Jump to content

IS-2 - front turret and gun mantlet armor - measured


Amizaur
 Share

Hello everyone!

 

Background:

 

I'm a long time fan of wargames focusing on armored warfare (Steel Panthers and CM series, mainly Eastern Front) and also tank sims like Steel Beasts and Steel Fury. Lately I enjoy plaing RT and SM in War Thunder, as it gradually becomes more realistic. I always appreciated high level of detail and accurate, realistic modeling of equipment (like optics) and physical events (like spotting, targeting, shooting, ballistics, armor penetration and post-penetration damage).

As time passes, games (some of them) become more and more realistic with help of much more armor & penetration data available today, than were not available 15 years ago. For example today we know that the mantlet of Tiger I tank is not uniform 100mm, which we believed 15 years ago. For years the 100mm was "official" because it was cited by reputable sources and authors.

Another example is the armor thickness of IS-2 front turret and mantlet armor. But in this case, we still don't have good and reliable information (like production line drawings or precise measurements) up to this day. For years all information available was that it's 100mm thick and that idea of thickening front turret armor/mantlet protection was considered, but was rejected because it would cause the turret to be unacceptably unbalanced.  The turret is rounded and mantlet is not an uniform piece of steel. It's visibly thicker at center and thinner above and below, the new wide mantlet also had some area where mantlet armor and front turret armor overlapps. Some sources claim 160mm thickness for IS-2 front turret armor. Some people wondered if the new wide mantlet was same thickness like old narrow one, or not ?

 

For years I observed people on forums citing various sources (books) and debating which one is more reputable - I wondered why nobody just take a ruler, visit some museum or monument and just measure it to end the discussion ? For almost decade nobody did anything to satisfy my curiousity, so one day I decided to do it for myself. 

 

Fortunately, I live in Poland. There are some nice samples of war production IS-2 tanks in my country, some in museums, some others on monuments. The nearest one is in small town of Lebork some 80km from the place I live - model with new one-piece front hull armor and wide mantlet.

 

IS-2 armor measurements:

 

So one sunny day I just took a ruler, a camera, and went to visit the beast to measure it personally and "just know". Measuring it was not so easy, some parts are hard to reach, some are unreachable from either outside or inside. After putting all the gathered data together, I noticed that some data was not consistent/unambiguous so I visited it again few month later to do some additional measurements and check again some details of armor layout - out that you have to know the armor layout to measure some elements correctly. After that, with this additional data I finally knew the maximum thickness of mantlet armor and was able to reconstruct the armor layout of front turret and mantlet of IS-2. The maximum thickness of the mantlet was 115mm, with about 77mm of thickness for the part covering optics. The tape measure showed 120mm i some places, but it was false result, the edges of the mantlet were extending few milimeters above the main mantlet surface.

 

While visiting friends I had also an occasion to visit another IS-2 example in,  model with an older two-piece front hull armor but same turret (wide mantlet) which is displayed as a monument in Nowa Huta (part of Krakow city). Measuremensts have shown that thickness of the mantlet is almost the same. The "almost the same" thing is probably effect of war production of crude cast armor elements. Maximum "regular" mantlet thickness 115mm, reinforced to 120mm in place near coaxial MG port, the part covering optics was up to 75mm thick.  

 

Few years later I got my hands on simple but functional ultrasonic thickness gauge (OK, OK, I admit - bought it just for armor measuring :-)). So I visited both IS-2 tanks again to confirm my measurements with ultrasonic meter and to measure some armor elements I could not measure with a ruler. Using the meter on a rough surface of crude Russian castings - that were covered with many laters of old paint - turned out to be next to impossible. But after some effort I managed to find some small, smooth places stripped from paint where I got solid readings. There were no problems with measuring RHA plates - they were much more smooth, so finding good place was much easier. Using the ultrasonic thickness meter I could confirm thickness of front armor plates, side armor, side and rear turret armor, and of course front turret. I also confirmed my previous physical measurements of mantlet armor. The Lebork IS-2 - mantlet up to 115mm thick, Nowa Huta - up to 115mm thick too. The only place of mantlet where I got 120mm readings was a flat, reinforced area near coaxial MG port in Nowa Huta tank. But it's not a "normal" shape of IS-2 mantlet.

