Main Battle Tanks and Armour Technology

[STGN]

This might solve a problem with Zaloga's claim.

The placement of tow-cable is the same on all production Abrams with little variance between vehicles, that is at-least my observation.
STGN

 

[Damian]

But what Zaloga says is that not the armor is 9 inches thicker but that distance between cable attachement to the front armor edge is 9 inches greater.

 

[STGN]

But what Zaloga says is that not the armor is 9 inches thicker but that distance between cable attachement to the front armor edge is 9 inches greater.

Because the location of the cable is the same on both M1 and IPM1, the armor would have to be increased by 9" on the x axis if the distance was to be 9" greater which its not its ~6" greater.
STGN

 

[methos]

Well that is one of them. And the question you are asking is can you ever be sure of anything? which is a philosophical question you have to answer for yourself but do you really think there is room there for both? and how did it get out with the springs still attached?

My question was rhetorical. Take a look at the images Damian posted earlier. You can see there that the armour at the turret bustle is intact, while the armour at the sides of the crew compartment is damaged. Now in the image I posted is not a single evidence that the armour at the crew compartment was damaged, still you assume so.
Then the next point is, why would the outer steel layer of the damaged armour section be bend, if that wasn't done by anything like the coiil-spring array?
And please note the turret's position and the position of the coil-spring armour array: Why is the coil-spring array located on top of the engine compartment, if the location were you claim it would be is nowhere near the crew compartment? Did the tank crew take the armour from the side and lift it at the top of the engine compartment?

The most reasonable tool someone can use for estimating armour thickness/arrays etc. should be the logic. And logic does not support your claims, but rather speaks against them.

Look I realize you haven't spent too much time trying to model the Abrams but what you think you are seeing is not the whole picture, look hard at page 195 in Hunnicutt you will hopefully see what you are missing.

Page 195 does not show anything in relation to the armour thickness, just a tank with fully installed roof laking the main sight. If you took a look at the image excerpt from the turret rebuild or at the drawing from Damian, you would notice however that the armour ends in front of the main sight (or about at the location of the ballistic cover), not inside the main sight tunnel as shown by your CGI.

Have you ever tried to take a photo of a M1 Abrams and extend the turret by 9"? Try it some day, then compare to real M1A1 Abrams photo.

The difference between T-72A and T-72B armour is also about 9 inches. There is not much difference in appearance also.
In case of the M1 and M1A1 the turret armour is definetly thicker, I cannot say how much thicker with my pure eye. But when I have to choose between an author who did the measurement on the actual tank and someone who uses a CGI and also extended the armour to far into the crew compartment, I rather believe the first mentioned.

I think I actually confirmed Micheal Green, the whole array is 2 feet thick, its just sloped.

No, your unreasnable. How would it be logical to measure the tank's turret without taking the slope into account, when he is talking about actual frontal protection?
Besides there is still a 10% difference between your figures and that of Green.

What kind BS is this, M60 copula, you could not insult me more. So I gather that you have never really looked properly at the CATTB turret, try again and you will realize that it uses a M1 copula with the MG removed.

It neither an insult nor bullshit. It is the simple truth: The CATTB has a completely new turret with two men crew and autoloader. Just because something looks similar (and it doesn't really), it doesn't have to be the same. Especially since I provided you proper data for the hatch size you simply ignore. You also notice that the commander is located at the other side of the turret in CATTB?
The engine comparment in the hull was also redesigned.

Interesting, the hole for the loader is 22" wide and the commanders is ~20" wide and ~14" long which is an average of 17".

It says that the width is 17 inches, not the average of length and width. Also the value 22 inches is only supported by one source, another source (and also the CAD drawings from P. Matthews) give 19 inches.

So what do you think, is it way off?:

Do you want to ask me how it looks like, considering that the Leopard 2 armour looks like 65 cm for Taransko and looked like 100 cm for Paul Lakowski; that the turret width of the Arjun looked like 3.2 m for some Indian members of the forum.
But if you really insist: On Thunderbolt the driver's sights weren't completely covered by the turret front.

 

[militarysta]

Well my hypothesis is that the springs does one thing and that is too keep the array in place, they would be almost completely compressed, the array weight is supported by the bottom of the armor cavity. Whether or not there is something behind it is off cause unknown. But it seems strange to me that there would be springs and something behind it to support it, why not just remove the springs then.
STGN

Intresting discuss is starting no, as I see..
My old post from here:

