Their virtues?
An airship with roughly the same dimensions as a regular aircraft can carry a larger payload, both in cargo space and weight. . . . . Most blimps currently use less fuel in an hours flight than most jets use to taxi to the runway. . . . the airship can load up at, say, a factory, and then fly directly to the distribution center with a huge load. And, the shipping costs become roughly the same as maritime shipping. Shipping by boat is much cheaper per mile than shipping by road. Airships apply this same concept to the air, making inland shipping much more cost effective. . . . Canada is currently looking to airships to supply their remote locations in the Northwest Territories. . . . Airships can also reach remote areas in underdeveloped nations during disasters, or in areas where huge disasters completely destroy all other infrastructure (including traditional airports). Cheaper to fly than Helicopters, and able to carry larger payloads, airships can bring waves of humanitarian aide in less time than it would take to rebuild an airport, or try to rebuild roads, bridges, etc. to allow ground shipping in an area. They can land in any open field (or convention center roof top), drop their payload, and continue back to get more materials.
More background available here.
Popular Mechanics review three designs that sought be ready for consideration in 2009, which Defense Tech notes. One interesting application suggested in Popular Mechanic's was to use airships to fight fires in remote locations.
I noted as a comment to that thread that:
I can see a few commercial, paramilitary, and military niches for airships.
Most prominently, airships make sense for large cargo delivery in roadless areas (e.g. Alaska, inter-island transport in Hawaii, Northern Canada, the Australian outback, interior South America, Africa, Antarctica, Western Pakistan) with larger volumes/lower costs than cargo planes and without the need to transfer shipments onto and off of ferries to ground transporation. An airship is, for example, the perfect way to get building materials to the site for your fishing cottage on a lake a hundred miles from the nearest road.
Indeed, airships are a good competitor with ferries in almost any application where the ultimate destination is not right at the coast (e.g. from Great Britain to Ireland). They also make sense as an alternative to short surface ship trips like those from North Africa to Europe.
Tourism, particularly eco-tourism is another positive niche where airships are used. Indeed, airships make the notion of having large roadless areas without removing roadless areas entirely from availability to the general public much more viable.
In a related notion, airships could greatly mute environmental opposition to natural resource exploration and extraction efforts in isolated, otherwise pristine areas. A fenced in 40 acre site with an underground uranium or gold or copper mine in the middle of nowhere is much less objectionable if hundreds of acres don't have to be cleared to provide access in and out of the location, and if temporary housing and equipment can be dropping in and dropped out. (The analysis is harder for oil and surface mining of coal which is high volume/low value).
Airships are a sensible alternative to building new intercity passenger rail lines or expanding highway in high population density areas (e.g. Florida, the I-70 corridor through the Rocky Mountains, and the Pacific Coast) where obtaining rights of way for new surface corridors would be expense. I suspect that airship service could be set up for costs comparable to Amtrak (admittedly not a great economic model), more rapid and reliable service than Amtrak due to a lack of competition with freight rail, and similar spaciousness/tourist view virtues.
Airships are quite attractive for civilian search and rescue missions (on land in and coastal areas), for delivery of supply packages to locations foreign and domestic that have experienced disasters that disrupt transportation routes, and for mass evacuations (a la Katrina). One can similarly imagine an airship outfitted to be a mobile hospital (similar to the Navy's two hospital ships) for use in disaster areas foreign and domestic becoming a fixture in the American consciousness and symbol of American goodwill worldwide. They would be perfect for the Air National Guard and Coast Guard.
In military applications, one plausible use is as an alternative to fast sea lift/military convoy for shipments too large for airlift to be practicable with deliveries made only to behind the front lines destinations (e.g. from Hawaii or Japan to Kuwait).
The other plausible military use is as a localized alternative to spy satellites and communication satellites in places where allied forces control the air.
Of course, an airship's modest speed and manuverability, large size, and lack of armor makes it a poor choice for battle zones, any place where air superiority has not been secured, and places where surface to air missiles are a worry.
In the civilian world, a cooperative initiative of the Department of Transportation, Department of Homeland Security (Coast Guard and FEMA), the Department of Agriculture (since it would serve rural areas and roadless public lands), the Department of Interior (due to public lands service), and the Environmental Protection Agency, probably in an independent agency strucutre similar to Amtrak (which has had great bureacratic staying power despite poor delivery of services for reasons to a great extent due to the inherited system).
The regular Air Force seems like an agency whose primary missions are ill matched with these niches. Reassigning airship authority would be a quite trivial adjustment in the Key West Accord. In the military, the Army and the Air National Guard would probably be the best lead agencies.
Another military application would be as a base for fighter aircrft and drones, similar to an aircraft carrier.
Fuel Efficiency
While many articles proclaim in generalities the fuel efficiency virtues of airships, their modest fuel consumption has to be balanced against their slow speed. Current technology airships have fuel efficiencies comparable to highway vehicles and general aviation fixed wing aircraft. Airships are vastly more fuel efficient than helicopters and most ground based military vehicles and weapons systems equipment (which are typically not designed for fuel efficiency) and have potentially greater cargo capacities than aircraft or semi-trucks typically seen carrying freight on a highway. But, the current technology doesn't appear to offer great fuel efficiency benefits over cars, trucks and buses and Amtrak, and are both slower than less fuel efficient than long haul commercial aircraft or typically modern high speed passenger rail lines.
Still, while fuel efficiency may not be the killer benefit that some advocates attribute to it, there is room to improve fuel efficiency (e.g. with hybrid solar power systems) and fuel efficiency, at least, isn't a great minus for the technology.
Current technology airships are much less fuel efficient than sealift by ship or freight rail. Both of those methods are very slow, in the case of ships requires multiple change of travel mode (typically from truck to freight rail to ship to freight rail to truck) that aren't required for point to point airship transportation, and require only minimal infrastructure compared to typical ports and freight rail systems.
A 1930 British Airship carried 100 people for 4,095 miles with less than 73,920 pounds of fuel. This is about 43 passenger-miles per gallon, but understates the fuel efficiency because the 73,920 is for "fuel, oil and payload" (about the same as Amtrak with a typical occupancy). One would hope that 78 years later, we could do better. But, the 1930 figure isn't too far from the fuel economy of several small modern airships of about 40 passenger-miles per gallon. One modern airship with a 14 person capacity gets about 32 passenger-miles per gallon (comparable to a two person occupancy SUV).
As November 1977 study by NASA explores many specifications.
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