AMERICAN SUBMARINES FROM A RUSSIAN POINT OF VIEW

During the late 1980s the U.S. Navy had more than 90 nuclear powered attack and some 35 ballistic missile submarines. At the beginning of the 2000s the U.S. Navy could have a force of 14 strategic missile nuclear submarines and about 45-55 attack boats, including three Seawolf class attack submarines.

Every analog is conditional; nevertheless, no one can deny the usefulness of analogies. Let us go to surface ship terminology and think of an Ohio class ballistic missile submarine as a battleship with main caliber weapons in its 83 inch Trident 05 missile tubes; a Seawolf class attack submarine as a cruiser with a main caliber weapon battery of large torpedo tubes, and a Los Angeles/NSSN (new nuclear attack submarine) as a destroyer with main caliber weapons in 21 inch Mk 48 torpedoes.

Ohio Class Battleships

The Ohio class ballistic missile nuclear submarines (underwater battleships/aircraft carriers) provide the sea leg of the triad of the U.S. strategic offensive forces. By the tum of the century the 14 SSBN 726 class submarines, each with 24 05 missiles, will carry almost half the nuclear warheads of the U.S. strategic nuclear arsenal. By virtue of their missile’s range and patrol posture, they can deter and destroy a potential aggressor in every region of the world and they are highly survivable. They are also extremely flexible, capable of rapid retargeting of their missiles, using secure and constant communications links.

But in comparison with a strategic bomber and an aircraft carrier they have one, very significant, deficiency: they could not be used for deterring and waging a major conventional war. It is at those times when an important shift in submarine warfighting concepts and doctrine takes place; away from deterrence of global nuclear war to the support of U.S. national interests in regional crises and conflicts.

In this respect one can raise a question as to why the U.S. Navy does not use the design philosophy of the Air Force’s strategic bombers’ or its own aircraft carriers relating to the Ohio class strategic submarines.

That is, in addition to nuclear Trident missiles, why not develop and, if necessary, deploy conventional versions of these missiles?

At the beginning of 1990 I was in Washington and was invited to speak on political-military problems at the Anny and Navy Club for journalists writing on naval and maritime subjects.

One of them published the following:

“Soviet proposes boomless boomer for the U.S., Russian
Navies

.. A senior Soviet academician last week proposed arming
nuclear missile submarines with conventional weapons.
‘If I were Chief of Naval Architecture of the U.S. and
Soviet Union, I would propose conventional weapons’,
said George Sviatov. He is senior research fellow with
the Institute of World History of the Academy of
Sciences of the USSR.
‘You can use a strategic bomber in conventional and
nuclear war, but you cannot use a Trident submarine in
a conventional war’, he said.”

The underwater Ohio class battleship has a huge strategic weapons payload which is many times more than on a strategic bomber and comparable with that of an aircraft carrier. With conventional strategic offensive Trident missiles she can effectively participate in deterring and destroying any potential major regional aggressor in any point of the globe.

Another strategic mission could be conceived for the underwater battleship. She can be used in a regional ABM role or/and in a limited territorial ABM role of the U.S. using antiballistic versions of conventional Trident missiles for interception of a small number of ICBMs or SLBMs of a potential nuclear aggressor.

And in addition to, or instead of, conventional Trident-sized Land-Attack Strategic Missiles in the underwater battleship’s 24 main caliber missiles tubes it is possible to deploy very Long Range Anti-Ship Missiles with conventional warheads to strike aircraft carriers and other major warships using space-based target acquisition systems.

Seawolf Class Cruisers

SEAWOLF (SSN 21) is the U.S. Navy’s most advanced attack submarine design, originally intended as a class of 29 submarines to be built during a ten year period. The end of the Cold War and budget constraints have led to a revision of U.S. submarine planning. Now only a few submarines of this design are expected to be built.

The SSN 21 is significantly quieter than the previous Los Angeles (SSN 688) class, faster, has 26 inch torpedo tubes, and carries twice as many weapons (up to 50 torpedoes or/and full size missiles or 100 mines). She also introduces the advanced AN/BSY-2 combat system which includes a new, larger spherical sonar array, a wide aperture array and a new towed array sonar.

In the era of relatively noisy Soviet nuclear submarines American submarines operated primarily in the passive mode. The appearance of quiet Soviet and Russian nuclear submarines led to a renewed interest in active sonar techniques. The recent doctrinal shift of U.S. naval forces to littoral operations where relatively quieter, non-nuclear submarines could be encountered in adverse ASW environments further increases the need for advanced active sonar systems, weapons, and tactics.

Considering the Seawolf class submarine in the general picture of United States submarine development it is possible to present some kind of a Russian net assessment.

The number one difference between the Los Angeles and Seawolf class submarines is in the latter’s search with effectiveness lower self-noise level, better sonars, and the AN/BSY-2 system which will enable the Seawolfs to detect and locate targets at longer ranges. In addition, it can address multiple targets concurrently and reduce the time between detecting a threat and launching weapons.