Burlinghton works due to 3 diffrent but working in the same time mehanism - propably whole armour from front to backplate worke as one and whole armour can be decribe as Burlinghton. Those "special armour" 50cm block is only one component work on most semi-active way.
Details:
NERA efectivness is taken from moving HHS plates -the moving layer is energeting but not explosive polimer or aramid (etc.) layer between two HHS plates whit hight density. Optimum angle is 30-45. degree for that kind of armour
Burlinghton working mehanism is not explosing too but it's work on slightly diffrent principles then NERA:
a) "plate bending" - it's only one simmilar to NERA working mehanism when thin metal plates are moving so in result attackin HEAT jet or penetrator is still attacked by "new" moving meterial (made by HHS plate), and crosses the moving jet/penetrator line.
b) "spall debris"-this mehanism is depend on moving small debrits (which arising from armor attacked armour) into penetrator or jet line - IMHO it's somethng like secondary forced fragmentation used now in PELE rounds:
http://www.dtic.mil/ndia/2005garm/wednesday/borngen.pdf
when propably during penetration process HHS steel small parts (made by working APFSDS penetrator) hit in inner layers and those small debrits made by penetrator are caught by nonmetalic layer and push back in to penetrator way (path). It's simmilar in working to PELE munition but reverse.
c) whistle" effect -this is most mysterious part of working mehanism in burlinghton armour -it's not descibe yet in literature. I suppose that this mehanism work on principles referrals energy in a different direction -propably during working a) and b) mehanis.
Those 3 mehanism - "plate bending", "spall debris" "whistle" effect" are decribe in those aricles about Burlinghton. Names are taken from offical Burlinghton files.
If those knowledges and my assumptions? I think Yes. Ironnicly we know layout in M1A1 and Leopard-2A4, and it's armour layout in accordance with those what we known about Burlinghton.

On Open M1A1 side armour we can see simmilar layout:

B is without doubt NERA layers
C is Burlinghton ("sandwich)
So more then 65-70% of physical thickness is taken by two active working layers: B (more active - NERA) and simmilar but works slighlty diffrent "special armour" C layer.
And after that we have very simmilar to leo2A4 layout:
Thick HHS layer (A) and three non metalic layer (D-E-D) and inner backplate (A). It's almoust the same layout like in Leo-2A4. Only one exception is first active layer B (NERA) -in Leopard-2 is thinner armour so those layer is outside main armour (NERA wedges in Leo2A5-A7).. In very thick main M1A1/A2 armour where possible to place NERA inside armour as we can see.

 

[militarysta]

And My point of viev about Leopard-2 armour:

On west the have two advantages: Burlinghton armour and NERA.

http://www.wceo.wp.mil.pl/plik/file/WBBH/PH-W/PHW_4.pdf
http://www.wceo.wp.mil.pl/plik/file/WBBH/PHW3_tresc.pdf
In middle 1970 there was dependence between protection against APFSDS and HEAT
430 and 585mm RHA (1 to 1,36), but Increased armour protection against HEAT to 850mm RHA resulted with a decrease in armour protection vs APFSDS to "only" 405mm (1 to 2.09) etc -so the question is what was most important for germnas? In fact in the text are three important depending:
a) in 1964 the predecessor of the Burlington had mass Efficiency like ~1 vs APFSDS and ~2 vs HEAT in compared to homogeneous armor steel (RHA in tekst) of the same weight
b) In 1978 Burlinghton special armour had mass Efficiency like 1,5 vs APFSDS and 3 vs HEAT in compared to homogeneous armor steel (RHA in tekst) of the same weight
c) there was some ratios between protection against APFSDs and HEAT and there wasn't linear like this 430/585 and 405/850

And it is really posible exatly due to " thickness and KE requirement":
We have some dates (with bibliography of course). In 1978 Burlinghton special armour had mass Efficiency like 1,5 vs APFSDS and 3 vs HEAT in compared to homogeneous armor steel of the same weight.
So 1kg Burlinghton armour shoud offer protection like 1,5kg homogeneous steel armor vs APFSDs and 3kg homogeneous steel armor vs HEAT (of course it is only example).
Dimensions leopard-2 gun mantled mask are known, the same dimensions of blanks for L-44, FERO, and MG. And we know mass of gun mantled mask - 630kg. Rest is rather simple math base on qustion- how thick will be homogeneous steel armor block "inside" gun mask dimensions if it will be weight 950kg (630kg x1,5 vs APFSDS) and 1890kg (630kg x3 ve HEAT). The answer is:
a) 272 mm
b) 542 mm
So this protection offer by gun mantled mask should be:
a) 270 mm vs APFSDS
b) 540 mm vs HEAT


And If we want to talk about armour mass we should consider fact that if for erly burlinghton 1Kg Burlinghton armour = 1,5kg RHA vs KE and 3kg RHA vs HEAT then Leopard-2A4 turret with weight 16000kg (without crew, ammo, attachments) whit "special armour" weight equal 8900kg is like: 13.350kg RHA vs APFSDS and 26700kg RHA vs HEAT and it's the lowest ratio for 1978 not 1985. in reality it could be even better.

If we realize that gun mantled mask area in leopard-2 (420mm) is exactly half the thickness of front turret LOS armour (840mm), then we consider if Leopard-2A4 protection will be like:
~540mm vs APFSDS
~1080mm vs HEAT.
Of course it's based on Burlinghton mass Efficiency from 1978 and definitely Leopard-2A4 from 1985/1986 have diffrent (stronger?) armour then erly leopard-2A0-A2 from 1980/1982. Another question is how cloes to the Burlinghton was German special armour - we know that in 1974 Germans have full aces to the americans Burlinghton branch development program.