 

Now I could not only say how thick is armor in various places, but also reconstruct the armor layout of front turret and geometry of mantlet piece - it's theoretical geometry because the real one can differ up to +/-10mm from the "nominal" thickness. The casts are so raw and crude that such differences of  +/-10mm are quite normal when measuring for example thickness of cast front hull armor "plates" in various places. Talking about armor layout and geometry - there were some differences between tanks I measured and drawings I have found on the net. There were also some differences between those two tanks I measured. I guess it's the effect of war production realities - every factory did everything to simplify the production and did their own cast moulds, so tanks from different factories and different production batches varied in details, there were some improvements and some reductions and simplifications also. Details and dimensions that were not very important, were changed if that simplified production. So there are no absolute dimensions. There are only dimensions I measured on two pieces of IS-2 tanks, and using this data I tried to guess what were the dimensions of the original project designed by some intelligent and rational engineer at drawing board. Some big dimensions shown on my drawings are still not measured, for example the exact height of the mantlet piece. I didn't have such a big calliper to do that default_wink.png, the height is derived from other data but it may be not more than +/-10mm off.

 

Finally I satisfied my curiosity. And now while having such load of data, including ultrasonic measurements,  I thought that it may come in useful for others, so maybe I'll do some effort to put all this data together in nice graphical form and publish it on some wargamer's forums. I have also uploaded all photos I did while visiting those tanks, some of them documenting the measurements I did.

 

All results on my work are available for everyone in my public albums on flickr. 

 

https://www.flickr.com/photos/136792894@N05/albums

 

I hope this data will be used to improve armor modeling of IS-2 tanks in Combat Mission Red Thunder and also some other games I enjoy to play (for example War Thuner).

 

Here is link to flickr gallery with my work (drawings based on measuremensts). 

 

   Is-2 Tank - results of armor measurements    https://flic.kr/s/aHskrCY57j

 

   IS-2 tank  - screenshots of War Thunder's IS-2  armor with changes I would reccomend   https://flic.kr/s/aHskrw7yET
 

and galleries with photos documenting my visits and measurements - some interesting photos of exterior and interior of two IS-2 tanks there.

 

   IS-2 Tank, Poland, Lebork 1    https://flic.kr/s/aHskqLEAcw

   IS-2 Tank, Lebork 2, Poland        https://flic.kr/s/aHskrtkGkA

   IS-2 Tank, Poland, Lebork 3 (thickness gauge)    https://flic.kr/s/aHskq9HPoj

   IS-2 Tank, Poland, Lebork 4 (thickness gauge 2)    https://flic.kr/s/aHskqWLgQy

   IS-2 Tank, Poland, Krakow/Nowa Huta 1    https://flic.kr/s/aHskntK6iX

   IS-2 Tank, Poland, Krakow/Nowa Huta 2 (thickness gauge)    https://flic.kr/s/aHskqPsCB6

 

Ih shorts, the results are:

 

- the turret armor of IS-2 tank (model with wide mantlet) is 100mm all around (front, side, rear).

There are some differences due to crude castings, actual thickness vary from 90 to 100mm, with most of turret being 100mm. The armor of rounded parts (mainly front turret left and right of mantlet) becomes thinner up and down, where the angle increases. My drawing of front turret armor profile is approximate, I measured troughly only the front curved parts.

 

- the front turret armor in area of the gunsight port is thinner, about 80mm thick, but it's covered by 75mm thick part of mantlet armor. So armoring of this area is really 75...77mm of mantlet armor + 10-20mm of air + ~80mm of turret armor.

 

- max nominal thickness of gun mantlet armor was 115mm in both tanks I measured.

Mantlet in one tank was a bit "reinforced" in area around MG port and there up to 120mm thickness was measured, but the "original" shape would be 115mm. The mantlet is tapered up and down, becomes thinner where angle to vertical increases. I believe I reproduced the actual geometry of the cast moulds, being two cylinders 660mm in diameter, separated by 115mm (maybe they ment 110mm or 120mm in original plans, but on both tanks I measured it was 115mm). Such "model" when drawn, fits almost exactly to the measured mantlet profile.

 

- the left part of mantlet covering the gunsight port is only 75mm thick.  (maybe close to 80mm in one tank, but 75mm makes more sense - 115mm - 40mm = 75mm). In Lebork IS-2 it may close to 80mm thick at center (where the armor is vertical) and 75-77mm thick at height of gunsight hole. The actual measurements were from 74mm to 77mm at the height of gunsight hole, depending on place of measurement and tank. The IS-2 from Nowa Huta/Krakow was 75mm, the Is-2m from Lebork was bit closer to 80mm.  So again, thickness of that part of armor is combination of 75mm of matlet + 80mm of turret armor.

 

- The mantlet axis (it's thickest part) is about 130mm 33mm above the gun / gunsight axis. In other words, the gun is mounted slightly (33mm) below the thickest part of the mantlet, gun axis is 130mm 33mm below the mantlet axis. 

(the 130mm value has nothing to do with armor thickness!, I talk about mantlet geometry)

 

edit: I had a bug in the line above: the difference between mantlet axis and gun axis is only 33mm (3.3cm) not 130mm. I copied wrong value... 

