SSN: A Strategy Guide to Submarine Warfare by Tom Clancy
The second role of Soviet attack submarines was the so-called anticarrier role, designed to destroy American and NATO aircraft-carrier battle groups, the alliance’s most powerful and mobile strike weapon at sea. The Soviets and the Americans both knew that while a carrier’s aircraft and escorts might detect and intercept enemy bombers at great distances, the nature of the submarine threat meant that they would not be able to defend against Soviet boats with the same level of efficiency. The role of carrier-hunting submarines, like the missile-armed Project 670/Charlie I/II and Project 949/Oscar I/II SSGNs, was to sneak into range of an American battle group and attack the prey before they were ever detected. This was a very real threat during the Cold War, and it was for this reason that ASW was so vitally important.
One of the best ways to kill a submarine is with another submarine. Continued improvements to the Los Angeles class of submarines were extremely effective and significantly increased the 688I’s ability to conduct many types of missions. However, as much as the budget cutters hate to admit it, there comes a time when even the most advanced weapons designs begin to reach their technological limits. In the early 1980s, just as the Navy was ordering the first 688Is, thinking began in earnest about the follow-on to the Los Angeles-class boats.
In the past, much of the silent East-West submarine battle had been fought in the deep ocean depths, far from view of the nearest land. This was to have been the Seawolf’s true home. She would be faster, deeper diving, and quieter than any attack submarine the world had ever produced. With ASW already acknowledged as the U.S. Navy’s top mission, Seawolf would become the tool for meeting this essential priority. As might be imagined, the project was going to cost some money—lots of money! Initial FY89 cost estimates for the submarine ran in the neighborhood of $39 billion for the full class of thirty boats, which made them the most expensive such vessels in American history. Initial plans called for building three subs per year, which would allow the U.S. Navy to maintain a sufficient force of boats to conduct the required operations in the event the Cold War ever turned hot. It was a good plan, except for the fact that the war it had been designed to fight disappeared within a little over two years.
That type of money—$39 billion—was hard enough to come by during the height of the Cold War and became impossible once it ended. As an uneasy friendship between the U.S. and the former Soviet Union began to grow, so did pressure to trim the American defense budget, which had been slowly declining since the end of the Reagan years. As U.S. politicians clamored for their share of the so-called Peace Dividend, the Defense Department and the Navy began to reexamine exactly what role Seawolf might play in twenty-first-century submarine-force structure. One of the primary lessons learned from the Persian Gulf War was that while submarines were designed to operate in the depths of the blue ocean, there was also an all too frequently ignored requirement for them to support operations on land. Quickly, the Navy began to see the writing on the wall concerning spending on this very expensive weapons program. Several months after the end of the 1991 Gulf War, the chief of naval operations (CNO) announced that Seawolf construction would be cut from the planned three subs a year to a more modest one per year. However, even this plan was modified once the realities of post-Cold War finances and technology began to make themselves known in the 1990s.
The first of the problems for the new class were technical, as might be imagined for such a state-of-the-art weapons system. High-strength HY-80 steel had been used in nearly all previous American nuclear submarine designs since the Skipjack (SSN-585) class of the 1950s. Nevertheless, for the deep-diving Seawolf, stronger metal would be needed. Initial plans looked at material as strong as HY-130 steel, but this was eventually shelved in favor of HY-100. The HY-130 was just too hard to work and weld, and production problems with it looked inevitable. Therefore, the Navy and Electric Boat thought HY- 100 would be a good compromise between ease of manufacture and greater diving depth. Unfortunately, even the HY-100 steel had its problems when Electric Boat got working. In midsummer 1991, the Navy announced that massive weld failures had been uncovered on Seawolf’s hull as it underwent construction. These welding cracks, which might very well have been deadly had they not been discovered and repaired, meant that all welding done to date needed replacement. This caused production of Seawolf to be delayed an additional year and added more than $100 million to the already high price of the new boat.
