The increasing Soviet use of the Arctic for ballistic missile submarine patrols demands new alternatives to the current focus on attack submarines for antisubmarine warfare. One possibility is a mix of V/STOL aircraft and helicopters—flown by the U. S. Army.
Traditionally, the Soviets stationed nuclear-powered fleet ballistic missile submarines (SSBNs) off the eastern and western seaboards of the United States, close enough for their missiles to reach many important targets in the country. These SSBNs have not posed great detection problems to U. S. antisubmarine warfare (ASW) forces because they had to navigate through either the Greenland-Iceland-United Kingdom (G-I-UK) Gap from their bases on the Kola Peninsula, near Murmansk, or through the Japanese or Kuril Islands gaps from Vladivostok. In either case, they could be detected by underwater sound surveillance systems (SOSUS) or by nuclear attack subs (SSNs) that would lie in wait for them to emerge from the narrows and trail them to their patrol areas.
In recent years, however, the Soviets have developed long-range missiles for a number of submarines that altered the ASW calculus. One version of their SS-N-18 missile has a range of 8,000 kilometers. Another missile, the SS-N-20, carrying between six and nine reentry vehicles, has a range of 8,300 kilometers. Either one of these weapons could be fired from the Arctic Ocean and reach any target in the United States. Another missile, the SS-N- 23, also with an 8,300-kilometer range, carries ten independently targeted reentry vehicles. These developments pef' mit the Soviet Typhoon and Delta III and IV SSBN classes to avoid deploying into either the Atlantic or the Pacific where they might be vulnerable to detection by U. S. °r other NATO ASW forces.1
The Soviets now have 11 Delta III/IV and 4 Typhoon SSBNs assigned to their Northern fleet.2 By the eary 1990s, the Soviets could have as many as eight operations Typhoons with up to 1,440 warheads. The Typhoon is believed to be particularly suitable for Arctic operations, having a stubby sail structure and shrouded propellers designed to push the submarine up through the Arctic ice to fire her missiles.3
Wherever the SSBNs might deploy in the Arctic, they would be able to find suitable missile-launching positions- Even in the coldest months, about 3% of the ice pack >s open water.4 It also contains large areas of smooth, re^ tively thin ice, known as polynyas, through which SSBN5’ can break to surface and launch missiles.5
Under-ice deployment of the Soviet SSBNs cuts off (ne air and surface legs of the U. S. ASW triad. This leaves the subsurface leg—ASW submarines—on its own 10 hunt the quarry. And the possible deployment positi°nS
JiXK£f&
The Soviet Typhoon SSBN’s missiles can hit targets in the United States without deploying to the Arctic. Operating in the ice, however, makes hunting those submarines a difficult proposition—which up to now has fallen to the U. S. nuclear attack submarine force.
SOVIET MILITARY
for the SSBNs extend over some five million square mileS of sea, much of it perpetually covered with ice.
Soviet Northern Fleet submarine bases on the Kola Pe' ninsula are close to the ice pack, depending on the time 0 year, and these submarines would have little difficulty in reaching the pack before Western ASW submarines migh1 be deployed. There, the Soviets could position their own ASW SSNs in a defensive screen while their SSBNs with'
sors
*ne activity below and allow for instructions to be trans- ted to friendly attack submarines under the ice. ufortunately, even if all the technical problems in the ection and communications areas were solved, serious QPerational ones would persist. First would be the problem Piercing the screen of hostile attack submarines lying in Co Ush for the U. S. submarines. The U. S. SSNs could utplicate the Soviet ambush problem by entering the rctic Basin by multiple routes (e.g., the Bering Strait, e Barrow and M’Clure straits between the Canadian is- ?s’ or t*le Kennedy Channel between Ellesmere Island the northwest coast of Greenland). However, these sassages are shallow, and, therefore, vulnerable to clo- j re- As Former Chief of Naval Operations Admiral rnes Watkins remarked, “We are quite confident that we
vfew northward or eastward out of harm’s way. The So- let ^SNs would enjoy an enormous advantage, lying in t^31 ’ Practically motionless and soundless, listening for e irst sounds of their opponents’ approach. Even the vantage of the quieter Western submarine design would unt for little if the Soviets were not moving. The screen ■ght even be doubled with Soviet diesel-electric boats— >ch run remarkably quietly on battery power— Pirating on the ice pack’s fringes.
