NS Military Realism Consultation Thread Type 08

[Gallia-]

How effective would 65mm of armor sloped at 68 degrees from vertical be in WWII?

65 / cos(68)

Anyway it would probably just deflect or shatter depending on how much face hardening you bothered with.

[Roski]

How effective would 65mm of armor sloped at 68 degrees from vertical be in WWII?

65 / cos(68)

Anyway it would probably just deflect or shatter depending on how much face hardening you bothered with.

Wait

Is that seriously how you figure that out?

[Yukonastan]

65 / cos(68)

Anyway it would probably just deflect or shatter depending on how much face hardening you bothered with.

Wait

Is that seriously how you figure that out?

Yes. It's called trigonometry.

[Roski]

Wait

Is that seriously how you figure that out?

Yes. It's called trigonometry.

I know what trigonometry is.
I didn't know trigonometry was used to figure out the effectivness of armour.

[Atomic Utopia]

MAD in space would involve relativistic kill vehicles.

And unless you have tons of antimatter just lying around those would be horribly expensive.

[Atomic Utopia]

Yes. It's called trigonometry.

I know what trigonometry is.
I didn't know trigonometry was used to figure out the effectivness of armour.

Effectiveness no as there is a host of other factors that make your armor what it is. Thickness though...

[Roski]

I know what trigonometry is.
I didn't know trigonometry was used to figure out the effectivness of armour.

Effectiveness no as there is a host of other factors that make your armor what it is. Thickness though...

Apparently you do the thickness over the cosine of the angle of the armour to determine it


Unless I completely underthought what that meant.

[Gallia-]

Yes. It's called trigonometry.

I know what trigonometry is.
I didn't know trigonometry was used to figure out the effectivness of armour.

What is a tank but a triangle?

MAD in space would involve relativistic kill vehicles.

And unless you have tons of antimatter just lying around those would be horribly expensive.

Water is more valuable than antimatter for propulsion purposes.

[Roski]

I know what trigonometry is.
I didn't know trigonometry was used to figure out the effectivness of armour.

What is a tank but a triangle?

Uh.

Do I have the ability to phone a friend?

[Atomic Utopia]

And unless you have tons of antimatter just lying around those would be horribly expensive.

Water is more valuable than antimatter for propulsion purposes.

Assuming you have the immense energy reserves to accelerate something to relativistic velocities you will have at least the ability to obtain water from comets as that takes one hell of a lot less energy than accelerating anything to even 1% c.

I would also like to inform you that antimatter is outrageously energy intensive stuff to make, and you would need it for your hypothetical weapon.

[Mitheldalond]

65 / cos(68)

Anyway it would probably just deflect or shatter depending on how much face hardening you bothered with.

Wait

Is that seriously how you figure that out?

In theory, yes. In practice, it's much more complicated. That equation assumes a perfectly horizontal, directly head on shot that isn't likely to happen all that often. It doesn't take into account shell normalization or trajectory, or a million other factors.

I know that the line of sight thickness would be about 173mm, which would mean that a Tiger firing APCR from 100m away would struggle to penetrate it (171mm penetration). In fact, that would make it immune to pretty much anything short of the 8.8cm KwK 43 L/71 and the QF 17 pounder except at suicidally close range.

Basically, the math implies that facing this in a Tiger would be almost exactly like facing a Tiger in a 75mm Sherman. Which seemed kind of ridiculous since this tank is supposed to be my equivalent to the Sherman or T-34 (though I'm basing it on the Australian Sentinel). Hence my wondering how effective it would actually be.

[Yukonastan]

Effectiveness no as there is a host of other factors that make your armor what it is. Thickness though...

Apparently you do the thickness over the cosine of the angle of the armour to determine it


Unless I completely underthought what that meant.

Thickness of armor is your adjacent leg. Angle is your slope. Calculate hypotenuse for LOS armor thickness.

[Gallia-]

Wait

Is that seriously how you figure that out?

In theory, yes. In practice, it's much more complicated. That equation assumes a perfectly horizontal, directly head on shot that isn't likely to happen all that often. It doesn't take into account shell normalization or trajectory, or a million other factors.

I know that the line of sight thickness would be about 173mm, which would mean that a Tiger firing APCR from 100m away would struggle to penetrate it (171mm penetration). In fact, that would make it immune to pretty much anything short of the 8.8cm KwK 43 L/71 and the QF 17 pounder except at suicidally close range.

