Military Ground Vehicles of Your Nation [NO MECHS] Tranche 7

[Spirit of Hope]

How can I calculate the maximum speed of a tracked AFV?

The easy way is to compare your power to weight ratio to existing AFV's to get an idea of your speed, and then be logical about the results. Your AFV probably isn't going to be running around at 100km/h.

[The Akasha Colony]

Trolltastic?

To clarify, the inputs I used for this calculator were as follows:

• 1200mm lenght
• 30mm diameter
• 55mm frustum length
• 6 mm frustum diameter
• 17500 density
• 1.9 km/s for impact velocity

Material type is tungsten.

Not the best with math, so if the results seem wanky than it's probably to do with my difficulty with advanced math equations.

The problem is the MV and total muzzle energy are both too high, which the calculator doesn't indicate because it just accepts whatever numbers are punched in rather than actually evaluating whether they're possible.

We are talking about an autoloaded 140mm gun though

It's not a matter of the autoloader, it's a matter of the energy. Accelerating 25 kg to 1.9 km/s is a rather impressive feat, given that the current M256 120 mm gun gets a rod weighing only 10 kg up to only 1,555 m/s. The amount of powder and pressure needed to get a 25 kg rod to 1,900 m/s would be enormous.

[United Marxist Nations]

What about with a lighter round, like a 800/900/1000 mm length? How much lighter would those be?

[The Akasha Colony]

What about with a lighter round, like a 800/900/1000 mm length? How much lighter would those be?

M829A3 is 800 mm and is 10 kg.

How can I calculate the maximum speed of a tracked AFV?

There is no way to calculate it, at least not in a simple formula. It depends on a lot of things, from P:W ratio to how well the tracks/wheels and suspension can handle it, how efficient the transmission is, etc.

[United Marxist Nations]

What about with a lighter round, like a 800/900/1000 mm length? How much lighter would those be?

M829A3 is 800 mm and is 10 kg.

I'm really shit at math (like, seriously, the worst shit at math), so would you be kind enough to give me what the muzzle-velocities for those rounds I asked about to put into the calculator? Pwetty pwease?

[Assorted Sucrose-Based Lifeforms]

Your AFV probably isn't going to be running around at 100km/h.

How sure r u? ( ͡° ͜ʖ ͡°)
http://en.wikipedia.org/wiki/Splittersk ... sPlattform
(I have no idea how it achieves such lulzy speeds with ~15 kWt^-1)

[Krazakistan]

Trolltastic?

To clarify, the inputs I used for this calculator were as follows:

• 1200mm lenght
• 30mm diameter
• 55mm frustum length
• 6 mm frustum diameter
• 17500 density
• 1.9 km/s for impact velocity

Material type is tungsten.

Not the best with math, so if the results seem wanky than it's probably to do with my difficulty with advanced math equations.

The problem is the MV and total muzzle energy are both too high, which the calculator doesn't indicate because it just accepts whatever numbers are punched in rather than actually evaluating whether they're possible.

We are talking about an autoloaded 140mm gun though

It's not a matter of the autoloader, it's a matter of the energy. Accelerating 25 kg to 1.9 km/s is a rather impressive feat, given that the current M256 120 mm gun gets a rod weighing only 10 kg up to only 1,555 m/s. The amount of powder and pressure needed to get a 25 kg rod to 1,900 m/s would be enormous.

Ah. I see where the issues and the point that Kiev brought up is.

So how do 140mm guns go about achieving high penetration levels?

[Spirit of Hope]

Your AFV probably isn't going to be running around at 100km/h.

How sure r u? ( ͡° ͜ʖ ͡°)
http://en.wikipedia.org/wiki/Splittersk ... sPlattform
(I have no idea how it achieves such lulzy speeds with ~15 kWt^-1)

Ok, let me rephrase then, you aren't likely to be getting 100 km/h off road. And even if you physically could, it qualifies as a bad idea to try.

[The Kievan People]

https://dl.dropboxusercontent.com/u/617 ... 20v1.1.rar

[The Akasha Colony]

M829A3 is 800 mm and is 10 kg.

I'm really shit at math (like, seriously, the worst shit at math), so would you be kind enough to give me what the muzzle-velocities for those rounds I asked about to put into the calculator? Pwetty pwease?

M829A3's MV is 1,555 m/s. It's actually lower than M829A2 and M829A1's MV, but M829A3 uses a heavier penetrator. IIRC, it makes it somewhat less vulnerable to ERA, which is what the US has been trying to defeat for a while (each new M829 defeats current ERA, then the Russians make a new one).

