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There are quite a few gripes about Tanks and vehicles in 40k. I would like to address them from the viewpoint of Fantasy/sci-fi justifications.

Lack of sloping armour: This is the easiest one to deal with. While sloping armour is a must on 20th century tanks that is for 2 reasons. The first of which being the nature of our armor, it must be light enough to still have an effective maneuverable fighting platform so cannot just be ultra-thick sandwiched slabs of materials. 40k gets around this in the fantastic materials used (while we do not know the tensile strength of plasteel or ceremite it can be reasonably assumed to be incredibly high). The second reason for sloped armour is to defeat Solid projectiles. Again in 40k this is not as big of a problem, most weapons that threaten the armour of your average armoured vehicle are energy based. The exception to this being Auto cannons, Str6+ rending like assault cannon(which literally chew through the armour), and Missiles of all sorts. There is a third possible reason for a lack of sloped armour that stems from the energy weapons nature: A sloping surface presents more surface area to be burned through, and the armour itself may be able to dissipate the heat and energy of the weapons better when struck at a more perpendicular angle.

Rivets: Yes, welds are far stronger bonding of 2 plates than rivets. But, think about battlefield/front-line repairs. 30 Rivets made from a tough but slightly weaker material than the armour itself will be easier to cut through and remove then carving off entire sections of welded armour to be replaced with then welded back on new sections. If every given section of armour on your tank can simply be replaced by a whole new section when damaged, generally within an hour, you can have your tank back out on the front lines after receiving some particularly devastating hits in about the same amount of time it takes you to re-arm and re-fuel.

Tall thin Battle Tanks(the Leman Russ): I have already covered why low sloping armour(and thus a wider chassis) is not as necessary in 38,000 years, but why are the tanks so tall and thin? It is all about the width, but the height does come into play as useful. Leman russ tanks are tall because ethey are thin, you have to fit all the required components for them to run somewhere, and that makes them taller than they really should be. But why so thin? Urban Warfare. Battles against Xenos and traitors are not often fought out in the fields far away from the cities and Hives, they are fought in the streets and a thinner tank can maneuver between buildings better than a wider, longer tank. I mentioned the height adds a bonus, it does: LOS. The tall tank can shoot over fairly decent sized walls and rubble trustiong in its prodigious armour(and the cover of those walls or rubble) to protect it.
Treads: I cannot defend the treads, they are backwards and/or upside-down on every tank other than the Rhino and chimera Chassis. If the Taurox treads were not upside-down, I could at least defend the 4 independent treads; which I will still do. 4 independent treads are not a horrible design flaw, it allows each tread section to be on its own suspension which will allow for greater speed and handling on rough terrain. You still have maneuverability for 0-point turns the same as you do with 2 treads, but can add the element of “sluicing” around a turn while maintaining speed and stability so long as each tread hub has an independent motive system.

Sponsons: We haven’t had sponsons on our tanks since the early interwar period(between WWI and WWII), a large part of the reason for that is access to the tracks and changed Tactics. A thrown track on a WWI tank with sponsons crippled the tank considerably since 60-75% of the tracks were housed within an armoured sheath and the tracks went up around the sides of the tank(like in imperial tanks). The other reason, the change in tactics saw either more infantry support for the tanks to protect their flanks, or simply fielding more tanks. More tanks is not as much of an option in 40k(on the table top) so extra guns on the flanks makes sense. Infantry support can and is used \, but in game we want our vehicles to have more than 1 gun to put out more attacks, so the decision is really based around game mechanics.

If anyone thinks of anymore gripes about Imperial Tanks I would be happy to think on it and give a reason for it.

What's with the barrels? Why does the Anti Tank Leman Russ need a barrel longer than itself, and why does a lascannon need a barrel at all?

What do you mean by "Upside down Treads"?

How does flat armor resist lasers? You'd expect a slope to disperse the energy of the laser, meaning it won't melt straight through as easy.

Regarding barrel length, the longer the barrel, the more effect you can get out of your propellant, an thus the better projectile speed and penetration. If you look through the history of effective anti-tank guns, there are a lot of awfully long guns out there

The battle cannon seems better as an infantry support gun, then. The short barrel that fires high explosive shells that do pie plate splash damage seems ideally suited to anti infantry.

Why it's so large, however.

