The SHARC—SURTASS Headline and Roll Control—is a net mitigation and array stabilization device in use with SURTASS towed sonar arrays. It was designed to survive the harsh marine environment for multiple underwater deployments, each up to three months long.
The SHARC operates within ±3° of roll, though it is only required to operate within ±15°. Even with a destabilizing force (such as a fishing net) on one side of the SHARC, it can maintain the operational requirement. The SHARC has been successfully tested at speeds up to 12 Knots and remains stable at turn rates over 200°/min. These advances allow the Captain to maneuver aggressively without endangering the ship or the arrays, which is a necessity in complex environments, such as shallow or heavily fished areas.
Since the SHARC is designed to avoid fishing net entanglement, and can operate effectively even when entangled it represents a significant advance in Navy surveillance capabilities. Before use of the SHARC, arrays became entangled in fishing nets often, sometimes daily, which greatly endangered the arrays. Furthermore, the net removal process is time consuming and meant the array was out of operation.
The SHARC was designed to be installed on the existing system with minimal effort. Locking, quick-release pins are used to attach the SHARC to the arrays. Installation and removal for each deployment can now be accomplished in a matter of minutes. Furthermore, the SHARC can be deployed very easily. Only one person needs to be
on the back deck, or “Stinger”, to aid the SHARC over the fair-lead. This is an improvement over the old system, which required two people for a considerably longer span of time.
Due to the SHARC’s modular design, it can be configured to allow the arrays to monitor a wide range of inputs. Currently, the SHARC supports variable headline spacings to optimize the system for a wide range of SONAR operating frequencies.
The SHARC is available with optional telemetry, which provides information on the unit’s roll, pitch, and heading. This data can be monitored by software on SURTASS ships to alert the crew of potential net entanglements as well as keep them posted on the operation of the SHARC.