HDAS Horizontal Directional Drilled Export Cable Shore Landing, Wake Island

 

The Hydroacoustic Data Acquisition System (HDAS) is the marine element of the worldwide system for monitoring for clandestine nuclear tests for the Comprehensive Test Ban Treaty Organization (CTBTO).  SST was contracted by NFESC to support the installation of systems at Wake Island in the Pacific Ocean and at Ascension Island in the Atlantic Ocean.  Both sites are very remote and presented challenging logistics requirements. SST’s role included design of the shore landings, marine engineering and bathymetric survey, both in near-shore shallow water as well as in full ocean depth, and installation of the HDD shore ends.

 

The bathymetric survey included the full suite of survey along two 300+ km long cable routes plus the shore landing.  SST cable engineers directed the survey and instituted cable route corrections to avoid seafloor obstructions and optimize the survivability of the cable systems.

The HDD included three 800-foot long x 4-inch diameter HDPE boreholes installed using a portable Ditchwitch HDD drilling system; The Ditchwitch system was airlifted to and from the island.

 

SST also designed and managed the construction of a 30 ft x 20 ft modular, pre-fabricated concrete.  The building was built to support the short electronics, power, and satellite transmission system on the island.