Navy chooses Ultra Electronics for torpedo-defense decoy to lure enemy weapons away from surface warships

Jan. 18, 2021
The AN/SLQ-25 -- commonly referred to as Nixie -- is a passive decoy system that provides deceptive countermeasures against acoustic-homing torpedoes.

KEYPORT, Wash. – U.S. Navy torpedo-defense experts needed an electro-acoustic towed torpedo-countermeasures system to defend surface warships against wake-homing, acoustic homing, and wire-guided enemy torpedoes. They found their solution from Ultra Electronics Ocean Systems Inc. in Braintree, Mass.

Officials of the Naval Undersea Warfare Center Division in Keyport, Wash., announced a $186.4 million contract for the AN/SLQ-25E electro-acoustic towed torpedo countermeasure system.

The AN/SLQ-25 -- commonly referred to as Nixie -- is a passive decoy system that provides deceptive countermeasures against acoustic-homing torpedoes; the system lures enemy torpedoes away from U.S. and allied surface ships.

Related: Navy chooses Argon ST to build eight additional shipboard torpedo-defense decoys

The AN/SLQ-25A/C is a digitally controlled modular electro-acoustic soft-kill countermeasure decoy system that employs an underwater towed body acoustic projector deployed on a fiber optic tow cable from the sterns of surface warships.

The AN/SLQ-25 towed decoy emits simulated ship noise like the sounds of propellers and engines in attempts to defeat a torpedo's passive sonar. The idea is to spoof torpedoes into missing their targets and eventually sink or explode harmlessly away from the ship.

The AN/SLQ-25 is deployed on U.S. and allied surface warships, and consists of the TB-14A towed decoy device and a shipboard signal generator. The decoy emits signals to draw incoming torpedoes away from their intended targets.

Related: Navy ready for another look at Next-Generation Countermeasure (NGCM) submarine torpedo defense

The AN/SLQ-25A uses a fiber optic tow cable and winch, and includes extensive use of commercial off-the-shelf (COTS) components. The AN/SLQ-25C is an upgrade to the AN/SLQ-25A, and includes new countermeasure modes and a longer tow cable.

This contract has options that could increase its value to $268.5 million. Ultra Electronics will do the work in Braintree, Mass.; Manchester, N.H.; Lititz, Pa.; and Huntington Beach, Calif., and should be finished by December 2026.

For more information contact Ultra Electronics Ocean Systems online at, or the Naval Undersea Warfare Center Division-Keyport at

About the Author

John Keller | Editor-in-Chief

John Keller is the Editor-in-Chief, Military & Aerospace Electronics Magazine--provides extensive coverage and analysis of enabling electronics and optoelectronic technologies in military, space and commercial aviation applications. John has been a member of the Military & Aerospace Electronics staff since 1989 and chief editor since 1995.

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