May 15, 2012: Often simple changes can have large consequences. The U.S. Navy, seeking to save money on fuel, found that by upgrading the control system on the LM2500 gas turbine engines it can reduce fuel use by 16 percent. On DDG-51 class destroyers (a major user of the LM2500, with four per ship) it can save over $2.5 million a year per ship in fuel costs. As the price of oil rises so do the savings. The new digital controls enable the destroyers to use less fuel at low speeds. The big advantage with gas turbines is that they can increase speed rapidly. But subs often move slowly, especially when searching for submarines.

Most people are unaware that many warships are propelled by jet engines. But by the late 1960s, the huge TF39 jet engine developed for the C-5 aircraft was reworked as a maritime power plant (the LM2500). By the 1990s, the gas turbine ship engine was common not only in merchant ships but warships as well.