It's probably large because the weapon's power comes from the size of the shell used rather than any advanced weapons design. Or maybe because thinks sensible tank design is dumb. Everyone's tanks except maybe the Tau do not make much sense.

The lascannon may need it's barrel to focus the light into better coherency. It could do this with a variety of mechanisms but it would require some sort of tunnel.

The interesting thing about the leman russ "tank" is that it is not a tank at all. It is a heavy duty vehicle STC with armour plates bolted on. That is why it's profile is all wrong. It is supposed to be incredibly cheap and easy to produce however so the IoM uses it in preference to malcador or other dedicated but expensive tanks.

Sloping armour would actually help against even light based attacks as the beam could diffract from the surface easier. However it could be though that the 40K tanks are not just tanks. They are also mobile fortress' which are often used to shield other more important stuff or troops from being shot at. The leman russ is actually a really small tank in comparison to shielding an infantry column.

I think a lot of the "why are 40K tanks junk" can be explained by orbital bombardments and D weapons. When your opponent can destroy any vehicle in a single shot with almost no effect from improved armour or better design what is better 5 tractor's with armour and guns or 1 actual tank?

Also the IoM has lots of planets (common materials like plastisteel) and lots of people but it has extremely limited numbers of production facilities and skilled laborers. Therefore if you can make vehicle with miscast plastisteel rather than machined parts then that is the best answer. When I look at a leman russ I see a vehicle that can be assembled with servitors. When I see an M1 Abrams I see a tank that requires a machine shop and skilled laborers just to change out armour plates.

Good point on the lascannon, ansacs.

However Flinty, that's not entirely true. The longer the barrel, the more accurately you place the round, at the loss of velocity. You're making the shot spin more to keep on target at the reduction of distance. That's why you see reasonably sized tank cannons. Not this.
http://img2.wikia.nocookie.net/__cb20080206125010/scratchpad/images/b/ba/Vanquisher1.jpg

 Kommissar Kel wrote:
There are quite a few gripes about Tanks and vehicles in 40k. I would like to address them from the viewpoint of Fantasy/sci-fi justifications.

Lack of sloping armour: This is the easiest one to deal with. While sloping armour is a must on 20th century tanks that is for 2 reasons. The first of which being the nature of our armor, it must be light enough to still have an effective maneuverable fighting platform so cannot just be ultra-thick sandwiched slabs of materials. 40k gets around this in the fantastic materials used (while we do not know the tensile strength of plasteel or ceremite it can be reasonably assumed to be incredibly high). The second reason for sloped armour is to defeat Solid projectiles. Again in 40k this is not as big of a problem, most weapons that threaten the armour of your average armoured vehicle are energy based. The exception to this being Auto cannons, Str6+ rending like assault cannon(which literally chew through the armour), and Missiles of all sorts. There is a third possible reason for a lack of sloped armour that stems from the energy weapons nature: A sloping surface presents more surface area to be burned through, and the armour itself may be able to dissipate the heat and energy of the weapons better when struck at a more perpendicular angle.

Agreed, there are few 'conventional anti-tank weapons' out there that are very effective at piercing 40k era metals in my experience (by playing the game and fluff). The best of them are lascannons, meltas, and 'lance' weapons;' all of them being extremely high heat energy weapons. Exepctions have been seen, like Vanquisher and Macro, and Demolisher Cannons as well as Tau/IoM Railguns (the Accelerator Cannons on the Fellblade and Sicarian Tanks).

Tall thin Battle Tanks(the Leman Russ): I have already covered why low sloping armour(and thus a wider chassis) is not as necessary in 38,000 years, but why are the tanks so tall and thin? It is all about the width, but the height does come into play as useful. Leman russ tanks are tall because ethey are thin, you have to fit all the required components for them to run somewhere, and that makes them taller than they really should be. But why so thin? Urban Warfare. Battles against Xenos and traitors are not often fought out in the fields far away from the cities and Hives, they are fought in the streets and a thinner tank can maneuver between buildings better than a wider, longer tank. I mentioned the height adds a bonus, it does: LOS. The tall tank can shoot over fairly decent sized walls and rubble trustiong in its prodigious armour(and the cover of those walls or rubble) to protect it.
Treads: I cannot defend the treads, they are backwards and/or upside-down on every tank other than the Rhino and chimera Chassis. If the Taurox treads were not upside-down, I could at least defend the 4 independent treads; which I will still do. 4 independent treads are not a horrible design flaw, it allows each tread section to be on its own suspension which will allow for greater speed and handling on rough terrain. You still have maneuverability for 0-point turns the same as you do with 2 treads, but can add the element of “sluicing” around a turn while maintaining speed and stability so long as each tread hub has an independent motive system.

