[PSUBS-MAILIST] exotic steel

[Jon Wallace via Personal_Submersibles]

I've calculated 1" thick 516-70 gets you 2000-3300 feet depending upon 
safety factor, with a weight of 4000 pounds.

2" thick 516-70 gets you 5000-6700 depending upon safety factor, with a 
weight of 9200 pounds.

Deepworker 2000 uses spherical segments welded together which lightens 
the shell because each segment is the same thickness.  In traditional 
forming of a hemisphere the metal will thin out at the apex and you must 
use that as your limiting factor in regards to max depth.  So spherical 
segments get you to the same depth with lighter weight.

You might consider taking the C-Explorer approach and lighten the 
overall weight by using a steel hemisphere for the bottom half and an 
acrylic hemisphere for the top half.

Jon