o, ^Capabilities for Arctic Operations: The United ^tes has 37 Sturgeon (SSN-637)-class submarines with P cial ice-operation features. These include ice-detecting ars, hardened sail and rudder, and sail-mounted diving anes that rotate 90° for ice penetration. The first 33 sub- u ^rines of the Los Angeles (SSN-688) class do not have er'ice features. But commencing with the USS Chi- So (SSN-721), the new-production Los Angeles subma- ,nes W'H be fitted with bow-mounted, retractable diving nes and other features for under-ice operations. Thirty- UrL°s Angeles-class submarines are currently in ser- , e- An additional 32 are either under constmction or 3;ebeen proposed for construction by 1990.6 lo . U. S. Navy is experimenting with techniques for cating Soviet submarines under the ice pack. The De- lanse Advanced Research Projects Agency (DARPA) has sUnched an experimental data relay satellite for linking all sensors on the ice pack with U. S. ground stations 1<- sbips. The satellite is small (16 inches in diameter and Sg Pounds) and cheap (about $1 million).7 This type of theS.or should be able to take advantage of properties of c lce pack that are especially favorable for submarine
Section.
Sea ice is salt-free and potable. It readily transmits ustic energy, particularly at low frequencies. The skel- n layer structure below an ice sheet helps match the nUstlc impedances of sea ice and sea water so that little tect‘0n occurs at their interface. A flat transducer at- ed to the surface of the sea ice may receive acoustic he.Wer fhrough the ice with little attenuation. Similarly, a avy ice pack can facilitate radio reception for subma- ^ues underneath. At f5 kilocycles, for example, the depth th Penetration of signals is about 100 times greater in ice n ln sea water because of differences in salinity.8 Sen- °n top of the ice could possibly detect hostile subma- can navigate up here [in the Arctic Ocean, except for] that time of year when the ice depth comes down and squashes the distance between the bottom of the ice and the floor under [the submarine].”9
At certain times in the winter, ice formations could occur that would permit Soviet deployments under the ice while denying Western submarines access in a number of areas. Even if U. S. submarines were not completely denied access, they might spend excessive time searching for access routes. Also, Soviet attack submarines could discover the access routes and concentrate their protective screens in those areas.
Alternatively, the U. S. Navy could maintain a number of units on patrol in the Arctic at all times. It might then at least partially turn the tables on the opposition, and perhaps ambush a number of hostile submarines as they deployed from their bases. However, the United States could not expect the Soviets to wait until hostilities had commenced before ordering its SSBNs to deploy. More likely, with both sides deploying units before the outbreak of war, the Arctic Ocean would be turned into a great target- rich submarine cauldron for hunting by both sides. However, in such an environment, important advantages would naturally fall to the side that was under no pressure to initiate action.
Soviet SSBNs could pose an especially difficult detection problem if they were to adopt an entirely passive posture. Once deployed, they could assume a slightly positive buoyancy and come to rest against the underside of the ice. Even in a major conflict between NATO and the Warsaw Pact, they quite possibly might not have a direct role to play other than to survive. As the Soviets have shifted their thinking regarding warfare on the European continent toward conventional operations, the likelihood of Soviet- initiated nuclear strikes has diminished. Accordingly, the SSBN fleet’s principal missions are likely to be that of survival and of deterrence of Western escalation.10 With the exception of occasional requirements for repositioning the submarine to accommodate changes in the perpetually moving ice pack, a Soviet SSBN should be able to remain in this passive posture for months.
Given the imbalance of forces between NATO and the Warsaw Pact, however, the land battle in Europe might not last long. If the conflict were to go nuclear, the SSBNs might become active quickly. If we could not destroy them before they launched their weapons, the ASW campaign would be for naught. Similarly, if the West wished to obtain a political-military bargaining advantage by destroying a significant number of Soviet SSBNs during a conventional phase of war, the case would be much more effective if the task could be accomplished while NATO was still capable of mounting a coherent defense on the continent. Considerations of this sort place a high premium on increasing the tempo of the effort.
