Starship Armor

[lightsenshi]

Hi! I'm currently in the process of designing a small (200 ton) starship for my group to use. I am considering adding armor to the starship, but the armor rules are confusing. Or more precisely, the only starship given with armor contradicts the build rules.

HELP!!

 

[R_Kane]

If I remember correctly (I don't have books on hand) what I did was calculate starship armor like this:

1)Determine what armor rating you want
2)add 1 to the rating desired
3)multiply the result by the Armor Factor on the table at the very beginning of the starship design section

Example: The Armor Factor is 25 and you desire an armor rating of 5 : (5+1)*25=150

So, you need to buy (and provide space for) 150 armor units. The cost and space required for each unit depends on the TL.

-Roger

 

[lightsenshi]

That sounds more or less right. However, the only listed ship with armor in the T20 book is the (you guessed it) System Defense Boat. This 200 ton spacecraft has an AR of 14 and allocates 15 tons to armor, which at TL14 translates to 15 units. Which is significantly less than the generation rules state.

Either the ship is broken or the armor rules need to be clarified. (at least for me!)

 

[R_Kane]

There are a number of errors in the Standard Designs for spacecraft, so it doesn't surprise me that Armor would be in error as well...
unfortunate, since me, you and many others look to the Designs as a guide to designing our own craft. I haven't looked at it extensively, but, did you check the errata file...perhaps this clarifies things...

-Roger

 

[lightsenshi]

I did and there is nothing about starship armor in the errata that I found.

 

[GBoyett]

Originally posted by R_Kane:
If I remember correctly (I don't have books on hand) what I did was calculate starship armor like this:

1)Determine what armor rating you want
2)add 1 to the rating desired
3)multiply the result by the Armor Factor on the table at the very beginning of the starship design section

Example: The Armor Factor is 25 and you desire an armor rating of 5 : (5+1)*25=150

So, you need to buy (and provide space for) 150 armor units. The cost and space required for each unit depends on the TL.

-Roger

Does your formula take into account the tech of the armor, mainly the volume per unit?

I actually developed a long formula for determining the armor tonnage

</font><blockquote>code:</font><hr /><pre style="font-size:x-small; font-family: monospace;">((2*U) + (R - 1)*U) * AF = Armour Tonnage
/\ /\
1st Remaining
Rating Ratings


U = Tons/Unit for a particular Tech Level
R = Armour Rating
AF = Armour Factor of the hull</pre>[/QUOTE]

 

[GBoyett]

Originally posted by R_Kane:
There are a number of errors in the Standard Designs for spacecraft, so it doesn't surprise me that Armor would be in error as well...
unfortunate, since me, you and many others look to the Designs as a guide to designing our own craft. I haven't looked at it extensively, but, did you check the errata file...perhaps this clarifies things...

-Roger

I know Hunter mentioned one or two issues with the Mercenary Cruiser and other vessels with small craft.

 

[lightsenshi]

It looks to me like the armor rating is determined like this:

(desired AR + 1) * (ship tonnage/100) = units of armor required

 

[GBoyett]

Originally posted by lightsenshi:
It looks to me like the armor rating is determined like this:

(desired AR + 1) * (ship tonnage/100) = units of armor required

Where does the Armour Tech Level come into play in the formula?

 

[Tom Schoene]

Originally posted by George Boyett:
Where does the Armour Tech Level come into play in the formula?

The size and cost of an "armor unit" varies with tech level.

 

[lightsenshi]

Originally posted by George Boyett:
</font><blockquote>quote:</font><hr />Originally posted by lightsenshi:
It looks to me like the armor rating is determined like this:

(desired AR + 1) * (ship tonnage/100) = units of armor required

Where does the Armour Tech Level come into play in the formula?</font>[/QUOTE]You would then multiply the number of units by tech level modifier.

 

[Commonman]

Reminds me of the Nuclear Weapons message board at the Oak Ridge National Labs.

 

[snrdg082102]

Evening all,

I like the suggested methods for determining Armor USP Rating posted and will probably use both to see which one I like best. However, I still have a need to see if I can understand the examples in THB on p268. The following is how I interpret the write up for the Standard Hull Armor rules:

1. Dispersed Structure (Hull USP 7) may not be
armored.

2. Manufactured hulls, with exception of
dispersed structures, may never have an Armor
USP Rating greater than the ship TL.

3. All manufuactured hulls without additional
armor has an Armor USP Rating 0.

4. Planetoid hulls have a base AR USP of 3 and
can have a maximum Armor USP Rating of ship
TL + 3.

5. Buffered Planetoid hulls have a base AR USP of
6 and can have a maximum Aromr USP Rating of
ship TL + 6.

At least the above points is what I got out of the write up. Is what I wrote near the mark?

From the write up under the heading of Armor USP Rating:

AR USP 0 is the basic hull

To increase Armor USP Rating from 0 to USP 1, or the first layer of armor, a ship must install "TWICE" as many armor units as the armor factor listed in the table on p259 for the hull size and TL of the armor.

Where is the TL factor found?

Example 1: A TL12, 200-ton ship adding armor to move from Aromr USP Rating 0 to 1 must install 8 units of armor.

How is the number of 8 armor units derived?