It's first proof, second one is simpler - why to hell near 1984-1985 sowiet start to developed and introduce SC (HEAT) warhed whit 900-1100mm RHA penetration? Metis, new Fagot, Ataka, Wihr, atc.

I't very simple to check how big protection Soviet developers try to overcome:
IMPORTANT - whole development cycle to create a new weapons take about 4-6 years, sow if some ATGMS start service in 1985 (ex:9M120) it means that its development started around 5 years erlyier (around 1980)

time before Burlinghton:
9M111-2 (Fagot 1975) - 460mm RHA
Konkurs - 1974 - 600mm RHA
9M112M (Kobra 1976) - 600mm RHA

time when first idea about Burlighton went to Soviet Union:
9M111M (Fagot 1983) -600mm RHA (development phase around 1978)
9M112M (Kobra "imroved" 1985) -700mm RHA (development phase around 1980)


little panic in ATGM thema:
9M120 (1985) - 950mm RHA (development phase around 1981)
Wihr-M (1990) -1000mm RHA (development phase around 1985)
9M115-2 (1992) -980mm RHA (development phase around 1988)
9M133-1 (1994) 1200mm RHA (development phase around 1989)
Since ~1985 in soviet developers studios they decide to incerase ATGMs SC (HEAT) penetration up to 1000mm RHA and more. Why? The same Leopard-2A4 turret, the same M1IP surret, but aloust twice better penetration then in 1980-1985 period.


Third prooof. Leopard-2 have very advanced laser trening system :
About AGDUS -it's laser posoration system (MILES type) - eacht tank, soilder, ATGM, etc have lasser system for one battalion (II) to practise trening.
AGDUS shoud be opspec due to rather realistic damage models included in that system. Some idiot from 10TkBDe post it in the internet. His problem not mine, so I can say few wors more.
In AGDUS (In Leopard-2A4 case) you have 6 tank area when you can take hit from enemy:
a)turret front
b) hull front, hull rear, hull side in genneraly
c) turret side
d) turret side at ammo rack (turret bustle)
e)hull side at ammo hull rack
f) hull side at turret basket

In AGDUS you have that possibility of beeing hit by enemy:
"-thurm aus" (turret faliture mode -there are several options)
"-destroyed"
-"Watch out!" (or - be cearfull)
-"No interaction"
-"engine off"
-"partial destroyed"

And you have 7 clas of "enemy thread" (of course it can by modifity):
1)
(...)

4)
HOT/PAH <3800m
HOT/JAGUAR <3800m
TOW <3000m

For Leopard-2A4 from circa 1985 in AGDUS system variant for taken hit in turret front, form group nr.4 (HOT/PAH, TOW) is not "destroyed" or even "partial destroyed". In fact AGDUS developers was sure that for Leopard2A4 direct hit in turret front by TOW/HOT/PAH will not destroyed tank. And as I know HOT/PAH and TOW had around 1000-1200mm RHA in end of 1980s.

So those values:
protection for Leopard2A3 and 2A4 (erly) can be as:
~430-480-540mm vs KE and 850-954-1084mm vs HEAT (turret sides at 30. and hull front - turret front at 30. - turret front at 0.)

For Leopard-2A4 since 1986 IMHO it will be slighty bigger:
500-550-630mm vs KE and -1000-1150-1300mm vs CE ((turret sides at 30. and hull front - turret front ad 30. - turret front at 0.)

Are really posible and consistent with a number of clues.

No, you don't understand. In AGDUS you can program many factors. I had acess only to small part with Leopard-A4 and typica PancerGranadier batalion equpment in ITOW, HOT-2 and others. And Leopard-2A4 turret was not destroyed after take frontal hit by those ATGMS. In worst scenario (HOT-2/TOW-2 in EMES sight area) AGDUS ordered to go in to one of the three failure modes for turret in Leopard-2A4. But there was no "partial destroyed" or "destroyed". In fact creators of the AGDUS where sure that ATGM whit tandem warhed and with perforation between 800-1000mm RHA is not able to kill Leopard-2A4 after frontal hit. And they known what thed did. And AGDUD values are diffrent for Leopard-2A5/A6, Leopard-2A3, TOW-2A, etc.

Rather all evidence proof that Burlinghton-style armour in M1IP and Leopard-2A4 provide the possibility of obtaining more than 800-1000mm vs HEAT:
a) technical possibilities Burlinghton armour in that dimensions and weight (armour LOS, and known armour weight)
b) soviet ATGMs penetration values and it's very fast grow in erly 1980s.
c) known fact about AGDUS and it's damage models included in Leopard-2A4 and TOW/HOT (creators of the AGDUS where sure that ATGM whit tandem warhed and with perforation between 800-1000mm RHA is not able to kill Leopard-2A4 after frontal hit)
d) "life test" from ex: ODS when M1A1HA take frontal hit by AGM-144 (more then 1000mm RHA penetation) and there was no perforation.
e) complete lack of any ( well known on west) ERA protection on western IIIgen tanks during whole 1980s.
More or less all evidence proof that Burlinghton amour had circa about 1000mm RHA vs HEAT in late 1980s.

