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I AM THE WALRUS: High-Tech Cargo Airships
EFL: In April of this year DARPA initiated a program to develop a heavier-than-air, intercontinental airship capable of rapidly transporting military men and equipment to a war zone. The plan, designated WALRUS, would call for a fleet of airships capable of transporting upwards of 500 tons of cargo 6,000 miles in 4 days. Not bad when you consider a standard C-130 C-130 cargo plane, can carry about 22 tons. In addition, it is expected that these airships will also carry sufficient supplies (food, ammunition, fuel, parts, and equipment) to sustain the force for at least 72 hours. In the current war on terrorism, with an increased need for strategic airlifts, that's a hefty amount of equipment and personnel, and given our current fuel crisis, the relative fuel efficiency of an airship compared to a standard cargo aircraft is something Defense budgeters can agree with. The reason for this innovative program? The development of the Army's new rapid response Units of Action (UA). Currently, the only means of deploying troops rapidly from the US is through airlift (the 82nd Airborne Division maintains a ready brigade which is deployable world wide in 18 hours), or via fast sealift cargo carrier (the eight 33 knot 55,000 ton Algol-class transports can deliver a mechanized division anywhere in the world in less than 18 days). Both of these options have their limitations; with the elimination of the M551 Sheridan from the Airborne TO&E, the 82nd lacks any creditable anti-armor capability, and 18 days is unacceptably long to deploy one of the new rapid response UAs. A key change in military philosophy, the new "10-30-30" doctrine, has also been instrumental in the development of this new technology. Simply put, "10-30-30" can be broken down as the following: to be able to deploy to a distant theater in 10 days, defeat an enemy within 30 days, and be ready for an additional fight within another 30 days. The WALRUS program could fulfill this strategy, at a cost savings in aircraft maintenance and use. The WALRUS airships will offer a number of advantages over current airlift and sealift transports. To begin with, they can operate from "unimproved" areas, land or sea, without a need for storage hangars or ground support. They will also be weather tolerant, and have the capability of transporting a motorized force from "fort to fight" without having to first unload at a port facility, and then transport cargo and/or personnel inland. Finally, with operating costs significantly lower that either ships or conventional aircraft, the WALRUS airships could provide logistical support to deployed UAs for a fraction of what it would cost to do so conventional airlift or sealift assets. The WALRUS would not resemble any existing airships as we know them. Rather than assume the traditional "cigar" shape (like the zeppelin Hindenburg for example) the WALRUS would be of a hybrid design and shaped more like a flat, lozenge-like lifting body. (cough) Big Black Delta (cough) This would allow the WALRUS to not only derive lift from the helium gas, but from the aerodynamic forces generated as it moves through the air. The WALRUS is expected to be powered through the use of thrust wings (TW), which are articulated lifting surfaces with internal thrust producing engines. The TW would be grouped in pairs, fore and aft, and would consist of several independent modules arranged on a single axis. The TW modules can be rotated along this axis to provide 360o of vectored thrust. This would enable some of the TWs to be angled vertically to provide for thrust-based lift, and some of them to be angled horizontally to provide aerodynamic lift. Once the WALRUS reaches cruising altitude, the TWs could all be aligned horizontally to provide forward motion and aerodynamic lift. The thrust wings would also eliminate the need for the WALRUS to take on ballast (to compensate for static gas lift) when clearing the landing zone, or when "deadheading" back for additional cargo. Phase I of this ambitious project has been completed, and Phase II, which will cost $50 million, will produce a 30-ton Advanced Technology Demonstrator by 2007, which the U.S. military will use to evaluate. If all goes well, a full-scale Phase III vehicle will then be developed and evaluated for potential production. Reality Check Commercially, heavy lift airships like the WALRUS make sense. While not nearly as fast as conventional aircraft, they can deliver cargo significantly faster than is possible by sea, and they are much, much more economical to operate than are either aircraft or ships. This would make airship transportation a viable and attractive alternative to more expensive air transport, or slower sea transport. WALRUS might even prove economically beneficial in transporting routine, non-critical military cargo, which would free up conventional transports for other, more hazardous, combat related duties. The biggest issue regarding the WALRUS is defense. Airships are extremely vulnerable to anti-aircraft artillery and surface to missile fire. While a balloon might not present much of a radar cross section to an enemy target acquisition radar, a balloon toting a brigade's worth of vehicles most certainly would. By DARPA's own admission, the WALRUS could not be used in areas where the Air force has not already established air dominance and in which all ground based air defenses have been suppressed. In addition, combat is a 24/7, rain sleet or snow affair and the issue remains, how manageable is a 500-1000 ton balloon in extreme weather conditions? Posted by: Steve 2005-04-26 |
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