The main cable(s) for HEMLIS is the umbilical(s) for the whole system. For a HEMLIS closed loop setup there will be two main cables and for a HEMLIS straight tail setup only one main cable is required. The main cable(s) transfers power, air and signal to the acoustic source(s). It transfers electricity for the UEP signal and it makes up part of the loop for the magnetic field generated. The main cables can vary in length but should be trimmed to match the desired length of the influence needed.
Acoustic Source Frame
This frame carries the acoustic source and is the hub of the HEMLIS system. The airguns are mounted on shock absorbers prohibiting vibration to transcend from the frame to the acoustic source. The frame is designed for stable towing at all speeds required, it has a light-weight construction that can easily be moved by personnel on deck when needed.
Buoyancy for the closed loop system is provided using the R2 buoys connected to the loop cable. The R2 buoys is a cylindrical construction with fastening points on both ends. The R2 buoys are filled with foam, meaning that these will still float even if somewhat damaged. These are delivered in a crib that can be secure on the boat carrying the system and are as such space-efficient to transport.