 

 

The thickness of other parts of armor (the hull) is in accordance with known data:

 

For the older hull (IS-2 mod. 1943) the upper front is 120mm cast, the slanted part 60-70mm thick, lower front hull 100mm thick cast, sides 90mm.  

 

The newer hull with single piece nose (IS-2 mod. 1944) - upper front 100mm thick cast (NOT 120mm), lower front 100mm, the front-side parts of upper hull up to 135mm thick and gradually becoming thinner on their way back, to 90 or 100mm (I forgot to check) where they are welded to the rear 90mm RHA plates.

Lower side hull 90mm.

 

So I can confirm that IS-2m upper front hull plate is 100mm thick for cast front-hulls. And probably it's made from 90mm plates in RHA-made front hulls.

Other thing I can confirm is that front-side belts of IS-2m upper hull are thicker than 90mm - they are up to 130mm thick and War Thunder model is almost correct here. Unfortunately I didn't check those front-side strips of armor for older-hull IS-2 model from Krakow. Will do that on occasion.

 

 

I wonder if I can attach some pictures here... let's try...

 

The mantlet profiles and thickness as measured, mantlet front view with proposed "zones" of armor thickness based on measured profile.

 

23671353710_cf1db316e8_b.jpg

 

Horizontal cross-sectional drawing showing armor layout of IS-2 mod 1944 front turret and mantlet, derived from all the data I collected. The mantlet is sectioned trough gun axis so almost trough thickest part (the difference may be +2mm for thickest part 13cm above).

In lower right of the picture you see original drawing from some Russian manual showing the same armor layout and general thickness proportions of Is-2 turret armor.

 

23338788494_ac14c9f25c_b.jpg

 

Mantlet side profile and original drawing from Russian manual.

 

23858764372_5ae3fa6943_b.jpg

 

Lebork IS-2m

 

23942457386_2647a72514_b.jpg

 

 

Hi there. It's really hard to find good, flat place for ultrasonic gauge on those casts... Place has to be smooth and flat and be either stripped of paint, or at least the paint cant' flake... 

23410361460_dac446565f_b.jpg

 

 

23340435039_44c8f41d55_b.jpg

 

https://flic.kr/p/ByiwAH

 

https://flic.kr/p/Byiw9R

 

https://flic.kr/p/BEFToL

 

https://flic.kr/p/BapsWD

 

https://flic.kr/p/C5vKJQ

 

https://flic.kr/p/BXe4cC

 

https://flic.kr/p/BZwL4R

 

https://flic.kr/p/ByiLyc

 

(side turret)

https://flic.kr/p/C5vQb5

 

 

See other photos in galleries.

 

Regards,

 

Amizaur

 

P.S. If someday I get my hands on IS-2 tank with narrow mantlet, I'll check it too. I wonder it it's the same.

 

P.S. I posted also in Data and Performance Errors part of forum claiming errors in Is-2 armor modeling.

 

I hope my work will allow to correct front turret and front upper hull modeling. If not, my claims can be easily confirmed by someone with access to Kubinka Tank Museum and basic ruler and/or ultrasonic thickness meter.

 

P.S. In those new albums I have uploaded everything related to IS-2 (pictures, schemes, photos) that I found on the net and used to better understand the subject. 

 

https://flic.kr/s/aHskrDhzc2 - 

https://flic.kr/s/aHskohNasS - 

https://flic.kr/s/aHskohNRQf -

https://flic.kr/s/aHskqMzuo8 -

https://flic.kr/s/aHskrDnJFT -

https://flic.kr/s/aHskrLj7Bs -

Edited by Amizaur
  • Upvote 86
medal

Share this post


Link to post
Share on other sites

IIRC Tiger 2 front turret plate is available somewhere in Poland, a dig-out piece of blown-up tank. Without zimmerit. So maybe ;).

medal

Share this post


Link to post
Share on other sites

so....does it mean its op? thats the only thing i care about

Edited by xenon90
medal medal

Share this post


Link to post
Share on other sites

UFP of the IS2 44 kinda is

GAAAAAAAIIIIIIIIJIIIIIIIIIIIIIIIIIIIIIINNNNNNNNNNNNNNNNNNNNNNNNNNNN!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

dxz4lx.jpg

#russianbias

is-2-44 90mm UFP RIGHT NOW!

  • Upvote 6
medal medal

Share this post


Link to post
Share on other sites

GAAAAAAAIIIIIIIIJIIIIIIIIIIIIIIIIIIIIIINNNNNNNNNNNNNNNNNNNNNNNNNNNN!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

dxz4lx.jpg

#russianbias

is-2-44 90mm UFP RIGHT NOW!

Only a prototype of the Is2 1944 had a 120mm front.

