Driven by Cold War pressures in the early 1980s, under the CNO, Admiral James Watkins, the Navy committed itself to developing a robust and viable Arctic Warfare capability. Before then, submarines made periodic deployments to the Arctic but they did not participate in extensive Navy-wide R&D efforts. Since then, the Navy and the Submarine Force efforts to improve and to understand Arctic performance requirements better have been very fruitful. Significant advances in knowledge and Arctic technology have been made. Progress continues steadily, and yet, because the Submarine Force knows so much more, it also has become more sensitive to what it doesn’t know. The thought of knowledge begetting more knowledge clearly applies to the Arctic. However, when one says “Submarine Arctic Operations,” the response from those not deeply involved has usually been: “Why?”
First, there is the requirement of national security. Admittedly, with the Soviet Union in domestic chaos it is difficult for the general public to comprehend that the Soviets remain as strong as ever militarily. The Soviets continue to modernize their Submarine Force with quieter and higher quality platforms. Further, in recent years they have deployed fewer SSN/SSBN/SS units out of area, and have shown a tendency towards more extended operations close to their own shores. While the United States has a fairly good understanding of the individual capability of their new submarines, it remains somewhat a mystery as to the ultimate national/naval strategy to be supported by these added submarines.
One need only look at a world globe to see that the extremes of the USSR land mass extend from 300E Longitude to 1700W, or 160 degrees, which is almost 45 percent of the circumference about the North Pole. In various political forums the Soviets have viewed (quite incorrectly) the Arctic as their ocean. They continue to exploit the Arctic aggressively as an area for naval deployment as well as for scientific development. To keep pace with such activity and to be ready for whatever the current activity might lead to, the U.S. must continue regular Arctic operations for training and tactical development, as well as for research into future Arctic capable system improvements.
The collection of Arctic environmental data is also important, for embedded within the U.S. Navy’s military research requirements in the Arctic is the need for a better understanding of the Arctic environment by the world as a whole. Thus, environmental data from the Arctic, made available for both military and civilian use, is the object of increasing Navy interest and investment.
The Arctic area is not as yet the subject of any treaty accepted by the U.S., quite unlike the Antarctic Treaty, which creates a level of restraint and cooperation between nations involved in Antarctica. However, there is a requirement that we exercise our right to freedom of the seas. This is perhaps more important than one appreciates at first glance, because various Arctic nations have expressed expansive ideas about who should control (parts ot) the Arctic. As mentioned earlier the USSR unofficially has stated the Arctic Ocean is their sea. More formally, they claim the Arctic is divided into pie-shaped sectors originating at the North Pole with the sides extending south to the extreme eastward and westward limits of their national boundaries around the pole. This is called the Sector Principle, and is similar to one of the tenets of the Antarctic Treaty. This concept would enable the USSR to claim over 1/3 of the ocean. Canada would get the next largest piece of the Arctic, while the U.S., Denmark, and Norway would be able to claim very small sectors.
Canada, on the other hand, subscribes to the Archipelagic Principle. This concept allows a nation to draw its claimed territorial waters around contiguous islands in an archipelago. This concept precludes the right of innocent passage in those waters by vessels of other nations without their first receiving diplomatic approval.
Other concepts of territorial water definition, such as the Straight Baseline Principle, have been suggested. In this concept nations draw lines connecting the seaward extremes of their continental shores and adjacent islands over which they have sovereignty, and lay claim to all water within these lines. Again the USSR and Canada could claim the majority of the Arctic. For example, Libya’s claim to the Gulf of Sidra south of the line of death is based on this principle.
On the contrary, the U.S. concepts of the Arctic simply support and exercise rights to the twelve mile limit and a 200 mile economic zone, concepts which are generally accepted in the world’s temperate oceans. (The U.S. has also negotiated positively with Canada over passage through the Canadian archipelago.)
Diplomatically, people often make comparisons between the similarity of the Antarctic and the Arctic, and suggest that they should exist under similar international protocols. This is difficult to accept when one sees the Antarctic Treaty as one addressing a very remote continent with almost no economically (easily) exploitable resources; while the Arctic is an ocean with vast potential to provide needed natural resources in the near term. Truly, the Arctic Ocean is more like the Mediterranean, — a large, rich sea surrounded by several nations who seek and need to exploit these resources for their own benefit.
