The Typhoons' missile tubes are forward of the midship sail, which gives the submarines a very unusual appearance. The sail sits atop what looks like a miniature flat topped pressure hull buried in the main hull. The twin screws are set unusually far apart. Internally, the massive submarine boasts amenities such as a sauna, a waterfall, and even an aviary, to remind her crew of life on the surface.
We now know that there are no fewer than five separate but interconnected pressure hulls buried in the submarine's outer hull. Two of them run alongside the row of vertical missile tubes—which are, in effect, small pressure bodies. Aft are the two sets of machinery: reactor, heat exchanger, turbines. A third (at the bow), connected to the two main pressure bodies, contains the torpedo tubes and reloads; a fourth, the command-and-communications center, is nestled between the two main pressure hulls. A fifth connects the two hulls abaft the command center.
When this configuration first became known, the reason for the twin pressure hulls became obvious: the missile tubes were far too massive to be cut into a normal pressure hull, as in other ballistic-missile submarines. There was very reasonable speculation that the unusual configuration, with missiles forward of the sail, had been adopted to make it easier to substitute newer missiles; previous classes of Soviet ballistic-missile submarines had missiles abaft the sail. Redesign to take newer weapons required considerable changes in the submarine, presumably to include rewiring the connections between command center and engines and rudders.
A key design requirement dictated that overall length be limited so that two of these massive submarines could be built on the same slip in a huge building at the Severodvinsk yard. Placing the command center aft of amidships rather than forward of the double line of missile tubes helped, since the command center could nestle above parts of the two big machinery spaces aft, whereas the missile tube section could not have been moved aft parallel to the fore ends of the machinery spaces.
What was not immediately apparent was just how massive the missiles were, or how that size affected the overall design of the submarine. The missiles were huge simply because Soviet solid-fuel technology was far behind that of the United States, something not well understood during the Cold War. We now know that a key to U.S. success in this field was a vigorous civilian plastics industry, which developed the key binders that hold together both plastic toys and solid-fuel rocket motors. It was an interesting early example of the impact of a large non -military economy on military industrial performance during the Cold War. The view in the United States was typically that the Soviets could always get whatever they needed, because they could command their economy to provide it. In many cases, however, those commanding the Soviet economy did not realize just what they needed; thus, they did not provide for the necessary research. Serendipity was quite a real force in the West. Computers are a much more familiar case in point. The military started up the U.S. computer industry, but eventually the civilian economy took over as its driving force.
Particularly in the 1970s, many in the United States worried that the Soviets were spending a far larger fraction of their gross national product on defense than the United States. What they did not realize was that, having militarized their economy so heavily, the Soviets left very little fat to convert to, for example, different kinds of military industry. The extent of the problem was not appreciated in the United States. In the late 1970s, the Chief of the Soviet General Staff, Marshal Ogarkov, began singing the praises of what he called "reconnaissance-strike complexes," which were computer-controlled highly integrated weapon systems. What was not appreciated was the extent to which Ogarkov really was saying that these systems were planned by the United States, that the Soviets could not match them (given their limited computer industry), and that, should they appear, they would be devastating. When President Ronald Reagan began to rearm America, he naturally bought exactly these systems, whose technology was just maturing. Ogarkov's nightmare had come true. Mikhail Gorbachev entered power with a mandate to expand the Soviet economy specifically so that it could produce the required flood of micro-computers. He found that he had to open Soviet society to do so—and the opening cracked the Soviet Union apart.
Given powerful solid fuels and compact warheads, it pays to buy solid- rather than liquid-fuel rockets. Energy-packed liquid fuels can be quite dangerous, as was graphically demonstrated when a fuel explosion in a missile fatally damaged a Yankee-class submarine (K-219) in the Atlantic in 1986. On the other hand, with less-energetic solid fuels, missiles can grow almost without limit. The R-39 (NATO SS-N-20) missile on board a Typhoon weighs 90 tons at launch, including a massive collar from which the missile hangs (for shock isolation). The collar also seals the tube so that the gas generator inside can pop the missile out. The collar is discarded as the missile flies out above the launch tube. By way of contrast, the R-29RM (NATO SSN-23) on a Delta IV, which has much the same performance as an R-39, weighs only 40.3 tons, and is only 1.9 meters (rather than 2.4 meters) in diameter. It has no shock collar. The equivalent U.S. missile, the solid-fuel Trident D-5, weighs about 59 tons and is 2.11 meters in diameter.
