**T20 ship Armor Cost Example**
**T20, page 268:** For example a TL 12, 200-ton ship with an Armor USP rating of 1 must have installed 8 units of armor.

**Armor Units required, Tonnage & Cost**
**Armor Factoring:** For a 200-ton ship = 2.

**Tonnage:** TL 12 armor = 2 tons per armor unit.

**Cost:** MCr 0.3 + MCr 0.2 per armor unit installed.

To achieve Armor USP of 1 (first layer of armor):

**Armor Units Required:** 2 armor factorings * 2 armor factorings = 4 armor units required.

**Tonnage:** 4 armor units * 2 tons of mass per armor unit = 8

**tons**. *8

*tons* is the

*tonnage space used in the hull* of

*4 *units* of armor*.*

**Cost:** MCr 0.3 + MCr 0.2 per armor unit installed.

Thus:

4

**armor units** requiring

**8 tons** of space in the hull = Armor USP of 1 for a 200-ton ship.

Let's do the costings

.

*Version A:*
MCr 0.3 + (MCr 0.2 * number of armor units installed)

=

MCr 0.3 + (MCr 0.2 *

**4 armor units**)

=

MCr 0.3 + (MCr 0.8)

=

MCr 1.1 for

**4 armor units** requiring

**8 tons** of space in the hull = Armor USP of 1 for a 200-ton ship.

*Version B:*
MCr 0.3 + MCr 0.2 * number of armor units installed

=

MCr 0.5 *

**4 armor units**
=

MCr 2 for

**4 armor units** requiring

**8 tons** of space in the hull = Armor USP of 1 for a 200-ton ship.

If you work the cost calculations out based on

*the tonnage of the armor units, i.e. 8 tons of armor units* you get:

*Version C:*
MCr 0.3 + (MCr 0.2 * tons of armor units installed)

=

MCr 0.3 + (MCr 0.2 *

**8 tons of armor units**)

=

MCr 0.3 + (MCr 1.6)

=

MCr 1.9 for

**8 tons of armor units** = Armor USP of 1 for a 200-ton ship.

*Version D:*
MCr 0.3 + MCr 0.2 * tons of armor units installed

=

MCr 0.5 *

**8 tons of armor units**
=

MCr 4 for

**8 tons of armor units** = Armor USP of 1 for a 200-ton ship.

I'm sure the problem I've been experiencing is from the use of the word "units" near the end of the sentence in the example. I'm certain the sentence should read something like this:

*For example a TL 12, 200-ton ship with an Armor USP rating of 1 must have installed 4 units of armor (requiring 8 tons of space in the hull) and costs MCr *<insert figure calculated using your preferred method!>.

Right - that's my problem sorted! I'm now certain there's a bug in the example in the book, I know how to work out the armor for my ship and I'm going to use the cheaper armor costing calculation

.

It would be nice (although not essential) if we could get definitive answers from Hunter or MJD on the issues we've highlighted here.

BTW, I'm not critising T20 here - it's a big book with lots of stuff in it and a helluva lotta work went into putting it together. I'm pleased I bought it

; I just want to make sure my ship stats are OK.