NS Military Realism Consultation Thread #6

[Padnak]

Just to clear it up, I don't use exclusively heavy artillery and while I do posses some it makes up the minority of my overall artillery arsenal

[Zeinbrad]

http://s741.photobucket.com/user/cpkeye ... sort=3&o=0

So I made another ToE. But am losing space on the page.

Anyways,besides it being able to hold five divisions, which I will probably change, anything amiss?

[Allanea]

But without DICTATOR who would buy SUPERAWESOMEMILITARIZEDBAGGER!?

btw are you still colonizing me in TF :3

can we just put the bloody mil-bagger out to pasture

Certainly not until Korva finishes drawing mine.

[San-Silvacian]

tanq

[Korouse]

(Image)

tanq

kool

[Licana]

So basically the speed (to you) is going down a steep road already haulin' ass.

Noep.

The Abrams seemed perfectly content to get up to over 80 km/h on flat ground, even if it stresses the vehicle's drivetrain. Sorry that you seem to think this is some impossible feat, but it really kind of isn't. It's just not a very smart thing to do in most circumstances.

also sand serb tank will be smashed by the legions of superior FAR armour.

[EsToVnIa]

(Image)

tanq

> 6 road wheels

>all the good tanks have 5

smh

[Calla]

Think I posted this in the wrong thread first.

CRULT 2 (WIP)
Combat Recon, Ultra Light Tank 2
(Image)

Crew: 2

Armor:
7039 Aluminum hull and turret, 8-35mm thick with 6mm perforated Ultra High Hardness steel plates. Resistant to 14.5mm class HMGs on frontal 135 degree arc. 12.7, 360 degree.

Armament:
20x139mm G-3 Semi-automatic light cannon. Magazine fed from 10 round box magazines. (5 magazines stores in turret, further 10 stored below the turret ring[Possibly more.])
7.62x51mm G-5 GPMG (M240 based). 200 round belt fed. (400 rounds stored in turret, further 600 stored below turret ring)

Weight: ~6700 kg (working on calculating actual weight.)
Length: 3.56m Hull. 4.15m including gun.
Width: 2.31m
Height: 1.79m
Ground Clearance: 400mm
Fording Depth: 700mm
Armament Elevation limits: -12, +51 degrees from horizontal

Top Speed, Road: 115 kph
Top Speed, Off road: 80 kph

Engine: 4.1L Flat 6, 2 stroke turbo diesel, turbocharged. 247 Kw output (345 hp.) Made using Compacted Graphite Iron technology, along with mono-block cylinders and heads, eliminating headgaskets, and allowing higher compression ratios with high boost. Utilizes poppet valves for uniflow exhaust scavenging, increasing efficiency, paired with overhead camshfts tuned for the engine's three operating RPM settings, Idle, half, and full power. The gear driven, screw-type blower is actuated on a clutch mechanism to disengage it once the turbocharger has spooled to take over aspiration.
Transmission: Electric transmission, driving a pair of high torque, liquid cooled, ring motors at the rear sprockets.
Features a battery pack capable of delivering 300 Kw peak power, 23.4 Kw/h capacity.
250L Fuel tank.
Range:
At maximum road speed? Assuming 3.4 Km/L (8 mpg) 850 KM.
Cruising...could go much farther. (I might be reducing fuel tank size as it seems...almost excessive.)
Silent Range: Electric only, ~60 Km cruise. ~10 km at maximum output.
36.7 Kw/T (46.7 HP/T)

Suspension:
Compact dogleg, long travel suspension modules, utilizing coil-over shocks (310mm of travel)
Active front idler, automatic track tensioning.
5 section rubber-band tracks.

Development:
The CRULT was developed as a means for Calla's fast response, light airborne to have some form of armour when deploying to low intensity conflicts. The vehicles small size, light weight, and modest ground pressure enable it to be utilized in locations where few other armoured vehicles can reach, such as much of Calla's own remote, northern mountains. In larger conflicts, it is used in the Recce role, aided by its ability to run silent and cold, running purely off of battery power for up to 30 minutes at a cruise of 60 kph, its noise signature further reduced by the utilization of rubber band tracks vs steel.

The suspension is unique, in being modular, bolt on units, making repairs, and maintenance quite easy. It also features an active front idler, a system designed to keep the track properly tensioned at all times. Especially needed when traveling at high speed, preventing the track from throwing itself due to excess slack that other tracked vehicles are prone to, as their track must be kept slack to accommodate any suspension droop.

