Hull down - is it worth it?

[MikeyD]

This doesn't sound like my experience (with the right vehicles). If you've got a JpzIV hull-down on the back slife of a slope the combination of increased armor angle and reduced silhouette makes it just about unbeatable.

Then again, if you've got a light tank hull-down but so close to the enemy it'd be impossible to miss a turret penetration is still a turret penetration.

[gredeker]

<blockquote>quote:</font><hr>Originally posted by MikeyD:

This doesn't sound like my experience (with the right vehicles). If you've got a JpzIV hull-down on the back slife of a slope the combination of increased armor angle and reduced silhouette makes it just about unbeatable.

<hr></blockquote>

I'd agree, and the figures above discuss only the percentage chance to hit, not to kill, and make no distinction between HD gained by being behind a wall vs. HD by being on a reverse slope. Having something like a Hetzer on a reverse slope HD position, with an effective armor angle of 70+ degrees, is just about indestructible with a normal (i.e., not a weak point) hit.

[gredeker]

<blockquote>quote:</font><hr>Originally posted by MikeyD:

This doesn't sound like my experience (with the right vehicles). If you've got a JpzIV hull-down on the back slife of a slope the combination of increased armor angle and reduced silhouette makes it just about unbeatable.

<hr></blockquote>

I'd agree, and the figures above discuss only the percentage chance to hit, not to kill, and make no distinction between HD gained by being behind a wall vs. HD by being on a reverse slope. Having something like a Hetzer on a reverse slope HD position, with an effective armor angle of 70+ degrees, is just about indestructible with a normal (i.e., not a weak point) hit.

[Fangorn]

Yes, armour is irrelevant to the test, only the chance to hit.

One element that is missing to further analysis is the size of the turret in comparation with the rest of the tank. I have *no* clue about that. I would guess that it represents between 20-30% of the sillouette.

Therefore, if my estimate is right, the further the distance, the better benefits will be gained with hull down (that means, the relative difference tends to become the same as the proportion between the turret and the rest of the tank). From the numbers I'm getting, it is too easy to hit the tank's turret, like it is the biggest part of the tank. As distance grows, hull down positions get better.

I'll run another battery of tests, this time at 1000 and 1200 meters.

If anyone can tell me the size of the PzIVG and the Panther G tank and turret that would help me a lot.

[ 11-15-2001: Message edited by: Fangorn ]</p>

[Fangorn]

Yes, armour is irrelevant to the test, only the chance to hit.

One element that is missing to further analysis is the size of the turret in comparation with the rest of the tank. I have *no* clue about that. I would guess that it represents between 20-30% of the sillouette.

Therefore, if my estimate is right, the further the distance, the better benefits will be gained with hull down (that means, the relative difference tends to become the same as the proportion between the turret and the rest of the tank). From the numbers I'm getting, it is too easy to hit the tank's turret, like it is the biggest part of the tank. As distance grows, hull down positions get better.

I'll run another battery of tests, this time at 1000 and 1200 meters.

If anyone can tell me the size of the PzIVG and the Panther G tank and turret that would help me a lot.

[ 11-15-2001: Message edited by: Fangorn ]</p>

[Fangorn]

Again, the chance to hit of the 57 and 76 mm AT guns, and the 90 mm AA gun are about the same, I'll just put them together.

1000 m

Hull down Panzer IVG / Hetzer / Stug IV / Panther G

90/76/57 - 14 - 16 - 19 - 17

40 AA g -- 37 - 40 - 46 - 43

105 how. - 06 - 07 - 08 - 07

In the open:

90/76/57 - 26 - 21 - 25 - 30

40 AA g -- 60 - 50 - 58 - 65

105 how. - 12 - 09 - 11 - 13

Difference:

90/76/57 - 12 - 05 - 06 - 13

40 AA g -- 23 - 10 - 12 - 22

105 how. - 06 - 02 - 03 - 06

Now at 1200 m

Hull down Panzer IVG / Hetzer / Stug IV / Panther G

90/76/57 - 11 - 12 - 14 - 13

40 AA g -- 30 - 32 - 37 - 34

105 how. - 03 - 04 - 05 - 04

In the open:

90/76/57 - 20 - 16 - 19 - 24

40 AA g -- 48 - 41 - 47 - 55

105 how. - 07 - 05 - 07 - 08

Difference:

90/76/57 - 09 - 04 - 05 - 11

40 AA g -- 18 - 09 - 10 - 21

105 how. - 04 - 01 - 02 - 04

Analysis of the chance of hitting a Panther G (90 mm gun):

In the open (1000m): 30

Hull down position: 17

Difference: 13

Chance of hitting the hull: 43,33

In the open (1200m): 24

Hull down position: 13

Difference: 11

Chance of hitting the hull: 45,83

Analysis of the chance of hitting a Panzer IVG (90 mm gun):

In the open (1000m): 26

Hull down position: 14

Difference: 12

Chance of hitting the hull: 46,15

In the open (1200m): 20

Hull down position: 9

Difference: 11

Chance of hitting the hull: 55

[Fangorn]

Again, the chance to hit of the 57 and 76 mm AT guns, and the 90 mm AA gun are about the same, I'll just put them together.

1000 m

Hull down Panzer IVG / Hetzer / Stug IV / Panther G

90/76/57 - 14 - 16 - 19 - 17

40 AA g -- 37 - 40 - 46 - 43

105 how. - 06 - 07 - 08 - 07

In the open:

90/76/57 - 26 - 21 - 25 - 30

40 AA g -- 60 - 50 - 58 - 65

105 how. - 12 - 09 - 11 - 13

Difference:

90/76/57 - 12 - 05 - 06 - 13

40 AA g -- 23 - 10 - 12 - 22

105 how. - 06 - 02 - 03 - 06

Now at 1200 m

Hull down Panzer IVG / Hetzer / Stug IV / Panther G

90/76/57 - 11 - 12 - 14 - 13

40 AA g -- 30 - 32 - 37 - 34

105 how. - 03 - 04 - 05 - 04

In the open:

90/76/57 - 20 - 16 - 19 - 24

40 AA g -- 48 - 41 - 47 - 55

105 how. - 07 - 05 - 07 - 08

Difference:

90/76/57 - 09 - 04 - 05 - 11

40 AA g -- 18 - 09 - 10 - 21

105 how. - 04 - 01 - 02 - 04

Analysis of the chance of hitting a Panther G (90 mm gun):

In the open (1000m): 30

Hull down position: 17

Difference: 13

Chance of hitting the hull: 43,33

In the open (1200m): 24

Hull down position: 13

Difference: 11

Chance of hitting the hull: 45,83

Analysis of the chance of hitting a Panzer IVG (90 mm gun):

In the open (1000m): 26

Hull down position: 14

Difference: 12

Chance of hitting the hull: 46,15

In the open (1200m): 20

Hull down position: 9

Difference: 11

Chance of hitting the hull: 55

[Jeff Duquette]

This was some REAL WORLD™ data I plotted and posted the last time this topic came up. British Army Test firing conducted during the war in order to compare hit probability against both hull-up and hull-down targets. At short range the benefits to a hull down target (relative to hit probability are low). As range increases the hull-down tank gains a lot of advantage over a hull-up tank. Intangibles not covered in the test data include reduction in visible target size at all ranges. Presumably this will result in decreased probability in spotting hull-down targets.

http://www.geocities.com/jeffduquette/stuff/hullup_hulldwn.html

Two things that should be at work here:

1)Reduced ability in spotting of hull-down targets

2)Reduced hit probability against Hull-down targets at moderate to long ranges

[Jeff Duquette]

This was some REAL WORLD™ data I plotted and posted the last time this topic came up. British Army Test firing conducted during the war in order to compare hit probability against both hull-up and hull-down targets. At short range the benefits to a hull down target (relative to hit probability are low). As range increases the hull-down tank gains a lot of advantage over a hull-up tank. Intangibles not covered in the test data include reduction in visible target size at all ranges. Presumably this will result in decreased probability in spotting hull-down targets.

http://www.geocities.com/jeffduquette/stuff/hullup_hulldwn.html

Two things that should be at work here:

1)Reduced ability in spotting of hull-down targets

2)Reduced hit probability against Hull-down targets at moderate to long ranges

[offtaskagain]

This brings up the old King Tiger front turret penetration stuff. Here's a pic of how small the front of the turret was.

The turret is far smaller than the glacis plate and it would really benefit from hull down.

This pic shows a little closer just how little of the turret armor plate is actually not covered by the mantlet, which was effectively not able to penetrated. Also the side turret plates would extened a fair distance into the face of the turret providing more protectin.