While this is true of most Imperial Guard tanks, actual tanks that do see time are more tradition in tank design (examples being the Machiarus, Predator/Rhino-Chassis and Baneblade/Fellblade varients. Heck the original STC designation for the Baneblade was 'Medium Battle Tank'.

Sponsons: We haven’t had sponsons on our tanks since the early interwar period(between WWI and WWII), a large part of the reason for that is access to the tracks and changed Tactics. A thrown track on a WWI tank with sponsons crippled the tank considerably since 60-75% of the tracks were housed within an armoured sheath and the tracks went up around the sides of the tank(like in imperial tanks). The other reason, the change in tactics saw either more infantry support for the tanks to protect their flanks, or simply fielding more tanks. More tanks is not as much of an option in 40k(on the table top) so extra guns on the flanks makes sense. Infantry support can and is used \, but in game we want our vehicles to have more than 1 gun to put out more attacks, so the decision is really based around game mechanics.

After seeing plenty of 40k tanks, most of the sponson weapons are IMO actually motivated by an onboard cogitators being used by tank crews, with the Predators being the most obvious and the Hammerheads using actual Drones. My point being that due to having small enough targeting cogitators and the need for more guns on the field necessitate the usage of tank sponsons.

 Will1541 wrote:

However Flinty, that's not entirely true. The longer the barrel, the more accurately you place the round, at the loss of velocity. You're making the shot spin more to keep on target at the reduction of distance. That's why you see reasonably sized tank cannons. Not this.
http://img2.wikia.nocookie.net/__cb20080206125010/scratchpad/images/b/ba/Vanquisher1.jpg

I always figured that the vanquisher shells effects are due to the "charge" being carried (something like a thermite shell vs a HE shell, though for all I know melta could be an anti matter shell). The vanquisher shell may be a bit heavier or some such and so rather than the barrel making the shell have a higher speed or some ridiculousness it is meant to increase the accuracy back up to a reasonable level. This would also explain why the shorter varients of the battle cannon have reduced range while the battle cannon and vanquisher have the same range.

Also, keep in mind that all of these vehicles need to be able to move by spaceship. Imagine packing in your tanks into an interstellar transport if they had a wide and long footprint. I tend to think the imperial designs are about practicality and cost. And you can't launch missions to transport tanks to another system all the time, so each shipment needs to count. And, once deployed, your tank might need to drive over multiple planets, hundreds of aliens, and through all the mud in the universe between maintenance check ups. This includes high gravity, low gravity, ice planets, volcanic planets, death worlds, desert worlds, these tanks need to survive everything, just like the trusty lasgun.

Are the Leman Russ tracks backwards or upside down? I thought the real issue was the fact that the armour seems to come all the way down to the track, leaving no room for the suspension to work.

The main advantage of sloped / rounded armour is that it wraps over the tank's interior parts more efficiently than armour which follows the exact shape of the components. If the underlying shape happens to be a flat box, then flat armour is more efficient. It's not like most imperial tank armour isn't sloped anyway. The only real shell trap is that front hull weapon mount on the leman russ and that could easily be a sloped armour hull with a lightly armoured structure on top of it.

Rivets holding the structure of the tank together is arguably bad, but there's nothing to say that the visible rivets are doing anything more than holding the outer layers of the armour in place. The hull underneath could easily be welded / chemically bonded / cast as a solid piece. Or maybe it's just not practical to weld ceramite. Are they even confirmed to be rivets, rather than molecular bonding studs or whatever those things on space marine shoulder pads are called?

Vanquisher gun length doesn't seem that daft. Plenty of real world tanks have had long guns. The Rheinmetall 120 mm L/55 is 22 feet long, for example, which is almost as long as a vanquisher barrel. The really ridiculous elements are the absurd width of the barrel and the lack of space for the breech to recoil inside the turret or for any loader or autoloader to work in there.

 TheCustomLime wrote:
It's probably large because the weapon's power comes from the size of the shell used rather than any advanced weapons design. Or maybe because thinks sensible tank design is dumb. Everyone's tanks except maybe the Tau do not make much sense.

