starship.hulls.txt

OK, let's get unconfused on this issue.  Going into FF&S, I see:

"As indicated above, the base values for hulls assume a spherical shape.  As
all hulls of the same rate have the same interior volume, hulls in less
space-efficient shapes than spheres will have more surface area, greater
length, and require more hull material to achieve an equivalent volume.  The
Hull Form and Configuration Table (pp.12) indicates the various hull forms
available and the effects on length and material volume."  --- FF&S pp.10

"Note also that the hull form will affect the surface area of the hull.
Note at this time how much surface area is available.  Surface area is used
for the attachment of weapons, sensors, communicators, launch ports, etc.
Keep a running record of how much sirface area is used as the ship is
designed." --- FF&S pp.11

Unfortunately, the explicit formula for surface area *isn't* included, which
makes things confusing.  When John Bogan noted the problem, mentioning hull
thickness confused the matter even more.  Here's my take on the whole thing:

Hull Plating:

	AVmin = (Gmax * 10)
	where 	AVmin is the minimum armor value for the hull, and
		Gmax is the maximum allowable accelleration in Gs

	Hpv = (AV / Thm) * Mv * Mvm
	Hpva = (AV / Thm) * Mv * Mvm * 1.3
	where	Hpv is the hull plating volume (in m^3) 
		Hpva is the hull plating volume (in m^3) for airframe hulls
		AV is the desired armor value (but not less than AVmin)
		Thm is the toughness of the selelected hull material
		Mv is the hull material volume from the Hull Size table
		Mvm is the MV modifier from the Hull Form & Configuration table

	Hpm = Hpv * Mhm
	Hpma = Hpva * Mhm
	where	Hpm is the mass in tonnes of the hull plating
		Hvm is the hull plating volume in m^3
		Mhm is the mass of the selected hull material
		Hpma is the mass of the hull plating for airframe hulls
		Hpva isthe hull plating volume in m^3 for airframe hulls

	Hpc = Hpv * Sm * Phm
	Hpca = Hpva * Sm * Phm
	where	Hpc is the hull plating cost in MCr
		Hpv is the hull plating volume in m^3
		Sm is the streamlining modifier from Hull Form & Config table
		Phm is the price of the selected hull material
		Hpca is the cost in MCr for airframe hulls
		Hpva is the volume in m^3 for airframe hulls
		
	Hsa = Mv * Mvm * 100
	Hsaof = Mv * 100
	where	Hsa is the hull surface area in m^2 
		Mv is the hull material volume from the Hull Size table
		Mvm is the MV modifier from the Hull Form & Configuration table
		Hsaof is the hull surface area in m^2 for open frame hulls

	Hl = L * Lm
	where	Hl is the hull length in meters
		L is the length of a spherical hull form the Hull Size table
		Lm is the length modifier from the Hull Form * Config table


Interior Structure:

	Isv = (Mv * Mvm * Gmax) / Thm
	where	Isv is the interior structure volume in m^3
		Mv is the hull material volume from the Hull Size table
		Mvm is the MV modifier from the Hull Form & Configuration table
		Gmax is the maximum allowable accelleration in Gs
		Thm is the toughness of the selelected hull material

	Ism = Isv * Mhm
	where 	Isv is the interior structure mass in tonnes
		Mhm is the mass of the selected hull material

	Isc = Isv * Phm
	where	Isc is the interior structure cost in MCr
		Phm is the price of the selected hull material


The total available interior volume of a hull is given on the Hull Size
table.  The volume of the hull and the internal structure are subtracted from
the available interior volume (both the hull and the interior structure take
up space inside the vehicle).  The mass of the hull and the interior structure
are added to the total mass of the vehicle.  The cost of the hull and the
interior structure are added to the cost of the vehicle.  The surface area
of the hull plating is the available surface area for mounting weapons,
electronics, and other components that require surface area.  The length of
the hull is used to determine characteristics of certain sensors, defenses,
and weapon systems.


Does this help clear things up?

Guy "Wildstar" Garnett / wildstar@quark.qrc.com