The U.S. Navy’s Self Defense Test Ship (SDTS) went underway for final-phase testing of two alternative fuels, May 31. The SDTS traveled to San Diego, where it took on approximately 30,000 gallons of two types of alternative fuels. The ship then proceeded on a normal cruise, demonstrating that the alternative fuels could function as a drop-in replacement, requiring no changes to equipment or operating procedures. The two fuels were developed using different methods: Synthetic Iso-Paraffin (SIP) and Catalytic Hydrothermolysis Conversion Diesel (CHCD).
SIP is a fuel derived from alternative feedstock and blended with military-grade petroleum-based fuel, known as F-76, with 20 percent non-petroleum sourced. CHCD is a military grade drop-in replacement for traditional F-76 that is 100 percent non-petroleum sourced.
“The goal is to qualify as many alternative fuel sources as possible,” Diane Mattingly, in-service engineer with Naval Surface Warfare Command, Philadelphia Division, said. “A range of operational fuel sources will give our mission planners and commanders increased operational flexibility.”
The objective of this particular test was twofold; first, to demonstrate that these alternative fuels are drop-in replacements for petroleum-sourced F-76- meaning they require no equipment modifications or operational modifications by the crew; second, to ensure that approved alternatively-sourced fuels perform equally to, or better than, existing petroleum-sourced fuels.
For this mission, the alternatively-sourced fuels were loaded into the two gas-turbine engines and the two gas-turbine generators. The test period lasted approximately 12 hours along the Southern California Coast, while returning to Port Hueneme.
While under the power of the alternatively-sourced fuels the ship successfully completed multiple engine starts and speed changes. There were no mechanical, operational or qualitative differences when operating on either fuel. The data collected from the trial will be fully analyzed and coupled with borescope results into a final report.
In 2011, the SDTS tested 15,000 gallons of a 50/50 blend of fuel and it was a success. There were no adverse effects in the gas path of the gas turbines. The fuel was tested in one of the SDTS’ ship-generator sets and one propulsion engine.
Source & Image Credit: US Navy