Military Ground Vehicles of Your Nation [NO MECHS] Mk.V

[Registug]

Might have to spam telegrams at RB for that.

As long as we don't get some big debate about a topic we're still quite a ways off from page 500.

[Oaledonia]

big debate about a topic

What's the best tan....

Nah

[Anemos Major]

I'll clarify that the total capacity of the tank is 8. The 8 includes the driver, gunners, a medic and an engineer, whose duties could be subsumed by the driver. The two rear cannons are not actually cannons, but more like automatic guns. The side cannons are mounted on the frame itself, and can only turn in a limited angle. The main cannon is the one used most. The side cannon (and back cannons for that matter) is not designed to be used as the main cannon. This means that 8 is the absolute limit of how many people can go into the tank; it is comfortable at 6. The medic is present in anticipation of injured civilians or tank crew.

Rear cannons are superfluous though - if an enemy's gotten behind your tank, the first priority isn't to enter a protracted engagement with them, but to displace. In any event, if you place a commander's machine-gun on top of your turret, you'll have a decent enough weapon that can actually rotate 360 degrees independently of the turret without having to put machine-guns on top of where your engine or storage bay should be (depending on how you end up laying out your tank). You don't need two rear cannons. As for the two 'side cannons' the Russians had two additional forward automatic grenade launcher turrets on the first iteration of the BMPT, but got rid of them on the Terminator 2/BMPT-72; there just isn't much practical use for two smaller turrets of some sort when the benefits they provide can just be provided on the main turret. Look at it this way - you have your main gun on your turret, you'll have a co-axial weapon of some sort that can be anything up to a 20mm autocannon, and modern remote weapon stations (in lieu of the commander's machine gun) can house anything up to an autocannon or an automatic grenade launcher. What can two bulky, constraining, crew-increasing sponson (side) guns do that a tank can't already do with their current crew complement of 3/4 and weapons that are all housed on the turret, where they should be? If you're really desperate for additional firepower at the expense of armour integrity and crew safety, you can always do what the Slovakians did and put autocannons on the side of your turret. No additional crew required, though I wouldn't recommend it.

Fig.A: What the Slovakians did.

With the engineers and the medics, there's no sense in stuffing them into the tank - if anything, by forcing the tank to carry two additional personnel while retaining a reasonable combat weight and dimensions, you need to decrease the thickness of your protection, thus increasing the potential for casualties and damage to your tank. Pretty much all militaries in the world today don't put their medics and their engineers in their tanks for a reason; there's really not much an engineer or a medic can do when they're stationed inside a burning vehicle, or a vehicle being shot at, with limited access to equipment in the middle of a battlefield facing a task so serious you'd need specialist personnel to handle it (i.e. something you can't just patch up with first aid). Which is why most tanks only carry the crewmen they need for combat purposes, and the specialist medical or engineering personnel get their own specialist vehicles which they can use to respond to battlefield emergencies in force, with the equipment they need. It works much better, with the added bonus that you need fewer medics and engineers, who're expensive to train and replace.

Fig.B: A specialist engineering vehicle (Trojan).

Essentially, you don't need additional side-mounted guns, or rear-mounted guns, or a specialist medic and engineer on-board a main battle tank. The roles the former two could potentially played are covered much more efficiently by turret based options, and the latter two are slightly useless in that whatever role their expensive presence could play inside a tank is sorely mitigated by the fact that they'd be under fire, prone to casualties and damage and stuck in the same vehicle as the personnel they're supposed to be saving; under battlefield conditions, a rudimentary knowledge of first aid is about all the people in the tank need to know, with anything above that requiring specialist assistance with specialist vehicles, and off the battlefield tank crewmen perform basic maintenance on their tanks in most militaries already. If you really want, you can do what the Israelis did with the Merkava family and put the engine up front with an ammunition bay at the back of the tank which can be converted into space for casualties or other troops who need shelter in an emergency, but there's no need to do anything more comprehensive than that on a battle tank. Even if it's an infantry tank - I still don't see why having a 105-125mm gun and soldiers in the same vehicle is a particularly good idea.

Fig.C: The Merkava's rear compartment in its usual ammunition carrying iteration.

[Anemos Major]

Fofanov mentions that the rubber flaps are meant to be HEAT pre-detonators - which might explain why the Russians chose not to use them and the Ukrainians did (differing opinions concerning the threat posed by HEAT warheads).

Mind you, it might just be them trying to avoid replicating the silhouette of the T-80 family

Hmm.