 

[militarysta]

And I made mistake in compare mas (kg of armoured steel) in turret armour for T-72B and Leopard-2A4.

T-72B nacked turret weight not 11 600kg but, only circa 8 688 kg. It change a lot.

First I will make sevral general assumptions:

1. Leopard-2A4 turret have frontal volumen 25% bigger then T-72B.
2. BUrlinghton style armour in Leopard-2A4 have mass efficiency -at lest 1,5 x kg vs KE and at lest 3 z kg vs HEAT -according to the data from 1978, and posted in two greate articles about erly Burlinghton ( I've already quoted them before)
3. The same mass efficiency is taken for T-72B "NERA style" special armour -maybe it's revaluation but I'd rather prefer to overestimated soviet tank then understimated.
4. In T-72B 80% turret mass is taken for frontal protection (+/- 30.degree) - rest (20%) of nacked turret mass is taken for roof, rear sides and turret back. So from 8 680kg it give 6 950kg (inluding NERA special armour). Both NERA armour inserts weight 740kg, so rest of turret armour weight 6 210kg.
5. From known Leopard-2A4 "special armour mass" 8 900kg ~22% is taken for turret sides, so only frontal armour (+/-30 -without turret sides) we have 6 942kg

Now small compare:
T-72B 6 210kg of cast steel turret x0.9 as RHA converter = 6 210kg x0,9= 5 588kg. So whole cast steel T-72B turret armour act like 5 588kg RHA. Now "special armour" cavities (both NERA inserts).
Against APFSDS: 740kg x 1,5 = 1100kg, and against HEAT: 740kg x 3 = 2220kg. So those values are RHA equivalent, and we shoud add them to previous mass.
5 588kg + 1100kg RHA= ~6 688 kg stell armour vs APFSDS
5 588kg + 2200kg RHA= ~7 788kg stell armour vs HEAT


Leopard-2A4 turret weigh 16t, special armour weight 8 900kg, 22% of it ist taken for turret sides, so for +/-30. we have only 6 942kg of special armour. Now x 1,5 vs APFSDS and x 3 vs HEAT:
10 410kg RHA vs APFSDS
20 826kg RHA vs HEAT

Now compare for both tanks:


vs APFSDS
T-72B : 6 688 kg stell armour vs APFSDS
Leopard-2A4: 10 410kg RHA vs APFSDS

So leopard-2A4 armour have 35% more kg of steel armour for protection. Even after taking into account 25% bigger front turret, we have still 10% diffrence against T-72B.

vs HEAT:
T-72B ~7 788kg stell armour vs HEAT
Leopard-2A4: ~20 826kg RHA vs HEAT

So Leopard-2A4 have ~63% more kg of steel armour for protection. Even after taking into account 25% bigger front turret, we have still 38-40% diffrence against T-72B.


So as I wrote -in reality, Soviet cast steel turets shoud have less density protction in kg of RHA plates equivalent. And whe take only one from many factor - how many kog of steel plates is placed in some volumen. When we included other factor like:
- higher hardnes of western plates included in armour
- fact that stack of steel plates whit the same weight and thckness is 1.2 better then RHA monoblock
and others
then this difference will be even greater (against soviet tanks)..[/QUOTE]

 

[militarysta]

@STGN
and here part of translate by mayself those polish artcile about Burlinghton armour:

Rosyjscy autorzy podają, że to układ grodziowy
z przegrodami z pÅ‚yt przekÅ‚adkowych z materiaÅ‚em inercyjnym (zob. Zaszczita tankow..., s. 125–126), co wyraźnie
nawiÄ…zuje do możliwej do zrekonstruowania na podstawie materiałów źródÅ‚owych postaci "žBurlingtona" oraz jest
argumentem za brytyjskim rodowodem niemieckiego pancerza.

Translate:
Russian autors claim that (erly Leopard-2 armour) is "the bulkhead system" whit layers whit inert material inside (so NERA...). This clearly refers to the very erly possible Burlinghton shape and mehanism and is argument in favor of a British pedigree of German armor.