Then further bad news arrived. In 1992, after concluding an agonizing analysis of the situation, the DoD (under then Secretary of Defense Dick Cheney) decided to cut funding for all of the planned SSN-21-class submarines except for the Seawolf herself, which was already under construction. As might have been predicted, with the 1992 presidential election looming, the Seawolf program would become a hotly contested political issue.
Running in a tight Democratic primary, a young governor from Arkansas named William Jefferson Clinton announced in 1992 that if elected president, he would save the Seawolf program and continue production past the first unit. Though criticized by some Democrats as supporting a weapons program even the Republicans wanted to cancel, Clinton’s gambit paid off. When he won the White House in 1992, he took with him Connecticut’s electoral votes, something that might have been impossible without the support of one of that state’s biggest employers and its workers—General Dynamics Electric Boat Division—the Seawolf submarine’s prime contractor. It is interesting to note that the second submarine of the class was appropriately named USS Connecticut (SSN-22).
The year 1992 also marked the beginning of a changing strategy for U.S. Navy forces. It was during this year that the Navy and Marine Corps released their seminal document that was to serve as a guide for planning the Navy and Marine Corps of the twenty-first century. Entitled From the Sea: Preparing the Naval Service for the 21st Century, the document spelled out the biggest change in U.S. naval strategy and policy since the end of the Second World War. Declaring boldly that the Navy’s current command of the seas allowed it to concentrate on areas of more likely future conflicts, namely the “littoral” or coastal zones of the earth, the Navy would dramatically alter the planned environment in which they were preparing to fight. In essence, From the Sea declared that the ability of the Navy and Marine Corps team to project power from the water and impact events on land would be of dramatically greater importance to future naval planning—more so even than the deep ocean operations of the Cold War. Gone were the days when the so-called blue-water navy took top priority while brown-water units (riverine, mine-hunting, and amphibious forces, among others) languished as a result of a lack of training, funding, and attention from the senior leadership. Impacting events on land was something the U.S. Marine Corps and SEALs community had done for decades, but it was something the majority of U.S. Navy officers and sailors had to learn quickly if the Navy was to have a seat at the table when new conflicts erupted.
While this confident new plan was essential to the Navy’s future, it was not good news for the Seawolf program. Seawolf had been designed to fight in the ocean depths and to hunt Soviet submarines. To this end, it was the quietest, deepest-diving attack submarine America had ever planned. The problems facing warships in the shallow, murky “brown” water of the coastal regions were entirely different from those encountered in the open ocean. This was especially true for submarines, which relied on deep diving depths and sensitive passive sonars to maintain their stealth—both of which would be of limited use in the brown-water combat environment.
As if this was not bad enough, the new Seawolf-class boats were also extremely expensive. Practically every part of the Seawolf’s design was controversial. While this was largely due to the high cost of incorporating advanced systems into a revolutionary design, there seemed to be problems all along the way, which some of the world’s best experts were put to work solving. The result was a truly amazing piece of machinery, which has run taxpayers somewhere in the neighborhood of $2.8 billion per unit of the class. While
Fortunately, plans for a new submarine that would incorporate the technology of the Seawolf into a boat the size and cost of the Los Angeles class were already in the works. Faced with these fiscal and strategic realities, the Navy put new emphasis on a submarine they were calling Centurion—today known as the Virginia (SSN-774) class. It thus came as no surprise when, in October 1993, Secretary of Defense Les Aspin released the results of the Bottom-up Review (BUR) in which it was explained that Seawolf production would end after only three boats, holdovers from Clinton’s election ’92 promise, had been constructed.
Seawolf (SSN-21): A Guided Tour
Once you get over the sticker-price shock (something Congress never seemed to do!), you can discover exactly how revolutionary Seawolf actually is, and it’s something of which every American can be justly proud. Let’s start out by discussing the design of this big, beautiful boat. Prior to Seawolf’s design, every class of U.S. submarine since the Skipjack (SSN-585) class of the 1950s had been an “iterative” design. That is to say, the basic design of submarines was modified so that each new class was based on the solid design of an older ship, incorporating a mix of old and new technology.
