Article by Alexander George, The Awl
Luxury vehicles make a statement — but too often, you can’t hear it over the roar of their engines. So the makers of top-line craft are dummying up the decibels, with a technological silence that’s 24-karat golden. Indeed, keeping quiet has become a science of its own. Whether at sea, in the air, or on land, merely piling on the insulation or amping the scrambler frequencies isn’t enough. The most effective solutions for shielding pampered passengers now require nothing less than restructuring the entire architecture and engines of boats, jets, and car engines. The result: a more efficient and (read our lips) quiet ride.
The yachting gurus over at Ned Ship Group are looking to make a softer, more luxurious splash with a motor as quiet as a sailboat’s. The company is building a pair of ships —starting with a 65-foot catamaran and followed by a 131-foot trimaran — outfitted with solar cells that will supply on-board hybrid power plants. The designers promise that while your boat’s at anchor, you will, say, snorkel in silence, without even a gurgle from the idling engines. Since the boat’s power comes from sunlight and not a combustion engine, those who prefer to keep their heads above water will avoid diesel fumes, aft and stern.
The cost of a quiet ride is diminished cruising distance, but the yachts’ stats are still remarkable. In hybrid mode, the catamaran can cruise for six hours a day at a top speed of up to 18 knots. The trimaran, which offers a power reserve, will go a bit further: about 4,000 nautical miles (4,603 land miles) at 25 knots while running in hybrid. That’s more than enough for a jump to the Caribbean, and well beyond the range of many midsize yachts with standard engines.
It’s far more difficult to quiet air than water, as you might have noticed if you’ve ever flown without noise-canceling headphones. Water insulates and swallows the boat propellers’ growl. But on heavy airplanes, the massive engines needed to lift them rotate quickly and sit close to passengers’ ears. Mapping a quiet flight means conquering not only deafening turbines but deafening wind. No matter where you sit in in a commercial cabin, you’ll brave decibel levels of 80 to 85, only slightly less than the blender (90) used for first-class pina coladas. Sophisticated private jets, for all their amenities, are only slightly calmer, ranging from 70 to 76. And their size can make the trip more rattling: As a Learjet, for instance, hits currents exceeding 500 miles per hour, the air passes over the airplane body and hits every point of friction.
A private jet’s interior suffers noise from the turbofan engines, which are attached to the fuselage; noise from the mechanicals under the cabin floor; and turbulent boundary layer (TBL) noise, which springs from external air pressure.(On most airplanes and flights, TBL worsens the further back you sit from the wings, a little physics trivia you can drop when booking your next seat in coach.) For the Bombardier company’s redesigned Learjet 85 (and its sister the Learjet 70), which will arrive next year, acoustic solutions start with the twin Pratt & Whitney PW307B turbofan engines. Sound attenuation features are added to the engine inlets to reduce the noise produced by the fan and, inside each engine, a three-stage low-pressure turbine feeds into a high-efficiency exhaust mixer. This keeps the plane’s interior quiet enough for passengers to operate their seats’ pop-up, touch-screen displays, and for the pilots to flip through their tablet computers—all while traveling 515 miles per hour.
For passengers watching a film, the insulated interior protects the craft’s surround sound system. Unlike your average home theater, whose speakers are nailed to the corners of the room, the Learjet 70’s entire cabin wall is a speaker. You hear what you want, not stowaway noise from the fuselage. Don’t expect unibody jets and solar-powered boats in commercial transportation anytime soon. At first, for instance, only passengers with Flexjet accounts will be hopping aboard the Learjet 70 and 85. The good news is that, like most design advancements, technology that first appears in primo luxury goods inevitably migrates to the mainstream, including the mechanical tweaks that hush luxury vehicles, cut emissions, reduce waste, and protect the environment. But if you are an environmentally conscious Learjet shopper, know that you’d be helping the ecosphere more by traveling in a Rolls-Royce Phantom Series II, with its double-layered floor and intake-mounted sound resonators. Or, if it’s a pure noise you want, enjoy the Lincoln THX Certified Audio System, ably protected from outside interference.