Do listopada 1970 r. Niemcy uzyskali wiedzÄ™ z poziomów 1–4. (...) W maju 1972 r., podczas
spotkania poświęconego przyszłemu czołgowi podstawowemu, Brytyjczycy przekazali
Niemcom większość informacji technicznych z zastrzeżeniem wykorzystania wyłącznie na
potrzeby FMBT76. W lutym 1974 r. za zgodą Brytyjczyków pewną wiedzą o pancerzu podzielili
się z RFN Amerykanie77. Zgodnie z założeniami programu Chieft ain mk 5/2 oraz
Leopard 2 miały pozostać wozami przejściowymi i wejść do służby do połowy lat siedemdziesiątych.
FMBT byłby gotowy dekadę później.
Ambitne plany nie zostały zrealizowane, gdyż w 1976 r. Niemcy przerwali współpracę78.
W ocenach brytyjskich był to celowy zabieg, umożliwiający wykorzystanie zdobytej wiedzy
głównie na temat "žBurlingtona" bez koniecznoÅ›ci ponoszenia kosztów nabycia technologii79.
Jeszcze w drugiej połowie 1973 r. Niemcy skompletowali prototyp Leoparda 2 z wieżą
z osłoną warstwową, w 1975 r. ukończyli budowę wozu tzw. drugiej generacji z pancerzem
specjalnym – Leoparda 2AV – "žskrojonego" z myÅ›lÄ… rywalizacji o kontrakt na czoÅ‚g podstawowy
Armii Stanów Zjednoczonych80.

Translate:
Until november 1970 Germanc recive acces to the 1-4 levels (about Burlinghton -milit.). I may of the 1972, during meting about new future main battle tank, The British handed over Germany, most of the technical information about Burlinghton -but to use only durig working at
FMBT76 program. In February 1974,with the consent of the British, Americans shared some knowledge of Burlinghton armor with Germnas. According to the program FMBT76 both tanks: Leopard-2 and Chieftain mk 5/2 shoud be "temporary" and came into service in midlle 1970's -and new (the target) FMBT will be ready a decade later. Ambitious plans have not been implemented, becouse Germans break out cooperations in 1976. In british oppinion it was "deliberate action" - allowing using of knowledge about "Burlington" without having to pay the cost of acquisition of technology.
Rest is about that in 1973 Germnas ended Leopard-2 prototype whit layerd armour, and in 1975 the ended building tank with second generation "special armour" -Leopard-2AV - prepered to USA trade.

W konfi guracji z przełomu lat sześćdziesiątych i siedemdziesiątych, w konfrontacji
z amunicjÄ… kumulacyjnÄ… "žBurlington" byÅ‚ od 2 do 3 razy skuteczniejszy od jednorodnego
pancerza stalowego o tej samej masie – przy zbliżonej odpornoÅ›ci przeciwko pociskom
kinetycznym.

Translate:
In configuration from at the turn of 1960/1970, against SC warhed "Burlinghton" was 2-3times better then monolithic steel armour whit the same mass, and had (Burlinghton armour-milit.) similar resistance (as those monolithic steel armour ) against kinetic energy rounds.

Efektywność masowa nowych odmian osÅ‚ony wzrosÅ‚a do 1,3–1,5 przeciwko amunicji kinetycznej i do ponad 3 przeciwko gÅ‚owicom kumulacyjnym116 (...)
116 Ibidem, DEFE 68/69, Preliminary systems study of MBT 80 main armament, 1978, s. 3.

Translate:
The mass efficiency of the new armour variants (Burlinghton -milit) increased to 1.3-1.5 agains KE and do more then 3 against SC warhed (HEAT) This part is about Burlinghton from circa 1978r.







Translate part 1:
In the second half of the seventies began to pay more attention to the protection against kinetic munitions. "Biscuits" (Burlinhton-milit.) developed for Chieftain mk 5/2 was able to stop 105 mm APDS shot virtually "with relief" (0m distance) or 120 mm APDS from a distance
1200-1300m. In 1975 in the United States, "Americanized" armor was successfully tested against 152 mm XM578 APFSDS munition and HEAT projectiles (unspecified caliber) which represented the expected level of the warhed in 1980s'. The bigger challenge was more modern sub-caliber (APFSDS) ammunition. During one of the tripartite weapon test (UK, FRG, USA about main gun -milit) one APFSDS fired from a German smoothbore 120mm gun overpass on of he "Cobhan" armour variant whit velocity simulating the hit from 6000m distance. Developed heavier version of the armour was however, pierced only from 200m distance.


Translate part 2:

Later, the designers were able to increase the resistance of the modules. At the beginning of 1970, reported: "All technical problems attaching armor so that it have the ability to repel (windstand) many attacks have been overcome. For example, the first module of the front of the hull withstood (survive?): 9 SC warhed attack, including 5 SC whit 152mm caliber (diameter) and 4 whit 127 mm caliber (diameter). Second (Buringhton module -milit) stopped 120mm HESH round, which was followed by many 127mm diameter SC warhed hits. The other (Burlinghton armour module -milit) survive 3 APDS cal.105mm and after that hits (more then two? milit) by 127mm diameter SC." In July 1970 the "biscuit" No. 4 (Burlinghton version -milit) mounted whit some kind of amortisation on 50mm thick RHA plate (front hull) survive multiple hits by: 105mm round from "0m distance", 152mm diameter "žShillelagh" warhed, two SC 152mm dimater test warhed and finnaly 120mm APDS whit velocity like on 1300m distance hit. Ability to protect against multiple attacks has become an important asset, of the "Burlington" armour.