Production versions had 90mm for non cast and 100mm for cast.

 

So yes, overperforming, or you can say, ''best case scenario''.

Like the T-34 76 shells having literailly special exclusive ammo from 1943 who performed better.

Otherwise that tank would hardly penetrate 80mm on range.

  • Upvote 15
medal medal medal

Share this post


Link to post
Share on other sites

GAAAAAAAIIIIIIIIJIIIIIIIIIIIIIIIIIIIIIINNNNNNNNNNNNNNNNNNNNNNNNNNNN!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

dxz4lx.jpg

#russianbias

is-2-44 90mm UFP RIGHT NOW!

afaik those are prototype stats...afaik the production ones were 90 (100)mm on the other hand... better armour on Soviet Prototypes that get put ingame like that... T-50 anyone?

 

btw the OP who measured the IS-2 said:

 ''- the thickness of other parts of armor (the hull) is in accordance with known data.  For the older hull, the upper front is 120mm cast, the slanted part 60-70mm thick, lower front hull 100mm thick cast, sides 90mm.  The newer hull with single piece nose - upper front 100mm thick cast (NOT 120mm), lower front 100mm, the front-side parts of upper hull up to 135mm thick and gradually becoming thinner on their way back, to 90 or 100mm (I forgot to check) where they are welded to the rear 90mm RHA plates. Lower side hull 90mm. So I can confirm that IS-2m upper front hull plate is 100mm thick for cast front-hulls. And probably it's made from 90mm plates in RHA-made front hulls. Other thing I can confirm is that front-side belts of IS-2m upper hull are thicker than 90mm - they are up to 130mm thick. Unfortunately I didn't check them for older-hull IS-2 model from Krakow. Will do that on occasion.''
 

Edited by RohmMohc
  • Upvote 4
medal medal medal medal

Share this post


Link to post
Share on other sites

Only a prototype of the Is2 1944 had a 120mm front.

Production versions had 90mm for non cast and 100mm for cast.

 

So yes, overperforming, or you can say, ''best case scenario''.

Like the T-34 76 shells having literailly special exclusive ammo from 1943 who performed better.

Otherwise that tank would hardly penetrate 80mm on range.

i agree see #rusisanbias right here

90mm or go home

 

is2_2.gif

"Новый корпус, с так называемым "спрямленным" носом, сохранил прежнюю толщину брони. Из лобового листа изъяли люк-пробку механика-водителя, существенно снижавшую его прочность. Сам лист расположили под углом 60° к вертикали, что обеспечило при курсовых углах обстрела ±30° непробитие его из 88-мм немецкой танковой пушки KwK 36 даже при стрельбе в упор. Уязвимым местом оставался нижний лобовой лист, имевший угол наклона 30° к вертикали. Для придания ему большего угла наклона требовалось существенное изменение конструкции отделения управления. Однако, учитывая, что вероятность попадания в нижний лобовой лист меньше, чем в другие части корпуса, его решили не трогать. С целью усиления бронезащиты нижнего лобового листа с 15 июля 1944 года на нем между буксирными крюками начали размещать укладку запасных траков."

http://armor.kiev.ua/Tanks/WWII/IS2/is2_1.html

"new "straight" plate kept previous armor thickness"

oops....

i think what gaijin needs to do here is to add an "inconsistent russian armor" modifier that will essentially bring down the thickness to 90mm

like say when you queue up, an rng machine comes up which decides how much armor you will have

90mm min 120mm max

can we at least agree on that one???

Edited by xenon90
  • Upvote 1
medal medal

Share this post


Link to post
Share on other sites

i agree see #rusisanbias right here

90mm or go home

 

is2_2.gif

"Новый корпус, с так называемым "спрямленным" носом, сохранил прежнюю толщину брони. Из лобового листа изъяли люк-пробку механика-водителя, существенно снижавшую его прочность. Сам лист расположили под углом 60° к вертикали, что обеспечило при курсовых углах обстрела ±30° непробитие его из 88-мм немецкой танковой пушки KwK 36 даже при стрельбе в упор. Уязвимым местом оставался нижний лобовой лист, имевший угол наклона 30° к вертикали. Для придания ему большего угла наклона требовалось существенное изменение конструкции отделения управления. Однако, учитывая, что вероятность попадания в нижний лобовой лист меньше, чем в другие части корпуса, его решили не трогать. С целью усиления бронезащиты нижнего лобового листа с 15 июля 1944 года на нем между буксирными крюками начали размещать укладку запасных траков."

http://armor.kiev.ua/Tanks/WWII/IS2/is2_1.html

"new "striaght" plate kept previous armor thickness"

oops....

i think what gaijin needs to do here is to add an "inconsistent russian armor" modifier that will essentially bring down the thickness to 90mm

like say when you queue up, an rng machine comes up which decides how much armor you will have

90mm min 120mm max

can we at least agree on that one???

