Dan wrote:

Interesting how that site doesn't mention one major problem with
ZMC-2: air sickness. The crews complained of getting sick in rough
air. apparently the metal envelope couldn't flex enough to smooth the
ride.

One thing I have never been able to find is diagrams or photographs
of the rivet machine designed for riveting the seams of the envelope.

I've never seen any of those either, although there's a good description
of the principle it worked on he
http://www.flightglobal.com/pdfarchi...0-%200492.html
I went over to the patent office to see if there's a patent for it (I
assume there is), but no luck finding it yet.

Pat