 

[STGN]

My question was rhetorical. Take a look at the images Damian posted earlier. You can see there that the armour at the turret bustle is intact, while the armour at the sides of the crew compartment is damaged. Now in the image I posted is not a single evidence that the armour at the crew compartment was damaged, still you assume so.
Then the next point is, why would the outer steel layer of the damaged armour section be bend, if that wasn't done by anything like the coiil-spring array?
And please note the turret's position and the position of the coil-spring armour array: Why is the coil-spring array located on top of the engine compartment, if the location were you claim it would be is nowhere near the crew compartment? Did the tank crew take the armour from the side and lift it at the top of the engine compartment?

The most reasonable tool someone can use for estimating armour thickness/arrays etc. should be the logic. And logic does not support your claims, but rather speaks against them.

Crew side:
https://forum.ioh.pl/graficzki2/1305927910_opancerz1.jpg
You know explosions tend to bend thin metal.
Logic stops where measurement begins.

Page 195 does not show anything in relation to the armour thickness, just a tank with fully installed roof laking the main sight. If you took a look at the image excerpt from the turret rebuild or at the drawing from Damian, you would notice however that the armour ends in front of the main sight (or about at the location of the ballistic cover), not inside the main sight tunnel as shown by your CGI.

Thought you would say as much. See you don't have an eye for detail, well I guess detail that show that you are wrong.
Now heres a clear picture for you:

Can your logic see what this means? or do I have to explain that too?

The difference between T-72A and T-72B armour is also about 9 inches. There is not much difference in appearance also.
In case of the M1 and M1A1 the turret armour is definetly thicker, I cannot say how much thicker with my pure eye. But when I have to choose between an author who did the measurement on the actual tank and someone who uses a CGI and also extended the armour to far into the crew compartment, I rather believe the first mentioned.

That is why I measure, but you do as you will.

No, your unreasnable. How would it be logical to measure the tank's turret without taking the slope into account, when he is talking about actual frontal protection?
Besides there is still a 10% difference between your figures and that of Green.

Maybe because he doesn't really want to reveal practical thickness. Saying 2 foot is not really super accurate. Also my number was for the right side the left side is 600mm.

It neither an insult nor bullshit. It is the simple truth: The CATTB has a completely new turret with two men crew and autoloader. Just because something looks similar (and it doesn't really), it doesn't have to be the same. Especially since I provided you proper data for the hatch size you simply ignore.
The engine comparment in the hull was also redesigned.

Just because its a new turret it doesn't mean that they redesigned all the parts for the test vehicle and that cupola looks like and probably is a modified M1 cupola. Also you know there is a difference between hatch size and the size of the hole for the CWS installation.

It says that the width is 17 inches, not the average of length and width. Also the value 22 inches is only supported by one source, another source (and also the CAD drawings from P. Matthews) give 19 inches.

Ever heard of simplifying a text to make short and understandable? also as the commanders hatch hole is not round which distance is the 17" is it along the length or the width of the tank? And P. Matthews CAD drawing doesn't give 19" it gives 23" for loader hole and 31.6" for CWS installation hole, how did you get that number?

Do you want to ask me how it looks like, considering that the Leopard 2 armour looks like 65 cm for Taransko and looked like 100 cm for Paul Lakowski; that the turret width of the Arjun looked like 3.2 m for some Indian members of the forum.
But if you really insist: On Thunderbolt the driver's sights weren't completely covered by the turret front.

Sorry I should have said that the picture is of a M1A1 not the M1.
Here is both:

Textures are not complete.
STGN

 

[STGN]

Intresting discuss is starting no, as I see..
My old post from here:

Here is how I see the armor configuration over the crew compartment side, from the info I have using a 1" side RHA plate gives a 2.5" NERA array and using the rear of the blown up M1A2 turret gives me 3.5" inner wall, using 2.5" on the array on top of the engine compartment gives me ~5.5" spring cylinders.
Whether there is something in that big air gap?? However I remember reading somewhere that the turret has a hollow sound too it if you hit it.
STGN

 

[Damian]

@STGN every composite armor array will have a hollow sound when it is hit.

The fact is that @militarysta observed that these 5,5" bolts or supports for NERA array are too fragile and are empty inside, so they are uncapable on their own to how armor array.

Also notice my drawing I show there that inside cavity the backplate have snooth surface, attachement points, no weld lines.

Combining all these observations gives us a hint that these NERA array supports are "slided" in to slots inside additional layers of armor, how it looks like exactly, we do not know, not to mention that it might be one of several variations of the side armor protection.

BTW I somehwere seen unconfirmed claims for a person that claimed it worked on armor replacement in the M1, that armor is in form of replaceable modules inside a cavity, these modules do not stick with the main vehicle structure and this is why it cause an hollow sound effect when you hit is with hammer. But then again as I said, all composite and spaced armor arrays will have such sound effects. Thats their nature after all.