Pressures for rapid mission accomplishment, however, would not justify resorting to extensive use of active sonar detection techniques. The ice pack’s underside is highly irregular, and an SSBN hugging the “ceiling” could readily select a spot—using sonar and on-board closed-circuit TV cameras—that would provide her with downward pro-
*
The alternative force’s initial mission would be to establish small bases that would link sensors with a control center. The sensors would direct such elements of the helicopter/V/STOL force as the Army’s UH-60A Black- hawk to suspected target areas. C-130s would provide logistical support.
jecting ice “curtains” of protection on one or more sides. Active sonar, besides disclosing the originator’s location, would have great difficulty in sorting out the scrambled returns from ice stalactites and up-ended ice “rafts” along ice pack fissure lines from returns from a submarine hull.
The greatest operational problem probably would be the movement of the U. S. submarine to a point where it might attack an SSBN. The distance could be hundreds of miles. The lethal range of a torpedo running under the ice for the full duration of its mission is likely to be quite short. That of the advanced capabilities Mk-48, Mod-4 torpedo is about 24 miles.11 For an attack submarine to transit under the ice for several hundred miles to intercept a moving SSBN in waters likely to be strewn with hostile SSNs would be extremely hazardous. About the only way to accomplish it would be to advance at a very low speed (under five knots), and take a strong chance of losing the target. If the distance were as much as 500 miles, and the target were not moving away from the attack submarine, it might take as long as three and a half days to maneuver within firing range. A different approach is needed to circumvent the current restrictions on anti-SSBN operations.
The Alternative Force: The need for a faster reaction to detection of submarine activity under the ice pack suggests a shift away from the current focus on SSNs as the principal means for target location and weapons delivery. Ho^ ever, the cover the ice pack affords potential targets daunting. Fixed-wing aircraft have great range and weig bearing capabilities, but they lack a facility for “working the seams” of a target problem. They require substantia base support and have limited staying power over sus pected target areas. The lead systems within the mix 0 ASW systems capabilities required should be able to con^ verge rapidly on the area of detection, and, employ111^ multiple sensors simultaneously, to locate, identify, 3,1 destroy the target quickly.
The force must be rapidly deployable to the polar area 3t any time of the year, relying largely on its own lift cap3' bility. It must not need large quantities of strategic airlm- The potential for such a force exists in one composed prl' marily of modem vertical short takeoff and landing (V/STOL) aircraft and helicopters of proven performan<> in the Arctic climate. The tilt-rotor V-22 Osprey, design^ to lift 24 combat-equipped troops or some five-and-a-ha* tons of cargo with a top speed of 400 miles per hour, would be a promising candidate for the central role.1' fulfill such a role, the aircraft would have to have a sell' deployment capability with add-on fuel packages.
The Army’s CH-47 Chinook and UH-60A Blackhawk have performed well in Alaska, often under conditions more severe than those normally found at the pole. Both ° these aircraft are self-deployable with minimum crew ano auxiliary internal fuel tanks, affording ferrying ranges >i* excess of 1,000 miles.13
The force’s initial mission would be to deploy to the icC pack, establish rudimentary base stations with multipl*- remote acoustic monitoring points, and prepare for reconnaissance. The units would deploy the remote sensors
lished
at regular intervals, some 25 miles apart, with 100
along baselines for triangulation and identification of sus- icious underwater activity. If the sensor sites were estab
__ • i o ’ uio j owniv iinivo tiptu i^ w mi i’
1 os between deployment lines, the entire permanent ice ac' could be covered with about 600 sensors—omitting ^°se along the edges of the pack where their utility would f ac*versely affected by noises related to wave action and eRuent splitting of the ice. In winter, the required num- wCr scnsors might double. The principal limiting factor °u d be how close to the Soviet northern coast the force w°uld be able to work.
he sensors would be linked, either through airborne ^ansmission platforms or satellites, such as the DARPA xperimental vehicle, to control centers on the ice pack.
ese control centers would direct elements of the ^copter/V/STOL force—perhaps totaling some 700 air- in 1 types—to suspected target areas for complete ^stigation, target location, and identification. vv | other part of the helicopter/V/STOL force mission . be to conduct aggressive reconnaissance, within i !§ned sectors, to search out submarines not otherwise ‘cated. Hostile SSBNs may well seek the security af- e<t by underwater ice projections developed through e action of pressure ridges in the pack. Accordingly, the lrmobile force should employ full suites of acoustic and
nonacoustic detection mechanisms—including magnetic anomaly, infrared, green-blue lasers, and active sonar detectors—concentrating on suspicious areas.
Some units would carry ASW ordnance—both mines and homing torpedoes. In view of the Arctic Basin’s great depths (up to 4,000 meters), most mines would be designed for suspension from the ice pack. Torpedoes—with hardened entry cones—would be slipped through open water leads or dropped from the air to break through polynyas before assuming search routines beneath the ice. Where there were no polynyas, the crew would drill or blast entry holes in the ice. Considering the similarity of operations on the ice pack to land warfare, the Army, with its “air cavalry,” may prove a more suitable service for the mission than the Navy. The Army has extensive experience in Arctic helicopter operations in Alaska, including occasional missions onto the polar ice cap.
Support aircraft (C-130s) would deliver collapsible shelters, fuel, and communications equipment. C-130s have been regularly used to resupply floating ice stations. In the summer, when landing might be difficult, they would use parachutes or low-altitude free drop delivery. Airborne Warning and Control System aircraft would give an early warning of hostile air reaction. Fighter aircraft, possibly operating from the ice pack itself when condi-
Flying Conditions in the Arctic
The polar region is well characterized as a cold, inhospitable ^esert. Mean temperatures range r°m 35° down to —32° Fahren- but periods with temperatures as low as -60°F are not Uncommon. The air’s moisture c°ntent is low most of the year, and precipitation is light. The dominant climatic condition, particularly in winter, is a polar nigh, with fair, cold weather.
The winter consists of long, ctear cold periods. The sky is ctear almost half of the time, and ls at least partially clear three days out of four. While the temperature tends to run about 5° below that at inhabited subarctic latitudes (e.g., central Alaska), Polar winds are usually more moderate, resulting in consistently lower wind-chill conditions.
Winds rarely exceed 28 knots.
Flying conditions in the Arctic tend to be best in late winter (February to May). During this Period, there is an increasing amount of daylight, the surfaces of the ice pack are still frozen, and there are not yet sufficient areas of open water to produce much fog. As the warmer weather advances, landings by fixed-wing aircraft become more difficult because of fog and water accumulation on top of the ice. Drainage is required even for vertical landings in some areas unless the aircraft is equipped with flotation gear. Blowing snow is a hazard to air operations from October to April; however, it does not normally extend more than 10 or 15 meters in the air and may last for only a few hours. It seldom obscures ground structures from the air, even though forward visibility may be limited to 100 meters or less. High-intensity stroboscopic lights are advisable for operations during such conditions.
Arctic water under the ice pack has unique characteristics, some of which are especially favorable to long-range sound transmission.
Ambient noise under continuous ice tends to be lower than that in the open ocean because of a lack of shipping, waves, or sea life. In the central part of the ocean, the water’s temperature and salinity are fairly constant with respect to depth because of year-round ice cover. Sound velocity increases steadily with depth. This positive sound-velocity profile at all depths produces the characteristics of a deep sound-channel with its axis at or near the surface. The roughness of the underside of the ice sharply attenuates high- frequency signals, but it has a negligible effect on low frequencies, such as those from rotating propellers. Small explosions have been detected at ranges up to 1,500 miles.
Edward Atkeson
tions would permit, would provide the principal means of air defense. In addition, depending upon the sensitivity and value of particular base centers, some surface-to-air missile units might be required.
Air attack would be the greatest threat to the force. However, it would not be necessary to establish large bases on the ice pack that might offer remunerative targets. Scores of small communications, rest, and supply centers—of which no one or two would perform functions critical to the entire force’s effectiveness—would give the support structure great resilience by confronting the attacker with an overload of small, marginally important targets. While the helicopters and V/STOL aircraft might be subject to hostile air attack, their chances for survival through dispersal and camouflage on the ice pack would be greater than those of fixed-wing aircraft, which would be obliged to remain in the air. Cloud cover and fog in the summertime and darkness in winter would assist their efforts to avoid destruction.
