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I’M NOT surprised that the guy who prefers coal to renewables is also in favor of steam over electromagnetics. Indeed, his latest encounter with science and technology is textbook Trump.
At issue are the methods of launching and retrieving carrier aircraft. I note that my information on this comes from readily available Internet sources, likely not as deeply classified as briefings available to Trump.
Then again, even before his inauguration Trump told Fox News Sunday that he didn’t need daily intelligence briefings: “I’m, like, a smart person.”
We’ve heard this before.
But back to aircraft carrier launches and retrievals.
The earliest launches of aeroplanes off water-based craft depended upon mechanical springs or compressed air. When ships evolved to have decks dedicated to launch and retrieval, for a time aircraft lifted off solely by their own power and, on return, continued to snag a cable with a tail hook.
By the mid-1950s, aircraft carriers had developed steam-operated catapults for launching larger, heavier aircraft. Steam-driven pistons travel in cylinders beneath the carrier’s slotted flight deck, hardware connecting the pistons to the aircraft being launched. Metal zipper-like surfaces along the cylinders help to recycle the steam pressure for the next launch.
Indeed, building up pressure takes more than a minute and is one reason for developing new catapult technology. Other reasons involve launching yet heavier aircraft, reducing stress on their structure during the launch and reducing maintenance requirements of the launch system.
The EMALS, Electromagnetic Aircraft Launch System, was conceived in 1999. In place of steam, its linear induction motor produces electric currents generating magnetic fields that propel a carriage along a track. It’s not unlike the technology propelling Maglev trains. As with a steam catapult, the carriage is linked to the aircraft being launched.
EMALS advantages are many: It’s inherently simpler than its steam counterpart, and thus easier to maintain. It recharges in 45 seconds, significantly less than a steam system’s turnaround time. An EMALS is programmed for a linear acceleration curve, which reduces the stress on the launched aircraft. It generates 29 percent more energy than its steam counterpart, thus launching heavier aircraft. Yet an EMALS can be tailored to launch everything from a unmanned drone to large aircraft.
By June 2014, the U.S. Navy completed EMALS prototype testing of 450 manned launches of its carrier-based aircraft. In May of 2015, shipboard tests began. The U.S.S. Gerald R. Ford, CVN 78, is expected to be commissioned later this year. It features both EMALS launch as well as an AAG, Advanced Arresting Gear which replaces the method of snagging aircraft that dates from the 1930s.
On a traditional carrier, the kinetic energy of a returning aircraft is transferred by cable to a hydro-pneumatic damping device located below deck. An AAG replaces this device with a water-turbine feeding electricity into a large induction motor. The AAG can accept a wider range of aircraft, is less bulky and requires less maintenance than the device it replaces.
However, these advanced features of CVN-78 are not without development complexities. In initial 2014 evaluations, EMALS testing recorded 201 failures out of 1967 launches; AAG testing revealed 9 failures out of 71 attempts.
Acting Navy Secretary Sean Stackley is quoted as saying on May 12, 2017, “Ford [the carrier] right now is on track to get out to sea before Memorial Day. We came out of builders’ trials strong. We are correcting those deficiencies… that we need to correct prior to going into Acceptance Trials (AT). I’m pretty confident right now in a good AT and a quick turnaround to delivering the ship.”
By contrast, what follows is Trump’s scientific analysis of launch options, as offered in a Time interview and reported by the Navy Times:
In discussing this digital launch system, Trump said, “It sounded bad to me. Digital. They have digital. What is digital? And it’s very complicated, you have to be Albert Einstein to figure it out. And I said—and now they want to buy more aircraft carriers. ‘What system are you going to be—’ ”
“ ‘Sir, we’re staying with digital.’ ”
“I said, ‘No, you’re not. You’re going to goddamned steam, the digital costs hundreds of millions of dollars more money and it’s no good.”
It’s not difficult to image steam coming out his ears when Trump made these scientific pronouncements. ds
© Dennis Simanaitis, SimanaitisSays.com, 2017