Since there were some questions about FF&S starship designs in recent issues
of the TML, I thought the following might help. This is a complete and
detailed, step-by-step guide to building FF&S hulls.
OK, let's get unconfused on this hull 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. 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
whereHpv 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 selected 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
whereHpm 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
whereHpc 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
whereHsa 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
whereHl 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
whereIsv 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
whereIsc 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?
[email removed]
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Science-Fiction Adventure
In the Far Future