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The RNZN’s four “Lake”-class patrol craft (Taupo, left) enforce the country’s fishery laws. Sometimes, they are backed up by old harbor defense motor launches (like the one pictured below) operated by reservists.
ferences, the general concept of running and maintaining one class of ship has many advantages, not the least of which are in the standardizations of training and stores support. While there are many details which are the subject of current staff studies, there is little doubt that the RNZN will remain capable of making a significant contribution to the ANZUS blue water forces well into the foreseeable future.
In addition to the frigate purchase, an undisclosed sum has been set aside for the building of four patrol craft- type vessels to serve with the reserve divisions of the RNZN. These ships will be built in New Zealand.
New Zealand’s contribution to its maritime force should be measured against other factors. The two main islands of New Zealand have a total area nine-tenths the size of the Italian mainland. While the population of Italy is 55 million. New Zealand's is just three million, a trifle more than the population of Rome. Against this must be placed the requirement to provide the funds necessary to maintain and develop the road systems, public utilities, and the myriad of other internal requirements of a country of its size. To many outsiders, the provision of a navy of the size of New Zealand’s in the face of such constraints says much for its determination to fulfill its ANZUS commitments and, in addition, to be capable also of looking after its own interests in the South Pacific generally.
A paragraph in the introduction to New Zealand's 1978 Defence Review sums up the attitude of New Zealand toward defense and should serve as an assurance to its allies. “It would be rash to assume that our [New Zealand’s] sovereignty will never be challenged. What is more. New Zealand may be small and isolated but New Zealanders themselves have never been isolationists. A sense of realism in security matters is not only practical but consistent with our history. We have always been ready to defend our way of life when necessary and have always recognized that to do so we have to work with others and contribute to the common cause.”
Commander Davies is currently serving on the Royal New Zealand Navy's Naval Staff at Defence Headquarters in Wellington.
Some Hope Against Incoming Missiles
By Lieutenant Commander P. Roullett, French Navy Reserve
Missiles sank the Israeli destroyer Eilath in 1967 and signaled the development of many successors that now provide formidable offensive capabilities. Endowed with a destructive power far greater than any previous naval weapon system, a fast patrol boat can sink a major warship with one blow—or at least inflict severe damage. The efficiency of surface-to- surface missiles was confirmed in 1971 when an Indian Navy “Osa” fast strike craft crippled several Pakistani warships and merchantmen. Had the last word been said? It seemed that any navy, regardless of size, could place a major warship at its mercy
with the point of an antiship missile.
Inspired by such success, shipyards designed and built many fast patrol boats armed with missiles developed by various countries; these hornets swarmed in all parts ot the world—ready to strike.
But another conflict showed that the missile threat did not spell ultimate doom for the fleets of the world. During the 1973 Arab-Israeli War, some 50 "Styx” missiles fired by Egyptian or Syrian attack boats did not strike home, while the Israeli "Gabriel” missiles generally found their targets. Against the new sword, a shield had been forged: electronic warfare (EW).
It is a science halfway between magic and bluff, a battle of wits where the weapon generates its own counter. Scientists as well as operational staffs are always keen to observe the latest battle tactics and evaluate results, obtaining this information with various forms of intelligence. Any government that did not take into account the new importance of electronics in warfare would soon find its warships doomed.
In all combat information centers (CICs), an EW corner—small at first—grew more important in size and role. Behind a modest screen, more and more black boxes were to be
found: analyzers, jammers, oscilloscopes, and more exotic instruments that had one aim in common—to prevent enemy missiles from reaching the ship by active or passive means. Other arms were integrated into the ship defense, such as surface-to-air missiles and close-in weapon systems. These were meant to destroy or render inoperative an attacking missile.
One may question the cost and limitations of such weapons that counter
Dagaie “suitcase” fires chaff from a launcher on board a French frigate. This system can deal with five missiles at once, and position a chaff decoy in three seconds.
the air-, surface-, and subsurface- launched missile threats. A more subtle defense is to decoy the missile from its target with “soft” weapons, antimissile EW systems with a high degree of sophistication and versatility.
In the decoying of missiles, two distinct approaches exist: confusion and deception.