Mate im just saying that the OP measured the same.

 

The IS2 44's he measured (so production versions) had 100mm cast, or 90mm RHA UFP.

What you are showing here doesn't tell me anything, and a random internet site doesn't tell me something important aswell.

 

You know, can you agree atleast to me that the IS2 44 we have ingame, is literailly the best case-scenario IS2 we can have ingame.

Looking at how it basicly has the proto 120mm armor (or where it comes from) instead of most measured 100-90mm plates in production models.

And don't forget the postwar shell.

 

So please, don't go full retard on me with this. You ask:

 

so....does it mean its op? thats the only thing i care about

Were I say:

 

UFP of the IS2 44 kinda is

What would be true looking at the OP, if you took the time to read:

 

''- the thickness of other parts of armor (the hull) is in accordance with known data.  For the older hull, the upper front is 120mm cast, the slanted part 60-70mm thick, lower front hull 100mm thick cast, sides 90mm.  The newer hull with single piece nose - upper front 100mm thick cast (NOT 120mm), lower front 100mm, the front-side parts of upper hull up to 135mm thick and gradually becoming thinner on their way back, to 90 or 100mm (I forgot to check) where they are welded to the rear 90mm RHA plates. Lower side hull 90mm. So I can confirm that IS-2m upper front hull plate is 100mm thick for cast front-hulls. And probably it's made from 90mm plates in RHA-made front hulls. Other thing I can confirm is that front-side belts of IS-2m upper hull are thicker than 90mm - they are up to 130mm thick. Unfortunately I didn't check them for older-hull IS-2 model from Krakow. Will do that on occasion.''

 

And you respond with:

GAAAAAAAIIIIIIIIJIIIIIIIIIIIIIIIIIIIIIINNNNNNNNNNNNNNNNNNNNNNNNNNNN!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

#russianbias

is-2-44 90mm UFP RIGHT NOW!

 

Seriously?

  • Upvote 4
medal medal medal

Share this post


Link to post
Share on other sites

Hello everyone!
 
I'm a long time fan of wargames focusing on armored warfare (Steel Panthers and CM series, mainly Eastern Front) and also tank sims like Steel Beasts and Steel Fury. Lately I enjoy plaing RT and SM in War Thunder, as it gradually becomes more realistic. I always appreciated high level of detail and accurate, realistic modeling of equipment (like optics) and physical events (like spotting, targeting, shooting, ballistics, armor penetration and post-penetration damage).
As time passes, games (some of them) become more and more realistic with help of much more armor & penetration data available today, than were not available 15 years ago. For example today we know that the mantlet of Tiger I tank is not uniform 100mm, which we believed 15 years ago. For years the 100mm was "official" because it was cited by reputable sources and authors.
Another example is the armor thickness of IS-2 front turret and mantlet armor. All information that is available is that it's 100mm thick and that idea of thickening front turret armor was considered, but was rejected because it would cause the turret to be unacceptably unbalanced.  But the turret is rounded and mantlet is not an uniform piece of steel. It's visibly thicker at center and thinner above and below, the new wide mantlet also had some area where mantlet armor and front turret armor were overlapped. Some sources claim 160mm thickness for IS-2 front turret armor. Some people wondered if the new wide mantlet was same thickness like old narrow one, or not ?
For years I observed people on forums citing various sources (books) and debating which one is more reputable - I wondered why nobody just take a ruler, visit some museum or monument and just measure it to end the discussion ? For almost decade nobody did anything to satisfy my curiousity, so one day I decided to do it for myself. 
Fortunately, I live in Poland. There are some nice samples of war production IS-2 tanks in my country, some in museums, some others on monuments. The nearest one is in small town of Lebork some 80km from the place I live - model with new one-piece front hull armor and wide mantlet. So one sunny day I just took a ruler, a camera, and went to visit the beast to measure it personally and "just know". Measuring it was not so easy, some parts are hard to reach, some are unreachable from either outside or inside, it turned out that the data I gathered was not consistent/unambiguous so I visited it again few month later to do some additional measurements and check again some details of armor layout - it turned oout that you have to know the armor layout to measure some elements correctly. With additional data I finally knew the maximum thickness of mantlet armor and was able to reconstruct the armor layout of front turret and mantlet of IS-2. While visiting friends I had also an occasion to visit another IS-2 example,  model with an older two-piece front hull armor but same turret (wide mantlet) which is displayed as a monument in Nowa Huta (part of Krakow city). Measuremensts have shown that thickness of the mantlet is almost the same. The "almost" thing is probably effect of war production of crude cast armor elements.
Few years later I got my hands on simple but functional ultrasonic thickness gauge (OK, OK, I admit - bought it just for armor measuring :-)). So I visited both IS-2 tanks again to confirm my measurements with ultrasonic meter and to measure some armor elements I could not measure with a ruler. Using the meter on a rough surface of crude Russian castings - that were covered with many laters of old paint - turned out to be next to impossible. But after some effort I managed to find some small, smooth places stripped from paint where I got solid readings. There were no problems with measuring RHA plates - they were much more smooth, so finding good place was much easier. Using the ultrasonic thickness meter I could confirm thickness of front armor plates, side armor, side and rear turret armor, and of course front turret. I also confirmed my previous physical measurements of mantlet armor.
Now I could not only say how thick is armor in various places, but also reconstruct the armor layout of front turret and geometry of mantlet piece - it's theoretical geometry because the real one can differ up to +/-10mm from the "nominal" thickness. The casts are so raw and crude that such differences of  +/-10mm are quite normal when measuring for example thickness of cast front hull armor "plates" in various places. Talking about armor layout and geometry - there were some differences between tanks I measured and drawings I have found on the net. There were also some differences between those two tanks I measured. I guess it's the effect of war production realities - every factory did everything to simplify the production and did their own cast moulds, so tanks from different factories and different production batches varied in details, there were some improvements and some reductions and simplifications also. Details and dimensions that were not very important, were changed if that simplified production. So there are no absolute dimensions. There are only dimensions I measured on two pieces of IS-2 tanks, and using this data I tried to guess what were the dimensions of the original project designed by some intelligent and rational engineer at drawing board. Some big dimensions shown on my drawings are still not measured, for example the exact height of the mantlet piece. I didn't have such a big calliper to do that default_wink.png, the height is derived from other data but it may be not more than +/-10mm off.
Finally I satisfied my curiosity. And now while having such load of data, including ultrasonic measurements,  I thought that it may come in useful for others, so maybe I'll do some effort to put all this data together in nice graphical form and publish it on some wargamer's forums. I have also uploaded all photos I did while visiting those tanks, some of them documenting the measurements I did.
 