In this vein it is interesting to note that only one treaty, the Treaty of Barcelona signed in 1924, has ever been collectively ratified which relates to the international nature of the Mediterranean. Because of a similar competition among nations for natural resources, the Arctic Ocean area will probably see no significant international agreement in the near future.
From this discussion on territory, perhaps it is easier to see that the requirement for freedom of the seas is of more importance when one addresses the Arctic.
Fourth on the list of why the Arctic is important to the U.S., is the need to foster or ensure the well-being of high latitude people. This tenet is in keeping with the principles of a caring democratic nation, and although not directly connected to the Submarine Force, is certainly one of the prime reasons our nation supports a military organization.
Finally, there is the need to oversee and preserve our rightful access to the use or preservation {as appropriate) of the natural resources in the Arctic Ocean. These resources start with the obvious fossil fuels, but also include land based minerals, ocean life and seabed resources within the U.S. economic zone.
Next, let us examine the challenges facing the submarines in the Arctic. The unique facets of submerged operations under ice must be added to the already lengthy list of operational sensitivities one must possess in order to conduct submerged operations in the open ocean, – things for which the submariner continuously trains.
One must consider the bathymetry of the Arctic Ocean initially. First of all, the ocean is bigger than most appreciate. Its surface area is five times that of the Mediterranean. Hardly can the Arctic be identified as small. Second, the ocean possesses more critical shallow areas than the rest of the world’s oceans. It should be noted that the 50 fathom curve includes some very important areas — most notable the Bering Strait, where a submarine must traverse about 1000 nautical miles in water 50 fathoms deep (and frequently less) in order to complete entry or exit to the Arctic Ocean from the Pacific. In fact during this transit, the submarine spends days within twenty feet of the bottom, while concurrently within twenty feet of ice keels above the sail.
Next is the 200 fathom curve, which is generally treated as the limit of the continental shelf. It is important to note that ocean areas of tactical significance lie within this curve. For comparison, 36% of the Arctic Ocean and its adjoining seas are considered to be continental shelf areas, while the average for the temperate, ice free oceans is 15%.
Let us shift from concern for shallow water to the Arctic sea ice. It is large and thick, and its presence is limited to deep water areas. It is also dynamic; it is in constant motion pushed by the wind at speeds up to 0.8 knots.
The annual ice cover is that ice which grows and melts each year. Ultimately at the end of the winter growing season, it increases the size of the Arctic sea ice pack by over 40% and effectively covers the entire ocean. Its thickness normally reaches 6 feet, but because it is more easily set in motion, the collision of two ice floes can result in ice ridges 20 feet tall and ice keels which extend into the water over 100 feet Ninety-five percent of the annual ice cover is over shallow, easily mineable water.
When one summarizes both Arctic bathymetry and ice cover into a single picture, one can clearly see submarine Arctic operations assume an extremely challenging and unique character. The submariner must think constantly overhead as well as underneath. In essence he must be capable of conducting warfare in a tunnel. How does the submarine safely do this? Submarines possess an under-ice sonar suite that enables them simultaneously to look ahead for ice keels that may be positioned in the SSN’s path, to take soundings of the bottom and to profile the ice overhead for surfaceable features. The suite’s functional make up has not been significantly altered since the early 1960s. However, numerous improvements have been made to components and subsystems to eliminate performance shortfalls. A second (and perhaps less important) underice system is the precision bubble that enables the submariner to know the trim angle on the ship with high accuracy. This system is routinely used when operations are conducted near the ice canopy and/or near the bottom. The submariner under the ice knows that for a 1° change in trim angle on a SSN-637 class, the ship’s stem rises or lowers approximately 25 feet. During SSN passages of some of the shallow areas of the Arctic, such as the Bering Strait, every six inches of depth change is critical.
Other than when operating near the ice canopy, the ahead looking sonar is employed when in the vicinity of icebergs. Iceberg areas in the Arctic Ocean and its adjacent seas are found in Baffin Bay, Davis Strait, off Ellesmere Island, near Franz Josef Land and the Denmark Strait. We think we can appreciate just how massive icebergs are, but usually underestimate their size. A survey on one iceberg actually encountered a few years ago in the Arctic showed its peak to be 300 feet above the water and its draft to be approximately 1000 feet.
