The Cold War had been a cradle of technological development due to the intense competition between the United States and its foremost competitor, the Soviet Union. Great advances had been achieved during this time in space, aerospace, and, notably, in the sphere of submarines. Of two such mighty achievements, encapsulated by the Soviet Union, were those of the Alfa-class and the Sierra-class submarines, which both had revolutionary new titanium hulls.
The Type 705 Lyra Alfa class was, in the history of submarine development, an ambitious attempt on the part of the Soviet Union to close the gap finally and properly with the United States. Behind every aspect of submarine technology, the Soviets coveted a boat that could outrun, and outdive, any NATO opponent. The result was a true brute force monster of the deep, marrying brute force to high-risk technology.
The Alfa class included a titanium hull and used a lead-cooled reactor, allowing them a speed of 41 knots and a maximum diving depth of 2,200 feet. However, the high speed of the Alfa class was coupled with an expensive maintenance regime and not the best reliability. Only seven were built and they lasted through the mid-1990s.
After this came the Project-945 Barrakuda of the Sierra I-class submarines from the Soviet Union. Their hulls were titanium-made, giving other benefits like decreasing weight, higher tensile strength, and being corrosion-resistant. They were capable of playing at high speeds, diving very deeply, and then operating with low levels of noise, which made them very formidable adversaries in underwater warfare.
Relatively high prices of work with titanium and labor input make the production of those submarines uneconomical. By now only two submarines of Sierra I class have been made, as well as improved two pieces of the Sierra II class, modification of Sierra I.
However, the use of titanium in submarines blows it out and exemplifies the dedication of the Soviet Union’s technological development at the time of the Cold War. According to the Royal Society of Chemistry, it is a “hard, shiny, and strong metal” that is “as strong as steel but much less dense.” With these attributes, it was especially crucial for military use, not only in submarines but also in aircraft and missiles.
Despite the difficulties and expense of operating a titanium submarine, there were long-term legacies from lessons learned in the Alfa and Sierra classes. The Barracuda-class (Sierra) submarines picked up some of the Alfa attributes but dialed back performance to make the submarines more maintainable. The Shchuka class (NATO: Akula) also borrowed automation techniques pioneered by the Alfa class, enabling similarly relatively small crews.
The innovative ideas of the Cold War era have morphed submarines into the Alfa and Sierra class of today, a testament to superpowers with increasingly growing technological competition. Though very low in number and with problems of overwhelming maintenance, these titanium titans reached the bounds of possibility for underwater warfare. Their legacy impacts submarine design and technology even today.