Russian Titanium Submarines: Faster and capable of diving in the US Navy

What you need to know: During the Cold War, the Soviet Union sought an edge in undersea warfare by designing the Lira-class (Alfa) submarines with titanium hulls, which allowed for faster, deeper, and quieter operations.

Despite titanium’s benefits, including its strength, lighter weight and corrosion resistance, the U.S. Navy has chosen not to follow suit due to its high costs and complex manufacturing challenges.

-Instead, the US focused on developing superior torpedoes and anti-submarine weapons, such as the MK 48 torpedo and the Sea Lance missile.

-Ultimately, the limited success of the Soviet titanium subs validated the US decision to prioritize affordability and usability.

Why the US Navy Rejected Titanium Submarines During the Cold War

The Soviet Union once thought it had an advantage over the United States in submarine warfare during the height of the Cold War.

The Russians designed their Lira-class boats with titanium hulls that allowed the submarines to have better propulsion and to dive faster, deeper and quieter. They might even be able to outmaneuver the incoming US and NATO torpedoes.

The US Navy never followed suit because the titanium hulls were more expensive and challenging to build. Let’s take a closer look at the pros and cons of titanium submarines to see if the Navy made a good choice to succeed or if it made a big mistake.

Could this be the Soviet submarine that would dominate the Americans?

The Soviet nuclear submarine Project 705 “Lira” (also called the Alfa) was state-of-the-art in the 1960s. It would reach speeds previously unattainable and become the quietest submarine in the Russian Navy. Titanium would be used for Lira hulls and a new lead-cooled reactor would power the ship so it could dive and turn quickly. The Lira class was the fastest submarine ever built, reaching a speed of 41 knots. It could reach that speed quickly and nimbly change direction when necessary.

Titanium has many advantages

Titanium alloy is usually stronger than steel, but weighs half as much. It is more expensive, up to three to five times more expensive than steel. Titanium is also less corrosive in salt water. It can handle more pressure during deeper dives – all the way up to 600 meters. Making titanium to make a hull is no easy feat. Welding is difficult and the slightest mistake during the welding phase can make the titanium brittle and less strong. Welders worked in expensive facilities where argon gas was present, which made for dangerous work.

But not enough positives for the US Navy

Aware of the Lira class’s power, speed and stealth, the United States took a closer look at its titanium construction. Titanium is rare and expensive compared to iron. Titanium is also not easy to shape. Welders would require an external source of oxygen during the workday. Any misstep by the welders would create a submarine that would be dangerous to make deep dives. The higher pressure could endanger the weakened hull.

Just build better torpedoes and other weapons for submarine combat

The US Navy considered setting up its own titanium supply chain and concluded that the effort and expense would not be worth it. Instead, it wanted to improve its undersea warfare capabilities rather than opting for a titanium hull. The Navy developed the heavyweight torpedo MK 48 that would power the Lira boats at a speed of 63 knots. The British made a high-speed torpedo called the Spearfish. The Americans also began work on the Sea Lance anti-submarine missile that could carry a torpedo or depth charge to destroy a Lira class.

Not as dominant as thinking

The Soviets produced only seven Lira submarines. They had a complicated reactor that made repairs difficult. The titanium proved problematic as some boats developed cracks in the hull, requiring expensive and challenging repairs. The Liras were also not as quiet as the Soviets had hoped, even though the titanium was believed to be paramagnetic and would provide a quieter ride. Despite being expensive to maintain, they remained in service until the end of the Cold War, but were then decommissioned and scrapped.

The US Navy made the right decision

The US Navy then made a good choice not to pursue titanium boats. The material is expensive and complicated to work with. Sometimes when thinking about new defense acquisition designs, it’s better to let your opponent jump ahead and see where the weaknesses lie and figure out the best way to counter the advantages. The Russian boats were fast because of the titanium, but they were not as quiet as advertised. The Americans felt that titanium was not worth the effort and expense.

About the author

Dr. Brent M. Eastwood is the author of Humans, Machines, and Data: Future Trends in Warfare. He is an expert on Emerging Threats and a former US Army infantry officer. You can follow him on Twitter @BMEastwood. He has a Ph.D. in Political Science and Foreign Policy/International Relations.

Image credits: Creative Commons.