Eldar tanks are actually fairly well designed, or at least don't suffer from the design flaws if they were slow vehicles. Eldar heavy support functions more like a low altitude gunship zipping around speeds above mach 2-3 that hits incredibly hard and is gone before you can even get a shot off it. Hell they're not even that low altitude, IIRC Eldar "tanks" can function fairly high up in the air to the point that they're almost like Harriers with a lot more dakka and strafing.

In short, Eldar tanks are bs.

 Perfect Organism wrote:
Vanquisher gun length doesn't seem that daft. Plenty of real world tanks have had long guns. The Rheinmetall 120 mm L/55 is 22 feet long, for example, which is almost as long as a vanquisher barrel. The really ridiculous elements are the absurd width of the barrel and the lack of space for the breech to recoil inside the turret or for any loader or autoloader to work in there.

This is pretty much true for all the guns in the game, so that they're easily identifiable on the table. A bolt pistol would be like 10 lbs and would probably take your arm off when you shot it. The round is like four times the size of a 0.50 cal bullet.

 Wyzilla wrote:

 TheCustomLime wrote:
It's probably large because the weapon's power comes from the size of the shell used rather than any advanced weapons design. Or maybe because thinks sensible tank design is dumb. Everyone's tanks except maybe the Tau do not make much sense.

Eldar tanks are actually fairly well designed, or at least don't suffer from the design flaws if they were slow vehicles. Eldar heavy support functions more like a low altitude gunship zipping around speeds above mach 2-3 that hits incredibly hard and is gone before you can even get a shot off it. Hell they're not even that low altitude, IIRC Eldar "tanks" can function fairly high up in the air to the point that they're almost like Harriers with a lot more dakka and strafing.

In short, Eldar tanks are bs.

That's a terrible way to use an AFV even if it has the capabilities to do so. It's gun is turret mounted meaning you'll have to depress the vehicle to a great degree leaving it's undercarriage open to attack. Even if they can go fast the weaponry is not designed to fire at those speeds meaning they'll hit feth all. They are also very open to attack by dedicated aircraft who do have weaponry designed to engage targets at those speeds.

The biggest issue I have with their tanks is their glass canopies. They don't seem to serve much purpose other than to give the pilot a new view of the world. Even if Eldar super tech means they aren't as brittle as glass it's still a big "Shoot here!" sign. I would hazard to guess that a good chunk of Eldar tank losses are a result of the canopy being hit by an AT shell.

I also don't understand why they are so garishly painted but I guess that's a whole 'nother kettle of fish.

But yeah, otherwise they are pretty good for GW. Get rid of the glass canopies, have them fly lower to the ground and paint them in more natural colors and you got some nice tanks.

 TheSilo wrote:

 Perfect Organism wrote:
Vanquisher gun length doesn't seem that daft. Plenty of real world tanks have had long guns. The Rheinmetall 120 mm L/55 is 22 feet long, for example, which is almost as long as a vanquisher barrel. The really ridiculous elements are the absurd width of the barrel and the lack of space for the breech to recoil inside the turret or for any loader or autoloader to work in there.

This is pretty much true for all the guns in the game, so that they're easily identifiable on the table. A bolt pistol would be like 10 lbs and would probably take your arm off when you shot it. The round is like four times the size of a 0.50 cal bullet.

Yeah, I generally like to tell myself that the guns are in heroic scale just like the models' hands are. The 'real' version would be a lot slimmer.

Even handwaving away relative proportions though, the Leman Russ still has a stupid turret. A commander's hatch directly behind the gun means that the commander has to drop down out of the way when the gun is fired. It's like sculpting a human being with his thumb in the middle of his palm or something.

 Perfect Organism wrote:

 TheSilo wrote:

 Perfect Organism wrote:
Vanquisher gun length doesn't seem that daft. Plenty of real world tanks have had long guns. The Rheinmetall 120 mm L/55 is 22 feet long, for example, which is almost as long as a vanquisher barrel. The really ridiculous elements are the absurd width of the barrel and the lack of space for the breech to recoil inside the turret or for any loader or autoloader to work in there.

This is pretty much true for all the guns in the game, so that they're easily identifiable on the table. A bolt pistol would be like 10 lbs and would probably take your arm off when you shot it. The round is like four times the size of a 0.50 cal bullet.

Yeah, I generally like to tell myself that the guns are in heroic scale just like the models' hands are. The 'real' version would be a lot slimmer.