Crew comfort was a large concern when developing a tank of this size, and performance capabilities, leading to the intention from the design outset to utilize rubber segment band tracks to reduce vibration transmitted to the vehicle, and reduce running noise inside the vehicle as well. Further attenuating sound and vibration characteristics is the use of a sprayed on, high density, rubberized polyurethane spall liner, that is bonded to the hull, dampening harmonics, acting as a sound barrier, in addition to its primary role of protecting the crew from spalling. The seating is unusual for a tank of any sort, is being suspended not purely for blast attenuation, but also as a secondary suspension to keep the driver and the commander safe, when traveling off road at high speed. The suspension of these seats is active, as are the safety harnesses to keep the occupants in their seat, rather than being freely knocked around inside. The system utilizes the gyroscopic stabilization system of the main gun, for vertical acceleration figures.

However, it is not without its criticisms, such as being armed with an out of date, semi-automatic, magazine fed cannon in 20mm. Many feel that the vehicle should be armed with at least, a 20mm autocannon with dual feed. To be fair though, most other vehicles in a similar weight class, rely on heavy machine guns, or 30 to 40mm grenade launchers. Currently being trialled, are three turrets, armed with a 20mm, a 30mm, and a 35/50mm autocannon respectively. The 50mm autocannon variant offering is currently drawing a good deal of interest, utilizing case telescoped ammunition, smoothbore barrel, unique, split-breech mechanism to keep the receiver length able to fit within the confines of the 1015mm turret ring, and the Fire Control System that works in conjunction with it, enabling its HEMP (High Explosive Multi Purpose) rounds several different time delay fuzing options, from standard airburst, to gated proximity, proximity, and wall breaching. The 50mm offering would give the CRULT much improved capabilities against armor, and infantry, being able to deliver a substantially larger HE payload per shot. But in question is if the reduced amount of ammunition that can be carried, and the additional cost of implementation worth the benefits.

More images of the CRULT in the spoiler:

(Image)
(Image)
(Image)

For visual size reference:
(Image)
(Image)

SUV is a Suzuki Grand Vitara, or Escudo.

IE: I'm working on a 50mm Supershot split-breech revolving cannon, akin to the MK18 40mm Grenade launcher idea, scaled up. Also based on the British "Nut Cracker" guns, of similar design and idea, but intended for high rates of fire as air-craft cannons. This gun I am working on would only have a rate of fire in the 100-120 rpm range, thus eliminating one of the largest problems facing the Nut Cracker idea: having a breech opening before chamber pressure had dropped to safe levels. Also, yes, it would be utilizing a combined Bofors 3P idea fuze, with the 35mm AHEAD Muzzle Velocity measurement/magnetically encoded fuze. Additional complexity, yes, but the idea of the added accuracy, would require fewer shots on target, thus sparing precious ammunition reserves. Smoothbore because, if it is only running two types of ammunition, then you just make both fin stabilized and call it good. Also gives cost savings on the barrel itself (And partly because I was trying to figure out how to rifle the goddamn barrel in sketchup, and that was proving to be a nightmare). Working on the 50mm cause I like the idea of it, and I am curious to know just how much ammunition it could hold, and, or...where the hell it would hold it. Currently thinking it might be limited to a linklessfeed system mounted to the gun itself, offering a five round magazine for APFSDS, and teen or fifteen for the HEFSMP. But again, I won't know until I model it, and try to fit all of this, into a tiny ass tankette, cause I am crazy.

Edit: Also working on redesigning the hull. Narrower and fitting 350-400mm wide tracks, vs the 280mm wide tracks currently employed. Need FV101 like mobility through everything, cause I want it. Might also switch out of the engine, to a "In research" engine design that looks like a Wankel engine on steroids. Minimizing engine size, keeping power output, making the vehicles smaller still, quieter...cause. Stealth Tank.

[Vitaphone Racing]

Think I posted this in the wrong thread first.

CRULT 2 (WIP)
Combat Recon, Ultra Light Tank 2
(Image)

Crew: 2

Armor:
7039 Aluminum hull and turret, 8-35mm thick with 6mm perforated Ultra High Hardness steel plates. Resistant to 14.5mm class HMGs on frontal 135 degree arc. 12.7, 360 degree.

