The LRT is depth rated to 500 metres making it the ideal choice for use in continental shelf waters. Field replaceable alkaline or long-life lithium battery packs give a listening life of 18 months and 51 months respectively. A ‘screw-off’ release mechanism ensures a positive release action that overcomes any biological growth and all external parts are made of high-strength plastics that provide excellent environmental corrosion resistance. LRTs are controlled using the Type 7967 Surface Command Unit (SCU) comprising a low-cost deck unit and remote transducer on 10 metres of cable.

The SCU is initially used to program the acoustic identity of the LRT, test the transponder and load the release nut prior to deployment. Once deployed, the deck unit can measure ranges to the transponder and prior to sending a secure release command, relocate the transponder. The SCU can be controlled via RS232 enabling raw range data to be logged to a PC.

Key features

• Safe Working Load of 125kg
• Depth rated to 500 metres
• Up to 51 months deployment with long-life lithium battery pack
• Hundreds of secure identities; field programmable with deck unit
• Reliable, 'screw-off' release
• Rugged, compact design
• Compatible with Scout USBL, ROVHomer, Homer-Pro and Prospector positioning/relocation systems

An optional attachment for the LRT is a rope canister that allows items left on the seabed, for example; tools, cables and salvage, to be quickly and easily hauled up. It works by mooring one end of the rope to the item on the seabed and the other end to the LRT via the attached canister of rope. As the transponder ascends to the surface, the high-strength rope is deployed from the canister. This line can then be used to pull up the item directly or retrieve heavier tag lines. LRTs can be supplied with ±15° or ±30° tilt sensors. This allows the user to acoustically check that the LRT and its mooring have been correctly deployed on the seabed.