My notion that the flaps are for RCS reduction comes from KMDB's description of the Oplot. Also, their sudden appearance on this T-72 covered in Nakidka. Granted they could still be a protective measure there, but then why only on that T-72...?

_{Or they could do both.}

Probably both - at least, this thinks so. (Only referring to one of the comments made under the T-80UK's turret entry, not the other, somewhat questionable assertions made here)

As for the latter point, they've definitely been stressing signature reduction and its appearance alongside Nakidka is no coincidence (they've been pairing Nakidka and Relikt in a lot of their recent press releases, so their intent is probably to release a new T-72 variant to the forces, followed by a T-90, equipped with some sort of signature reduction scheme) - this is meant to be a field upgrade for what're essentially second line forces. They're probably bringing back the skirts in an effort to make the hitherto mothballed T-72s a viable option for combat as they increase their force presence over to the East, but the continued Russian presence in the Caucasus republics is also probably a decent enough reason for them to invest in some form of rudimentary protection that covers a notorious 'blind-spot' in post T-80 Russian frontal tank protection, which the flaps sort of are. Bit of both?

[New Vihenia]

Might have to spam telegrams at RB for that.

As long as we don't get some big debate about a topic we're still quite a ways off from page 500.

How about tank gun design ?

[Anemos Major]

Might have to spam telegrams at RB for that.

As long as we don't get some big debate about a topic we're still quite a ways off from page 500.

How about tank gun design ?

Mmm...

E: Got this one.

Multiple-gunned signature-reduced casemate tanks are a viable and desirable option for combat in a high-intensity, asset-saturated NS ground combat environment. Discuss.

[Gallia-]

You forgot speed is armour.

[Anemos Major]

You forgot speed is armour.

I'm just posing the question, not coming to any personal conclusions.

[Oaledonia]

I'm making a striker unit for my Lafayette, should I place the Ctiv station on a witch's head, or on the shoulder?

[Gallia-]

I'm making a striker unit for my Lafayette, should I place the Ctiv station on a witch's head, or on the shoulder?

It should be a hat.

[Oaledonia]

I'm making a striker unit for my Lafayette, should I place the Ctiv station on a witch's head, or on the shoulder?

It should be a hat.

Like the AMX 56 girl?

[Anemos Major]

I'm making a striker unit for my Lafayette, should I place the Ctiv station on a witch's head, or on the shoulder?

Make it a sinister bat-creature.

[Registug]

I'm making a striker unit for my Lafayette, should I place the Ctiv station on a witch's head, or on the shoulder?

It should be a hat.

There was no other answer

[Oaledonia]

I'm making a striker unit for my Lafayette, should I place the Ctiv station on a witch's head, or on the shoulder?

Make it a sinister bat-creature.

Like, spaced armor and all that, or simple like the Sherman?

[Immoren]

How about tank gun design ?

Mmm...

E: Got this one.

Multiple-gunned signature-reduced casemate tanks are a viable and desirable option for combat in a high-intensity, asset-saturated NS ground combat environment. Discuss.

Obviously needs heavy duty VI/AI and then we are go. *nods*

[Oaledonia]

It should be a hat.

There was no other answer

I'll put the commander's copula on the left shoulder.

[Imperializt Russia]

How about tank gun design ?

Mmm...

E: Got this one.

Multiple-gunned signature-reduced casemate tanks are a viable and desirable option for combat in a high-intensity, asset-saturated NS ground combat environment. Discuss.

No.
End discussion.

While I still believe the casemate design has some limited advantages in the early stages of a defensive war in a heavily covered environment, that second gun will help it none.

[Kaledy]

Having two main guns might make for a superior individual tank but an inferior total tank force.

I think that it is unlikely that a second main gun would be worth it.
The tank would need to be bigger to house not only the main gun but also extra ammo, possible crew member and all the armor to keep the protection level the same. The extra weight and size would make the tank less flexible and a bigger target as well.

[The Kievan People]

Mmm...

E: Got this one.

Multiple-gunned signature-reduced casemate tanks are a viable and desirable option for combat in a high-intensity, asset-saturated NS ground combat environment. Discuss.

(Image)

Rebuttal!

If you are willing to forgo an armored turret, a remote gun is clearly the superior option. Only the remote gun can achieve a true hull down position with all vital areas concealed, and it retains the benefits of a turret (a clear advantage in close combat).

