Naval warfareFire and forget: How do you stop a torpedo? With a better torpedo.
Torpedoes are a lot smarter than they used to be. In the 1980s, the Soviets brought out a torpedo that shot to the head of the class. Instead of looking for a ship, it uses upward-looking sonar to detect a ship’s wake.Now, the U.S. Navy has a potential defense against this threat: an even smarter torpedo. The Countermeasure Anti-Torpedo Torpedo, or CAT, is part of a defense system that can find and destroy a wake-homing torpedo.
Torpedoes are a lot smarter than they used to be.
Originally, torpedoes weren’t too bright. They went where they were aimed, but couldn’t change course to follow a target. Later, sonar let them home in on a ship’s acoustic signals. That made them a little smarter, but they could be fooled by ship-mimicking signals.
In the 1980s, the Soviets brought out a torpedo that shot to the head of the class. Instead of looking for a ship, it uses upward-looking sonar to detect a ship’s wake. When it finds one, it zigzags from one side of the wake to the other until it reaches its target. The ship can’t take evasive action because wherever it goes, its wake follows. And because the torpedo is not tracking the ship’s noise, it can’t be diverted by phony ship-sounds.
Now, the U.S. Navy has a potential defense against this threat: an even smarter torpedo. Designed at Penn State’s Applied Research Laboratory, the Countermeasure Anti-Torpedo Torpedo, or CAT, is part of a defense system that can find and destroy a wake-homing torpedo. When a sensor array towed behind the ship detects an incoming threat, the CAT is launched. From then on, it’s on its own — “fire and forget,” says acoustics scientist Russell Burkhardt, director of ARL’s Undersea Systems Office.
“It goes out with its own sensors, searches, determines its own targeting, and makes decisions on how to maneuver,” says retired Naval officer Gary Watson, who has managed the CAT project for the past year. “The level of technology in the vehicle, nose-to-tail, is light years ahead of other torpedoes in our fleet. This is probably the smartest torpedo that’s ever been produced.”
Perhaps as impressive as the torpedo itself is the way it was developed — and how fast ARL got it into the water.
The Lab had already done some work on an anti-torpedo torpedo when, in December 2011, Chief of Naval Operations Admiral Jonathan Greenert gave them the full go-ahead on the project — with a catch.
“He challenged us to deploy this within roughly twenty-four months,” says Burkhardt — which meant building and testing a prototype themselves rather than having the Navy put it out for bids by industry. “We had to finish our design, then go through all of the testing that has to be done to prove that the weapon is safe for the sailor,” says Watson.