All results on my work are available for everyone in my public albums on flickr. 
 
https://www.flickr.com/photos/136792894@N05/albums
 
I hope this data will be used to improve armor modeling of IS-2 tanks in Combat Mission Red Thunder and also some other games I enjoy to play (for example War Thuner).
 
Here are links to flickr galleries with my work (drawings based on measuremensts). 
 
   Is-2 Tank - results of armor measurements    https://flic.kr/s/aHskrCY57j
 
   IS-2 tank  - screenshots of War Thunder's IS-2  armor with changes I would reccomend   https://flic.kr/s/aHskrw7yET
 
and galleries with photos documenting my visits and measurements:
 
   IS-2 Tank, Poland, Lebork 1    https://flic.kr/s/aHskqLEAcw
   IS-2 Tank, Lebork 2, Poland        https://flic.kr/s/aHskrtkGkA
   IS-2 Tank, Poland, Lebork 3 (thickness gauge)    https://flic.kr/s/aHskq9HPoj
   IS-2 Tank, Poland, Lebork 4 (thickness gauge 2)    https://flic.kr/s/aHskqWLgQy
   IS-2 Tank, Poland, Krakow/Nowa Huta 1    https://flic.kr/s/aHskntK6iX
   IS-2 Tank, Poland, Krakow/Nowa Huta 2 (thickness gauge)    https://flic.kr/s/aHskqPsCB6
 
Ih shorts, the results are:
 
- the turret armor of IS-2 tank (model with wide mantlet) is 100mm all around. There are some differences due to crude castings, actual thickness vary from 90 to 100mm, with most of turret being 100mm. The armor of rounded parts (mainly front turret left and right of mantlet) becomes thinner up and down, where the angle increases. My drawing of front turret armor profile is approximate, I measured troughly only the front curved parts.
- the turret armor in area of the gunsight port is thinner, about 80mm thick, but it's covered by 75-80mm thick part of mantlet armor. So armoring of this area is really 75...78mm of mantlet armor + 10-20mm of air + ~80mm of turret armor.
- max nominal thickness of gun mantlet armor was 115mm in both tanks I measured. Mantlet in one tank was a bit "reinforced" in area around MG port and there up to 120mm thickness was measured, but the "original" shape would be 115mm. The mantlet is tapered up and down, becomes thinner where angle to vertical increases. I believe I reproduced the actual geometry of the cast moulds, being two cylinders 660mm in diameter, separated by 115mm (maybe they ment 110mm or 120mm in original plans, but on both tanks I measured it was 115mm). Such "model" when drawn, fits almost exactly to the measured mantlet profile.
- the left part of mantlet covering the gunsight port is only 75 to 80mm thick. It may be up to 80mm thick at center and 75-77mm thick at height of gunsight hole. The actual measurements were from 74mm to 77mm at the height of gunsight hole, depending on place of measurement and tank. The IS-2 from Nowa Huta/Krakow was 75mm, the Is-2m from Lebork was closer to 80mm.  So again, thickness of that part of armor is combination of 75mm of matlet + 80mm of turret armor.
- The most thick part of mantlet is about 130mm above the gun and gunsight axis. In other words, the gun is mounted slightly below the thickest part of the mantlet.
 