Basically, the math implies that facing this in a Tiger would be almost exactly like facing a Tiger in a 75mm Sherman. Which seemed kind of ridiculous since this tank is supposed to be my equivalent to the Sherman or T-34 (though I'm basing it on the Australian Sentinel). Hence my wondering how effective it would actually be.

60' was considered optimum for armour plate to cause shattering or some other form of disruption of the projectile for steel armour.

Why do you think all conventional tanks had 60' slope practically everywhere?

Anyway 2mm of armour wont stop a shell, it'll break the armour most likely. Perhaps cause a catastrophic failure of the weld or something, it depends on what kind of steel is used and a bunch of other dumb shit I don't really care to know. Principal methods of stopping conventional AP/HE full bore shells were through shattering or deflection, which is going to be the main reason you slope your armour in WW2.

[Laywenrania]

65 / cos(68)

Anyway it would probably just deflect or shatter depending on how much face hardening you bothered with.

Wait

Is that seriously how you figure that out?

That way you calculate LoS Thickness.
LoS (Line of Sight) Thickness does NOT equals effective armour for any WW2 ammo besides HEAT (and HEAT would likely not ignite at that angle).

The effective armour depends also on your Hardness, type of armour (cast, face hardened, etc), the diametr of the projectile fired at it, the type of ammo fired at it (Basically APCR is way less effective against sloped armour) etc.

Assuming 240 BHN RHA armour, firing with a 88mm APCBC on it would be around 290mm of effective armour with a shell hitting at 90°.

Also at 68° most ww2 shells would probably bounce at most ranges.

In theory, yes. In practice, it's much more complicated. That equation assumes a perfectly horizontal, directly head on shot that isn't likely to happen all that often. It doesn't take into account shell normalization or trajectory, or a million other factors.

I know that the line of sight thickness would be about 173mm, which would mean that a Tiger firing APCR from 100m away would struggle to penetrate it (171mm penetration). In fact, that would make it immune to pretty much anything short of the 8.8cm KwK 43 L/71 and the QF 17 pounder except at suicidally close range.

Basically, the math implies that facing this in a Tiger would be almost exactly like facing a Tiger in a 75mm Sherman. Which seemed kind of ridiculous since this tank is supposed to be my equivalent to the Sherman or T-34 (though I'm basing it on the Australian Sentinel). Hence my wondering how effective it would actually be.

At any practical combat range the trajectory plays not big of a role and is most likely in the less then 1° range. At least if they don't fire with stubby howitzers at you.

Also shell normalisation is a factor but: ww2 shells don't dig into the armour, they usually "slide away" (get pushed by the physical forces), meaning that sloped armour is ususally way more effective then the LoS-Thickness. Soviet APBC tends to be better against sloped armour, APCR tends to be awful against sloped armour.

I guess with 65mm at 68° you will have first: A rather high weight of your tank (not anymore in the T-34 range - your glacis is about twice as heavy - and you have to compensate the additional frontal weight somehow or your tank will be front heavy and have problems) and second either cramped interior or a rather long (and then even heavier) tank.

[Gallia-]

60' is probably better just for the mass savings really.

[Mitheldalond]

It weighs 32 metric tonnes, so it is heavier than a T-34 and about on par with later versions of the Sherman. I'm basing it on the Sentinel AC III/IV, which already had an upper glacis sloped at 66 degrees. The crew was only four (no bow gunner) to make room for more 25 pounder ammo in the AC III, so there shouldn't really be issues with it being cramped.

[Shuggy555]

(questions about orbital insanity)
Are expense and the possibility of SAM's a reason to not have ODSTs at least until one controls more than one star system, and also the reason no space weapons have been deployed yet?

Weapons in space have not been deployed yet for one very simple reason, a lack of a reason to do so. There is no advantage as far as a nuclear deterrent goes as ground based missiles are much cheaper. There is also a dearth of targets in space, making it useless to deploy space weapons to fight other nations !!!IN SPACE!!!

The only reason one would want to use weapons in space is if there are valid (big) targets in space as well. This does not mean that you need to control more than one solar system, far from it. In fact we could only control a colony on mars or the moon, and if it is very economically or militarily important and the enemy is sufficiently aggressive, there will be large scale weapons in space within the decade that that occurs in, but not before that occurs.

You may then ask what such a space weapons system would look like or be used as. There is extensive discussion on the matter on the atomic rockets website, and I would advise you visit there, but none the less I would like to state what I think it would look like, and to put it simply it would not be near as romantic as the movies show it as.

