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T20 Armor Calculation - Help!


I've tried repeatedly to figure out how to calculate cost and tonnage for T20 armor on ships and I'm just not getting it right. I want to create a formula for excel.

Can someone lay it out step by step?

Your assistance will be much apprectiated.

Each ship tonnage has an armour factor - this is the number of armour units that are needed for each armour point. The first point is double.

So, with AF 4 (4 units per point), AR 1 costs 8 units, AF2 12 units, and so on.

Each unit is multipled by the cost of it at whatever tech level (plus the base). Also it takes up a tonnage equal to the units times the tons at that tech level.

So, AR 4 for 6 points at Tech 13:

TL 13 is 2 tons per unit, KCr300 per unit (plus a one-off base of KCR200).

AF 4 for AR 6 = 28 units (8+4+4+4+4+4).

28 units takes 56 dtons, and KCr(28*300)+200 = MCr8.6.

So in Excel you would need the following parts:

Number of units:
(AR+1)*AF -- (the AR+1 takes care of the double first point cost).


(((AR+1)*AF)*cost)+cost base

If you use lookups for them on a table the formulas will look something like this... (anything in capitals is a variabel you have too supply).For this you need to put the DU/AF table on page 259, and the armour details on page 268 in a column).

=(AR+1)*lookup(SHIP TONNAGE,du/af table co-ords,AF collumn)

=UNITS RESULT*lookup(ARMOUR TL,armour table co-ords,displacement column)

=lookup(ARMOUR TL,armour table co-ords,cost base column)+(UNITS RESULT*lookup(ARMOUR TL,armour table co-ords,cost column))

The table co-ords will be the cell range of the row you are using as a lookup not including any title you put up there (e.g. C6:C18). The xxx column will be the range of the row you want to get the result from in the same table (e.g. E6:E18).

A formula for lookup would look like:

How's that? Any use?

Oh, and the standard deisgns in the book have wildly varying values for the armour weights and costs, so use the ones in the downloadable eratta.

Originally posted by Shane Mclean:
How's that? Any use?

Helped set me straight at least, silly brain was just computing cost based on tonnage not units :rolleyes: so mucho thanks from this gearhead (who obviously had a screw loose reading that bit the first time).

Just one little typo in the above reply, the base cost factor is Kcr300 not Kcr200 (unless I missed that in an errata).
Originally posted by far-trader:
Just one little typo in the above reply, the base cost factor is Kcr300 not Kcr200 (unless I missed that in an errata).
AH well, I was doing it in a hurry between bouts of housework. Of course, this means I now have to face the fact that I'm fallible. Oh, the blow to my self-image! :eek:


My understanding is that T20 armor is calaculated in the same % as High Guard - so TL-14+ armor is 1+a% of the ship, a being the desired armor factor. So to get AF 10, you need to devote 11% of the ship's tonnage to armor.

For TL-12-13 armor the formula is 2+2a, where a is the desired AF. So with a TL-12 ship to get AF 10 you need to devote 22% of the ship.

Is this correct? I worked out that's what it was. T20 SDS is simply a more complex way of producing HG-like designs (which is fine by me).