Rules Only: Traveller Armor and Damage into RL units

[Nathan Brazil]

OK then. On one of my Don Quixote conversion projects to and from Traveller, I would like to convert Traveller armor ratings (vehicles and spacecraft armors) into actual cm (or inches for the metricly impaired) thickness of steel or other material in RL. Damage can be kg of TNT, joules of energy, gigawatts or whatever. But I want RL units. I am not asking for the best, just what is out there. So far, I have:

• Striker
• Traveller Hero
• TNE's Fire, Fusion and Steel.
• Guns, Guns, Guns 2.0 (3.0 not so good in this regard)

Were there others in the other versions of Traveller?
Does GURPS Traveller or GT:IW have something along those lines in their Core Rules or more generic Supplements?

 

[Rupert]

GURPS Traveller has Vehicles as the underlying 'engine' - all the modules, etc. were designed with it, the weights of armour come from it, and so on. I think GT:IW uses a system derived from GT's.

Striker has an explicit conversion rate of thickness of steel to armour. FF&S does too, and also explicit conversions of energy to damage. GURPS Vehicles likewise.

 

[infojunky]

OK then. On one of my Don Quixote conversion projects to and from Traveller, I would like to convert Traveller armor ratings (vehicles and spacecraft armors) into actual cm (or inches for the metricly impaired) thickness of steel or other material in RL. Damage can be kg of TNT, joules of energy, gigawatts or whatever. But I want RL units. I am not asking for the best, just what is out there. So far, I have:

On that path lies only Maddness....

Durning the TNE period I was seriously looking at the ducting requirements for Life Support....

 

[Badenov]

On that path lies only Maddness....

Durning the TNE period I was seriously looking at the ducting requirements for Life Support....

So I can tell you from RL that the ducting requirements from RL are wildly variable. I had to replace a heat pump once, and told my ducts were too small for the unit that was otherwise appropriate for my house. They had been fine for the previous unit. So ducting is apparently variable based on the vagaries of the life support system as much as the needs of the ship. So yes, this way definitely lies madness.

 

[kilemall]

I’ve done the math for joules of kinetic missile impacts from the missile supplement. Then I extrapolated the bay missiles from that to include two missile build systems plus ew/decoy add ons to explain the bay missile survival against PD.

I worked backwards to identify the power ratings of the standard laser weaponry of Striker I and by extension their battery packs cause I like having hard description of the equipment. Turns out those lasers pretty much align at the starship grade level but breakdown to some fudging at the personal level.

I worked out a shield BD wearers can carry, angling the shield yields potential survival against energy weapons. I also worked out double sized melee weapons BD can use with some ferocious damage kinetic/advanced material options.

Also combat exoskeleton frames based on LBB8 complete with integrated brains running different functions.

One of my faves is the armory book that lists explicit joules for lasers with a damage chart to match. Think the current MgT2 merc gun build book but with more a CT mechanic and house armor/rules. Have to look at the Traveller Plus rules to get the armor.

Crucible Highport: A Traveller Web Site

crucible.cc

This inspired me to do a complete set of Striker armor to do everything from cuirass, knight plate armor and modern Kevlar to rigid battle dress. Course keep in mind I do that hit location thing rather then the generic vest type ratings, with house rules on mobility costs for the rigid stuff.

Plus a range of kinetic gun upgrades prior to gauss based on the caseless/ETC dynamic, and my own ATR/assault gun form factor from TL 6 to TL 12 only rendered obsolete by those TL13 xray lasers.

 

[kilemall]

So I can tell you from RL that the ducting requirements from RL are wildly variable. I had to replace a heat pump once, and told my ducts were too small for the unit that was otherwise appropriate for my house. They had been fine for the previous unit. So ducting is apparently variable based on the vagaries of the life support system as much as the needs of the ship. So yes, this way definitely lies madness.

I extrapolate ducting in starships as being the hidden space of the classic 3x3x1.5 meter design standard. That yields 13.5 cubic meters- just call a dton 14 cubic meters and you have .5 cubic meters to play with.

That yields 37mm or 1.45 inches of ceiling/floor pipe room for air/water/power/control/fuel lines, not counting extra dtons allocated as part of major systems.

I am a maniac about certain quantifications so the world is more ‘real’ and unusual unique aspects come to organically generate out of the process.

But I will shortcut at a moments notice so I can spend more cycles on story rather than hardware. Example, use MgT2 vehicle gen then assign Striker values to it.

 

[Condottiere]

It was the Azhanti deckplans that made me realize that the actual plumbing doesn't have to be conventional.

 

[AnotherDilbert]

OK then. On one of my Don Quixote conversion projects to and from Traveller, I would like to convert Traveller armor ratings (vehicles and spacecraft armors) into actual cm (or inches for the metricly impaired) thickness of steel or other material in RL. Damage can be kg of TNT, joules of energy, gigawatts or whatever. But I want RL units. I am not asking for the best, just what is out there. So far, I have:

• Striker
• Traveller Hero
• TNE's Fire, Fusion and Steel.
• Guns, Guns, Guns 2.0 (3.0 not so good in this regard)

Were there others in the other versions of Traveller?
Does GURPS Traveller or GT:IW have something along those lines in their Core Rules or more generic Supplements?

MT uses the Striker system.

Note that they are not compatible, Striker uses an exponential armour rating and FF&S uses a linear rating, i.e. if you double the thickness of the armour TNE gives double armour rating, but Striker adds +8 to the rating.

You can just as well deduce an armour thickness from the armour volume in CT HG or MgT HG.

They will all disagree...

 

[Nathan Brazil]

On that path lies only Maddness....

<<<<< Have you seen my avatar?