In space there 1. would be no "conventional war"; 2. M.A.D., for the most part, would be eliminated (assuming you can survive without any co-occupied planets); 3. the focus would be more shifted upon covertly attacking the enemy, rather than overtly attacking the enemy; 4. and signals intelligence would be of paramount importance (more than it is today).

The first one is for two reasons, the cost of conventional weapons in comparison to the destructive power, and the lack of any real damage said weapons can do beyond the immediate in a space environment. Current costs per kilo for a launch into LEO are in the thousands of USD, even with the cheapest launch methods theoretically possible with today's technology (nuclear bomb propelled spacecraft), it would be well within the tens of dollars, much more than even transporting stuff by air, and this is referring to civilian spacecraft, not the missiles you are designing. This means that even minor weight savings mean HUGE reductions in costs, not to mention the size of the rocket needed to transport the stuff there, thus nuclear weapons present the unique and great incentive of an extremely low weight for the "punch" they pack. You would also want nuclear weapons, or at least have less inhibitions against their use because space, unlike earth, is a very radioactive environment and tends not to have much of an environment to begin with, so a few nukes will not change much as far as your mission requirements for permanent bases go.

Expansion into space would also eliminate the efficacy of M.A.D. as there would both be extreme warning times in any realistic environment due to the distances in space, but also the ability to (cheaply) intercept any missile headed your way assuming your location is not on the same planet as the missile's point of origin. With current spacecraft it is estimated that it would take nearly a month with a multi-billion dollar Orion (nuke propelled spacecraft) to reach mars. While this no doubt could be cut down significantly by making such a thing a missile it still highlights the non-trivial time it takes for things to travel in space. It is also advisable to note that the delta-V requirements for a spacecraft to go to another planet are huge, whereas to shoot it down is orders of magnitude less, unlike with ICBMs on earth. It would also be good to not that there is no, and I mean no, stealth in space. This also leads us wonderfully into the next section, why conventional war would become less frequent.

With the extensive ability of to defend against enemy attack, and the huge cost of enemy attack, you may wonder than what war would look like, and I will tell you very simply; not like what we see today. War would be more focused to the covert than it is now, the goal would at once become to defeat the enemy sensor network and fund terrorists freedom fighters to attack and harass the enemy as it would be nearly useless to attempt to bury the enemy in missiles as they, for significantly less money, could merely destroy your missiles. This goes doubly so for any manned spacecraft as they would be the size of your original spacecraft squared at least due to the need for the ability to mount a return trip. The only way to effectively conduct a strike would to know how the enemy anti missile missiles work, and sabotage them shortly before they fire in defence. The best way to defend against these enemies would be SIGINT, and guess what section is next.

To say that SIGINT is an important part of warfare today would be an huge understatement, and to say it would be even more important is also an understatement. In this theoretical universe, having the ability to know when the enemy is moving militarily important things around ect. would allow for the only kind of viable attack in this universe, the covert destruction of enemy equipment. Conversely the enemy would need the ability to obfuscate that movement. Because of all warfare now relying upon these two things and them alone you would see a vast increase in SIGINT expenditures. Likewise should the enemy be able to identify the attacker they can immediately quash them with retaliative ease due to them being within their heavily controlled territory.

Thus, we will not see war as we know it today in space, moreover some weird combination of state funded terror- I mean freedom fighters, and overwhelming force where necessary, resulting in relatively short wars with large amounts intelligence agency and special operations supporting them.

EDIT: I may not be able to post a decent response for a while as I am working on a research paper for school, and school takes precedent to NS

I agree with most of your analysis but i do disagree on some points, stealth in space for instance can exist, for one if a spacecraft release's a radar stealthed missile via springs that has been cooled to extremely low temperatures and a simular dummy payload is launched in the other direction, then you wont be able to detect it until it reach's its intended target or actively changes its orbital path for its not emitting anything and is shaped against radar. which by then could be to late to react. and i also dis agree with the premiss of being able to cheaply intercept any launched missiles as well, for this ignores decoys and counter measures. if i have a bomb bus that releases hundreds of decays and a handful of real bombs just after it releases and detonates a nuke near by, the flash and radiation from the nuke will shield the bomb bus from sensors long enough to deploy both bombs and decoys so that the target cannot determine which are real or not. making it far more costly to intercept.

And then there are things like lasers and bomb pumped weaponry that change the dynamics as well.

[Imperializt Russia]

Wait

Is that seriously how you figure that out?

