1969 & 2015 Silence IS


(and Hybrid) GOLDEN F


or nearly a century, the military motorcycle has roared through American warfare, from troops riding with GEN John J. “Black


Jack” Pershing chasing Francisco “Pan- cho” Villa across the southwestern United States in 1916, to evacuating the wounded from the battlefield during World War I, to delivering vital messages to forward units during heated battles in World War II. Used again in Vietnam and in Operation Desert Storm, with rid- ers scouting hostile territories and leading convoys to American special forces units crisscrossing the treacherous terrain of Afghanistan, the military motorcycle, with its courageous and skilled riders, has proven irreplaceable on the battlefield.


While the utility of military motorcycles may reverberate through the decades, when it comes to stealth and eluding enemy reconnaissance, the roar of such bikes may be history.


NO MORE ROAR


Concept drawing shows the SilentHawk hybrid motorcycle, developed in response to DARPA’s requirement for a lightweight, rugged, single-track vehicle that can operate in near- silence for extended periods while traveling over hostile terrain. (Photo courtesy of Logos Technologies)


Tat’s potentially thanks to SilentHawk, the hybrid-electric motorcycle prototype under development by Logos Tech- nologies LLC in partnership with Alta Motors, now in phase II of a Small Busi- ness Innovation Research award from the Defense Advanced Research Projects Agency (DARPA).


Te requirement is for a lightweight, rug- ged, single-track vehicle that can operate in near-silence (quieter than 55 decibels in “quiet” mode, or roughly the volume level of a conversation) for extended peri- ods while transporting small numbers of troops over hostile terrain. Tis initiative will mark the first time that a two-wheel- drive, multifuel hybrid capability has been integrated into a full-size off-road motorcycle.


BUILDING ON SILENCE SilentHawk promises to fill DARPA’s demands with the combination of Logos’ drone multifuel hybrid-electric power system and Alta’s off-road RedShift MX electric motocross frame as a basis for the prototype. Te preproduction Red- Shift MX all-electric off-road racing bike weighs 260 pounds, produces 40 horse- power and runs on a 5.2-kilowatt-hour battery. Its new hybrid system incorpo- rates a multifuel generator comprising a Wankel-type rotary engine and an elec- tric motor.


Among other qualities, rotary engine is noted for its


the Wankel relative


silence. Indeed, an article on Page 169 of the November 1969 edition of Army AL&T’s predecessor publication, Army Research and Development, car- ried an article about the silent YO-3A


ASC.ARMY.MIL


167


THEN & NOW


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