 

[STGN]

@STGN every composite armor array will have a hollow sound when it is hit.

The fact is that @militarysta observed that these 5,5" bolts or supports for NERA array are too fragile and are empty inside, so they are uncapable on their own to how armor array.

Also notice my drawing I show there that inside cavity the backplate have snooth surface, attachement points, no weld lines.

Combining all these observations gives us a hint that these NERA array supports are "slided" in to slots inside additional layers of armor, how it looks like exactly, we do not know, not to mention that it might be one of several variations of the side armor protection.

BTW I somehwere seen unconfirmed claims for a person that claimed it worked on armor replacement in the M1, that armor is in form of replaceable modules inside a cavity, these modules do not stick with the main vehicle structure and this is why it cause an hollow sound effect when you hit is with hammer. But then again as I said, all composite and spaced armor arrays will have such sound effects. Thats their nature after all.

Maybe @militarysta can explain why they are too weak, they are strong enough to push out both NERA array and RHA plate when the weld breaks. I don't think they are bolts they are hollow cylinders which capture the spring, they don't need to be attached, the springs expansion creates the tension needed to effectively fix the cylinder and array in place. And that is why the spring solution, makes you able to easily(relative) replace the armor. That is however not what we see over the turret bustle here there are a rack or rail which is probably used to fix the array we see in the picture Methos posted.
STGN

 

[Damian]

Maybe @militarysta can explain why they are too weak, they are strong enough to push out both NERA array and RHA plate when the weld breaks. I don't think they are bolts they are hollow cylinders which capture the spring, they don't need to be attached, the springs expansion creates the tension needed to effectively fix the cylinder and array in place. And that is why the spring solution, makes you able to easily(relative) replace the armor.

This is a bad solution, tension is ok to keep it in one place when nothing happens but when projectile hits and array start to move it can be displaced, so IMHO is it nos that way, and there is something else deeper.

Also we should remember that this is probably one of many side armor variants from the older tank variants. The more recent documents says that tanks received side armor upgrades after Iraq.

http://www.fas.org/man/dod-101/sys/land/wsh2013/12.pdf

You can read here that M1A1SA and M1A2SEP received frontal and side armor upgrades, so the armor design, its structure and materials defenitely changed. Damaged tanks that we seen on photos are mostly M1A1HA's and M1A1HC's as well as M1A1AIM's that are older than M1A1SA's.

 

[STGN]

The difference between T-72A and T-72B armour is also about 9 inches. There is not much difference in appearance also.
In case of the M1 and M1A1 the turret armour is definetly thicker, I cannot say how much thicker with my pure eye. But when I have to choose between an author who did the measurement on the actual tank and someone who uses a CGI and also extended the armour to far into the crew compartment, I rather believe the first mentioned.

We have several shots of how far back the armor goes on the left side. it goes back to the approximately the edge of the turret ring:

That is why we can see a cut out at the bottom, in this picture:

To allow access to bolting on the turret.
On page 9 in "M1 Abrams In Action" by Jim Mesko we can also see it.
STGN

 

[Damian]

Interesting details, I never noticed them before, thanks!

 

[militarysta]

Here is how I see the armor configuration over the crew compartment side, from the info I have using a 1" side RHA plate gives a 2.5" NERA array and using the rear of the blown up M1A2 turret gives me 3.5" inner wall, using 2.5" on the array on top of the engine compartment gives me ~5.5" spring cylinders.
Whether there is something in that big air gap?? However I remember reading somewhere that the turret has a hollow sound too it if you hit it.
STGN

Maybe @militarysta can explain why they are too weak, they are strong enough to push out both NERA array and RHA plate when the weld breaks. I don't think they are bolts they are hollow cylinders which capture the spring, they don't need to be attached, the springs expansion creates the tension needed to effectively fix the cylinder and array in place. And that is why the spring solution, makes you able to easily(relative) replace the armor. That is however not what we see over the turret bustle here there are a rack or rail which is probably used to fix the array we see in the picture Methos posted.
STGN

Im respecting your job, but it haven't sense from protection point of viev. This on Your draw is triple NERA or NxRA layer whit depreciation in the form of springs in metal sleeves. But it's not enought to achive some protection level. Even for 30 degree when LOS is double it too les to portect turret sides. And what is more important - it's illogical - why turret bustle sides (armour layout is visible very good on known photo posted by methos) have more layers then your model whit only front plate, tripple NERA/NxRa layers and backplate? On turret sides at crew comperment? Whit American "obsession" with the safety of the crew? It haven't sense.
On that model:
(BTW: please rememnber that my draw skills are very weak...)

I suggest more logical option - NERA layers + burlinghton sandwith + inner heavy HHS/ceramis/kevler layers. Only NERA + backplate is to weak to achive some protection level. And we shoud remember that protection for turret sides at 30 degree shoud be like at least 70-80% frontal protection (LOS ratio on turret front and sides). Model whit only NERA and backplate haven't chance to achaive that level. They just must be inner layers -like on that photo when is visible armour at turret bustle sides.