Thus the classes between the Skipjack and Los Angeles were all modified designs of the same original boat. This all changed with the Seawolf design. Seawolf was the first submarine design in over thirty years to be planned totally new from top to bottom.
USS Seawolf (SSN-21) interior layout. RUBICON, INC., BY LAURA DENINNO
Everything about the Seawolf (SSN-21) and her sister boats, Connecticut (SSN-22) and the not-yet-in-service Jimmy Carter (SSN-23), is new and improved. She is big, displacing an impressive 9,137 tons submerged. Starting from the stern, we begin our look with what many people would mistakenly think is one of the simplest parts of a submarine: its screw. Known as a propeller to those outside the Navy, the screw is actually one of the most complicated parts of a submarine, and its construction is a closely guarded national secret. The construction of the Seawolf’s screw has been essential to her requirement for quiet running at high speeds.
As mentioned earlier, the British built their Trafalgar-class SSNs with a shroud covering the propeller, which had the benefit of quieting excess noise generated by the sub’s screw out into the water. A similar design is used in the U.S. Navy’s Mk 48 torpedo, albeit on a smaller scale. Known as a “pumpjet propulsion system,” the design works well. According to one report, running at 25 knots, Seawolf is quieter than a 688I that is just sitting at the pier! Other stories indicate that Seawolf is able to run quietly at twice the speed of any previous American attack submarine. Other sources are more direct and attribute to Seawolf a virtually “silent speed” of 20 knots. While numerous elements go into these quieting secrets, you can bet that the Seawolf’s pumpjet propulsor plays a key role. Hidden inside the covering shroud of the propulsor is a single propeller shaft similar to those that have been used by U.S. attack submarines since the advent of nuclear propulsion.
If you were to look at a photograph of a Seawolf under construction or in dry dock, you would be able to see many of the sub’s sensors as you glance at the sides of its hull. In particular, the boat is designed with a unique surface tail configuration and gives the impression of six thin, flat “fin stabilizers” jutting from the aft of the boat, which face out at varying angles from the shrouded prop. Fitted to the stabilizer at the four- and eight-o’clock positions are shrouds through which the sensitive TB-16D and TB-29 towed array sonars are streamed out from the boat. As you move around to the sides of the lower hull, you’ll notice one of the biggest advances perfected between the construction of the last of the 688I boats and the new Seawolf. This is the addition of the BQG-5D Wide Aperture Array (WAA) system sensor fittings. Although invisible when the sub lies in the water, the WAA is one of the most distinctive features of this revolutionary warship design. An advanced passive sensor system fitted into three rectangular housings attached to each side of the lower hull, the WAA performs an essential mission when the boat is in the detection and tracking phases of an engagement, and Seawolf is the first full class of submarines fitted with the system. The WAA has been so successful in trials that plans currently call for fitting it into the future Virginia (SSN-774) class as well.
In the bow is a large, 24-foot/ 7.3-meter-diameter spherical sonar array, which is the heart of the BSY-2 combat system. Based on the earlier BSY-1 system we showed you aboard Miami, BSY-2 is, in terms of software, processing power, and integration, a generation ahead of the earlier system. By tying together all the various sonar and other sensors systems into the BSY-2, Seawolf has a capability for multitarget combat engagements and situational awareness matched only by the Aegis combat system on the Ticonderoga (CG-47) and Arleigh Burke (DDG-51) missile cruisers and destroyers.
As we continue along our journey on Seawolf, you’ll notice many bulges and bumps along the hull, each of which serves a vital purpose. Walking along the long hull, which is 353 feet/107.6 meters long and 40 feet/12.2 meters wide, you’ll see a long, thin faring that is raised several inches off the deck. This is where the towed array sonars are stored. Also, as during our visit to Miami and Triumph, you’ll notice that the deck is made of a thick, spongy coating known as anechoic tiles. These black rubberlike tiles do much to seal sound inside the Seawolf as well as keep other sounds from bouncing off the boat and reflecting sonar “pings” back to prowling surface ships, sonobouys, or enemy submarines. Every now and then you might see a submarine, especially those of the former Soviet Union, missing a tile or two. These occasionally fall off and make for some interesting photo ops!