Armament:
20x139mm G-3 Semi-automatic light cannon. Magazine fed from 10 round box magazines. (5 magazines stores in turret, further 10 stored below the turret ring[Possibly more.])
7.62x51mm G-5 GPMG (M240 based). 200 round belt fed. (400 rounds stored in turret, further 600 stored below turret ring)

Weight: ~6700 kg (working on calculating actual weight.)
Length: 3.56m Hull. 4.15m including gun.
Width: 2.31m
Height: 1.79m
Ground Clearance: 400mm
Fording Depth: 700mm
Armament Elevation limits: -12, +51 degrees from horizontal

Top Speed, Road: 115 kph
Top Speed, Off road: 80 kph

Engine: 4.1L Flat 6, 2 stroke turbo diesel, turbocharged. 247 Kw output (345 hp.) Made using Compacted Graphite Iron technology, along with mono-block cylinders and heads, eliminating headgaskets, and allowing higher compression ratios with high boost. Utilizes poppet valves for uniflow exhaust scavenging, increasing efficiency, paired with overhead camshfts tuned for the engine's three operating RPM settings, Idle, half, and full power. The gear driven, screw-type blower is actuated on a clutch mechanism to disengage it once the turbocharger has spooled to take over aspiration.
Transmission: Electric transmission, driving a pair of high torque, liquid cooled, ring motors at the rear sprockets.
Features a battery pack capable of delivering 300 Kw peak power, 23.4 Kw/h capacity.
250L Fuel tank.
Range:
At maximum road speed? Assuming 3.4 Km/L (8 mpg) 850 KM.
Cruising...could go much farther. (I might be reducing fuel tank size as it seems...almost excessive.)
Silent Range: Electric only, ~60 Km cruise. ~10 km at maximum output.
36.7 Kw/T (46.7 HP/T)

Suspension:
Compact dogleg, long travel suspension modules, utilizing coil-over shocks (310mm of travel)
Active front idler, automatic track tensioning.
5 section rubber-band tracks.

Development:
The CRULT was developed as a means for Calla's fast response, light airborne to have some form of armour when deploying to low intensity conflicts. The vehicles small size, light weight, and modest ground pressure enable it to be utilized in locations where few other armoured vehicles can reach, such as much of Calla's own remote, northern mountains. In larger conflicts, it is used in the Recce role, aided by its ability to run silent and cold, running purely off of battery power for up to 30 minutes at a cruise of 60 kph, its noise signature further reduced by the utilization of rubber band tracks vs steel.

The suspension is unique, in being modular, bolt on units, making repairs, and maintenance quite easy. It also features an active front idler, a system designed to keep the track properly tensioned at all times. Especially needed when traveling at high speed, preventing the track from throwing itself due to excess slack that other tracked vehicles are prone to, as their track must be kept slack to accommodate any suspension droop.

Crew comfort was a large concern when developing a tank of this size, and performance capabilities, leading to the intention from the design outset to utilize rubber segment band tracks to reduce vibration transmitted to the vehicle, and reduce running noise inside the vehicle as well. Further attenuating sound and vibration characteristics is the use of a sprayed on, high density, rubberized polyurethane spall liner, that is bonded to the hull, dampening harmonics, acting as a sound barrier, in addition to its primary role of protecting the crew from spalling. The seating is unusual for a tank of any sort, is being suspended not purely for blast attenuation, but also as a secondary suspension to keep the driver and the commander safe, when traveling off road at high speed. The suspension of these seats is active, as are the safety harnesses to keep the occupants in their seat, rather than being freely knocked around inside. The system utilizes the gyroscopic stabilization system of the main gun, for vertical acceleration figures.

However, it is not without its criticisms, such as being armed with an out of date, semi-automatic, magazine fed cannon in 20mm. Many feel that the vehicle should be armed with at least, a 20mm autocannon with dual feed. To be fair though, most other vehicles in a similar weight class, rely on heavy machine guns, or 30 to 40mm grenade launchers. Currently being trialled, are three turrets, armed with a 20mm, a 30mm, and a 35/50mm autocannon respectively. The 50mm autocannon variant offering is currently drawing a good deal of interest, utilizing case telescoped ammunition, smoothbore barrel, unique, split-breech mechanism to keep the receiver length able to fit within the confines of the 1015mm turret ring, and the Fire Control System that works in conjunction with it, enabling its HEMP (High Explosive Multi Purpose) rounds several different time delay fuzing options, from standard airburst, to gated proximity, proximity, and wall breaching. The 50mm offering would give the CRULT much improved capabilities against armor, and infantry, being able to deliver a substantially larger HE payload per shot. But in question is if the reduced amount of ammunition that can be carried, and the additional cost of implementation worth the benefits.

