Instead of trying to justify the building and operation of very large blimps by exploiting their unique VTOL (vertical take off and landing) capabilities, here’s a different approach. Let’s look at finding a niche for blimps in an established, commoditized and analyzable industry: container shipping.
There’s a “hole” in one’s options to ship a container across the ocean. It’s either on a super-slow and super-efficient ship or on a super-fast and super-gas-guzzling jet plane. The fuel-burn ratio is like 100:1.
There’s no middle ground, and economic dogma states that The Market always wants to be segmented.
o Mac Mini, iMac or Mac Pro? 15″, 17″, 19″, or 21″?
o Chevy, Pontiac, Buick, Oldsmobile or Cadillac?
o Old Navy, Gap or Banana Republic?
(etc.)
Thesis: Some containers are late, and cause losses due to downtime at their intended destination. The only choice in these situtations is to eat the downtime losses or repack everything into a cargo airplane and pay through the nose to get it there on time. Either way, it’s expensive, and that expense is bourne by the economy in various ways.
A Container Blimp, then, is that middle ground. It has a speed and fuel efficiency somewhere between a ship and an airplane, truck-ish or train-ish. Surely my math is simplistic when I try to locate the correct size, but it’s definitely there somewhere. Blimps double their fuel/ton-mile efficiency with every doubling of scale.
Besides conventional container traffic, such a contraption would also allow “UPS Ground to China.” Just three days across the Pacific Ocean (or two days for the Atlantic), for instance, would let “about a week” thinking still work when shipping packages to foreign countries.
And an added trick is the idea of not landing the blimp at some airport and having stuff loaded into it, but rather to hoist it up and set it down all at once in the form of a special-purpose barge (exchanging it with water mass each time). That way, interfacing with the existing infrastructure (cranes, trucks, railroads) is entirely conventional. Also, it means the blimp is never flying over land, which will surely help regulatorially.
Longshot City 
January 8, 2009 at 1:50 pm
I think you are neglecting an important component in your analysis of the different classes of transport — the size of the cargo load per vehicle, as it relates to logistics. It is no good to have a vehicle that can quickly and efficiently transport 32 containers from point A to B if you only can find 3 containers to send. 747 airplanes have great numbers in terms of speed and cost per passenger mile, but they are apparently too big for airlines to logistically organize on most domestic routes, thus the immense popularity of 737’s.
Trucks have the great advantage of being small and yet still relatively efficient (plus the government pays for the vast majority of the infrastructure costs, but that’s another issue).
It makes me wonder if your “null hull” might be a better option for intermediate mode shipping — what if it was a *powered* “null hull” where the parafoil was used only (or mostly) for lift?
January 8, 2009 at 9:56 pm
Indeed, yes. If a container blimp has to carry 32 containers in order to have a decent-enough fuel efficiency, but no big port ever has 32 containers per day that would need that kind of service, then things don’t look very good for the concept.
> It makes me wonder if your “null hull” might be a better option for
> intermediate mode shipping — what if it was a *powered* “null hull”
> where the parafoil was used only (or mostly) for lift?
I’d appreciate it if you could elaborate on what you mean by that, because I’m not quite getting the picture yet.
January 8, 2009 at 10:16 pm
Here’s the thing. Beyond about 35 miles/hour, it’s really hard to do any kind of watercraft at all due to cavitation. The trailing edge of just about any shape (a ship hull, a propeller, a rudder, etc) starts making those vacuum-bubbles that collapse and destroy things.
(Nuclear submarines, on the other hand, can go faster than that when they’re deep underwater and the water pressure is higher.)
So that part, right there, tells me that speeds beyond about 35 miles/hour aren’t really possible or economical if any part of the vehicle is moving through the water.
‘Which is a stinker because I had this crazy vision of a NullHull-type contraption towing an unpowered blimp. But the 35mph limit kinda shuts that down. Shoot.
Does that cover it in your view?