The confusion of enemy surveillance or target designation radars in their appreciation of the real situation can be achieved with chaff particles that create a cloud that modifies or cancels the radar image of the target (vessel or force), or a missile can be confused by drowning the ship’s echo
with a noise jammer, thus saturating the enemy target designation radars. The deception or distraction approach means to produce an echo that will make the tracking seekers either lose their target or acquire a false one; this decoy echo has to be more attractive than the original one if it is going to unlock the missile seeker from its intended target.
Several Western manufacturers have investigated this field of missile decoy. Whereas it is rather simple to launch a cartridge filled with chaff of a predetermined type to deal with various radars, it is a more difficult affair to obtain a credible decoy.
Attack missiles have developed “brains” in keeping with this galloping technology: from the crude early types of guidance, they gradually have been fitted with more resourceful homing systems, with combined electromagnetic (EM) and infrared (IR) radar seekers. New models are being developed. These “brains” must be confronted with adequate decoys: the homing system will be looking for a credible target and will be quite able to identify a chaff cloud which does not have the characteristics of a vessel, a fact which is easily crosschecked if the seeker is of a combined EM/IR type.
This type, which will be more frequently employed in the future, is difficult to lure: the chaff cloud must cover a significant surface and have a useful shape which will be picked up in the missile range gate; a decoy is useless if not “confirmed” by characteristics that correspond to the IR signature of a vessel. We must remember that a ship is not a single punctual heat-radiating source and her temperature is fairly well known.
Not only has the villain improved its characteristics, but its battle tactics are more formidable, launching simultaneous attacks:
► From the same azimuth or at very short intervals
► From various azimuths
► With different types of missiles
Electronic warfare provides some
efficient answers that have been proven in tests or in combat, and amply justify the interest now given by naval staffs and some industrial manufacturers to that field.
Last but not least, the EM and IR decoys must enhance one another, besides being positioned closely to the vessel. They also must be colocated.
Deployment of the decoys has to be rapid and ensure a good colocation. This use of chaff—based on the “Centroid Mode” principle—allows the ship to escape the missile, which is locked on the decoys.
Among the various systems based on this mode of operation, Dagaie is the one that has been ordered by the French Navy and several other navies. (It is currently marketed in the United States as the Squid.) From the start of its development, Dagaie was to be as autonomous as possible so as to not increase the technological load on a vessel’s weapon systems.
To this effect, the only necessary external parameters for Dagaie operation are the vessel’s own course and speed, wind velocity and direction, and the azimuth or bearing of the threat from ship sensors (radars, optical or optronical detection, electronic support measures, etc.).
Fed into the processing cabinet, these parameters will provide the firing elements for the trainable launcher and will also generate a recommended course to the ship, taking her into a safe area from the blooming decoys luring the missile. This recommended course, displayed on the system supervision unit location in the CIC, is repeated on a maneuver indicator on the bridge.
Whereas the type of decoy (EM, IR, or both) selection is set by the operator, the whole operation is entirely automatic and the launcher receives its firing elements from the processing cabinet through the servo-control unit. The automatic operation is the normal mode, but the system can still be operated manually.
Besides its simplicity of installation, Dagaie has a very fast reaction time: once a missile alarm has been received from one of the ship sensors, an effective decoy is positioned in three seconds; the efficient duration of the decoys is 30 seconds for IR and at least five minutes for EM.
A realistic situation will most likely include attacks not only by one, but by several missiles coming from various bearings simultaneously. Dagaie can handle five missiles coming simultaneously from different directions with different guidance systems. One decoy can deal with several threats flying on a neighboring path in relation to the processed missile in the order of priority given by the detection sensors. When the decoy has reached a preset threshold and no longer offers adequate protection to a vessel, the Dagaie can renew the decoy by firing another one. Nevertheless, the processing of new threats always takes precedence over the renewal calculation function.
The operation of Dagaie does not interfere with other weapons on board, and its efficiency is not degraded by sea conditions. Normally fully loaded, the launcher can be easily reloaded with fresh ammunition “suitcases.” Each suitcase, either an electromagnetic decoy or infra-red decoy, weighs about 50 kilograms. They are easily locked into firing position and disposed of after use. A complete reloading takes less than five minutes.
The firing signal is transmitted through an electromagnetic process (without connector) insensitive to radar beams. In addition, through the base of a suitcase in position, type of decoy (EM or IR) and loading status are displayed on the supervisor unit. The Dagaie suitcase launches decoys distributed in space and time as a result of the flight parameters and payload dispersion structures of the 33 dual projectiles simultaneously fired by 33 predirected mortars located inside the suitcase.
