TAMPA, Fla. — What runs on electricity and mystery fuel, moves at 80 miles per hour, generates enough power to run communications gear and is quieter than a conversation? Say hello to the military’s stealth motorbike.
The Defense Advanced Research Projects Agency, or DARPA, launched the stealth bike competition back in 2014. Today, the two prototypes faced off on the expo floor of the of the Tampa Convention Center, part of the National Defense Industrial Association’s Special Operations Forces Industry Conference. The Silent Hawk by Logos and the Nightmare from LSA Autonomy could be cousins. DARPA has funded both to phase two development under a small business innovative research award, essentially two non-competing grants to develop the technology.
Both bikes feature cutting-edge hybrid multi-fuel engines that can burn a variety of combustibles like JP-8, Jet A-1, gasoline, propane, etc.. “If it’s gasoline, tell it it’s gasoline, tell it it’s something else. It will figure it out,” said Alex Dzwill, and engineer with Logos.
Could you run it on lipids, olive oil? “Theoretically, yeah,” said Dzwill.
The Silent Hawk stealth bike prototype from Logos
Of course, running a bike on regular fuel is loud, which runs contrary to the idea of a “stealth bike.” When not operating in quiet mode, both are as loud as a garbage disposal, roughly 80 decibels. When operating in quiet mode, both rely on a lithium-ion electric battery, which keeps the noise down to around 55 decibels, about as loud as an indoor conversation.
Of course, lithium ion batteries, at one point, developed a bit of reputation for blowing up.