Craig Farnsworth, brother of Blue Flame co-builder Pete Farnsworth, is a missile engineer.
When one DOES THE MATH and examines various tank configurations, a 4,000 pound empty weight car with sufficient volume to hold 13,000 pounds of water may very well be feasible.
Glad you brought that up.
Let's see... the last three successful ALSR cars (and one hopefully in the future) were designed by:
Thrust SSC: Ron Ayres and Glynn Bowsher, a missile engineer and a top ME.
Fossett LSR: Craig Breedlove and Eric Ahlstrom, a 5 time ALSR holder and a rocket scientist.
Thrust 2: John Ackroyd, a world recognized ME
Blue Flame: Dick Keller and Pete Farnsworth, rocket scientists would be an apt description.
And the structural fractions were...
51%
53 to 58% (depending on mod state)
60%
63%
Pretty narrow range there... Not too close to 10% either.
Now in concert with this august company, I claim that 60 to 75% is rational for a poor design and half of that is good design. Only a fool would claim that he could reduce the weight fraction by a factor of 6 and stand up to DOUBLE the dynamic pressure. Please stop with the irrational and unsupportable claims. While the historical documents are interesting for perspective, this "steam rocket fantasy" is equivalent to saying that we could build a 1200 lb Goldenrod to go 650 mph wheel driven.
It's
Not
Rational.