Ok, on p620 it lists starship armor under "Construction Materials", presumably for comparison's sake. Now it says that it is "TLx10". That's nice. What is "TLx10" exactly? Is that per armor "layer", or as the chart suggests, per cm of armor? If the former, then that conflicts with p336 where it says that (plate at least) =TL. Or is this because of some x10 conversion for personal to ship combat modifier (which if so should really be specified there)? If the latter, that would mean that each "layer" of armor is only 1mm thick, since it would take 10 to equal 1 cm. So which is it? Or is it something else entirely? I've checked the latest errata and it had nothing to say on this (so far).
Starship armor values
- Thread starter Murdoc
- Start date
esampson
SOC-13
My guess is that that is a poorly written shorthand.
It appears that the difference between personal weapon combat and starship weapon combat is or was suppose to be a factor of 10. By this I mean that if a T1 Laser shoots a person it is suppose to do 10 dice of damage, not 1 die. Similarly if you unload on a starship with an OMFG-15 that does 20 dice of damage in personal combat it would only do 2 dice to a starship.
So what that poorly written shorthand is trying to say is that you should treat any ship armor as 10x its normal value. If it is a single layer of plate (the most common situation) then that is TL x 10. If it is is 3 layers of charged then it would be TL x 60.
As for how thick a 'layer' of starship armor is, that's a little more tricky. In theory a ship could have 26 layers of armor, without staging effects. A 100 Dton sphere would be 1350 m3 which works out to a radius of 6.85m. 6.85/26 coincidentally happens to be very close to .26m. Because I'm approximating I would round that to .25m or 25cm, before staging effects.
It appears that the difference between personal weapon combat and starship weapon combat is or was suppose to be a factor of 10. By this I mean that if a T1 Laser shoots a person it is suppose to do 10 dice of damage, not 1 die. Similarly if you unload on a starship with an OMFG-15 that does 20 dice of damage in personal combat it would only do 2 dice to a starship.
So what that poorly written shorthand is trying to say is that you should treat any ship armor as 10x its normal value. If it is a single layer of plate (the most common situation) then that is TL x 10. If it is is 3 layers of charged then it would be TL x 60.
As for how thick a 'layer' of starship armor is, that's a little more tricky. In theory a ship could have 26 layers of armor, without staging effects. A 100 Dton sphere would be 1350 m3 which works out to a radius of 6.85m. 6.85/26 coincidentally happens to be very close to .26m. Because I'm approximating I would round that to .25m or 25cm, before staging effects.
Yeah, that is what my guess was too, which led me to doing the same sort of calculations you did actually:
Hmm, that's not what I got at all. Firstly I got 14.77m radius. Also, you can't just divide the radius by the number of armor layers because a percent of volume would be a different radius (which kind of makes the concept sketchy, but that's what I was going with anyway). So I worked with 10 layers of additional* armor for a round figure, which works out to 40% of the hull volume. Then I figured out the volume of the remaining 60% so I could get a new radius, and then from those figure out the radius (or depth) of the armor by subtracting one from the other. Now I'm not 100% certain of my math but what I got works out to 222 cm of depth for that much armor (actually pretty close to your 0.26m, which, since my radius is almost twice the one you used, shows how different the layer thicknesses can be depending on your assumptions).
Working out an equivalent armor value of TL 8 armor (TLx10=80 x10 layers = 800 AV) in TL 8 steel (1cm=70 AV) so 800/70 = 11.43cm of steel for the same armor value as 222cm of starship armor. So am I getting something wrong? *(Yes, I'm not counting the first level of armor because there is no way to count it in volume.)
PS: "OMFG-15" :file_21: I'm so using that!
esampson
SOC-13
Not sure how you got that. The volume of a sphere is 4/3PiR3, so the radius based on a given volume should be ((.75V)/Pi)1/3.
Yes, the thickness of a layer changes with each additional layer. I'm sure this is because trying to calculate how much volume would be lost on an irregular shape each time you add 25cm of armor would be a nightmare, even though that's the more realistic way of making it work.
Your technique of using 10 layers is exactly the same as what I'm doing. The only difference is the number of layers we are using.
If we use different layers we will come up with different values because those the thickness of each layer increases. Since you're averaging fewer layers they'll have a lower value.
That's what I was pondering as well when I first did my math, but then I realized something; the 25cm of hull on the starship is almost certainly not solid steel. If it was the weight would be horrendous, so it is almost certainly some kind of alloy or construction technique that gives the equivalent protection but at a lower weight than the steel (but at greater bulk, which isn't as big an issue for a starship). For reasons of making things simpler we don't worry about the 'real weight' of components of starships, but I'm sure that the Imperial engineers probably do.