Assessment: The capability of a VSTOL/helicopter force to operate quickly without generating aquatic noise or masking incoming signals, and to dispatch reconnaissance and ordnance delivery teams rapidly to locate and engage targets at extended ranges, could prove more cost- effective than current subsurface forces pursuing the same mission. Some scenarios may favor a helicopter/V/STOL force over SSNs. For example, if the Soviets were to husband their SSBNs in the peripheral seas (Barents, Kara, Laptev, etc.) and to deploy their own SSNs in forwar screening positions under the central ice pack, the SSI^ ASW component could be withheld until the top-of-the- ice-pack force had reduced the risk of ambush for the SSNs. Depending on the time of year and the condition o the ice pack, either component—or both—could then at tack the Soviet SSBNs.
This type of a combined arms ASW force offers a formidable option. Compared to SSNs, the V/STOL/helicop- ter component of the force would enjoy:
- Rapid strategic deployment capability .
- Virtually immediate target-area coverage capability> once deployed
- Full target area coverage for the duration of the deployment of the force
- Capability for rapid tactical closure on areas of target detection or suspicion, and rapid delivery of ordnance
- Good communications with the directive authority an between cooperating units
- Low vulnerability to ambush or hostile reaction
- Ease of reinforcement, replacement, resupply, reconsti
tution, and withdrawal for other missions ,
- Capability for nonacoustic sensors from airborne and surface positions and of low-risk use of active acoustic devices
- Simultaneous multiple target attack capability
- Capability for casualty evacuation following attack by a
Any activity in the Arctic will be undertaken in a largely pristine marine or terrestrial environment characterized by prolonged periods of darkness, dense fog, storms, diverse climate and geography, low temperatures, and ice, all of which force constraints on military operations.
The most obvious environmental factors in the Arctic are the sea ice and low temperatures. The sea ice cover, with the exception of shorefast ice, is in nearconstant motion. The major forces that produce ice motion and deformation are winds and currents. Variable stresses within the ice fields, created by the winds and currents, cause ice floes to fracture and separate, producing leaaS (open water) and polynyas (semipermanent open water). Differen' tial ice motion along these openings may cause floe collision resulting in the formation of ice hummocks and ridges.
comparative advantages in the following y f:'8h environmental habitability
ores trie ted access to under-ice and open water areas ow vulnerability to hostile air attack
33-;
3Noi
f'lan Polmar, Guide to the Soviet Navy (Annapolis, MD: Naval Institute Press,
hostile force
Capability for reaching ice pack areas that might be 0 ®P°rarily denied to friendly SSNs because of blockage access routes by heavy ice formations in shallow waters he SSN component, on the other hand, would enjoy
areas:
y Ustained independent operational capability y . ra^ition and experience in ASW operations ► !tyu!nerability to weather conditions ^ °''ity to monitor hostile SSBN base areas and to trail Parting submarines in advance of a conflict the components were to operate in concert, the entire tfpaign might be concluded much sooner than by either Perating alone. The development of procedures for inter- tr()|,l^°nent cornmun'cation and joint command and con- Would be a challenging task. Submariners are accus- med to minimal supervision, and U. S. forces have little ^ Pcience operating on top of the ice pack, while the Vlets have much more. But the prize is worth the corned effort.
'1 34 Apartment of Defense, Soviet Military Power 1987, Washington, DC, pp.
198fi?an P°lmar' C 86)’ PP- 114-118.
3David A. Boutacoff, “Soviets Upgrade Submarine-launched Ballistic Missile Forces,” Defense Electronics, September 1984, p. 152.
4John E. Sater, A. G. Ronhovde, and L.C. Van Allen, Arctic Environment and Resources (Washington, DC: The Arctic Institute of North America, 1971), p. 47. 5Craig Covault, “Soviet Ability to Fire Through Ice Creates New SLBM Basing Mode,” Aviation Week and Space Technology, 10 December 1984, p. 16.
6John Alden, “Tomorrow’s Fleet,” May 1987 Naval Review/Proceedings, pp. 180 and 185.