Another environmental factor which influences the submarine’s capability to operate in the Arctic Ocean is the large variation in salinity, — a phenomenon most frequently encountered in the warm months. This variation is caused by the large input of fresh water into the Arctic from melting sea ice and from fresh water (river) run-off from the Asian and North American continents the year around. It is surprising to know that the Arctic basin receives approximately 30% of the world’s fresh water continental run-off.
Salt water salinity is nominally 34 to 36 parts per thousand. Salinity directly affects sea water density. It is approximately this range of salinity variation for which a submarine is designed. Any salinity below the lowest design limit causes the submarine to sink to a deeper depth (if it dispels no variable ballast}, finally reaching a point where the water density is sufficient to support the ship.
As this low salinity water enters the Arctic basin, it is lighter than the sea water already there. Thus it effectively forms a surface wedge above normal density (heavier) sea water. Further, because of the ice cover, there is little subsequent ocean mixing, which is strongly influenced by the sun’s heating and wind action. When a submarine under the ice attempts to come shallow for whatever reason, and encounters this low salinity water, its ascent is quickly stopped. The SSN then settles back to more dense water. Such a situation either delays the ascent significantly (while internal ballast is adjusted), or in worst case (if the need to come shallow is critical), forces the submarine to compromise its presence by expelling main ballast. In any case these effects just create another thing the submariner must think about while doing his job.
The salinity variation, when coupled with the ice cover, influences another aspect of Arctic submarining. They create a unique sound velocity profile (SVP). The water directly under the ice is usually the coldest in the water column. It is also the least saline. But temperature and salinity both increase as depth increases. These factors cause a positive SVP to exist, a condition which is much less frequently encountered in the open ocean. There is no deep sound channel, just a surface 1/2 channel. Therefore in the Arctic, in order to maximize the SSN’s acoustic effectiveness, being shallow is better. This is contrary to the open ocean. Here is one more different thing the submariner must consider when contemplating optimum detection or best counter detection depths.
The anomalies of Arctic acoustics lead to one real operational requirement. Here in the Arctic, — almost more than anywhere else, there is a strong need for the use of tactical oceanography. And yet, we know less about the Arctic than any other ocean when it comes to oceanography and bathymetry. At this point it is only fitting to acknowledge other elements outside the USN Submarine Force that have contributed to our Navy’s ever improving Arctic ASW and operational capabilities.
The first of these are the ice camps which are staged by the Navy to conduct submarine-related R&D during each ice exercise. Like all things related to the Arctic, they are expensive to establish and maintain; and are time dependant and fragile in the face of mother nature. Second is the emerging warfare capability of our own maritime patrol aircraft. Their Arctic ASW performance has been considerably enhanced by repeated participation in Arctic exercises. The ASW skills of the maritime patrol aircraft now are able to nicely complement those of the submarine, which still must be considered the ultimate Arctic ASW platform. Lastly, the Royal Navy of the United Kingdom has been active in the Arctic through the last decade, performing R&D work, sometimes in concert with our submarines. They, too, have developed an Arctic operational capability and technological understanding in parallel with our submarine force. In summary, our Navy has made real progress in Arctic operations over the last decade. Arctic capability specifically designed into warfare systems has been confirmed to be effective. Significant understanding has been gained in the Navy’s under-ice tactics. Submarines can now employ tactics to mitigate the effect of the Arctic environment and to optimize their ASW capability under the ice. By virtue of an increased operating tempo in the Arctic, the Submarine Force has gained more operational platform experience and personnel training than ever before.
The reservoir of the Navy’s Arctic submarining skills is now quite full and broadly distributed within the force. In conclusion, the Navy is constantly improving its Arctic Warfare capability. Progress over the last decade has been both measurable and noteworthy. The goal — to be every bit as effective when operating under the ice as when in the open ocean, is clearly achievable. Understanding and thus exploiting the environment remains the key. For as the Navy, R&D project teams and the Submarine Force learn during every ice exercise, the Arctic is the most complex and dynamic ocean (acoustic) environment on earth!