- the thickness of other parts of armor (the hull) is in accordance with known data.  For the older hull, the upper front is 120mm cast, the slanted part 60-70mm thick, lower front hull 100mm thick cast, sides 90mm.  The newer hull with single piece nose - upper front 100mm thick cast (NOT 120mm), lower front 100mm, the front-side parts of upper hull up to 135mm thick and gradually becoming thinner on their way back, to 90 or 100mm (I forgot to check) where they are welded to the rear 90mm RHA plates. Lower side hull 90mm. So I can confirm that IS-2m upper front hull plate is 100mm thick for cast front-hulls. And probably it's made from 90mm plates in RHA-made front hulls. Other thing I can confirm is that front-side belts of IS-2m upper hull are thicker than 90mm - they are up to 130mm thick. Unfortunately I didn't check them for older-hull IS-2 model from Krakow. Will do that on occasion.
 
I wonder if I can attach some pictures here... let's try...
 
23671353710_cf1db316e8_b.jpg
23338788494_ac14c9f25c_b.jpg
 
23858764372_5ae3fa6943_b.jpg
23942457386_2647a72514_b.jpg
 
Hi there
23410361460_dac446565f_b.jpg
Regards,
 
Amizaur
 
P.S. If someday I get my hands on IS-2 tank with narrow mantlet, I'll check it too. I wonder it it's the same.
 
P.S. I posted also in Data and Performance Errors part of forum claiming errors in Is-2 armor modeling.
I hope my work will allow to correct front turret and front upper hull modeling. If not, my claims can be easily confirmed by someone with access to Kubinka Tank Museum and basic ruler and/or ultrasonic thickness meter.

Wow, just.... amaizing work
You should post all of this in a bug report. Also you should check if the mantlet overlap the turret armour making it 100+100 mm like in game
medal medal medal

Share this post


Link to post
Share on other sites

Good to see people actually take the time and do measurements of real tanks. Even well known tanks offer quite some interesting new aspects.

 

I duno if that bug report will be approved as gaijin rejects user measurements (see maus)

 

 

Wow, just.... amaizing work
You should post all of this in a bug report. Also you should check if the mantlet overlap the turret armour making it 100+100 mm like in game

 

 

Look at the drawing of measurements. The measurements of the overlaping parts are 75-70+80mm, and for the other side 45-40+115.

 

So to ~155-160mm for the overlapping parts.

Edited by Hornet331
medal medal medal medal

Share this post


Link to post
Share on other sites

Good to see people actually take the time and do measurements of real tanks. Even well known tanks offer quite some interesting new aspects.
 
I duno if that bug report will be approved as gaijin rejects user measurements (see maus)
 
 



 
Look at the drawing of measurements. The measurements of the overlaping parts are 75-70+80mm, and for the other side 45-40+115.
 
So to ~155-160mm for the overlapping parts.

So it s overperforming. Also if those datas are real it means that the turret is very vulnerable at 88 mm fire from tiger I and the hull in game can be pierced by KwK43...
  • Upvote 2
medal medal medal

Share this post


Link to post
Share on other sites

So it s overperforming. Also if those datas are real it means that the turret is very vulnerable at 88 mm fire from tiger I and the hull in game can be pierced by KwK43...

 

Well wada ya know.. just like in RL.

  • Upvote 4
medal medal medal medal

Share this post


Link to post
Share on other sites

I already know.. but finally this is an undeniable confermation. Also for slanted part on the hull it means the cheecks? If those are the cheecks value there is another overperforming value...
medal medal medal

Share this post


Link to post
Share on other sites

Thank you for kind words. I`m really glad that my works are pleasing for someone.

 

"Also if those datas are real it means that the turret is very vulnerable at 88 mm fire from tiger I and the hull in game can be pierced by KwK43... "

 

 

Maybe, from close range... 60deg in real life was really awfull slope for most projectiles, generating slope multiplers close to 3 in some cases. Such armor would give protection of much more than 240mm, I guess it would be around 300mm of RHA or more, depending on shell atacking it.

 

UFP of 120mm sloped at 60deg would be an absolute overkill for IS-2 and unnecesarily weight. The rest of the tank was much less armored.

