True, and I -could- travel in a sealed tube at lethal speeds, breathing in
other peoples farts, or I -could- (maybe, one day) saunter out onto the
viewing deck with a gin and tonic and relax in a comfortable deck chair as I
watch the world go by. I'm too old to hurry.
I've never been convinced that any shape other than used in the twenties
and thirties has any real advantage.
The airship has some fundamental advantages for air travel at speeds
below 100 mph. It has the same efficiency equation as a super-tanker. I
see it viable for cargo, and possibly passenger carrying at a low price
for a longer trip time than current airliners.
Big problem is that it would take a lot of capital and the payback would
be slow. I don't see any reason a cargo airship could not be lifted by
hydrogen, but a passenge ship would probably need helium.
BTW, at least two airship kits currently available. I built the
Lindenberg Graf Zeppelin, and have the Glencoe Navy blimp kit in the que
to my workbench.
...personally, I hate gin...but as long as I have a window seat, I can
still buy a beverage of my choice and look out the window...biz-class on
a 777 rocks - particularly on a trip from LA to Stockholm.
I travel on biz so much that I look to NOT traveling at all as being my
"vacation", so I don't really care much "how" I travel. But it would be
pretty cool to be able to make a trans-lant crossing on a real, genuine
Zeppelin - not a saucer.
: be slow. I don't see any reason a cargo airship could not be lifted by
: hydrogen, but a passenge ship would probably need helium.
Problem I see with hydrogen is that shipping insurance
would be very high if it were available at all.
If you can't get insurance on the cargo, your not going
to get many customers shipping their cargo, even at ruinously
cheap rates to cover the lack of insurance. Then your backers
are going to be howling...
=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 Bruce
urden =A0 =A0Austin, TX.
Thinking about this, I'm not sure that I'd ~like~ to see these come
I mean, can you imagine a Zeppelin being bought by DHL? Even SLOWER
service in package delivery!
There is the sort of teardrop shape that is the optimum low drag shape
(the shape of many external tip or drop tanks).
However, the difference in drag between those and a cylinder with a good
aerodynamic nose and tail is likely not enough to pay off over the
increased production cost.
The neat thing about an airship, like a supertanker, is that drag is
only proportional to square of the length, while payload is proportional
to the cube. So if you make it big enough drag becomes less important.
Beyond a certain size, inertial forces dominate. It takes a lot of
power to get it moving (and to stop it) but it will almost coast forever :-)
However, Coriolis force is an inertial force, and the thing would then
want to keep turning right in northern hemispere :-) However, a bit of
rudder will hold it on course, and the rudder trim drag is an aero force
that is negligible anyway.
Unless operator could convince insurance companies that it is safe
enough. Many insurance companies have pretty good technical staff. We
have made great strides since the thirties in handling hydrogen. One aid
is to not vent it but recompress it instead.
They insured cargo planes fueled by gasoline, and gasoline is one wicked
fuel for safety. In earliest days of motorized vehicles the fuel
properties were indeed a big holdback to spark ignition engines, in
favor of steamers that could use kerosene, a much safer fuel. Yet we
learned to live with gasoline and even use it in consumer vehicles.