Even handwaving away relative proportions though, the Leman Russ still has a stupid turret. A commander's hatch directly behind the gun means that the commander has to drop down out of the way when the gun is fired. It's like sculpting a human being with his thumb in the middle of his palm or something.

Unless Leman Russ tanks have very well designed recoil dampeners. I mean, it is 38,000 thousand years into the future...

Rivets:

This is kind of nit-picky, but welds are actually weaker than rivets in some cases because welding a material reduces its strength both at the weld and in the heat affected area. Some materials (like aluminum, titanium, and certain high-yield steels) are also very difficult to weld, or the above-mentioned heat affect hurts them too much. This is one reasonwhy many aircraft use rivets, because they are more consistent and predictable and aluminum doesn't weld well.

Also to your point about repairs, riveting was (in its heyday) a job requiring very little skill. Some welding jobs today require extensive schooling.

 Wyzilla wrote:

 TheCustomLime wrote:
It's probably large because the weapon's power comes from the size of the shell used rather than any advanced weapons design. Or maybe because thinks sensible tank design is dumb. Everyone's tanks except maybe the Tau do not make much sense.

Eldar tanks are actually fairly well designed, or at least don't suffer from the design flaws if they were slow vehicles. Eldar heavy support functions more like a low altitude gunship zipping around speeds above mach 2-3 that hits incredibly hard and is gone before you can even get a shot off it. Hell they're not even that low altitude, IIRC Eldar "tanks" can function fairly high up in the air to the point that they're almost like Harriers with a lot more dakka and strafing.

In short, Eldar tanks are bs.

Yes! More firepower, mobility, and defensive capability than a Hammerhead for the exact same price!

Seriously, the Eldar Codex is so broken I'm no longer a Phil Kelly fan.

TheCustomLime wrote:That's a terrible way to use an AFV even if it has the capabilities to do so. It's gun is turret mounted meaning you'll have to depress the vehicle to a great degree leaving it's undercarriage open to attack. Even if they can go fast the weaponry is not designed to fire at those speeds meaning they'll hit feth all. They are also very open to attack by dedicated aircraft who do have weaponry designed to engage targets at those speeds.

The biggest issue I have with their tanks is their glass canopies. They don't seem to serve much purpose other than to give the pilot a new view of the world. Even if Eldar super tech means they aren't as brittle as glass it's still a big "Shoot here!" sign. I would hazard to guess that a good chunk of Eldar tank losses are a result of the canopy being hit by an AT shell.

I also don't understand why they are so garishly painted but I guess that's a whole 'nother kettle of fish.

But yeah, otherwise they are pretty good for GW. Get rid of the glass canopies, have them fly lower to the ground and paint them in more natural colors and you got some nice tanks.

I have a personal theory that all of the current eldar vehicles were not military vehicles before the fall. In other words venoms and ravagers were pleasure barges and waveserpents were eldar minivans...it actually explains a lot about the eldar vehicles and armament that way.

Also the canopy could be wraithbone the same material as the tank. Wraithbone is described as being crystalline and can be translucent. In fact the entire tank could be translucent if they wanted. The really interesting thing about CWE vehicles, armour, and weapons is that most of them seem to be just different varieties of wraithbone blended together into a final form and function and controlled with psychic impulses. I am not really sure if the controls in these models actually mean anything.

True, but it seems like a big target. It's like painting a large circle over the engine or ammunition rack. It may be well armored but it is still going to be targeted by AT gunners. I also would imagine that the reasons the controls exist is so that pilots who aren't as psychically gifted can operate the vehicle easily. Pilots who are could simply forgo them.

That theory about Eldar vehicles does explain a lot.

40k uses magic groxgaktanium materials and magic nonsuchinite power generators to get better than modern performance characteristics in spite of bad design philosophy.

/thread.

 Will1541 wrote:
Good point on the lascannon, ansacs.