Thus, the deployment of decoys at precise positions is achieved with a very large radar cross-section, located in the missile seeker resolution cell for the EM suitcase with a life span of about five minutes. An elaborate pyrotechnic process and the design of projectiles ensure that the initial action IR decoy, fired close to the vessel, will be continued by other projectiles, creating an apparent displacement of the decoy perpendicularly to the missile flight, with a life span of about 30 seconds.
Credibility was a priority goal in the development of Dagaie. While the EM decoy covers several radar frequencies, with appropriate dimensions (3,000, 5,000, or 10,000 square meters or more) and height, and a maximum useful radar cross-section (in direct relation with the ship’s own) in less than two seconds, the IR decoy has a high energetic brilliancy over the entire IR bandwidth at a credible height. Above all, it is colocated with the radar decoy, maintaining a short distance between the EM and IR clouds’ centers.
This sophisticated ammunition is also reliable, having been rigorously tested (heat, shock, humidity, fire, etc.). Dagaie ammunition has a guaranteed life of three years and a normal life of ten years! It can be optimized in relation to specific threats. This, added to the fact that it is tailor-made for each type of vessel, ensures the maximum efficiency of Dagaie.
Comparison of Dagaie with other current decoying systems leaves little doubt as to its lead in this field in terms of reaction time, credibility, and efficiency.
Commander Roullet joined the French Navy in 1961. His active service included a tour in the Algerian conflict, duty at Naval Headquarters, and assignments as a liaison officer with foreign navies. He is a member of the World Ship Society and the Australian Naval Institute.
Perim on the Red Sea: Geo-Strategic Flashpoint
By Alan M. Scham
If we try to ascribe a single characteristic to the countries situated where Africa and the Middle East meet around the southern entrance to the Red Sea—Ethiopia, the Republic of Djibouti, Somalia, the Yemen Arab Republic (North Yemen), and the People’s Democratic Republic of Yemen (South Yemen)—we cannot use the single word Muslim, Arab, or African, but we can apply the unifying adjective—unstable. It is indeed the intrinsic instability of this large strategic area which threatens world peace at the focal point of Perim. The Straits of Hormuz, for instance, are not the only areas of particular significance. Some oil and much mercantile and naval shipping still go through the Red Sea and the Suez Canal, and always will; such commercial shipping, for instance, is still vital to the economic interests of many countries, and certainly to the Egyptian economy. The Red Sea and Suez Canal access are also critical to the U. S. Navy’s ability to deploy forces rapidly between the Persian Gulf and the Mediterranean Sea.
Perim is the miniscule island which strategically straddles and controls shipping moving in and out of the southern end of the Red Sea. This rocky, but fairly flat, volcanic island is devoid of vegetation, and is 214 feet above the sea at its highest point, providing visibility of the sea-lanes for 20 miles. Perim has primitive harbor facilities, a small airstrip, and a weather and radio station. The Straits of Perim—the Bab al-Mandab—are divided into two channels by the island: the Small Strait—between Perim and North Yemen—which is 1.7 miles wide, with a maximum depth of 96 feet; the western or Large Strait, between Perim and the African coast, is 10.4 miles wide, with a depth of 1,611 feet. There are numerous shoals in these waters, and some difficult currents. Perim, formerly a coaling station for Great Britain, has been a part of South Yemen since 1967.
North Yemen, whose only important port is Hudaydah, is an extremely weak country politically and economically, though it is bolstered by Saudi Arabia. South Yemen, with the excellent harbor of Aden, is a traditional enemy of its northern namesake, and is squarely in the Soviet camp. On the other side of the Straits of Perim, Ethiopia, with thousands of Cubans and Soviets inside its borders, is also pro-Soviet. Ethiopia, once staunchly pro-Western during the days of Emperor Haile Selassie, has changed sides, and Somalia, which had previously afforded military facilities to the Soviets, is now leaning in a more Westerly direction. Finally, Djibouti, which gained its independence from France in 1977, remains strongly allied with France. Although Djibouti is a small country (only one-tenth the size of South Yemen), which cannot even provide its own water requirements, much less those of its 3,000- man army, it has an excellent harbor. These generalities must be understood to realize just how unstable this region is, and from which countries the United States and the Soviet Union may or may not anticipate local support. Presently, the U. S. Navy has access to the former Soviet facilities at Berbera, Somalia, facing the