Story Number: NNS140327-20Release Date: 3/27/2014 1:53:00 PM
By Joseph Battista, Naval Surface Warfare Center Carderock Division - Ship System Engineering Station Public Affairs
PHILADELPHIA (NNS) -- Engineers from the Naval Surface Warfare Center Carderock Division - Ship System Engineering Station completed the first submarine communications cable test at the newly constructed Tow Cable Test Site (TCTS), Naval Sea Systems Command announced March 27.
The new facility provides the Navy the capability to test and evaluate prototype synthetic and steel electrical, optical, and mechanical cables used in submarine communications systems. The site can also be used to test other systems like towed arrays, mast antenna cables and remote operated vehicle cables.
"This test site will allow us to learn more about the tow cable in order to develop better designs for our submarine force," said Jason Delisser, electrical engineer with Antenna Engineering and Sail Systems Branch, who oversaw the construction of the test site. "The ultimate goal is to significantly improve system reliability and the test site will allow us to understand how and why the cable fails during operation so that we can design out the most common failure modes."
The TCTS was funded by the Navy's Program Executive Office for Command, Control, Communications, Computers and Intelligence as part of a Lean Six Sigma initiative to increase system reliability. Similar testing was previously conducted by private industry and this capability will reduce costs, test and other lead times, as well as reduce dependence on outside contracting.
The TCTS incorporates two separate test fixtures. The first fixture is a tension test fixture capable of simulating loads up to 25,000 pounds. This test fixture is primarily used to assess the tensile properties of the cable, including breaking strength, cable strain and torque balance.
The second fixture is a Bend Over Sheave fatigue test fixture. This fixture uses a belt-driven actuator to drive a tow cable around a set of two fixed sheaves while under tension in order to assess the bending fatigue life of a cable. The bending fatigue life can often be the most important determinant for the expected lifecycle of a cable design.
During all mechanical testing the cable core is connected electrically to a dielectric analyzer, and optically to a fiber spectrometer and light source. The dielectric analyzer measures the insulation resistance and continuity of the electrical lines, and the fiber spectrometer measures the continuity of up to two fiber optic lines. Understanding the relationship between the structural component of the cable and the cable core is critical in tow cable design.
One of the most important design aspects for this site was the requirement for safe operation. Delisser recognized this early on.
"We realized that applying high tensions at a fast rate could create potentially dangerous situations for the test operators if all safety measures weren't incorporated in our design."
The test site is configured with multiple levels of safety including structural guards against cable whipping, multiple emergency stops and a control system that prohibits operation of any mechanical equipment if the test area is not secured. The test site also utilizes solenoid locks on the gates to further prevent access to the test area during testing or if power is unexpectedly lost. In addition, eight cameras are stationed within the test area in order to allow test operators to safely set-up and perform testing without entering the test area.
The Ship Systems Engineering Station, Philadelphia is a major component of Naval Surface Warfare Center Carderock Division. It is the Navy's principal test and evaluation station and in-service engineering agent for all hull, mechanical and electrical ship systems and equipment and has the capability to test and engineer the full range of shipboard systems and equipment from full-scale propulsion systems to digital controls and electric power systems.
For more news from Naval Sea Systems Command, visit www.navy.mil/local/navsea/.