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Upgrading tanks that have steel armor


Proyas
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Hi guys,

 

I recently read about upgrade packages to old tanks like the M-60 and T-55, but kept seeing comments from people saying they would still be obsolete. Is this because the M-60 and T-55 are made entirely of steel (and not composite) armor?  

 

I have this theory that thick steel armor is probably totally obsolete, and is just dead weight in the age of lighter weight composite armor. You can bolt on upgrades to an M-60 or T-55, but you're still hamstrung by the fact that either tank will be carrying around tons of useless steel. Am I right? 

 

Also, if we wanted to upgrade old tanks like that, wouldn't the best idea be to develop a new turret--with lighter, modern composite armor and better technology inside--and just drop it into the old tanks? The hulls would still be made of heavy steel, but that could be helped a bit by adding applique armor. 

 

Here are some of the upgrades I read about: 

 

https://youtu.be/NG89Zh9qQrQ

 

http://www.army-guide.com/eng/product1907.html

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Upgrading old tanks like M60 and T-55 is still somewhat economically viable, but only for poor states, or those with very old fleets. For example Taiwan, Turkey, or the Philippines.

 

The two big issues are the all steel construction and integrated armor, and the design that accounted for decades old tech.

Another issue that could arise is cracked hulls but those can be fixed in relatively cheap refurbishment processes. 

 

Indeed the integration of the heavy steel armor into the construction of the hull, adds a ton (actually, tens of tons) of weight. Parasitic weight. It cuts into the weight of upgrades that can be added thus limiting any sort of applique armor. 

 

And the tank is obviously not built to accommodate any of the new tech built after its entry to service. Things like NBC may already have been standard on all tanks we can see on the battlefield today, but proper air conditioning was not. Any new sights, sensors, or gadgets, will require a completely new electrical grid coupled with a new generator, for which a new compartment must be made.

The ammunition has to be carried outside a safe compartment or is just placed in a horribly vulnerable place. 

The engine is likely no longer supported by the manufacturer, or any other part really.

The ergonomics were shitty even before any new stuff were added to the turret or driver's station.

 

 

You either replace so many things that you're ought to buy a new tank at that point, or you make enough cost cutting compromises that your tank is no longer worth shit.

 

I believe that in about 5 years, upgrades like the Sabra but for any tank built prior to the 1970's, will no longer be viable. Economically-wise, that is.

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The other approach is redefining role.  A Leopard 1 for example would make a potent recon asset - once upgraded to suit.  All Mighty_Zuks comments apply regarding support of eng/trans etc but the older steel base armours can be upgraded to withstand 30mm (which is the typical standard for recon now) without stupid size/weight barriers.   There will still be a weight penalty but not impossible.  The other issue is that an old tank is old....  Leopard 1 for example developed lots of cracking around all suspension mounts - rewelded many time over service life.  Then there is EMI/EMC - old vehicles are were designed to lower standards so will be electronic beacons compared to modern standards.

 

Probably best used s gate guardians or suppressing unarmed populations....

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14 hours ago, Mighty_Zuk said:

The two big issues are the all steel construction and integrated armor, and the design that accounted for decades old tech.

...And the tank is obviously not built to accommodate any of the new tech built after its entry to service. Things like NBC may already have been standard on all tanks we can see on the battlefield today, but proper air conditioning was not. Any new sights, sensors, or gadgets, will require a completely new electrical grid coupled with a new generator, for which a new compartment must be made.

What about my idea to develop new turrets for old tanks? The turrets would be lighter weight because they would be made of modern armor, and would come integrated with other modern tech. The old tank turrets would be removed and the new ones dropped in. 

 

Quote

The ammunition has to be carried outside a safe compartment or is just placed in a horribly vulnerable place. 

Is the ammo storage location in the M-60 and T-55 safe? If not, could it also be fixed by dropping in a new turret that stored all the ammo safely in the back, like in the M1 Abrams? 

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1 hour ago, Proyas said:

What about my idea to develop new turrets for old tanks? The turrets would be lighter weight because they would be made of modern armor, and would come integrated with other modern tech. The old tank turrets would be removed and the new ones dropped in. 