In theory, yes. In practice, it's much more complicated. That equation assumes a perfectly horizontal, directly head on shot that isn't likely to happen all that often. It doesn't take into account shell normalization or trajectory, or a million other factors.

I know that the line of sight thickness would be about 173mm, which would mean that a Tiger firing APCR from 100m away would struggle to penetrate it (171mm penetration). In fact, that would make it immune to pretty much anything short of the 8.8cm KwK 43 L/71 and the QF 17 pounder except at suicidally close range.

Basically, the math implies that facing this in a Tiger would be almost exactly like facing a Tiger in a 75mm Sherman. Which seemed kind of ridiculous since this tank is supposed to be my equivalent to the Sherman or T-34 (though I'm basing it on the Australian Sentinel). Hence my wondering how effective it would actually be.

171+/- margin of error*

Penetration not binary.
There would be a number of shots where this plate may be fully penetrated. In any case, the plate is substantially weakened by a significant partial penetration and may fail under follow-up fire.

[Purpelia]

for one if a spacecraft release's a radar stealthed missile via springs that has been cooled to extremely low temperatures and a simular dummy payload is launched in the other direction, then you wont be able to detect it until it reach's its intended target or actively changes its orbital path for its not emitting anything and is shaped against radar.

And where would the heat go? If you are cooling the missile down you have to transfer the heat to something. And what ever that something is will heat up. So I'll see your ship become hotter before you launch.

Plus, how did your ship even get into firing range without getting spotted?

and i also dis agree with the premiss of being able to cheaply intercept any launched missiles as well, for this ignores decoys and counter measures.

The cheapness is relative. As in, it's cheaper for me to fire N+K interceptors at your missile than it is for your missile to carry N decoys. And as long as this holds true I can just build those extra K missiles knowing I am getting my moneys worth.

if i have a bomb bus that releases hundreds of decays and a handful of real bombs just after it releases and detonates a nuke near by, the flash and radiation from the nuke will shield the bomb bus from sensors long enough to deploy both bombs and decoys so that the target cannot determine which are real or not. making it far more costly to intercept.

On the other hand the costs you have to pay to build and deliver said bomb buss are such that I can afford to deploy plenty of various countermeasures to destroy you at the same price.

[Husseinarti]

And unless you have tons of antimatter just lying around those would be horribly expensive.

The cost to rid space of those Red bastards on Mars has no limit.

[Yukonastan]

The cost to rid space of those Red bastards on Mars has no limit.

Welcome back.

[United Marxist Nations]

Another question regarding the RP I am in. I am currently Japan in the l8 1700's; it's alt history, so I am acquiring flintlock muskets. Would it still be advisable to issue musket troops Ashigaru armors? Also, is there any downside to having heavy cavalry remain in armor well into the 1800's? Would having a separate corps of melee infantry for internal rebellion for a while still a good idea?

[Rich and Corporations]

How effective would 65mm of armor sloped at 68 degrees from vertical be in WWII?

65 / cos(68)

Anyway it would probably just deflect or shatter depending on how much face hardening you bothered with.

you forgot to add a factor for slippage. that slippage does not exist for modern armor as long rods dig in.

171+/- margin of error*

Penetration not binary.
There would be a number of shots where this plate may be fully penetrated. In any case, the plate is substantially weakened by a significant partial penetration and may fail under follow-up fire.

APCR is more vulnerable to slippage because I guess the momentum of the penetration is not uniform?


you guys have learned well

[Laiten]

Another question regarding the RP I am in. I am currently Japan in the l8 1700's; it's alt history, so I am acquiring flintlock muskets. Would it still be advisable to issue musket troops Ashigaru armors? Also, is there any downside to having heavy cavalry remain in armor well into the 1800's? Would having a separate corps of melee infantry for internal rebellion for a while still a good idea?

Cuirassiers say hello.

Ditch the armour for the infantry.

[Muscatatuck]

65 / cos(68)

Anyway it would probably just deflect or shatter depending on how much face hardening you bothered with.

you forgot to add a factor for slippage. that slippage does not exist for modern armor as long rods dig in.

171+/- margin of error*

Penetration not binary.
There would be a number of shots where this plate may be fully penetrated. In any case, the plate is substantially weakened by a significant partial penetration and may fail under follow-up fire.

APCR is more vulnerable to slippage because I guess the momentum of the penetration is not uniform?


you guys have learned well

is the apcr more prone due tot he softer outer covering smashing down into a larger lifting surface, sorta like a ramp?