However Flinty, that's not entirely true. The longer the barrel, the more accurately you place the round, at the loss of velocity. You're making the shot spin more to keep on target at the reduction of distance. That's why you see reasonably sized tank cannons. Not this.
http://img2.wikia.nocookie.net/__cb20080206125010/scratchpad/images/b/ba/Vanquisher1.jpg

Some examples of AT guns with awfully long barrels, comparable in length to the tank that carries it:
http://en.wikipedia.org/wiki/8.8_cm_PaK_43
http://en.wikipedia.org/wiki/SU-100
http://en.wikipedia.org/wiki/Jagdpanther
http://en.wikipedia.org/wiki/Nashorn
http://en.wikipedia.org/wiki/Archer_%28tank_destroyer%29

They just don't look as stupid becasue they aren't at GW's foolish macro-calibre. The longer the barrel, the more time the propellant charge has to accellerate the projectile. I think if you look through the examples above, all of the truly high velocity AT guns had inordinately long barrels.

Regarding flat surfaces and non-angled armour, its still hard to justify not taking an easy win on angled armour. Marine tanks have it, why not Imperial tanks at large?

It might be that the large calibre (and presumably smooth barrels) allow the Vanquisher to fire the Devil's own APFSDS round.

http://en.wikipedia.org/wiki/Kinetic_energy_penetrator

 Kommissar Kel wrote:

Sponsons: We haven’t had sponsons on our tanks since the early interwar period(between WWI and WWII), a large part of the reason for that is access to the tracks and changed Tactics

I was thinking that sponsons may help in a urban fighting scenario where infantry would be a greater threat. Coupled with weapons with high penetration but short range (melta and power weapons) that easily penetrate most armour it may be more pressing to keep infantry at bay. Sloped armour would also presumably be less effective than more flat armour against attacks from a higher elevation (though that may not be much of a concern). This fits with how 40K battles seem to be focussed around a few key areas of a planet; starports and the like. The most common enemies the Imperium faces are Orks and other Humans. Orks in particular require heavy firepower to put down (also contributing to the existence of sponsons) and since enemy humans are generally rebels they often field the same vehicles (so it wouldn't be much of an advantage).

 Will1541 wrote:
Good point on the lascannon, ansacs.

However Flinty, that's not entirely true. The longer the barrel, the more accurately you place the round, at the loss of velocity. You're making the shot spin more to keep on target at the reduction of distance. That's why you see reasonably sized tank cannons. Not this.
http://img2.wikia.nocookie.net/__cb20080206125010/scratchpad/images/b/ba/Vanquisher1.jpg

Actually the longer the barrel the higher the velocity. Its also more accurate.

That's why even if a pistol and rifle fire the exact same bullet, the rifle will have a longer range and greater velocity.

The shorter the barrel, the less time the bullet is under the entire pressure of the charge. Once it leaves the barrel, the gases begin expanding in all directions and not just in the one the bullet is traveling.

The only advantage a short barrel has is portability and ease of transport. its why Bullpup design firearms are such a powerful concept, you get the power and range of a rifle in a much smaller easier to use package.

It's not quite that simple. A gun barrel needs to be the right length for the round it is firing. If it's too long, the propellant stops pushing it before it reaches the end and it starts to slow. If it's too short, the propellant doesn't have to time to finish expanding fully before the bullet leaves the barrel and some of the force is wasted.

Every round has an ideal barrel length. Ones which are built to go faster generally have longer ideal barrel lengths. There are some weapons where making the barrel longer makes the round come out faster because the original barrel was a bit too short. There are others where making the barrel shorter would speed up the round, because the barrel was too long. There is no universal rule that a longer or shorter barrel has one particular effect and you can keep making it longer or shorter to get more of that effect though.

 Flinty wrote:

 Will1541 wrote:
Good point on the lascannon, ansacs.

However Flinty, that's not entirely true. The longer the barrel, the more accurately you place the round, at the loss of velocity. You're making the shot spin more to keep on target at the reduction of distance. That's why you see reasonably sized tank cannons. Not this.
http://img2.wikia.nocookie.net/__cb20080206125010/scratchpad/images/b/ba/Vanquisher1.jpg

Some examples of AT guns with awfully long barrels, comparable in length to the tank that carries it:
http://en.wikipedia.org/wiki/8.8_cm_PaK_43
http://en.wikipedia.org/wiki/SU-100
http://en.wikipedia.org/wiki/Jagdpanther
http://en.wikipedia.org/wiki/Nashorn
http://en.wikipedia.org/wiki/Archer_%28tank_destroyer%29

They just don't look as stupid becasue they aren't at GW's foolish macro-calibre. The longer the barrel, the more time the propellant charge has to accellerate the projectile. I think if you look through the examples above, all of the truly high velocity AT guns had inordinately long barrels.

