation aircraft is still very large, despite the development of weather satellites, weather observation rockets, fixed point observation ships, and weather observation radar.
Air Sea Rescue—The Maritime Self- Defense Force has rescue aircraft but no specialized rescue organization. The Air Self-Defense Force, however, has a rescue wing, composed of small twin-engined search planes and helicopters. The Maritime Safety Agency has medium and small rescue aircraft, but these land-based planes cannot drop rescue crews into the sea. Therefore, Japan must continue to rely on the U. S. Air Force Aerospace Rescue and Recovery Squadron and the U. S. Navy’s carrier-based rescue aircraft.
Research and Development—One of the major successes of Japanese maritime aviation is the development of the P-2J from the P2V-7. Too, Japan is the only country that is developing a four-engined flying boat. This turboprop aircraft, PS-1, has excellent performance that assures the landing on and take-off from rough seas of about 10-foot high waves. The antisubmarine flying boat, however, has some drawbacks—difficulty in finding proper sea-bases on the coast of Japan and a special problem arising from operating only from the sea. A plan is under study to modify this aircraft into an amphibian.
Since World War II, Japan has had little experience in independently developing military aircraft, major airborne equipment, and weapons. The testing of aircraft and airborne weapons requires a longer time in Japan than in the United States because there is less availability of good aircraft test centers, more unfavorable weather conditions, and less air space. Moreover, the export of military aircraft and weapons is prohibited, and universities and many national research institutes do not co-operate in the research and development of military technology. This special domestic situation inevitably helps to raise the cost of domestically-developed and produced military aircraft and weapons.
The present situation of Japan’s naval air strength does not result entirely from social, economic, and technical reasons, but derive also from the insufficient acknowledgment of the importance of the maritime air force. For about 20 years since the establishment of the Maritime Self-Defense Force, no rated pilot has been assigned as Chief or Vice Chief of the Maritime Staff. There is reason to believe, too, that Japan’s defense, especially its maritime defense, lacks a comprehensive, established policy. There are also military critics who consider the Defense Build-up Plans, ending in March 1972 and the new one starting in Fiscal Year 1972, are procurement plans rather than defense plans.
What deserves special attention is the fact that 90% of the crude oil, one of the most important materials that sustain Japan’s present prosperity, is transported from the Persian Gulf. No matter how safe Japan and its vicinity may be, serious trouble at some point along the long route from the Gulf to Japan will gravely affect Japan’s economic activities in a very short time, with a serious effect on its national security. But, for the present, it appears that the Maritime Self-Defense Force must continue to have no direct influence on the security of the areas far from Japan.
It is very difficult to defend the seas around Japan with the present defense setup, and for the time being, the United States is accepting the responsibility for the nuclear defense of Japan. But for its conventional defenses, Japan must henceforth look only to itself, to handle any aggression, and to maintain peace and freedom.