The number two difference, which correlates with number one, is 26 inch {instead of 21 inch) torpedo tubes allowing the use of new heavier torpedoes (or missiles) similar to the 65 cm wakehoming torpedoes now used on the latest Russian nuclear classes of submarines such as Alcula, Sierra, and Victor-ill.

With only 30 percent bigger displacement and with lesser length, the U.S. Navy gets a ship which differs from the LOS ANGELES as a cruiser differs from a destroyer. She has 26 inch guns instead of 21 inch guns and two times more torpedo-size weapons. Her potential weapons payload, considering the bigger caliber, is three times more. Taking into account her advanced sonar and combat system, one can assume that her general combat effectiveness is perhaps six times better than that of the Los Angeles class submarine. Comparing with an Improved 688 class submarine in principle gives the same picture, but it is not relevant because the Seawolf class could have had an additional 12-16 vertical launchers outside the pressure hull without difficulties.

By the way, a naval architectural decision to install 12 Tomahawk launchers outside the pressure hull on the 6881 class submarines is a palliative which was very popular on Soviet cruise and even some ballistic missiles submarines. It is possible to do, but it does not allow regular inspection and maintenance of missiles at sea.

The Seawolf class submarine project probably has some deficiencies. Which ones are apparent from the point of view of an outsider.

If one compares the weapons payload of the SEA WOLF with the payload of the LOS ANGELES the result will be in the decisive favor of the former. But comparison of the Sea wolf class submarines with the Ohio class or a surface cruiser shows that the relation of her weapons weight to displacement (as a percentage) is much smaller. By increasing her displacement, let us say by about 300 tons, it is possible to increase the number of her torpedo-size weapons from 50 to 100.

Every unbiased naval architect-submariner understands the advantages of one reactor, one propeller, and a single hull architectural scheme. But in American nuclear submarine designing it became a formal religion. It is clear that two reactors, two propellers, and a double hull architectural scheme also have advantages which are obvious with regard to surface ships, aviation and also U.S. WWII submarines.

Another orthodox naval architectural decision in American submarine designing is to use approximately 15 percent reserve buoyancy and put it in several bow and stern ballast tanks, in the absence of an outer light hull around the pressure hull. But a double hull scheme with ring-like ballast tanks and frames outside of the pressure hull, with 30 percent reserve buoyancy and only one bow and one stem ballast tanks could give its own advantages.

Such an alternative to the Seawolf class submarine would have, for example six compartments with five transverse bulkheads (1 – hydroacoustic and living, 2 – torpedo room, 3 – control room and living, 4 – forward reactor and turbine, 5 – aft reactor and turbine, 6 aft torpedo, planes and rudders equipment), eight ballast tanks, and contrarotating propellers. She would have had not only surface but also underwater unsinkability with one flooded compartment.

Such a real revolutionary naval architectural decision (an attempt to implement it in the U.S. took place in the late 1950s on the TRITON nuclear radar picket submarine) could be reached by using hydrodynamic forces of high speeds (even with one flooded engine compartment) and by blowing relevant undamaged ballast tanks which should have kingstons. To do it, it is sufficient to have bulkheads with 50 percent of operating depth pressure strength, some more strengthened ballast tanks, and maybe, a little higher pressure air reserves.

Of course, the SEA WOLF is an excellent submarine with its own architectural scheme, but it seems that for a next generation underwater cruiser with 100 torpedo-size 26 inch weapons such an alternative approach might be reasonable.

Los Angeles/New Attack Submarine Classes Destroyers

Los Angeles is the largest class of nuclear submarines built by any nation, with 62 units in commission, or already decommissioned, or under construction. These submarines will form the backbone of U.S. attack submarine force at the beginning of the 21st century.

The Los Angeles class submarines are fast, have four 21 inch torpedo tubes and carry 25 torpedo-size weapons. The last 31 units additionally have 12 vertical-launch tubes for Tomahawk cruise missiles. Of these, the final 23 lmproved-688 submarines are quieter, incorporate an advanced AN/BSY-1 fire control system, and are configured for under-ice operations with their forward diving planes moved from the sail to the bow.

Their standard Advanced Capability (ADCAP) Mk 48 torpedo is a highly capable weapon (it was published that its range is 35,000 yards at 55 knots). It can be used against submarines and surface ships.

These submarines can carry and lay mines. They are launched through torpedo tubes and replace torpedoes on a two-for-one basis. The two principal types of their mines are the Submarine Launched Mobile Mine (SLMM) and encapsulated torpedo (CAPTOR).

Instead of the deck-mounted artillery of WWII U.S. attack submarines, the Los Angeles class submarines have cruise missiles launched from their torpedo tubes and vertical launchers.

There are two types of anti-ship missiles: the Harpoon with a mine size and range of some 75 nautical miles, and the Tomahawk (TASM) with a torpedo size and range of more than 250 nautical miles.

