Russian media has been trumpeting plans to launch two additional Lada-class diesel-electric submarines, two decades after the hull of the lead boat, the St. Petersburg, was laid down. Left delicately unstated in some of the press releases is that these new boats will lack the Air Independent Propulsion (AIP) systems that were intended to be the class’s defining feature.
Nuclear-powered submarines can easily cost four to eight times more than traditional diesel submarines—but they come with tremendous advantages in quietness, speed and range, plus virtually unlimited underwater endurance. Not only are air-breathing diesel engines noisier, but they require a submarine to periodically surface or snorkel to regenerate the air supply—placing them at great risk of detection. Still, economic and technological considerations dictate that most countries operate mostly or exclusively diesel submarines. Besides, a diesel sub’s short range is le