Navy and contractor personnel man the underway main control watch, aboard Seawolf. OFFICIAL U.S. NAVY PHOTO
Underneath the tiles is one of the hardest steel hulls ever constructed on an American ship. Once the welding work of Seawolf was fixed, the real benefits of HY-100 steel became apparent. With a significant (meaning classified) increase in diving depth over the 688I class, Seawolf is able to operate farther into the ocean depths than any attack submarine in American history. This has restored much of the tactical capability lost when the HY-80 hulls of the Los Angeles-class boats were thinned down to save weight and displacement. As the recent loss of the Russian submarine Kursk illustrates, the ocean depths can be anything but hospitable, and the deeper a submarine goes the more pressure is exerted on its hull. It was just these dangers that the submarine designers had in mind when they built in the next feature we run across as we tour Seawolf’s deck—the submarine escape trunk and Deep Submergence Rescue Vehicle (DSRV) mating hatch.
This aft hatch, along with a second hatch farther forward, is where a rescue chamber or submarine like the DSRV would mate with Seawolf in the event she suffered a catastrophic accident and the crewmembers were still safe. This is, of course, a really big if. It is, however, a very real possibility that was demonstrated quite sadly by the loss of the Kursk and her crew in 2000. A number of the Kursk’s crew survived the sinking of their boat and might have been saved had their government allowed U.S. or British DSRVs to be deployed earlier during the search-and-rescue operations.
There have been some changes in the field of submarine rescue since the first edition of Submarine went to press, and this seems like a good place to cover them. The first is that the American DSRVs are rapidly coming to the end of their useful service lives and require replacement or upgrade. Also, the dedicated rescue ships that could operate the old McCann rescue chambers have been retired, meaning that the DSRVs delivered on the backs of submarines are now the only deep-water rescue system in the U.S. inventory. On the plus side, though, new rescue technologies are being designed and tested, and may be backfitted onto existing DSRVs.
The arrangement of periscopes, sensors, and communications masts on the conning tower/sail of USS Seawolf (SSN-21). RUBICON, INC., BY LAUR
One of the most promising of these is a new kind of mating collar, composed of angular slip rings that allow docking even if the downed boat is resting at a severe angle. Whether this new system will be retrofitted to the existing DSRVs as part of a comprehensive overhaul or to a completely new vehicle remains to be seen. For now, though, submarine rescue still remains an “iffy” proposition at best.
Farther forward is the sail, which is, frankly, one of the slickest such structures ever built onto a U.S. submarine. Unlike traditional American nuclear subs, Seawolf has a curved faring blending the front of her sail into the hull to help reduce resistance and flow noise. It is just one of many little touches designed to keep the Seawolf-class boats the quietest ever to roam the world’s oceans. As in previous American SSNs, the sail contains all of the sensor masts, as well as the control station for conning the boat on the surface. The mast-mounted sensors include:• Periscopes: As in previous U.S. submarine designs, the Seawolf is equipped with a pair of optical periscope masts. These include both Type 8 Mod 3 and Type 18 scopes, of the same variety as those described earlier on Miami.
• Radar: To provide surface and some limited air search capabilities, a BPS-16 set is installed for operations in poor visibility and at night.
• Radio Masts: A pair of AN/BRA-34 communications masts are provided to support the growing bandwidth requirements for littoral operations.
• Electronic/Signals Collection Masts: To support intelligence collection and tactical situational awareness, Seawolf has an AN/BRD-7/BLD-1 mast with the collection heads for the WLQ-4 (V)1 and BLD-1D/F radar and signals receptions systems.
• Trailing Antenna: To provide command cueing while submerged, the Seawolf has an OE-315 trailing wire antenna that can receive transmission from the Navy’s Extremely Low Frequency (ELF) communications system.