 

[whartung]

Note that they are not compatible, Striker uses an exponential armour rating and FF&S uses a linear rating, i.e. if you double the thickness of the armour TNE gives double armour rating, but Striker adds +8 to the rating.

So, since I don't know the math, is a linear system more appropriate? Does something 4 times as thick (of whatever material) simply ("simply") take 4x more energy to penetrate? That SEEMS intuitive, to a point, but I don't know. I mean, it must be, right? Otherwise every MBT on the planet would have "just one more inch" of armor because of the geometric gain it would provide.

 

[AnotherDilbert]

So, since I don't know the math, is a linear system more appropriate? Does something 4 times as thick (of whatever material) simply ("simply") take 4x more energy to penetrate?

I have no idea.

This source says for cannon:

where B is penetrated armour, V is velocity, P is mass, D is diameter, and K is a constant ≈ 2400.
https://www.tankarchives.ca/2014/10/penetration-equations.html

Note that the numerator is the square root of the muzzle energy, so highly simplified: thickness ≈ √energy, so not linear.

 

[whartung]

Well, that's a linear equation.

If you graph it (say, V vs B), you get nice straight lines.

However, we know that energy (momentum) is not linear, being 1/2 m v ^2.

So, even though the Velocity may increase linearly, and that results in (naively) a linear amount of armor being penetrated, the actual energy is quadratic. None of this accounts for actual material effects, of course, which indeed matter.

 

[McPerth]

On that path lies only Maddness....

I guess that's why he mentions Don Quijote...

 

[kilemall]

So, since I don't know the math, is a linear system more appropriate? Does something 4 times as thick (of whatever material) simply ("simply") take 4x more energy to penetrate? That SEEMS intuitive, to a point, but I don't know. I mean, it must be, right? Otherwise every MBT on the planet would have "just one more inch" of armor because of the geometric gain it would provide.

Here’s a quick and dirty on straight up old school armor penetration against steel. Note it’s not dealing with differences in angled armor or warheads, but good for giving a feel for results. Note that velocity is a major factor along with round size, which is really about mass.

Penetration Equations

A blog about World War II era archive documents, primarily dealing with armoured warfare.

www.tankarchives.ca

 

[atpollard]

High Guard armor is in magical units … (% of ship) … tiny ships are as hard to penetrate as a shell thicker than the entire tiny ship on a large ship.

 

[bookwyrm]

High Guard armor is in magical units … (% of ship) … tiny ships are as hard to penetrate as a shell thicker than the entire tiny ship on a large ship.

No, the armor isn't in magical units (armor that doesn't require a % of the ship), you are using a real % of the ship for armor. Also, small ships have less space for armor than larger ships of 1k dtons+ due to bridge space constraints, and possibly other architectural considerations. I think hull configurations have a bigger impact on armor thickness than just the % of the ship itself, let alone the size of the ship.

One big problem with the OP is that Traveller assumes(?) that futuristic materials are being used for armor that we have to extrapolate/guestimate/hand wave their densities & thickness' in comparison to materials we have and know of in the real world.

And yes, even though it took me awhile, I finally realized that % of ship for armor does seem kind of 'wonky', but I didn't really want to go down the slippery slope (my view point) that the OP and others might be interested in going, and so am happy enough with % of ship for armor.

 

[Badenov]

High Guard armor is in magical units … (% of ship) … tiny ships are as hard to penetrate as a shell thicker than the entire tiny ship on a large ship.

No, the armor isn't in magical units (armor that doesn't require a % of the ship), you are using a real % of the ship for armor. ....

And yes, even though it took me awhile, I finally realized that % of ship for armor does seem kind of 'wonky', but I didn't really want to go down the slippery slope (my view point) that the OP and others might be interested in going, and so am happy enough with % of ship for armor.

This seems like a place to apply Clarke's Third Law: Any sufficiently advanced technology is indistinguishable from magic.

The weapons and armor available at futureTech Levels are sufficiently divorced from physics that it's all what my instructors in tech school referred to as PFM (Pure F-ing Magic, which admittedly they applied to anything more complicated than a transistor).

 

[Dragoner]

So, since I don't know the math, is a linear system more appropriate? Does something 4 times as thick (of whatever material) simply ("simply") take 4x more energy to penetrate? That SEEMS intuitive, to a point, but I don't know. I mean, it must be, right? Otherwise every MBT on the planet would have "just one more inch" of armor because of the geometric gain it would provide.

The energy curve has a steep rise and then plateaus, ohio state used to have some good graphs, it is basic materials science and thermodynamics, with the conservation of momentum (energy). There is armor density, and the projectile burrows through it, where sloped armor is effective because dimensionally it is thicker, however ultimately making projectiles out of dense materials, will defeat similar armor. That is also the old days when most shots impacted the glacis, vs now when there are efp's vs top armor which is thinner.

 

[Rupert]

So, since I don't know the math, is a linear system more appropriate? Does something 4 times as thick (of whatever material) simply ("simply") take 4x more energy to penetrate? That SEEMS intuitive, to a point, but I don't know. I mean, it must be, right? Otherwise every MBT on the planet would have "just one more inch" of armor because of the geometric gain it would provide.

Very roughly speaking, the energy required goes up by the square of thickness (which is why most weapons in FF&S have penetration proportional to the square root of energy - this matches a liner armour value). This is why two layers of armour one right behind the other aren't as good as a single thick one of the same total mass, clever tricks aside.

 

[Rupert]

One big problem with the OP is that Traveller assumes(?) that futuristic materials are being used for armor that we have to extrapolate/guestimate/hand wave their densities & thickness' in comparison to materials we have and know of in the real world.

Striker, FF&S, and Vehicles all give hard numbers, so we know what those assumptions are.