A Soviet Delta I SSBN on patrol

Only in 2000 would the U.S. Navy reveal some of the details of trailing Soviet SSBNs. In conjunction with an exhibit at the Smithsonian Institution’s Museum of American History commemorating one hundred years of U.S. Navy submarines, heavily censored reports of two U.S. trailing operations were released: the trail of a Yankee SSBN in the Atlantic,¹⁰ and that of a Project 675/Echo II SSGN in the Pacific by SSNs.¹¹

This particular Yankee trailing operation – given the code name Evening Star – began on March 17, 1978 when USS Batfish (SSN-681) intercepted a Yankee SSBN in the Norwegian Sea. Batfish, towing a 1,100-foot sonar array, had been sent out from Norfolk specifically to intercept the SSBN, U.S. intelligence having been alerted to her probable departure from the Kola Peninsula by the CIA-sponsored Norwegian intelligence activities and U.S. spy satellites. These sources, in turn, cued the Norway-based SOSUS array as the Soviet missile submarine sailed around Norway’s North Cape.

After trailing the Soviet submarine for 51 hours while she traveled 350 nautical miles, Batfish lost contact during a severe storm on March 19. A U.S. Navy P-3 Orion maritime patrol aircraft was dispatched from Reykjavik, Iceland, to seek out the evasive quarry. There was intermittent contact with the submarine the next day and firm contact was reestablished late on March 21 in the Iceland-Faeroes gap.

The trail of the SSBN was then maintained by Batfish for 44 continuous days, the longest trail of a Yankee conducted to that time by a U.S. submarine.¹² During that period the Yankee traveled 8,870 nautical miles, including a 19-day “alert” phase, much of it some 1,600 nautical miles from the U.S. coast, little more than the range of the submarine’s 16 RSM-25/R-27U missiles. The Batfish report provides day-to-day details of the Yankee’s patrol and the trailing procedures. Significantly, the SSBN frequently used her MGK-100 Kerch active sonar (NATO designation Blocks of Wood).¹³This sonar use and rigidly scheduled maneuvers by the Soviet submarine, for example, to clear the “baffles,” that is, the area behind the submarine, and to operate at periscope depth twice a day continuously revealed her position to the trailing SSN.¹⁴Batfish ended her trailing operation as the Yankee SSBN reentered the Norwegian Sea.

The routine repetitiveness of the “target” was used to considerable advantage by Batfish. Certain maneuvers indicated a major track change or impending periscope depth operations. But would such predictable maneuvers have been used in wartime? The repeated use of her sonar in the Batfish operation was highly unusual for a Yankee SSBN on patrol. Would the missile submarine have employed countermeasures and counter-tactics to shake off the trailing submarine during a crisis or in wartime? “You bet they would change their tactics and procedures,” said the commanding officer of the Batfish, Cmdr. Thomas Evans.¹⁵

There are examples of tactics being employed by Soviet submarines to avoid U.S.-NATO detection. Among them have been transiting in the proximity of large merchant ships or warships in an attempt to hide their signatures from Western sensors, and reducing noise sources below their normal level when transiting in areas of high probability of SOSUS detection.¹⁶

Not all U.S. trailing operations were successful. Periodically Soviet SSBNs entered the Atlantic and Pacific without being detected; sometimes the trail was lost. A noteworthy incident occurred in October 1986 when the U.S. attack submarine Augusta (SSN-710) was trailing a Soviet SSN in the North Atlantic. Augusta is reported to have collided with a Soviet Delta I SSBN that the U.S. submarine had failed to detect. Augusta was able to return to port, but she suffered $2.7 million in damage. The larger Soviet SSBN suffered only minor damage and continued her patrol.

(top) A Soviet Yankee SSBN transiting on the surface. Yankees, designed for high speeds while submerged, could reach 25 knots (bottom) An Echo II sail with radio antenna raised at the after end of the fairwater structure.

(U.S. and Soviet submarines occasionally collided during this phase of the Cold War, many of the incidents undoubtedly taking place during trail operations. Unofficial estimates place the number of such collisions involving nuclear submarines at some 20 to 40.)

The limited range of the Yankee’s RSM-25/SS-N-6 missile forced these submarines to operate relatively close to the coasts of the United States. Under these conditions, and upon the start of hostilities, the trailing U.S. submarines would attempt to sink the Soviet SSBNs as they released their first missiles (or, under some proposals, when their missile tube covers were heard opening). If feasible, the U.S. submarines would call in ASW aircraft or surface ships, and there were proposals for U.S. surface ships to try to shoot down the initial missiles being launched, which would reveal the location of the submarine to ASW forces. These SLBM shoot-down proposals were not pursued.¹⁷

U.S. anti-SSBN efforts again were set back in 1972 when the first Project 667B/Delta I ballistic missile submarine went to sea. This was an enlarged Yankee design carrying the RSM-40/R-29 (NATO SS-N-8 Sawfly) missile with a range of 4,210 nautical miles. This missile range enabled Delta I SSBNs to target virtually all of the United States while remaining in Arctic waters and in the Sea of Okhotsk. In those waters the SSBNs could be defended by land-based naval aircraft as well as submarines and (in ice-free waters) surface warships. These SSBNs were equipped with a buoy-type surfacing antenna that could receive radio communications, target designations, and satellite navigational data when the ship was at a considerable depth.

Further, communications with submarines in Arctic waters were simplified because of their proximity to Soviet territory. The use of surface ships and submarines for communications relay were also possible. It was possible that civilian nuclear-propelled icebreakers – which were armed on their sea trials – were intended to provide such support to submarines in wartime.¹⁸

Also, having long-range missiles that would enable SSBNs to target the United States from their bases or after short transits, fit into the Soviet Navy’s procedure of normally keeping only a small portion of the submarine fleet at sea, with a majority of their undersea craft held in port at a relatively high state of readiness. These submarines – of all types – would be “surged” during a crisis.

This procedure was radically different than that of the U.S. Navy, which, for most of the Cold War, saw up to one-third of the surface fleet and many SSNs forward deployed. More than one-half of the SSBN force was continuously at sea – nautical at a cost of more personnel and more wear-and-tear on the ships.

The Soviet SSBN operating areas in the Arctic and Sea of Okhotsk-referred to a “sanctuaries” and “bastions” by Western intelligence-were covered by ice for much of the year and created new challenges for Western ASW forces. U.S. attack submarines of the Sturgeon (SSN-637)-class were well suited for operating in those areas, being relatively quiet and having an under-ice capability.¹⁹ However, the Arctic environment is not “ASW friendly”: communications – even reception – are extremely difficult under ice; passive sonar is degraded by the sounds of ice movement and marine life; and under-ice acoustic phenomena interfere with passive (homing) torpedo guidance. Also, the Arctic environment, even in ice-free areas, is difficult if not impossible for Allied ASW aircraft and surface ship operations.

The Soviet SSBN force thus became an increasingly effective strategic strike/deterrent weapon, especially when operating in the sanctuaries or bastions.

(c) 2003 N. Polmar and K. J. Moore, Cold War Submarines (Dulles, VA: Brassey’s - Potomac Books).