Quite early in the race to build long-range ballistic missiles, the United States largely abandoned liquid fuels. Probably in the early 1970s, Soviet proponents of solid fuels gained favor. D.F. Ustinov, the Communist Party's main military industrialist, and later Minister of Defense, pressed both the Strategic Rocket Force and the Soviet Navy to switch to solid fuels. In the case of the land-based missile force, the great advantage of solid fuels may have been drastically reduced maintenance requirements, i.e., less manpower, at a time when Soviet demographics were in serious decline. In the case of submarines, one key argument may have been that a ship armed with solid fuel missiles could remain on patrol for much longer. Typhoon may have been conceived as a second-strike weapon, to stay at sea waiting out an initial exchange of weapons between the United States and the Soviet Union—thus the size and the special amenities for the crew.
Unlike earlier Soviet strategic submarines, the Typhoons were intended to operate in the Arctic. According to recent Russian accounts, the sail and the curved pressure body under it are specially designed to break through ice as the submarine surfaces. The bow planes can be retracted into the hull. The propellers are shrouded, which (among other things) ought to protect them from ice damage as the submarine surfaces. The method of launching missiles is also adapted to ice operation. In the Arctic, a submarine generally will not fire missiles submerged, for fear that they will hit floating ice as they rise. Previous Soviet missiles, at least from the Delta class onward, relied on the missile's buoyancy to bring it to the surface before its booster fired. Missiles launched this way clearly cannot be fired by a surfaced submarine. The Typhoons followed U.S. practice, in which the missile is popped out of its tube by a gas generator. It ignites after passing through the surface. That method works both underwater and on the surface, although there is always the possibility that the missile will fail to ignite and will fall back (as happened to a Typhoon in 1991). There is also another potential problem: the water spout produced by the gas generator may damage the missile as it rises. That severely slowed the U.S. Trident program in the early 1980s, before it was cured by strengthening the underside of the missile.
In any case, the Typhoon design seems to have been dictated by the sheer size and weight of the R-39 missile. The paired main pressure hulls were needed because the missile was far too large for its tube to pierce a pressure hull, as in all other strategic submarines. What was not known until recently was that the Soviets also limited the submarine's draft, because, although they were willing to spend heavily on the ships, they were unwilling to pay for enlarged base facilities. That recalls British practice before World War I, when money was not available for enlarging drydocks; they could be lengthened relatively easily, but widening was far more difficult. Thus new battleships, down to the World War II King George V class, had limited beams. That in turn limited the depth of their underwater protection. Later a lack of large drydocks limited the size of British aircraft carriers. In the U.S. case, the key limits were the locks of the Panama Canal (110-feet wide) and, for many years, the height above water of the Brooklyn Bridge, under which ships had to pass to enter the New York (Brooklyn) Navy Yard.
To carry the very heavy missiles, and the heavy, silenced, new machinery (which also was used in other submarines of this generation: the Oscars, Sierras, and Akulas) at a shallow enough draft, the Typhoons needed enormous reserve buoyancy, which meant massive ballast tanks. They were so large that the new submarines were often sarcastically called "water carriers" rather than missile carriers. The submerged displacement exceeded that of a Kiev -class aircraft carrier. The cost per unit was astronomical. Handling qualities must have been abysmal. Submarines could be refitted only by the building yard.
Even so, plans called for a follow-on strategic missile, R-39UTTKh (NATO SS-N-28), which was to have rearmed the Typhoons, as well as an entirely new class of strategic submarine. Work began in 1982, i.e., almost immediately after the first Typhoon went to sea. Unfortunately, the new missile's three tests all failed. Its designers protested that earlier missiles often had experienced 40 or even 60 failures before succeeding. In this case, however, the new Russia could not afford such a lengthy test series and he new missile had to be abandoned. That (if not disastrous Russian finances) surely doomed the Typhoons, because their R-39 missiles were running out of service lifetime. To make matters worse, Ustinov had pressed his case for a future all-solid-fuel force by forbidding development of a liquid-fuel follow-on to the many existing liquid-fueled submarine missiles. Cleaning their tanks and refueling them can extend their service lives, but not much more can be done, at least in the short and medium term. The future strategic submarine missile is to be a modified version of the Topol-M mobile strategic missile, which weighs about 47 tons. The one new strategic submarine, Yuri Dolgorukiy (Project Borey), laid down with fanfare in 1996, has been suspended (partly because there is so little money), to be redesigned completely to accommodate the new missile.
The Typhoon project certainly did provide its designers and builders with experience in building a truly massive submarine. Unfortunately, as in many other things, the Russians had little interest in the cost of their projects. Under the Soviet regime, cost was essentially meaningless—no one really knows what a Typhoon cost the Soviet Union, because there was no attempt to estimate what else the same effort, otherwise directed, might have bought. Things are not much different in Russia today.