More images of the CRULT in the spoiler:

(Image)
(Image)
(Image)

For visual size reference:
(Image)
(Image)

SUV is a Suzuki Grand Vitara, or Escudo.

IE: I'm working on a 50mm Supershot split-breech revolving cannon, akin to the MK18 40mm Grenade launcher idea, scaled up. Also based on the British "Nut Cracker" guns, of similar design and idea, but intended for high rates of fire as air-craft cannons. This gun I am working on would only have a rate of fire in the 100-120 rpm range, thus eliminating one of the largest problems facing the Nut Cracker idea: having a breech opening before chamber pressure had dropped to safe levels. Also, yes, it would be utilizing a combined Bofors 3P idea fuze, with the 35mm AHEAD Muzzle Velocity measurement/magnetically encoded fuze. Additional complexity, yes, but the idea of the added accuracy, would require fewer shots on target, thus sparing precious ammunition reserves. Smoothbore because, if it is only running two types of ammunition, then you just make both fin stabilized and call it good. Also gives cost savings on the barrel itself (And partly because I was trying to figure out how to rifle the goddamn barrel in sketchup, and that was proving to be a nightmare). Working on the 50mm cause I like the idea of it, and I am curious to know just how much ammunition it could hold, and, or...where the hell it would hold it. Currently thinking it might be limited to a linklessfeed system mounted to the gun itself, offering a five round magazine for APFSDS, and teen or fifteen for the HEFSMP. But again, I won't know until I model it, and try to fit all of this, into a tiny ass tankette, cause I am crazy.

I'll be brief. It's at least five tonnes too light based on what you described, your electric range-only range is probably three times higher than what it should be and you describe the existence of a supercharger in your description of your engine however you classify the engine as turbocharged.

[Calla]

I'll be brief. It's at least five tonnes too light based on what you described, your electric range-only range is probably three times higher than what it should be and you describe the existence of a supercharger in your description of your engine however you classify the engine as turbocharged.

Care to explain how it is 5 tons too light? It is physically, far smaller than the FV101, which is 8 tons. It has slightly superior armor, but again, not beating 20+mm caliber shells.
The hull last calculated (outside surface area, multiplied by thickness, multiplied by the density of 7039 aluminum [2.78mg/mm³]), plus the steel armour gave me 1172 kg. And I'm probably going overboard on the aluminum thickness, having trouble figuring out what thickness of aluminum is needed to back a 6mm plate of UHHS, to give the protection I am looking for. Turret itself will not be heavier than the hull, so I am figuring (estimate) 2000 Kg for total empty hull and turret weight. Then adding 4700 kg of engine (lightweight design, utilizing monoblock construction like the Steyr M14/M16. And other light weight construction methods to keep the weight down.), generator, motors, electical power systems, lithium ion batteries, gun systems, suspension (aluminum brackets, aluminum wheels, steel axles), light weight rubber tracks, etc.

According to every calculation I have made, it is unlikely that it would weigh as much as the FV101 Scorpion, let alone add another 3000kg on top of that mass. Please, inform me of where I am wrong.

Electric range, is very well possible that it is longer than it should be. I based it roughly off of what the Chevrolet Volt's 100L battery pack is capable of producing, and doubled that for the 200L battery volume I have reserved for this tank.

Yes. Because a 2 stroke diesel needs a supercharger to start up on, and idle with. I am basing the the idea off of the 2 Stroke Detroit diesels which had sealed crankcases, thus needed an external air pump to provide air into the engine. Thus, even though they have a supercharger, they were considered Naturally Aspirated. The supercharger did not provide any meaningful "Boost" for the engine. They also used exhaust valves, as I am using in this engine.

[San-Silvacian]

150 rounds of 20mm ammo is going to get expended at an most break neck pace with even low intensity engagements.

I'll stick with my 15 tonne armored vehicles for my QRFs.

[Vitaphone Racing]

I'll be brief. It's at least five tonnes too light based on what you described, your electric range-only range is probably three times higher than what it should be and you describe the existence of a supercharger in your description of your engine however you classify the engine as turbocharged.