[offtaskagain]

This brings up the old King Tiger front turret penetration stuff. Here's a pic of how small the front of the turret was.

The turret is far smaller than the glacis plate and it would really benefit from hull down.

This pic shows a little closer just how little of the turret armor plate is actually not covered by the mantlet, which was effectively not able to penetrated. Also the side turret plates would extened a fair distance into the face of the turret providing more protectin.

[Redwolf]

The same issue applies to the Panzer IV.

The part of the turret front that is not heavily angled is small. And most of it covered by the gun mantlet, which is about 30mm.

However, the angles sides of the turrets of King Tiger and Panzer IV mean that shots from 9-10 and 1-2 o'clock may be more dangerous than for a square turret. CMBO does not model this additional weakness, so that makes (partly?) up for the raised turret front size.

What about the gun mantlet? Does anybody know for sure whether the gun hits that CMBO models are gun mantlet hits and will prevent a turret penetration (at the risk of gun damage)? or is gun damage "standalone", not lowering the turret front penetration probability?

[Redwolf]

The same issue applies to the Panzer IV.

The part of the turret front that is not heavily angled is small. And most of it covered by the gun mantlet, which is about 30mm.

However, the angles sides of the turrets of King Tiger and Panzer IV mean that shots from 9-10 and 1-2 o'clock may be more dangerous than for a square turret. CMBO does not model this additional weakness, so that makes (partly?) up for the raised turret front size.

What about the gun mantlet? Does anybody know for sure whether the gun hits that CMBO models are gun mantlet hits and will prevent a turret penetration (at the risk of gun damage)? or is gun damage "standalone", not lowering the turret front penetration probability?

[gredeker]

<blockquote>quote:</font><hr>Originally posted by panzerwerfer42:

This brings up the old King Tiger front turret penetration stuff. Here's a pic of how small the front of the turret was.

The turret is far smaller than the glacis plate and it would really benefit from hull down.

<hr></blockquote>

Some would say that a KT is always hull down...

[gredeker]

<blockquote>quote:</font><hr>Originally posted by panzerwerfer42:

This brings up the old King Tiger front turret penetration stuff. Here's a pic of how small the front of the turret was.

The turret is far smaller than the glacis plate and it would really benefit from hull down.

<hr></blockquote>

Some would say that a KT is always hull down...

[Fangorn]

Thanks Jeff,

Those numbers are high, imho, but they show well the big difference between hitting a hull down and a hull up tank. I think the chance to hit the turret in CMBO is a bit too high.

Take a look at the size ot a King Tiger's turret, it's very small! I'll and the KT to my tests later to check the difference.

[Fangorn]

Thanks Jeff,

Those numbers are high, imho, but they show well the big difference between hitting a hull down and a hull up tank. I think the chance to hit the turret in CMBO is a bit too high.

Take a look at the size ot a King Tiger's turret, it's very small! I'll and the KT to my tests later to check the difference.

[Fangorn]

Results for the King Tinger:

@ 600 m

Hull down - Hull up - difference - relative difference

90/76/57 - 33 - 54 - 21 - 38,88%

40 AA g -- 70 - 91 - 21 - 23,07%

105 how. - 40 - 23 - 17 - 42,5%

@ 800 m

Hull down - Hull up - difference - relative difference

90/76/57 - 25 - 42 - 17 - 40,47%

40 AA g -- 58 - 81 - 23 - 28,39%

105 how. - 14 - 25 - 11 - 44%

@ 1000 m

Hull down - Hull up - difference - relative difference

90/76/57 - 18 - 33 - 15 - 45,45%

40 AA g -- 45 - 70 - 25 - 35,71%

105 how. - 08 - 15 - 07 - 46,66%

@ 1200 m

Hull down - Hull up - difference - relative difference

90/76/57 - 14 - 25 - 11 - 44%

40 AA g -- 36 - 58 - 22 - 37,93%

105 how. - 04 - 09 - 05 - 55%

[ 11-16-2001: Message edited by: Fangorn ]</p>

[Fangorn]

Results for the King Tinger:

@ 600 m

Hull down - Hull up - difference - relative difference

90/76/57 - 33 - 54 - 21 - 38,88%

40 AA g -- 70 - 91 - 21 - 23,07%

105 how. - 40 - 23 - 17 - 42,5%

@ 800 m

Hull down - Hull up - difference - relative difference

90/76/57 - 25 - 42 - 17 - 40,47%

40 AA g -- 58 - 81 - 23 - 28,39%

105 how. - 14 - 25 - 11 - 44%

@ 1000 m

Hull down - Hull up - difference - relative difference

90/76/57 - 18 - 33 - 15 - 45,45%

40 AA g -- 45 - 70 - 25 - 35,71%

105 how. - 08 - 15 - 07 - 46,66%

@ 1200 m

Hull down - Hull up - difference - relative difference

90/76/57 - 14 - 25 - 11 - 44%

40 AA g -- 36 - 58 - 22 - 37,93%

105 how. - 04 - 09 - 05 - 55%

[ 11-16-2001: Message edited by: Fangorn ]</p>

[c3k]

Gents,

All this hull-down or hull-up talk is great. But I've got one small question: how do you manage to ensure your tanks are hull-down?

I always seem to either drive them too far forward, thus exposing their pale, soft underbellies to every penetrating weapon in my opponent's tool chest, or I leave them short of the crest, safe, but unable to affect the battle.

How do you determine the hull-down location? Is it just experience (backed by many burning hulks), or is there some sort of marker I'm missing?

Thanks,

Ken

[c3k]

Gents,

All this hull-down or hull-up talk is great. But I've got one small question: how do you manage to ensure your tanks are hull-down?

I always seem to either drive them too far forward, thus exposing their pale, soft underbellies to every penetrating weapon in my opponent's tool chest, or I leave them short of the crest, safe, but unable to affect the battle.

How do you determine the hull-down location? Is it just experience (backed by many burning hulks), or is there some sort of marker I'm missing?

Thanks,

Ken

[Redwolf]

And another question:

Are you guys sure that the angle change of different elevation is being taken into account?

For example, if you shoot from a hill at a Hetzer's front, is the effective angle really reduced in the CMBO engine? And/or if you stand on a forward slope with a Hetzer, is it more vulnerable.

I know that all people assume that, but did anyone see Steve or Charles claiming that the CMBO engine does this and/or tested this (A Sherman 75 should do the hill test nicely).

The reason I ask is that I gained the impression that the CMBO engine really does only two angle computation:

- a vertical angle from the tanks shape

- combined with a horizontal angle from the shooters position

And no other angle computation, that means the vertical position of the shooter is not taken into account.

So anyone knows for sure?

[Redwolf]

And another question:

Are you guys sure that the angle change of different elevation is being taken into account?

For example, if you shoot from a hill at a Hetzer's front, is the effective angle really reduced in the CMBO engine? And/or if you stand on a forward slope with a Hetzer, is it more vulnerable.

I know that all people assume that, but did anyone see Steve or Charles claiming that the CMBO engine does this and/or tested this (A Sherman 75 should do the hill test nicely).

The reason I ask is that I gained the impression that the CMBO engine really does only two angle computation:

- a vertical angle from the tanks shape

- combined with a horizontal angle from the shooters position

And no other angle computation, that means the vertical position of the shooter is not taken into account.

So anyone knows for sure?

[Fangorn]

I've used a plan map and walls to creat the hull down position.

All units are regular and the guns are in the very edge of woods (the results would be better if they in open ground, but that would be unrealistic).

Redwolf,

Yes, I am quite sure CMBO does compute this. Firing from a higher ground reduces the effective slope of the enemy's armor. Place a hetzer in the top of a hill and in hull down position and you'll get a nice 70º slope or more.

One thing CMBO does not allow is direct gun fire hitting the top of armor. In those cases the tank will be in hull down position, and harder to hit. The same thing happens when a panzerschreck in the secound stage of a building tries to hit a nearby tank.

[ 11-16-2001: Message edited by: Fangorn ]</p>

[Fangorn]

I've used a plan map and walls to creat the hull down position.

All units are regular and the guns are in the very edge of woods (the results would be better if they in open ground, but that would be unrealistic).

Redwolf,

Yes, I am quite sure CMBO does compute this. Firing from a higher ground reduces the effective slope of the enemy's armor. Place a hetzer in the top of a hill and in hull down position and you'll get a nice 70º slope or more.

One thing CMBO does not allow is direct gun fire hitting the top of armor. In those cases the tank will be in hull down position, and harder to hit. The same thing happens when a panzerschreck in the secound stage of a building tries to hit a nearby tank.

[ 11-16-2001: Message edited by: Fangorn ]</p>