Bryan Clark, a former U.S. Navy submarine officer and now an analyst at the Center for Strategic and Budgetary Assessments, has his doubts about the concept:
At 3 to 5 knots, the torpedo or swarms of torpedoes won’t be able to catch submarines that normally travel 5 to 15 knots or surface ships that normally travel 15 to 25 knots. The mini-torpedo swarm could be launched from ahead of the target, if the attacker knows the target’s likely direction of travel and can preposition the launcher. If the target detects the torpedo and evades, the torpedo would be too slow to keep up or intercept the target.
A mini-torpedo lacks the space and power to carry a powerful sonar to detect targets at a distance, nor can it carry sophisticated navigation gear. And even if hits the target, it might not do much damage. "A heavyweight torpedo has a 1000-pound warhead to break the keel on a surface ship or rupture the pressure hull of a submarine," Clark says. "An 88-pound torpedo will probably have a warhead of only about 45 pounds. If it is a shaped charge, that could be enough to puncture a submarine pressure hull. But it would need to be precisely placed and be able to get right next to the submarine. That would be hard at only 3 to 5 knots."
However, Clark does believe these torpedoes could be useful against fixed targets like underwater cables and pipelines. But rather than torpedoes, he likens the Russian concept to unmanned underwater vehicles, or UUV. The United States and other nations are aggressively trying to develop small drones that will operate in swarms to flood the battlefield with cheap, lethal robots.
As for stealth, Clark points out that Russia will first have to suppress the mechanical noise of the torpedoes. Then, Russia must make the torpedo resemble an undersea creature. "If you go to the effort of making a UUV quiet, why incur new costs to create it more detectable in the hopes it will sound like a fish?"