BTW: first idea "only NERA + bacplate" was posted by taransenko on his blog. But Andriej (or rather guys using his blog) are pure Ukrainian industry propagandists able to made bullshit how to Leopard-2A4 is bad in compare with T-64B/BM or unable to propper mesurment Leopard-2A4 turret LOS (those funny 65cm for turret front posted on Tarasenko blog and btvt page). Next Tarasenko posted fake claiming how Burlinghton is weak in multihit case -what is wrong and I posted proof here: http://defenceforumindia.com/forum/...e-tanks-armour-technology-322.html#post676532, after that there was fake MTU MB783 data in btvt "article" in compare T-64 and leo-2 and other bigger and smaller fakes on his bloh and btvt.

Anyway - IMHO Abrams side armour is mucht more complicated then your model. Part of this can be visible here too:

BTW2: propably turret bustle have fabric technological weakness at the height of the bulkhead to store ammunition - cose to tore (in catastrophic ammo blow out) turret side on bustel hight not on crew comparment sides -so propably only difreces is thicker front plate and backplate at crew comparmetn hight.
And here we can see those place IMHO:

 

[Damian]

BTW, notice on this photo how fragile are these "bolts" attached to springs for NERA array. As I said, on their own it is immposible to fix armor array.

Note smashed "bolt".

 

[STGN]

Im respecting your job, but it haven't sense from protection point of viev. This on Your draw is triple NERA or NxRA layer whit depreciation in the form of springs in metal sleeves. But it's not enought to achive some protection level. Even for 30 degree when LOS is double it too les to portect turret sides. And what is more important - it's illogical - why turret bustle sides (armour layout is visible very good on known photo posted by methos) have more layers then your model whit only front plate, tripple NERA/NxRa layers and backplate? On turret sides at crew comperment? Whit American "obsession" with the safety of the crew? It haven't sense.
On that model:
(BTW: please rememnber that my draw skills are very weak...)

I suggest more logical option - NERA layers + burlinghton sandwith + inner heavy HHS/ceramis/kevler layers. Only NERA + backplate is to weak to achive some protection level. And we shoud remember that protection for turret sides at 30 degree shoud be like at least 70-80% frontal protection (LOS ratio on turret front and sides). Model whit only NERA and backplate haven't chance to achaive that level. They just must be inner layers -like on that photo when is visible armour at turret bustle sides.

BTW: first idea "only NERA + bacplate" was posted by taransenko on his blog. But Andriej (or rather guys using his blog) are pure Ukrainian industry propagandists able to made bullshit how to Leopard-2A4 is bad in compare with T-64B/BM or unable to propper mesurment Leopard-2A4 turret LOS (those funny 65cm for turret front posted on Tarasenko blog and btvt page). Next Tarasenko posted fake claiming how Burlinghton is weak in multihit case -what is wrong and I posted proof here: http://defenceforumindia.com/forum/...e-tanks-armour-technology-322.html#post676532, after that there was fake MTU MB783 data in btvt "article" in compare T-64 and leo-2 and other bigger and smaller fakes on his bloh and btvt.

Anyway - IMHO Abrams side armour is mucht more complicated then your model. Part of this can be visible here too:

BTW2: propably turret bustle have fabric technological weakness at the height of the bulkhead to store ammunition - cose to tore (in catastrophic ammo blow out) turret side on bustel hight not on crew comparment sides -so propably only difreces is thicker front plate and backplate at crew comparmetn hight.
And here we can see those place IMHO:

I have only modeled what I can see. Actually looking at this picture some more I think you are right that there is something behind it. there seem to be distinct layers visible behind the 2.5" array.

I am pretty sure its not the same as what is placed over the Bustle though. as we can see it popping its head up on your photos the NERA layers on that one is much thicker than the 2.5" array. and I doubt there is 3.5" backing plate or plates. BTW do you have unedited versions of picture 3&4 would love to have them.
STGN

 

[militarysta]

. BTW do you have unedited versions of picture 3&4 would love to have them.
STGN

Well it will be diffcilult (about unedited versions of picture) most of them are taken from russian forums and it's hard to find orginal photo :-/
Some good pict. are avaible here on one of the polish

I am pretty sure its not the same as what is placed over the Bustle though. as we can see it popping its head up on your photos the NERA layers on that one is much thicker than the 2.5" array. and I doubt there is 3.5" backing plate or plates

IMHO on turret bustle there is no NERA layers -but on hight at crew comparment it is.


btw: without marks:


btw well known?:
http://www.primeportal.net/m1_damaged_iraq.htm

 

[Damian]

Here one of official sources says that depleted uranium is also placed at turret armor sides.



Depleted Uranium + Polyurethane armor, claimed to have British origin. One of many "Burlington" variants?