Care to explain how it is 5 tons too light? It is physically, far smaller than the FV101, which is 8 tons. It has slightly superior armor, but again, not beating 20+mm caliber shells.
The hull last calculated (outside surface area, multiplied by thickness, multiplied by the density of 7039 aluminum [2.78mg/mm³]), plus the steel armour gave me 1172 kg. And I'm probably going overboard on the aluminum thickness, having trouble figuring out what thickness of aluminum is needed to back a 6mm plate of UHHS, to give the protection I am looking for. Turret itself will not be heavier than the hull, so I am figuring (estimate) 2000 Kg for total empty hull and turret weight. Then adding 4700 kg of engine (lightweight design, utilizing monoblock construction like the Steyr M14/M16. And other light weight construction methods to keep the weight down.), generator, motors, electical power systems, lithium ion batteries, gun systems, suspension (aluminum brackets, aluminum wheels, steel axles), light weight rubber tracks, etc.

According to every calculation I have made, it is unlikely that it would weigh as much as the FV101 Scorpion, let alone add another 3000kg on top of that mass. Please, inform me of where I am wrong.

You're smaller in external dimensions, yes, but you seem to have crammed even more into the hull than what the Scorpion did which is partially the root of my query. It's another story of how you intend to have enough space to fit in a 200L battery pack on top of this but we can leave that for later.

For starters, your empty shell is not going to weigh two tonnes. My new ute weighs one and a half without an engine and axles, and that's a ute. 4 tonnes is more likely. You can't simply work out the surface area of the thing, multiply it by the depth of the material because you'd be ignoring the structural frame, the internal mounts etc. You can see where you're adding weight by comparing them side by side. Your armor is thicker and you've also got steel plating on top of that. You're rocking a battery pack. You're using coil over suspension rather than lighter torsion bars. Further the weight savings that you have, rubber tracks, smaller gun etc., aren't going to save enough to compensate and more for what you've added on.

If you think your drivetrain weighs 5 tonne nearly then we'll use that estimate. Probably slightly high, but nevermind. Add that to the empty weight of the frame and we have 9 tonne, without adding anything else together. Keep in mind the extremely simple drivetrain of Scorpion (naturally aspirated engine, manual transmission without syncromesh) would have weighed a tonne or less.

Electric range, is very well possible that it is longer than it should be. I based it roughly off of what the Chevrolet Volt's 100L battery pack is capable of producing, and doubled that for the 200L battery volume I have reserved for this tank.

You'll have more electric systems and more rolling resistance than the Volt, therefore you need to take this into account rather than scaling off weights and powers.

Yes. Because a 2 stroke diesel needs a supercharger to start up on, and idle with. I am basing the the idea off of the 2 Stroke Detroit diesels which had sealed crankcases, thus needed an external air pump to provide air into the engine. Thus, even though they have a supercharger, they were considered Naturally Aspirated. The supercharger did not provide any meaningful "Boost" for the engine. They also used exhaust valves, as I am using in this engine.

It needs an air compressor. That can be a supercharger, or it can a turbocharger. I'm curious as to why you have both but only mentioning the turbocharger specifically while describing the supercharger. I've never heard of a two stroke diesel being considered a naturally aspirated engine before, and I work with Detroit Diesel engines. If something has a turbocharger, it has a turbocharger. It makes sense for everyone from mechanics to statisticians to regard them as such.

[Inyourfaceistan]

Is there any modern armor which the 120mm M829E4 APFSDS fired from an M1A2 Abrams won't be able to penetrate (at all)?

[Organized States]

Is there any modern armor which the 120mm APFSDS fired from an M1A2 Abrams won't be able to penetrate (at all)?

I can't imagine anything that's not totally impractical that an APFSDS round couldn't pierce.

[Allanea]

Is there any modern armor which the 120mm M829E4 APFSDS fired from an M1A2 Abrams won't be able to penetrate (at all)?

Pooooosssibly the front of a Merkava Mark 4 with all the ridiculous armor add-ons?

[Spirit of Hope]

Is there any modern armor which the 120mm M829E4 APFSDS fired from an M1A2 Abrams won't be able to penetrate (at all)?

Pooooosssibly the front of a Merkava Mark 4 with all the ridiculous armor add-ons?

I doubt that, it would probably penetrate and then get stopped by the engine. Crew survives, but the tank is still very dead.