By using first layer rule of twice the armor factor and the table on p259 gives a 200-ton Armor Factor of 2, I get 2(Twice from the write up) *2AF = 4. Or do they mean 2AF+(2AF*2)=2AF+4=6. Finally ,a third interpretation of the rule is 2*(2AF*2[TL weight?])=2*4AF=8.

Adding additonal armor to the hull, a ship need only allocate an amount of space equal to the armor armor factor specified for the hull size and TL of the armor per +1 improvement in the ship's Armor USP Rating.

Again, Where is the the TL factor found?

Example 2: The same TL12, 200-ton ship could improve its Armor USP Rating to a maximum of 12 (limited by its TL) after installing and additional 44 units of armor (for a total of 52 units).

From the above description I think this is how the 44 armor units is derived. To go from Armor USP Rating 1 to 12 is 11 steps.
(Design Armor USP Rating 12 - Armor USP Rating 1=11)*(2AF*2)=11*4=44.

So basically this is how I think the Armor USP Rule works:

Armor USP 0 to 1 = 2[Twice from write up]*(xAF] from p259]*2[from TL write up p268]).
To determine the Armor USP Rating for any other value up to the ship TL:

(Design Armor USP Rating - Armor USP Rating 1)*(2AF*2[TL write up p268)=# armor units needed.

Total Armor Units = Armor USP Rating 1 units + Design Armor USP Rating units.

I think I may be partially right, but I have a feeling that I am totally out to lunch. Edited 12/22/02 0931 PST

 

[Allensh]

Tha answer seems to be right out of High Guard, Book 5 for the original system.

HULL ARMOR TABLE:

Percent 7-9 10-11 12-13 14-15
pf ship 4+4a 3+3a 2+2a 1+a

Formula indicates percentage of ship required for armor (a is desired armor factor) Cost is MCr 0.3 per ton.

Working this formula, I came up with 8 tons for a 200-ton ship at TL 12. So perhaps this works? I'm not sure, might need to be checked out.

Allen

 

[princelian]

I took the "twice as many armor units" phrase to imply that an AR0 hull requires "one times as many armor units" as indicated on the table on p259. This being because even an "unarmored" starship is, in fact, pretty heavily armored, as the vehicles-against-starships [-5 dice] and people-against-starships [-10 dice] damage adjustments imply.

Hence, (AR+1) x (tons/100) x (TL modifier). If you want AR=0, it's (tons/100) x (TL modifier).

I could be wrong, but that's probably how I'll run it.

Allen, is your excerpt from HG supposed to read:

HULL ARMOR TABLE:

Tech Level 7-9 10-11 12-13 14-15
% of ship 4+4a 3+3a 2+2a 1+a

That's what I remember from the good ol' days, and if you look at this table, you'll see that a HG 0-armored hull still takes 1-4% of the available tonnage, dependent upon tech level.

The moral of the story? You really want a TL15 ship. No, scratch that, you really want a TL16 ship. No, scratch that....well, you get the idea.

 

[archhealer]

For the TL factor for ar mor, I actually just used the same TL factor from the Vehicle design sequence. It seems to work out more or less fine. Though, it does make for some DAMN bulky armor at low to medium TLs.

 

[Gruffty]

We've had an extensive discussion on T20 starship armor. Didn't we just go through all of this here 'cos I couldn't understand the armor rules, as well?

 

[Gruffty]

Problem is, I went and posted it in the wrong place.....fat lot of use I am...

 

[Allensh]

Originally posted by princelian:
IAllen, is your excerpt from HG supposed to read:

HULL ARMOR TABLE:

Tech Level 7-9 10-11 12-13 14-15
% of ship 4+4a 3+3a 2+2a 1+a

That's what I remember from the good ol' days, and if you look at this table, you'll see that a HG 0-armored hull still takes 1-4% of the available tonnage, dependent upon tech level.

The moral of the story? You really want a TL15 ship. No, scratch that, you really want a TL16 ship. No, scratch that....well, you get the idea.

Yep. I asked Michael Taylor over on another board about this and he said that in the 200 ton ship example, the example is wrong, it should be 4 armor units (which weigh 8 tons) not 8. This keeps the system consistent with High Guard which as I recall from the playtest was the goal wherever possible. Thus, I shall be using that when I build ships.

I might add that a Armor 0 ship still has a hull and the lower tech levels that hull will be pretty thick even if it provides no actual benefit in combat. That's how I rationalize it at least

Allen

 

[shadowdragon]

the way I read it, the error is in the description of whats being calculated. The author of the design sequence in T20 combined weight and units. The example should read "For example, a TL12 200ton ship with an armor USP factor of 1 must install 4 units of armor, which takes up 8dTons."

an Armor factoring of 2 (200 dTon ship)
Double AF for AR 1 (2*2=4)
Mass multiplier for TL12=2
total of 8 Dtons for 4 units armor


so an equation that might work would be:
((armor factoring)+(armor factoring*desired AR))*TL Modifier= dTons of armor to be subtracted from total dTonnage

((armor factoring)+(armor factoring*desired AR))=# of armor units only

so for a TL12 ship with AR12:
(2+(2*12)=26 units armor,
26*(TL12 modifier of 2)= 52 dTons mass


Armor factoring is listed on pg:259 in the Drives and Armor table. TL modifier is listed on pg:268 in the armor decription text.