Your AFV probably isn't going to be running around at 100km/h.

How sure r u? ( ͡° ͜ʖ ͡°)
http://en.wikipedia.org/wiki/Splittersk ... sPlattform
(I have no idea how it achieves such lulzy speeds with ~15 kWt^-1)

P:W has the most pronounced effect on acceleration (which is also very important). On a flat, low-drag surface, it wouldn't be unusual for such a vehicle to reach such a speed (although it may suffer from excessive wear), but it would take a while.

Ah. I see where the issues and the point that Kiev brought up is.

So how do 140mm guns go about achieving high penetration levels?

You were on the right path: it's by using larger KEPs and having a higher muzzle energy. Just not that high, and probably with bigger, heavier penetrators rather than faster ones.

[United Marxist Nations]

I'm really shit at math (like, seriously, the worst shit at math), so would you be kind enough to give me what the muzzle-velocities for those rounds I asked about to put into the calculator? Pwetty pwease?

M829A3's MV is 1,555 m/s. It's actually lower than M829A2 and M829A1's MV, but M829A3 uses a heavier penetrator. IIRC, it makes it somewhat less vulnerable to ERA, which is what the US has been trying to defeat for a while (each new M829 defeats current ERA, then the Russians make a new one).

How sure r u? ( ͡° ͜ʖ ͡°)
http://en.wikipedia.org/wiki/Splittersk ... sPlattform
(I have no idea how it achieves such lulzy speeds with ~15 kWt^-1)

P:W has the most pronounced effect on acceleration (which is also very important). On a flat, low-drag surface, it wouldn't be unusual for such a vehicle to reach such a speed (although it may suffer from excessive wear), but it would take a while.

Ah. I see where the issues and the point that Kiev brought up is.

So how do 140mm guns go about achieving high penetration levels?

You were on the right path: it's by using larger KEPs and having a higher muzzle energy. Just not that high, and probably with bigger, heavier penetrators rather than faster ones.

Danke.

[Assorted Sucrose-Based Lifeforms]

How sure r u? ( ͡° ͜ʖ ͡°)
http://en.wikipedia.org/wiki/Splittersk ... sPlattform
(I have no idea how it achieves such lulzy speeds with ~15 kWt^-1)

Ok, let me rephrase then, you aren't likely to be getting 100 km/h off road. And even if you physically could, it qualifies as a bad idea to try.

Hold on, Wiki page briefly mentions a wheeled variant, the speed might be for the wheeled version.

edit: Aye- http://www.military-today.com/apc/sep_8x8.htm

edit 2: O shit, look what Googling pictures of it lead me to- viewtopic.php?p=17282994&sid=5a3bd1badd228411f2f6880019e995e7#p17282994

[The Akasha Colony]

Ok, let me rephrase then, you aren't likely to be getting 100 km/h off road. And even if you physically could, it qualifies as a bad idea to try.

Hold on, Wiki page briefly mentions a wheeled variant, the speed might be for the wheeled version.

edit: Aye- http://www.military-today.com/apc/sep_8x8.htm

It does, although even for an 8x8 it's a bit fast given that the MOWAG Piranha and its variants normally do around 100 km/h.

[Krazakistan]

I'm really shit at math (like, seriously, the worst shit at math), so would you be kind enough to give me what the muzzle-velocities for those rounds I asked about to put into the calculator? Pwetty pwease?

M829A3's MV is 1,555 m/s. It's actually lower than M829A2 and M829A1's MV, but M829A3 uses a heavier penetrator. IIRC, it makes it somewhat less vulnerable to ERA, which is what the US has been trying to defeat for a while (each new M829 defeats current ERA, then the Russians make a new one).

How sure r u? ( ͡° ͜ʖ ͡°)
http://en.wikipedia.org/wiki/Splittersk ... sPlattform
(I have no idea how it achieves such lulzy speeds with ~15 kWt^-1)

P:W has the most pronounced effect on acceleration (which is also very important). On a flat, low-drag surface, it wouldn't be unusual for such a vehicle to reach such a speed (although it may suffer from excessive wear), but it would take a while.

Ah. I see where the issues and the point that Kiev brought up is.

So how do 140mm guns go about achieving high penetration levels?

You were on the right path: it's by using larger KEPs and having a higher muzzle energy. Just not that high, and probably with bigger, heavier penetrators rather than faster ones.