[Viritica]

(just listing MBTs here)

For a while the Merchant Empire made use of Leopard 2 tanks and heavily upgraded Patton M60 tanks known as Knights. Now, however, a program is underway to develop our own breed of MBT which will be called the Copperhead tank. The overall design for the vehicle is a low to the ground tank with an unmanned turret allowing the crew to remain safe in the hull and an automatic reloading system allowing for a small turret. Copperhead tanks will be able to achieve a top speed of 70 MPH.

[New Vihenia]

Gah... it's more laborious and difficult that what i previously expected.. But then the Rheinmetall handbook on weaponry finally give this result...

This is the pressure vs projectile travel curve for my NS-MBT70...like which now i call as "Edelweiss"
158mm Tank gun pressure curve of mine

The curve is for High Explosive shell weighs 25 Kg with 9Kg of propellant. It yields maximum pressure of 2375.6 Bar (237.56 MPa) With muzzle velocity of 832.18 m/s. Characteristic efficiency of the gun is 28% calculated right after propellant burnout.

One peculiar aspect of the calculation that i note is the very sharp drop of pressure across the entire length of the barrel. At the end of barrel (4.74 m of length) The pressure is calculated to be zero (more like -5 bar but that's not making any sense to me)

I wonder if that is acceptable or looks believable characteristics of low pressure gun.

For comparison, this is another curve that i calculated for real world 20mm RH-202 cannon for Marder

RH-202 Autocannon


One thing i noticed after doing all of those calculations are.. It seems predicting gun barrel weight by pressure curve may not be possible as feature of my spreadsheet because if i change calculation parameters like say... weight of the propellant.. It would yield different value on where the maximum pressure occur within the gun.

It will have to be determined "manually" by first calculating maximum pressure then size the gun appropriately. The calculation method is also not covering chamber pressure..but rather the pressure that occured within the base of the projectile, adding more difficulty to the calculations of the whole gun tube mass.

Nonetheless it seems work pretty fine in predicting muzzle velocity.

Another thing is.. The gun may have different ballistic curve for different type of round, even if they use same type of propellant.

Eventually perhaps.. a gun may need to have a spreadsheet of its own.

UPDATE.

Apparently calculating breech pressure from maximum pressure inflicted to the projectile seems possible. The breech pressure for my 158mm gun is calculated to be 4481 Bar with pressure at base of the projectile at propellant burnout of 3693 Bar

New Ballistic curve for the 158mm gun..

The Curve

This time using 30 Kg of HE shell with 12 kg of charge.. clearly autoloader is needed which is yes my tank will provide. The muzzle velocity is computed to be 894.3 m/s I think it's a reasonable value. Muzzle exit pressure is 1100 Bar. Nonetheless i do not know what kind of effect it would have to muzzle flash or other stuff like recoil.

Well thoughts are welcome.

[Imperializt Russia]

How do these stats compare to howitzer shells and performance?

[New Vihenia]

How do these stats compare to howitzer shells and performance?

According to this
Internal Ballistic performance for some guns

Very similar. Perhaps you can say that my 158mm tank gun is basically a howitzer gun in direct firing mode. My gun however compared to the 155 mm gun there are less efficient, but having higher muzzle velocity and higher maximum pressure.

[Imperializt Russia]

How do these stats compare to howitzer shells and performance?

According to this
Internal Ballistic performance for some guns

Very similar. Perhaps you can say that my 158mm tank gun is basically a howitzer gun in direct firing mode. My gun however compared to the 155 mm gun there are less efficient, but having higher muzzle velocity and higher maximum pressure.

I'm not familiar with some of those terms. What do eta and zeta refer to, and what is the X_e term?
Also, the muzzle velocity for the 155 gun seems very low, though between 105 and 155 the shell weight rises abruptly and the charge weight does not seem to rise to match, despite similar pressures.

[New Vihenia]

I'm not familiar with some of those terms. What do eta and zeta refer to, and what is the X_e term?
Also, the muzzle velocity for the 155 gun seems very low, though between 105 and 155 the shell weight rises abruptly and the charge weight does not seem to rise to match, despite similar pressures.

Oh sorry i should mentioned them earlier. Hmm

Eta here refers to pressure ratio between average and maximum pressure of the gun.
Zeta refers to characteristic coefficient of the gun .
Xe here is the projectile travel, the length travelled by the projectile inside the gun barrel (Not including the chamber length)

Regarding to the 155mm gun..Well unfortunately i can't really offer any explanation Though.. because i do not know the ballistic curve for it.