These submarines can also carry the Tomahawk Land-Attack Missile (TLAM) with a range of 700 nautical miles which provides the capability for long range precision strikes with conventional warheads against shore targets. First used in combat in the 1991 Gulf War, the TLAM proved to be a highly effective weapon.

Here it is not necessary to spend more space relating to the Los Angeles class submarines. Suffice to say that they are the best existing nuclear attack submarines in the world.

It will be better to concentrate attention on the NSSN class submarine and analyze her relationship with the Los Angeles class and the Seawolf class submarines.

In August 1992 the U.S. Navy issued the unclassified report on the new attack submarine in which required military capabilities, quieting impact, maximum speed aspects, and technical risk were discussed.

To reduce displacement and cost of the NSSN class submarine in comparison with the SEAWOLF, the U.S. Navy proposed to retain SEA WOLF’s quieting and the sonar detection sensor suites and to reduce weapon payload and weapons delivery rate, maximum speed and depth.

The U.S. Navy analysis showed that the NSSN’s submerged displacement could be realistically in the range from 6000 to 8000 tons. The lower level of displacement provided from four 21 inch torpedo tubes with total payload of 26 torpedo-size weapons and the upper level for eight 21 inch torpedo tubes with total payload of 50 torpedoes or full size missiles plus 16 VLS tubes for Tomahawks.

What kind of a Russian viewpoint could be presented relating to the NSSN class submarine in comparison with the Seawolf and Los Angeles classes submarines?

First, it seems that the naval architectural decision of the Seawolfs sonar-weapons complex is optimal for the NSSN. It means AN/BSY-2 sonar/fire control system, eight torpedo tubes and 50 21 inch torpedo size weapons.

Second, 26 inch torpedo tubes caliber is not proper for the NSSN because she is a destroyer but not a cruiser and the shift to a bigger main caliber means increase of displacement and cost.

Third, reduction of the total torpedo numbers on the NSSN in comparison with the SEA WOLF seems to be unreasonable because their number on the Seawolf class submarines can and should be increased. But 16 VLS tubes for Tomahawks outside the pressure hull should be rejected to reduce displacement and cost and increase the missiles’ maintainability and reliability.

Fourth, so far as the NSSN is a destroyer, classic American one reactor, one propeller naval architectural scheme would be optimal. So far as her nuclear power plant is designed for a pressure hull diameter and displacement Jess than SEA WOLF’s, its horsepower could be reduced. But, maybe technological progress could provide the same horsepower as on the Seawolf class submarines with lesser weights and sizes. In this case maximum speed of the NSSN would be more than of the SEAWOLF.

Fifth, the reduction of the NSSN’s displacement as regard to the SEAWOLF by 1000-1500 tons can be provided mainly by lessening of weight and size of the nuclear power plant, reducing caliber of torpedo tubes, lessening of computers and electronics sizes and by very significant reduction of the crew’s number with fully automated control in the power plant’s compartments.

And sixth, taking into account a very old love of the author for the idea of underwater (and, of course, surface) unsinkability with one flooded compartment, it is impossible not to suggest for the NSSN a five compartment scheme (1 – sonar and weapons, 2 – control room and living, 3 – reactor, 4 – turbines, 5 – planes and rudder devices), double hull with seven ballast tanks and 30 percent reserve· of buoyancy. A possibility should be considered to provide a capability for reactor and turbines to work for some time with the third or fourth compartments flooded.

Conclusions

With the changing character of global strategic nuclear deterrence from assured retaliatory destruction to discriminate deterrence, the number of U.S. strategic deliverable nuclear warheads will be reduced. What would it mean for SSBNs (18, 700 tons underwater battleships)? Certainly, a reduction in numbers of the Ohio class submarines or broadening of their mission spectrum, including conventional strategic deterrence and defense and warfighting capabilities from their 83 inch main caliber tubes. So it might be reasonable for the U.S. Navy to consider a program of the SSBN forces modification, using the approach which the U.S. Air Force always used relating to their strategic bombers. And to begin realization of this program from the four C-4 configured Ohio class submarines which are planned to go out of service in the not-so-distant future.

The U.S. Navy must continue building of the Seawolf class SSNs (9150 tons underwater cruisers) with their 26 inch main caliber because these attack submarines are the best in the world. But to use their big potential capabilities it might be reasonable to consider their modification with 26 inch diameter torpedoes and missiles and a payload of 100 such torpedoes and missiles.

The Los Angeles class SSNs (6927 tons underwater destroyers) are the backbone of the U.S. nuclear attack Submarine Force and the best existing SSNs in the world. Battle characteristics of the NSSN submarine (a 8000 ton destroyer) could be between the modernized Seawolf and Los Angeles classes. With the AN/BSY2 type combat/sonar system, eight 21 inch torpedo tubes and 50 torpedoes/missiles the NSSN can be affordable and cost effective as a substitution for the Los Angeles class submarines.