[Inyourfaceistan]

Is there any modern armor which the 120mm APFSDS fired from an M1A2 Abrams won't be able to penetrate (at all)?

I can't imagine anything that's not totally impractical that an APFSDS round couldn't pierce.

That's what I thought, but I keep seeing MBT tank cannons of increasing sizes creeping through the ranks of NS., and it's leaving me thinking "okay, seriously, why does everyone need a 150mm cannon on their MBT?"

[Padnak]

Speaking of penetrating stuff with APFSDS

My most advanced tank is a modernized/upgraded M-84 I call the tiger hunter, its equipped with a 125mm gun (2A46M-5) and I'm wondering, with DU perpetrators, could this gun pen an abrams/ns tank?


I have a feeling it couldn't, but I'd like some more informed opinions

[Inyourfaceistan]

Speaking of penetrating stuff with APFSDS

My most advanced tank is a modernized/upgraded M-84 I call the tiger hunter, its equipped with a 125mm gun (2A46M-5) and I'm wondering, with DU perpetrators, could this gun pen an abrams/ns tank?


I have a feeling it couldn't, but I'd like some more informed opinions

Yeah, probably.

I mean, foolish rookie! Behold my totally original 200mm ECT tank! Now post thine losses!

[Padnak]

god help us

at one point the thought crossed my mind to use a 203mm pion in direct fire as an anti tank weapon...

[Organized States]

Speaking of penetrating stuff with APFSDS

My most advanced tank is a modernized/upgraded M-84 I call the tiger hunter, its equipped with a 125mm gun (2A46M-5) and I'm wondering, with DU perpetrators, could this gun pen an abrams/ns tank?


I have a feeling it couldn't, but I'd like some more informed opinions

It might. However, the Abrams, Challenger II, and the Leo 2 are pretty tough nuts to crack when it comes to armor. I get the feeling penetration might be a little difficult.

[The Soodean Imperium]

Speaking of penetrating stuff with APFSDS

My most advanced tank is a modernized/upgraded M-84 I call the tiger hunter, its equipped with a 125mm gun (2A46M-5) and I'm wondering, with DU perpetrators, could this gun pen an abrams/ns tank?

"Penetration is not binary!!!"

Using this image as an imprecise estimate, Soviet 125mm DU ammunition stands a decent chance of penetrating with a hit on certain areas of the lower glacis. This, too, depends on range, angle of impact, and a whole variety of other factors. Hitting the sides or rear at 0 degrees will practically guarantee penetration, but I assume that's not what you're asking about.

The problem with Soviet 125mm ammunition is that because the cartridge is broken into two pieces to fit a T-72-style autoloader, there's a limit to how long you can make the penetrator itself, which means a cap on mass per a given diameter - recall that the longer penetrator is one of the reasons penetration jumped so far between M829A2 and M829A3. The latest ammunition on the T-90 fits a slightly longer "dart" by changing the autoloader dimensions and layout, but it still falls around 700mm RHAe.

My personal solution to this, as applied on the Su'Chong-6 I posted last month, was to design a single-piece 125mm round (classified as 127mm to reduce confusion) which allows a larger penetrator and more propellant. IIRC I got somewhere around 1000mm RHAe when I ran some estimated dimensions through the calculator; I'll see how it comes out when I run better numbers again.

[Padnak]

I see

The tank has a resigned enlarged turret with a bustle (which I'm just using for general storage at the moment) so redeveloping the auto-loader to take one piece ammunition wouldn't be too difficult

[The Greater Luthorian Empire]

So basically the speed (to you) is going down a steep road already haulin' ass.

Noep.

The Abrams seemed perfectly content to get up to over 80 km/h on flat ground, even if it stresses the vehicle's drivetrain. Sorry that you seem to think this is some impossible feat, but it really kind of isn't. It's just not a very smart thing to do in most circumstances.

also sand serb tank will be smashed by the legions of superior FAR armour.

That had nothing to do with his point. Hit point was that if top speed was the maximum speed it could reach than it would be a meaningless stat because you could only reach is when going down a steep, smooth hill. As Purp said top speed should be the maximum speed it can reach and safely sustain so for an Abrams it would be about 70 km/h, not 80 km/h since that stresses the drive train a lot and thus cannot be safely sustained.

[Allanea]

The top speed of an armored vehicle is typically meant to be the maximum speed achieved on a flat horizontal road surface.