The Alfa-class submarine was a ‘nuclear nightmare’ for Russia

Summary: The Alfa-class submarine, developed by the Soviet Union during the Cold War, was an innovative but problematic vessel. Its titanium hull and unique lead-bismuth cooled reactor allowed it to achieve record-breaking speeds and deep diving capabilities, making it one of the fastest submarines of its time.

However, the Alfa class had significant drawbacks, including noisy flights, complex maintenance and radiation risks to the crew.

Despite these problems, the Alfa-class remained in use for over 30 years.

While it posed a threat to NATO forces, it was hampered by the technologies that made it exceptional.

The Alfa class submarine was a nuclear nightmare for the Soviets

The Cold War era saw incredible technological advancements in both the Soviet Union and the United States, particularly in the areas of submarine research and development. Project 705 Lira, or the Alfa-class submarine built for the Soviet Navy, was one such advancement. Considered highly innovative for its time, this ambitious Cold War project featured a unique titanium hull and high-speed capabilities.

But the innovative design was tempered by operational challenges.

Alfa-class submarines were intended to counter NATO’s various fast attack submarines, most notably the ubiquitous Los Angeles-class submarines. The primary role of the Alfa-class submarine was to serve as an interceptor. In other words, it would seek out and destroy enemy submarines.

Soviet designers wanted the Alfa class to achieve high underwater speeds. The goal was to create a boat that would be faster and more maneuverable than its American or NATO rivals, both underwater and on the surface.

The hull of titanium alloy

Therefore, a titanium alloy was used for the ship’s hull.

This hull would be able to go deeper and faster than the steel hulls that most submarines for the US or Soviet navies could go. Titanium not only provides higher speed because it is lighter, but it can also withstand higher pressures than tinplate.

This meant that the Alfa class could go very deep underwater.

These boats could average 46 miles per hour (40 knots), earning the Alfa class submarine the title of the fastest submarine in the world for its time. The lighter titanium hull was only one reason for the high speed. Soviet engineers also installed a powerful liquid-metal cooled reactor.

These two factors together allowed the submarine to reach high speeds.

Speaking of reactors, the Alfa class featured a unique nuclear reactor. While most submarines use water-cooled reactors as their power source, the Alfa class was designed with a lead-bismuth cooled fast reactor. This unique cooling system meant that the boat could be equipped with a smaller reactor, allowing the Alfa class to sail faster.

And here we come to the disadvantages.

As innovative as the Soviets were in designing nuclear reactors, the Reds were equally sloppy in their application. I mean, how many nuclear disasters, both at sea and on land, did the Soviet Union endure?

And I’m not just talking about Chernobyl.

In any case, the reactor on the Alfa-class submarine was one of the biggest drawbacks to operating this craft. Notably, the smaller, lead-bismuth-cooled nuclear reactor created polonium-210 as an unfortunate byproduct. The submarine could thus move underwater faster and dive deeper than its rivals, but the longer the crew operated the boat, the greater their exposure to deadly radiation poisoning.

The nuclear reactor was literally a mess

Indeed, as Peter Suciu detailed on these pages a few weeks ago, an Alfa-class submarine designated K-64, the lead boat of this class, suffered a massive reactor failure in 1972. The problem with the lead-bismuth coolant was that the alloy had to be heated constantly to keep it from cooling, solidifying, and essentially clogging the reactor. When the reactor on K-64 leaked, the metal alloy solidified as soon as it hit the cooler air outside the reactor.

The leak was so severe that it damaged surrounding components and compromised the integrity of the K-64.

Soviet engineers chose to mothball the submarine rather than attempt to rebuild it. Interestingly, part of the dismantling process involved cutting the submarine in half and sending the forward section—with all its controls—to the Soviet Navy’s Submarine Warfare Training Center in Leningrad.

Leaving aside the K-64 fiasco, the liquid metal coolant even on the Alfa-class submarines operating “within standards” was corrosive, leading to massive maintenance problems for the ship.

Other issues related to the maintenance of the submarines. Its greatest strength, the titanium alloy hull, was also its greatest weakness. Welding the submarine’s hull was a complicated affair. As such, it was prone to cracking. That is definitely not something you want to happen on a ship, especially one whose primary function is to operate beneath the waves.

Even when operating according to design specifications, these boats were unsafe. Long-term exposure to unsafe levels of radiation posed a significant health risk to the crew. Over time, those who served continuously on the Alfa class submarines suffered from a decline in their health due to constant exposure to polonium-210.

Oh, and the internal temperatures of the submarines due to the reactor output made for terrible conditions for the crew.

Run poisonous (and loud), run deep

One of the primary goals of any submarine is stealth. But the Alfa class was one of the noisiest submarines the Soviets produced during the Cold War. In fact, despite their high speed and innovative hull design, the Alfa class failed at the primary mission of any submarine. These boats were far too noisy beneath the waves, meaning that rivals could hear them coming from over the horizon.

So the Alfa class gets high marks for innovation, agility, and speed. But it failed to deliver on the most important elements required of any submarine—namely stealth—and the Alfa was notoriously unsafe due to the very elements that gave it its greatest advantages: its unique hull and nuclear reactor.

Still, the Alfa class served for over 30 years, with the last examples being decommissioned in 1996. These boats were dangerous to their crews and did not always perform to specification. But they did serve for decades and proved a constant threat to NATO ships.

Author’s Experience and Expertise: Brandon J. Weichert

Brandon J. Weichert, a National Interest national security analyst, is a former congressional staffer and geopolitical analyst who contributes to The Washington Times, the Asia Times, and The-Pipeline. He is the author of Winning Space: How America Remains a Superpower, Biohacked: China’s Race to Control Life, and The Shadow War: Iran’s Quest for Supremacy. His next book, A Disaster of Our Own Making: How the West Lost Ukraine, will be published October 22 by Encounter Books. You can follow Weichert on Twitter @WeTheBrandon.

All images are Creative Commons or Shutterstock.

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