Regarding flat surfaces and non-angled armour, its still hard to justify not taking an easy win on angled armour. Marine tanks have it, why not Imperial tanks at large?

Those are Tank Hunters, not tanks. Their armor is... they have no armor. so they are actually only about what you see, wheras a portion of the Vanquisher cannon is in the tank. (Exception Jagdpanther which wasn't known for having range, which is my point.) The vanquisher cannon can have three models in base contact underneath it. Proportionally, that's a 10 foot gun, meaning 10 feet of velocity loss through spinning against the barrel. The Nashhorn had a 71 inch gun, meaning the vanquisher is almost double that length. And you expect that to go 72"?


Automatically Appended Next Post:
@Grey Templar, rifles reach father because they have more powder. The barrel only increases accuracy.

The Pak 43 had a 21 foot length barrel and had an effective range of 4 kilometers. There is nothing wrong with the Vanquisher cannon except that it should be AP1.

 Kommissar Kel wrote:
40k gets around this in the fantastic materials used (while we do not know the tensile strength of plasteel or ceremite it can be reasonably assumed to be incredibly high).

No, 40k doesn't get around this at all. Armor geometry is armor geometry regardless of how good the material is. Awesome materials may allow you to get away with using terrible designs as long as you aren't facing high-end threats, but that doesn't change the fact that a tank with good armor design AND superior materials will have much better defense.

Treads: I cannot defend the treads, they are backwards and/or upside-down on every tank other than the Rhino and chimera Chassis.

The Chimera is also stupid. Its ground clearance is virtually nonexistent, and there's no suspension. It would shake itself apart and be a nightmare to ride in (and impossible to shoot accurately from), except for the tiny problem that on anything other than a paved road it would get stuck immediately.

 Will1541 wrote:
Proportionally, that's a 10 foot gun, meaning 10 feet of velocity loss through spinning against the barrel.

I don't think you understand how guns work. Let's assume an infinite-length barrel. The shot is fired, with a lot of pressure behind the shell initially, producing a lot of acceleration. For a while as the shell moves down the barrel the pressure behind it will be more than the friction opposing its movement, and it will continue to accelerate. Meanwhile the gas is expanding behind the shell, and its pressure is constantly dropping. This will happen up until a distance X where the gas pressure and friction are equal. This is where maximum speed is reached, NOT at the beginning of the barrel. Then, as the pressure continues to drop, the shell will start to slow down until it stops.

What this means is that for any barrel length less than X adding more barrel length with increase the speed of the shell, not decrease it. You only get decreased velocity if you increase barrel length to such an absurd extreme that you exceed X. The reason for limited barrel length isn't preserving shell velocity, it's the fact that it's really hard to make a functioning turret with a gun big enough to maximize shell velocity. So on a standard tank you accept a compromise and go with a shorter barrel so your turret works properly. A dedicated tank killer, especially one with a fixed hull gun, sacrifices turret complexity/rotation speed/etc to have a longer barrel and therefore a more powerful shot.




Automatically Appended Next Post:

 Will1541 wrote:
@Grey Templar, rifles reach father because they have more powder. The barrel only increases accuracy.

No, Grey Templar is talking about guns with identical ammunition. Put the exact same bullet in a pistol and a rifle and the rifle will have much higher velocity.

it also should be noted that imperial tanks, like all imperial warfare tech MUST and WILL work on thousends of differents worlds, if anyone here has ever used a gun in the wilderness (like hunting in a forest or just carry it in a desert-like area) the reason why that's amazing will be obvious, think about it, a leman russ can fight in campaign on a arctic wolrd like Valhalla and then get relocated the next year to fight in a corrosive wasteland like Armageddon and it will still work pretty fine.
if you think, all those Hypertech-y tau a-gravs are waay more primitive since it need extensive tuning or a total workout (even if they can do that fast) for every different battlefield

and about armor thickness, geometry or even ammo types we should remember that imperial equipment/veichles in a single battlefield comes from dozens or even hundreds different worlds and their spare parts HAVE to be interchangable, unless you expect your AM (still have to get used on the name)army to end up like the "Lost and the Damned" after a couple of years of war


in the end why Imperial Armour is not bad? cuz' those tanks have thoughness, reliability, they're cheap, easy to mantain and easy to repair, they can fight in every kind of world , they use they easiest fuel produced in the galaxy and they're still a major threat to any "superior tech" counterparts