[Spaceships] simply fuel math...

[Fred Brackin]

Originally Posted by hal

So you can't simply state "Empty" for the slots in the hull? That sounds like a simplification from where I sit. Reduce mass by 5% for each hull section left empty/open. No cost, no mass, etc.

But, rules as written, the idea was never broached. Good to know.

Cal them "Cargo" rather than empty. It comes to the same thing if you never fill your holds but it screws with the damage charts less.

Spaceships isn't really written as a campaign/world-building aid as much as people want to use it for one. It's meant to do double duty as an rpg supplement _and_ a stand-alone space combat game. That's where some of the gamist elements come from.

[hal]

Originally Posted by ericthered

Its actually simpler to build the ship with 20 sections and multiply all costs and weights by the ratio of the two sizes. you also want to extrapolate DR, which is more complicated, because I can think of several valid ways of doing that. On the other hand, DR doesn't vary that much between sizes, so it doesn't matter nearly as much.

But that would largely be a "house rule" kind of thing. Not that I mind it!!! On the contrary, If someone were the layout the entire formula for me to follow (or I take the time to figure it out) - then it is a good house rule to utilize.

:)

[hal]

Originally Posted by Anthony

You'd multiply DR, hit points, and (if applicable) weapon damage by the cube root of the ratio.

So, if the ratio were to be .86666667 that of the next largest hull mass, the ratio would be the cube root of .86667 times what? The next smaller hull?

[Anthony]

Originally Posted by hal

So, if the ratio were to be .86666667 that of the next largest hull mass, the ratio would be the cube root of .86667 times what? The next smaller hull?

The hull it's a 0.86667 times multiplier of. You should probably use the next smaller hull size, though, so it would be the cube root of 2.6 x the stats of a 100 ton hull.

[Ulzgoroth]

Originally Posted by hal

So you can't simply state "Empty" for the slots in the hull? That sounds like a simplification from where I sit. Reduce mass by 5% for each hull section left empty/open. No cost, no mass, etc.

But, rules as written, the idea was never broached. Good to know.

That would be full of problems.

Reducing mass should increase the acceleration of drives and the delta-V of fuel tanks, and lower HP. Having slots on the ship that correspond to nothing makes a hash of the damage system.

[hal]

Originally Posted by Anthony

The hull it's a 0.86667 times multiplier of. You should probably use the next smaller hull size, though, so it would be the cube root of 2.6 x the stats of a 100 ton hull.

I'll give that a shot and see how it works.

Right now, I started working on how to calculate the values for hulls as given in the table. As best as I could figure...

It works out to:

if SM is odd, value = 3
if SM is even, Value = 10

Then, multiple the "Value" times 10^(round(SM/2,0)+2).

Where possible, I'm trying to reduce things to formulas that are a function of SM values. Otherwise, I need a table lookup to find out what values go where relative to the SM involved.

I know there is an Excel spreadsheet out there that does this, but I like to see what I can sleuth out on my own. :)

[RyanW]

If you really want to make intermediate size vessels, start with the stats for a vessel the size of the next smaller official hull.

• For any stat that progresses x10 for +6 SM, multiply the stat by the cube root of the ratio of mass to that of the next smaller official hull.
• For any stat that progresses x10 for +3 SM, multiply the stat by the square of the cube root of the ratio of mass to that of the next smaller official hull.
• For any stat that progresses x10 for +2 SM, multiply the stat by the ratio of mass to that of the next smaller official hull.
• For any stat that has a linear progression, use the stat of the smaller official hull if the mass ratio is less than 1.8, and that of the larger official hull if the ratio is 1.8 or larger.
• Be careful that many stats have substantial rounding or minima at the low end. It may be necessary to figure out the progression and calculate a theoretical value for your base hull, the reapply the rounding and/or minima after modifying for your actual hull. For example, SM+6 habitat should have 0.6 cabins.

So a 260 ton vessel would have 1.37 times the DR, 1.89 times the open spaces areas, and 2.6 times the cargo capacity per component of a 100 ton ship, and would have the handling and computer complexity (and SM) of a 300 ton ship. There are a few odd progressions, like hangar bay launch rate (though if you look carefully, you may note that if you express launch rate as seconds per hangar, you get a neat x10/+6 progression).

[hal]

Originally Posted by RyanW

If you really want to make intermediate size vessels, start with the stats for a vessel the size of the next smaller official hull.

• For any stat that progresses x10 for +6 SM, multiply the stat by the cube root of the ratio of mass to that of the next smaller official hull.
• For any stat that progresses x10 for +3 SM, multiply the stat by the square of the cube root of the ratio of mass to that of the next smaller official hull.
• For any stat that progresses x10 for +2 SM, multiply the stat by the ratio of mass to that of the next smaller official hull.
• For any stat that has a linear progression, use the stat of the smaller official hull if the mass ratio is less than 1.8, and that of the larger official hull if the ratio is 1.8 or larger.
• Be careful that many stats have substantial rounding or minima at the low end. It may be necessary to figure out the progression and calculate a theoretical value for your base hull, the reapply the rounding and/or minima after modifying for your actual hull. For example, SM+6 habitat should have 0.6 cabins.

So a 260 ton vessel would have 1.37 times the DR, 1.89 times the open spaces areas, and 2.6 times the cargo capacity per component of a 100 ton ship, and would have the handling and computer complexity (and SM) of a 300 ton ship. There are a few odd progressions, like hangar bay launch rate (though if you look carefully, you may note that if you express launch rate as seconds per hangar, you get a neat x10/+6 progression).

works for me. :)