From: "Robert S. Dean" [email removed]
>How many people use the advance character generation rules now? I though the
>updated "quick" rules provided a sufficiency of skills to keep the characters
>competitive, and more or less feel that all the extra die rolling in the
>advanced systems is a waste of time. Just an opinion...
I agree. I only use the basic character generator and selected parts from
the advanced sections (such as college and military academys). I had always
planned to expand slightly the pre-service skills section for the basic
system in a way similar to the college expansion posted a few messages ago.
>As two sample calculations, I considered a cylindrical pressure vessel capable
>of containing one standard atmosphere of pressure (14.7psi) <Sorry about the
>English units--I'm an engineer>. I considered it to be made of mild steel,
>with no special alloys, etc, giving a yield strnght of approximately 50,000psi.
>I also ignored end cap effects. I decided that a safety factor of 2.5 was
>sufficient, so I put in a value of 20,000psi as the maximum allowable stress
>in the skin. At those conditions, a cylinder 10ft in diameter would need a wall
>thickness of less than 0.05 inches, which is less than Traveller armor value
>1. A 100ft diameter cylinder (ship sized) would require a wall thickness
>of 0.44 inches, about Traveller armor value, between Traveller armor values 3
>and 4. 50,000psi mild steel would be the equivalent of armor type A (soft
>steel).
I have not designed many ships but I don't see how you go from thickness to
armor value (or vice versa). Again, I have not designed but maybe half a
dozen ships but if I understand things correctly a 100 ton ship occupies a
volume of 1350 cubic meters and has a mass of 40 tons. Multiply by 33 for an
armor factor of 40 and by 1.25 for soft steel and you get 1650 tons for weight
(mass). I believe a minimum surface polygon enclosing the volume listed would
be a sphere 685.6172 cm in radius. I don't know the density of steel but the
specific gravity of iron is about 8 gm/cc (which means the density of steel
is about the same?). If you assume a mass of 1,650,000 gms and calculate the
thickness of the skin of the sphere you find it to be 0.0349 cm or about
0.0137 in. If the density is greater than 8 gm/cc then the thickness will be
even less. Somebody check these numbers, you know how bad I am with numbers!
Assuming no miscalculations, wouldn't this coupled with your calculations
mean that the hulls should have a higher armor rating?
>P.S. There are a number of potentially useful technologies that Traveller's
>reliance on grav manipulation overshadows. Laser launch systems and
>beanstalks are two that spring immediately to mind.
True but these limit ships to civilized, high tech planets. Anti-grav
allows the ship to come and go when and where it wants (which is good for
smugglers and the like).
TLH
- - --
T.L.Hayes |
MIT/Lincoln Laboratory |
Lexington, MA |