 

100mm plate slanted at 60deg was enough, even 90mm of RHA was absolutely enough to be invunerable to KwK43 at normal combat ranges. It's twice the armor of T-34 front hull. Probably it could be penetrated sometimes (very unreliably) with KwK43 from very close ranges. So sometimes possible in WT, almost impossible in real life. 

 

If there was any mass budget left after redesign of front hull to single 100mm 60deg plate, it would be better to spend the remaining weight to increase LFP protection than to increase UFP above 100mm. If you took that extra 20mm from UFP you could increase LFP protection by almost 40mm with the same weight. But they didn't do that, at least not in the tank I checked. 

LFP was measured to be 100mm thick for both tanks (1943 and 1944 models).  UFP of 1944 is definitely 100mm thick (ranging from 95 to 105mm depending on place of measure - that'show crude the casting is).

 

[url=https://flic.kr/p/BZJKq2]23625867901_f13fb53ec3_o.jpg[/url][url=https://flic.kr/p/BZJKq2]IMG_0615[/url] by [url=https://www.flickr.com/photos/136792894@N05/]Marcin Ostrowski[/url], on Flickr

 

The "oil" like spills on the armor is actually a glyceryn, which is used to improve sound propagation between the ultrasonic head and the armor steel. It's soluble in water.  was wiped later, first rain removed the rest of it completly.

 

Looking with my eyes at quality of this casting, and knowing properities of high hardness cast steel, I would risk a statement, that IMO a 100mm of cast armor sloped at 60deg and attacked with nearly 1:1 T/W projectile could restist worse than more ductile (even though just as hard) 60deg 90mm RHA plate.

 

The Is-2 mod 1944 visualised in game have cast front hull, not welded one. So 100mm of cast armor on upper front hull.

 

 

You should post all of this in a bug report. Also you should check if the mantlet overlap the turret armour making it 100+100 mm like in game 

 

 

I filled a bug reports for turret/mantlet armor and upper front hull armor. 

 

As for mantlet overlapping the turret armor - check the drawings.  There is 75mm + 80mm of armor there.  There are other overlapping parts but maybe few centimeters wide, so should be ommited as any projectile penetrating armor would just bypass them using gaps in armor to penetrate easier and free edge effects to move away from thicker parts.

 

P.S. In those new albums I have uploaded everything related to IS-2 (pictures, schemes, photos) that I found on the net and used to better understand the subject. 

 

https://flic.kr/s/aHskrDhzc2

https://flic.kr/s/aHskohNasS

https://flic.kr/s/aHskohNRQf

https://flic.kr/s/aHskqMzuo8

https://flic.kr/s/aHskrDnJFT

https://flic.kr/s/aHskrLj7Bs

Edited by Amizaur
  • Upvote 25
medal

Share this post


Link to post
Share on other sites

Good, also i noted that turret armor decrease when the angle increase, meanwhile in WT it all 100 mm
Also link to the bug report? I can t find it -.-
medal medal medal

Share this post


Link to post
Share on other sites

Nice find. Btw it would be a rather useful buff to the turret armor. American 126 mm pen guns could as well just forget it and use only solid shot / APCR against the turret.

medal medal

Share this post


Link to post
Share on other sites

Nice find. Btw it would be a rather useful buff to the turret armor. American 126 mm pen guns could as well just forget it and use only solid shot / APCR against the turret.

actually it's a nerf to the turret armor of Is-2s.....

  • Upvote 4
medal medal medal

Share this post


Link to post
Share on other sites

Also link to the bug report? I can t find it -.-

 

Can't find it, too. I filled the repotrts and posted them, but there was a message that they have to be approved by moderator first... 

 

 

 

actually it's a nerf to the turret armor of Is-2s.....

 

Actually, it's about making it just like the real one, not buffed or nerfed. 

Edited by Amizaur
  • Upvote 1
medal

Share this post


Link to post
Share on other sites

Can't find it, too. I filled the repotrts and posted them, but there was a message that they have to be approved by moderator first... 

yea right.... i forgot that it should be approved before the report is on. Anyway, again good job, that pics show really well the turret/mantlet conformation.

Just a curiosity

i saw that you used glicerina, piece of chart with armor values attached on the turret and so on.... do you asked the permit to someone, or you just went straight there? :lol:

medal medal medal

Share this post


Link to post
Share on other sites

Good, also i noted that turret armor decrease when the angle increase, meanwhile in WT it all 100 mm
Also link to the bug report? I can t find it -.-

ah you see: only Panther can have this because out of some reasons... there the Mantlet is modelled with 5 parts with different thicknesses

  • Upvote 1
medal medal medal medal

Share this post


Link to post
Share on other sites

 Share

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...