7Craig Covault, "Spacelab 3 Mission to Launch University, Defense Spacecraft,” Aviation Week and Space Technology, 15 April 1985, pp. 14-15.
8S. M. Olenicoff, The Arctic Ocean as an Operating Environment for Submarines, (Santa Monica, CA: The RAND Corp., 1973), p. 32.
9Edgar Ulsamer, “Bobbing, Weaving and Fighting Smart,” Air Force Magazine, August 1983, p. 89.
10For a discussion of Soviet thinking regarding nuclear warfare in Europe see: MGen Edward B. Atkeson, USA (Ret.), “Soviet Emphasis Viewed as Desire to Avoid Nuclear Heat-Up,” Army, August 1985, pp. 20-23.
11Jane's Weapons Systems 1985-86 (London: Jane’s Publishing Co. Ltd., 1985), pp. 223-224.
12Robert Waters, “Sikorsky Gives Another Look at Tilt-Rotor,” Hartford Cou- rant, 10 November 1985, p. Cl.
,3James B. Thompson, “Self-Deployment of CH-47 Medium Lift Helicopters to Europe,” U. S. Army Aviation Digest, August 1979, pp. 6-7 and back page.
General Atkeson graduated from the U. S. Military Academy in 1951 and received an MBA from Syracuse University. During his Army career, his duty assignments included Assistant Army Attache at the U. S. Embassy, Helsinki, Finland; a tour in Vietnam; Director, Office of Policy and Planning Intelligence Community Staff; Deputy Chief of Staff, Intelligence, at Headquarters, U. S. Army, Europe; and National Intelligence Officer for General Purpose Forces at Central Intelligence Agency Headquarters. He was a Fellow at the Center for International Affairs, Harvard University. He retired from the military in 1984 and is currently an adjunct professor at the Defense Intelligence College and a private consultant on National Security Affairs.
eads can be very narrow or atly meters—or even kilometers—
kil 6 * may also be many ^°meters long as navigable lanes °pen water. Ice ridges can reach *ghts of ten meters and may ^|*Ve keels with depths as great as meters. Pressure ridges are j SUaHy formed from the thinner QCe types, although ridges can Ccur in any thickness of sea ice ■ m all ice types at any season. e thickness averages three me- s- The ice coverage usually aches its minimum extent by ^ate summer. With the onset of t°ntinuous below-freezing air Criperatures, the ice begins to §r°w seaward from the coastlines, 'thin and outward from the ice argin in mid to late September. e growth continues until March nen the ice reaches its maxi- um limit. Icebergs are fresh ater ice calved from the ice ‘ eets of Greenland and Canada.
1 emperature: The mean annual cniperature at the geographic °rth Pole is approximately — 23°C. Minimum temperatures of -40°C are common, although extremes in excess of — 50°C have been recorded. Temperatures rise as cloud cover and wind speed increase; maximum winter temperatures under overcast conditions without wind reach — 25°C.
Winds: Winds are the primary drivers of sea ice dynamics. Wind intensifies the cold and limits Arctic travel when blowing snow restricts visibility. Wind speeds in the Arctic Ocean typically are eight to ten knots. They can create heavy sea states and spray which, if the temperature is low enough, can cause severe shipboard icing. Icing can create stability problems as well as severe problems for weapons and antennae. The Arctic regions are also subject to Arctic lows—small, intense locally generated storms with winds up to 80 miles per hour that are a hazard to surface vessels.
Fog: A low, clinging fog is often seen over leads and other areas of open water. The air becomes saturated almost immediately where open water is exposed because the water-vapor capacity of cold air is low. Fog may be present up to 90% of the time along the edge of the ice.
Darkness: Dependent upon latitude, the Arctic is completely dark during the winter months and totally light in summer.
Marginal Ice Zone: The ice edge has its own special environment. This dynamic region is composed of very compact ice if the winds are blowing on ice or very diffuse in off-ice conditions. The ice edge’s interaction with the oceanic waves causes grinding and splashing, which fills this zone with high ambient noise levels. The ice edge is also a zone of sharp water temperature and salinity gradients; the resultant front causes distortion of the sound velocity field. All of these aspects make acoustic operations difficult in the marginal ice zone.
Leonard Johnson