I could almost buy that (even though the difference is a factor of 20), except for the reason for it. Volume in T5 is much more important than mass. Mass isn't mentioned anywhere, and doesn't affect a thing. A trader with half of its volume in cargo space experiences no difference whether that hold is empty, or full of solid uranium bricks (radiation aside, of course). On the other hand, if you expand a ship's volume outward, you change its performance for jump, maneuver, and even power plant. If you change it inward, then you have less room to put things in, like cargo, passengers, weapons, crew, swimming pools, animal trophies, etc., and that is very important to the ship's owners. So then the question becomes, why would they care about making the ship's mass less when it so greatly affects precious volume? They wouldn't; it is just an arbitrary way of play-balancing some ship's combat performance, one that wasn't correlated properly with the Construction Materials rules apparently.
I know I could whine about MT's way making more sense, but I know that wouldn't change anything. I just wanted to make sure that my math was right, and point out the discrepancy.
esampson
SOC-13
Yes. I understand that by the rules of starship design that's all true. My assumption (and I freely admit it is an assumption and the rules could be different in your Traveller universe) is that it is a game convention and not necessarily indicative of 'real life' in the Traveller universe. If you were to load up a trader's cargo bay with superdense bricks I would probably rule that it does in fact have an adverse effect on the ship's performance.
Think of it this way, if Traveller focused on weight rather than volume the computations for designing up a ship would be far more complicated. You would pretty much have to design a deckplan (rather than using the more abstract method of doling out 'tons') so you could see how many interior walls you had, how much flooring, etc. After totaling up your walls, flooring, and bulkheads you would multiply all 3 by different numbers (since they would probably have different densities) and add those numbers together. You would then add in the weight for all your engines, power plants, computers, consoles, and furnishings. Let's remember that the atmosphere actually has a not inconsiderable mass as well.
That's an awful lot more work.
Now, every time you take on or unload cargo you need to find the weight of your cargo. This itself isn't too bad. You just take the volume and multiply it by a given density depending on the cargo. Add that result to your 'dry weight' and now you can calculate the performance of your ship.
Except you can't.
We didn't take on fuel yet. I left that out of the 'dry weight' calculations because it will change, a lot. If you're in an Far Trader and you make a Jump-2 then your weight changes by 40 tons, not an insignificant amount, so you'll have to recalculate the performance of your ship pre-jump and post-jump. Also you might want to calculate the performance post-jump-1 for those shorter trips where you use less fuel.
Wow, that's a lot of work. Would some people like to do that level of detail? Probably. In fact I wouldn't mind it myself. Of course I would almost certainly use a spreadsheet to help me with that constantly adjusting performance which back when Traveller was first created wasn't really an option for most people (and even if it was it would have been horribly inconvenient because there were no tablets or laptops and computers weren't really designed with portability in mind).
So instead the game design relies on the rough correlation between volume and weight and uses a far simpler method for calculating performance, but just because that's how the 'in game' method handles the situation that doesn't mean that's how something actually happens in the Traveller universe. After all, you don't really assume that Traveller guns have an infinite amount of ammunition, do you?
Instead ammunition becomes an issue when the GM feels it is appropriate, and usually to enhance the story. Likewise the mass of cargo should only be important in circumstance where it enhances the story.
Of course that is just my interpretation for why ship design uses volume. I like it because it adheres a bit more to hard scifi conventions and helps to explain things like why a starship's hull is much thicker than its armor value would indicate without actually generating any more work. You are absolutely free to interpret that mass truly is unimportant in how ships operate in your Traveller universe.
T5 has those rules in common with MGT. It's how both "universes" were set up to operate, game wise.
Yeah, I get that there is always a balance to be struck between realism and playability, and that is why we employ levels of abstraction. I certainly don't advocate going into the level of detail you give as an example there, but on the other hand, MT managed to use weight in both its craft design and performance without getting too complicated, and thus didn't leave its players wondering why and having to come up with explanations for it themselves. Maybe it is just a matter of preference, but for me this level of abstraction is not worth the sacrifice in realism; it was just unnecessary, IMO.
I don't like the lack of ammunition rules either. When I play Star Wars, sure, that's space fantasy, but not in Traveller (or most games for that matter). The problem with leaving it up to the GM is that if done poorly, or too much, at best it can erode the verisimilitude, at worst the players can feel picked on because they know it's the GM's decision. That is why we have the rules in the first place, to make things more fair and balanced (if they're made well), otherwise the GM could just make everything up and not use any rules at all (as in "I shoot him." "You miss." "Why?" "Bad luck/Crosswind/Your arm hurts." etc.). Like I said, could just be a matter of preference as to where to draw that balance.
I don't think that that quite counts as hard SF unless you have some real engineering principles in there. It might make it seem that way to you, but not to me.
Yeah, I didn't like it there either.HG_B said:
