Re: [FT] Weapons Design System Concept - some numbers

Charles Taylor wrote:

>Ok, some further thoughtson this:
>
>Oerjan's 'total cost' (TC from now on) formula is:
>
>TC =
>Cost of system (MASS x COST/MASS)
>+ cost of fraction of engines used to push system (0.2 x MASS x 2 for
>Thrust 4 human engines)
>+ cost of fraction of FTL drive used for system (0.1 x MASS x 2)
>+ cost of fraction of hull that holds system + drive fractions ([1 +
0.2
>+ 0.1] x MASS x 1)
>
>where MASS is mass of system, COST/MASS is cost per mass of system.

Um, no. The engines don't use 30% (ie. 20% + 10%) of the Mass of the 
*system*; they use 30% of the Mass of the *system + engines*. That's a 
pretty important difference - your "0.2 x MASS" and "0.1 x MASS" in the 
engine terms above should in fact be 0.2*1/(1-0.2-0.1)*MASS and 
0.1*1/(1-0.2-0.1)*MASS respectively (ie., 0.29*MASS and 0.14*MASS), and
the 
hull cost is MASS*1/(1-0.2-0.1) = MASS*1.43

The full TC formula for an FTL-capable ship is

(System MASS)*(1 [basic hull] + Cm + THRUST/20/(1-0.1-THRUST/20)*(Ct+1)
+ 
0.1/(1-0.1-THRUST/20)*(2+1))

where Cm is COST/MASS, Ct is cost per mass of main drive, and THRUST is
the 
thrust value of the main drive.

For a thrust-4 Human-drive FTL-capable ship we get THRUST = 4, Ct = 2,
so 
the formula becomes

TC = (System MASS)*(1 + Cm + 4/20/(1-0.1-4/20)*3+0.1/(1-0.1-4/20)*3) =

= (System MASS)*(1 + Cm + 0.2/0.7*3 + 0.1/0.7*3) =

= (System MASS)*(Cm + 2.3)

Similarly for a thrust-4 Kra'Vak ship (Ct = 3) it becomes

TC = (System MASS)*(Cm + 2.6)

Now re-calculate all your values based on these updated formulae <g>

>Note: a lot of these involve fractional TC values - all fractions
should
>be kept until the final mass and cost values are determined, in which
>case they should be rounded up to the next highest integer value (if in
>doubt - over-price).

Yep.

>2) Reduce number of fire arcs
>
>At the moment, this only applied to Class-1 weapons (B-1s and K-1s),
>Class-2 beam batteries, stinger nodes, and placed marker weapons (SMs,
>PBLs) - B-1s, B-2s, K-1s, and Stingers are all too small to be further
>reduced. So we can probably do without this one ATM.

In Cinematic, a 6-arc weapon is worth somewhere between one-third and 
one-half more than a 3-arc one as long as the range is greater than
12mu. 
If the range is 12mu or less, the 6-arc weapon can be worth as much as 
double that of the 3-arc weapon.

The decrease from 3 to 1 arc depends heavily on the weapon's range and
on 
the ship's thrust, but again an increase of 50-100% is appropriate. The 
faster the ship is and the longer range the weapon has, the less worth
are 
extra fire arcs.

However, if you play Vector none of the above applies!

>3) Add PDS capability.
>
>Oerjan values this as +4 to TC for all-arc PDS capability, in which
case
>the cost of 'PDS as B-1' is +2 1/3 to TC, and the cost of 'PDS as K-1'
>is +1 2/3 to TC.

I'd estimate that 'PDS as B1' (exactly 1/2 of full PDS) is +2 TC, while 
'PDS as K-1' (1/3 of full PDS) is +1.33. (It is an addition to the TC,
not 
to the cost of the system alone - thus no extra 1/3!)

>Digression - IIRC somewhere it is stated that B-1s and K-1s used as PDS
>require an active fire control - but I can't find this in either Fleet
>Book!

That's in MT. I suggest that this rule be ignored though :-/

[hardening snipped - the figures look similar to what I arrived at long 
ago, but I no longer have those files]

Later,

Oerjan
oerjan.ohlson@telia.com

"Life is like a sewer.
  What you get out of it, depends on what you put into it."