Nuclear Weapons at Sea - Soviet SLBMs Part 2

While the Soviets were the first to take ballistic missiles to sea, their first generation of submarines were not particularly successful. Each could carry only three or four short-range missiles, making them more suitable for theater strike than attacks on the US mainland. The American Polaris program thoroughly eclipsed these submarines, and it wasn't until 1962 and the aftermath of the Cuban Missile Crisis that the Soviets decided to try again.

A Soviet Yankee class submarine

The initial plan was to build the submarine around 8 of the R-21 missiles that were being refitted to the Golf and Hotel classes. These were capable of underwater launch, but they were large enough that they would have to be carried horizontally, and a complicated mechanism would be required to turn them upright and prepare them for firing. This was quickly dismissed as overcomplicated, and studies were instead made of solid-fueled missiles very much like Polaris.

Unfortunately, Soviet industry of the time simply wasn't up to producing a solid-fuel rocket of acceptable performance, and two separate designs came to grief before they finally went back to liquid fuel in the form of the R-27 missile, known to NATO as the SS-N-6 "Serb". Improvements in rocket design allowed the R-27 to reach 1,350 nm, allowing the submarine carrying it to remain well offshore, in a package smaller than the R-21. Flight tests began in the mid-60s, and while the idea of rearming the Golfs and Hotels was considered, the decision was made to fit it to a new SSBN. The result, known as Project 667A, was more than a little reminiscent of a Polaris boat, with 16 missiles carried in tubes aft of the sail. However, the parallels were little more than skin-deep, as the new submarine, called the Yankee class by the west, had two reactors and two propeller shafts, and was capable of firing its missiles at much higher speeds (3-6 kts instead of stationary) and greater depths (165'/50m)¹ than could Polaris. It did have one major drawback: it was far louder than its American counterparts, thanks to the limits of Soviet technology.

R-27 missile

The first Yankee was commissioned in late 1967, just as Polaris boat construction was ending, and the first patrol off the US Atlantic coast followed in mid-1969. 34 were built through 1972, and at that point, it became standard practice to have at least two boats in the Atlantic and one in the Pacific, all within missile range of the US coast.² In practice, the Soviets found that the range deficit of the R-27 was largely made up for by the fact that the Americans had so much of their vital infrastructure near the coast, while the Polaris boats had to come closer inshore to hit targets in the Russian interior. As the building program wound down, a new missile variant, the R-27U, was introduced. It extended range to 1,620 nm and added an option for a 3-warhead MRV configuration similar to that on Polaris A3. All but one of the existing Yankees were refitted with the new missile, the exception being fitted with 12 R-31s/SS-N-17s, the first Soviet solid-fueled SLBM. This unique boat caused significant confusion in the west, as various theories tried to justify the importance of a single submarine with the new weapon, such as it actually having a secondary satellite-launch capability. In practice, it seems to have mostly been the product of the traditional Russian unwillingness to throw away military hardware. The regular Yankees were also the subject of much speculation, with many believing they were intended to get closer to shore and launch their missiles on a "depressed trajectory", which would be flatter and significantly faster, hopefully taking out important command targets before they could take action. In practice, the R-27 wasn't actually capable of flying a depressed trajectory, and the next generation of Soviet SLBMs would take an entirely different approach.

K-219 on the surface after the accident

And while the Yankees were generally successful, there were definitely problems. In 1979, K-219 suffered a leak in a missile tube, and the water reacted with the volatile liquid propellant,³ causing a serious fire. The crew brought it under control, and K-219 continued to make patrols with 15 missiles until October 1986, when a leak in another tube sparked a fire and explosion that breached the hull. Despite this, the crew managed to bring her to the surface and shut down the reactor, although doing so cost seaman Sergei Preminin his life. An attempt to tow the submarine by a nearby Soviet merchant ship failed, and the crew were forced to evacuate in the face of spreading fire and toxic gas. Ultimately, K-219 sank beneath the waves, and the Soviet Navy tried to blame the leak on a collision with the American attack submarine Augusta, a charge the USN and K-219's captain both deny.

The Yankee II, modified to carry R-31s

But the idea of a collision between an American SSN and a Soviet boomer wasn't the stuff of fantasy. When Yankee patrols began, the USN responded strongly. Previously, NATO ASW concepts had been built around fighting a third Battle of the Atlantic, bringing convoys across to supply the forces fighting in Europe. But the systems worked out for this, barriers that would attrit the Soviet submarine force as it entered the North Atlantic and returned home, would be ineffective against SSBNs, which could cross them in peacetime and then wait in the open ocean, where they would be much harder to track. The American solution was to rely on signals intelligence and SOSUS to alert them when a Yankee was leaving its base, and dispatch an attack submarine to trail it. These trails, hopefully undetected by the target, could last for weeks, and they placed the American SSNs in a prime position to stop missile launches if war broke out. However, this close-range maneuvering was hazardous, and on numerous occasions resulted in submarines from the two sides colliding.⁴

Despite their limitations, the Yankees would serve throughout the second half of the Cold War. Much like the early Polaris boats, a number were converted during the 1980s into attack submarines by the deactivation of their missile tubes, and a few were even rebuilt with new center sections to carry guided missiles. But while their successors would look similar, they would take a very different approach to the problems of nuclear deterrence. We'll take a look at them next time.