Unusually, they are powered by gas turbines, and in addition to an air/surface search radar and a fire control radar they have variable-depth sonar
but no antisubmarine weapons.
Cotaras worked with his colleagues and subcontractors to devise a variable-depth sonar that is deployed from the aft end of the Visby, concurrently with the towed array sonar.
"The variable-depth sonar enhances the hull-mounted sonar's anti-submarine capabilities by operating beneath the warm layer of water near the surface," Cotaras noted.
The funnels were twinned to make room on deck and all were fitted with new variable-depth sonar
. The St.
The history of surface ship antisubmarine system development includes the SQS-26 sonar, variable-depth sonar
, the Light Airborne Multipurpose System (LAMPS), towed arrays, and the SQQ-89 sonar and fire control integrated combat system.
A prototype Lightweight Broad-band Variable-depth Sonar (LBVDS) for the DD-21 will undergo sea trials this year and next year, using the SQQ-89(V) 15A towed array as its receiver.
* an integrated stern, providing stealthy handling of a broad-band variable-depth sonar, an advanced bi-static towed array, and towed torpedo countermeasures
* minimising the impact on the preliminary DD-21 hull-design by studies focused on variable-depth sonar, multiple towed bodies and conformal arrays.