I was a bit confused for second there. Thank you for the clarification.

I assume by bigger means a thicker diameter, correct?

[The Akasha Colony]

I was a bit confused for second there. Thank you for the clarification.

I assume by bigger means a thicker diameter, correct?

Both a thicker diameter and a longer rod. A longer L:D ratio is desirable but as Kyiv said tops out at 30:1. Beyond that, increasing the length requires increasing the diameter proportionately.

[Rich and Corporations]

800mm KEP length isn't terrible tbf.

That's how long my APFSDS round is and I manage to get roughly ~800mm of penetration with it.

Even conceptual 140 mm guns had round lengths close to a meter and a half, IIRC (this does not mean the KEP is that length). And this is before the decades of ammunition development that has created larger KEPs for existing weapons to maintain lethality. It kind of defeats the point of going to a big 140 mm L/55 gun as "proposed."

KEPs with more girth are less likely to snap when penetrating.

I'm usually somewhat reluctant to accept really trolltastic KEP figures (over 1,000 mm), since there's much more to it than length (although length helps and is one of the easiest things to increase, provided you don't have any limitations like autoloader or chamber length).

a long round allows for a long primer, reducing temperature variability in ignition

A longer L:D ratio is desirable but as Kyiv said tops out at 30:1.

it depends on what you're trying to penetrate

[Krazakistan]

I was a bit confused for second there. Thank you for the clarification.

I assume by bigger means a thicker diameter, correct?

Both a thicker diameter and a longer rod. A longer L:D ratio is desirable but as Kyiv said tops out at 30:1. Beyond that, increasing the length requires increasing the diameter proportionately.

Alright, thank you.

[Assorted Sucrose-Based Lifeforms]

Hold on, Wiki page briefly mentions a wheeled variant, the speed might be for the wheeled version.

edit: Aye- http://www.military-today.com/apc/sep_8x8.htm

It does, although even for an 8x8 it's a bit fast given that the MOWAG Piranha and its variants normally do around 100 km/h.

Yeh, more digging reveals this- http://www.army-technology.com/projects/sep/
It says "The top speeds for the wheeled and tracked variants of the SEP vehicle are 100km/h and 85km/h respectively."

[Imperializt Russia]

Yes. A 1200mm rod would weigh about 25kg. Which is crazy.

We are talking about a rod for an autoloaded 140mm gun though

Which, on its own, weighs more than an entire 120mm gun cartridge.
It weighs two and a half times as much as high-end M829 family KEPs.

[Doppio Giudici]

Does anyone know how good the "Dolly Parton" or the "Super Dolly Parton" armors are?

[Imperializt Russia]

I'm really shit at math (like, seriously, the worst shit at math), so would you be kind enough to give me what the muzzle-velocities for those rounds I asked about to put into the calculator? Pwetty pwease?

M829A3's MV is 1,555 m/s. It's actually lower than M829A2 and M829A1's MV, but M829A3 uses a heavier penetrator. IIRC, it makes it somewhat less vulnerable to ERA, which is what the US has been trying to defeat for a while (each new M829 defeats current ERA, then the Russians make a new one).

Since it's significantly easier to modify existing guns for lower-velocity and weightier penetrators (I assume) to defeat ERA - would going the other way have any effect? If we could push significantly closer to 2km/s, might it be possible to "defeat" the ERA by penetrating deeply enough before it detonates to resist much of its effect?

[Orussia]

Freaking huge.

(Image)
(Image)

T-55 for reference.

You haven't been browsing otvaga2004.ru... have you?

No, I actually haven't seen that prototype before. Kinda funny, though, that they turned out so similar.

[Lydenburg]

I really shouldn't be posting here until I finish that long damn storefront, but I can't help but comment on the choice of the MGS. Why?

First off, a storefront can be finished?
And also, You ate starting a storefront!

Will i be able to buy fully fleshed up South African tech there?

Yes.

South African tech on steroids. Lots of minibus taxis and lulzy biltong.

[Radicchio]

Yes.

South African tech on steroids. Lots of minibus taxis and lulzy biltong.

Well then get to work! LOL

[The Kievan People]

Since it's significantly easier to modify existing guns for lower-velocity and weightier penetrators (I assume) to defeat ERA - would going the other way have any effect? If we could push significantly closer to 2km/s, might it be possible to "defeat" the ERA by penetrating deeply enough before it detonates to resist much of its effect?

Very high speed (over 2,000m/s) is supposed to reduce the effectiveness of ERA. But there aren't many details available.