 

Is the ammo storage location in the M-60 and T-55 safe? If not, could it also be fixed by dropping in a new turret that stored all the ammo safely in the back, like in the M1 Abrams? 

   Example of a turret with fighting compartment that were made to upgrade T-72s and T-80s in Russian stocks:

image018.jpg

   New turret had modular frontal armor, allowed to quick replacement if damaged and could be upgraded easily with new packages.

Spoiler

03.jpg

 

   Burlak turret also had a  bustle, space inside of it was used to mount second autoloader and remove number of shells outside of original autoloader from tanks hulls into separated from crew compartment.

 

Spoiler

i9KMr.jpg

 

01.jpg

 

   On top of that turret also was equipped with APS to protect sides and RCWS that original T-72s don't have. Never saw service. 

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7 hours ago, Proyas said:

What is EMI/EMC? 

EMI - electromagnetic interference.  This is electromagnetic noise generated by the electrical systems of an object (the vehicle).  The present limits for EMI are very low.  They have to be.  EMI interferes with radio performance and leads to EMC failures.  There is also remote data reading (TEMPEST) potential.

EMC - electromagnetic compatibility is concerned with a systems ability to operate in an environment with particular levels of electromagnetic radiation.  Common EMC failures include one system performing strangely as a different system is operated.  Can be non-trivial.  I have seen cases where a poorly shielded crane caused the turret of a nearby vehicle to traverse....

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On 3/17/2019 at 4:00 PM, Proyas said:

Hi guys,

 

I recently read about upgrade packages to old tanks like the M-60 and T-55, but kept seeing comments from people saying they would still be obsolete. Is this because the M-60 and T-55 are made entirely of steel (and not composite) armor?  

 

 I have this theory that thick steel armor is probably totally obsolete, and is just dead weight in the age of lighter weight composite armor. You can bolt on upgrades to an M-60 or T-55, but you're still hamstrung by the fact that either tank will be carrying around tons of useless steel. Am I right? 

 

The extra useless steel certainly doesn't help, but it is far from the most serious problem.

 

Older tanks like the T-55 or M60 have much worse suspension than modern tanks.  Do you also upgrade that?  These older tanks also have drastically inferior engines and transmissions.  Do you upgrade those as well?  Their fire control systems are quite old.  Do you upgrade those too?

At this point, you are basically using a T-55 shaped box that you're going to put modern systems into.  Is that meaningfully cheaper than an all-new tank?

 

On 3/17/2019 at 4:00 PM, Proyas said:

Also, if we wanted to upgrade old tanks like that, wouldn't the best idea be to develop a new turret--with lighter, modern composite armor and better technology inside--and just drop it into the old tanks? The hulls would still be made of heavy steel, but that could be helped a bit by adding applique armor. 

 

 

Even modern tanks are made of steel.  Maybe even mostly of steel.  The underlying hull needs to be made of something that can withstand the automotive stresses and provide a firm backing for the composite armor packages that are welded/bolted to them.

 

Steel is cheap, and RHA-grade armor steel has enough toughness that it can work as a structural material while doubling as an additional layer of protection.

 

Furthermore, ERA doesn't _completely_ stop HEAT warheads.  The tip of the shaped charge jet, also called the jet precursor typically punches through the ERA without being disrupted very much.  So there needs to be some sort of armor behind the ERA element to stop the jet precursor.

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12 hours ago, Collimatrix said:

 

The extra useless steel certainly doesn't help, but it is far from the most serious problem.

 

Older tanks like the T-55 or M60 have much worse suspension than modern tanks.  Do you also upgrade that? 

What makes their suspensions worse? 

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On 3/19/2019 at 9:12 AM, Collimatrix said:

 

Older tanks like the T-55 or M60 have much worse suspension than modern tanks.  Do you also upgrade that?  [...] Their fire control systems are quite old.  Do you upgrade those too?

Back in early 2000s there was a proposal from Omsk design bureau to do that with T-55.  They suggested to replace turret, and also suspension, roadwheels, tracks (using those 3 components from T-80U, I guess), and proposed to bolt on an addiional armour module at front - so big that it required additional roadwheel per side. I don't know about engine though.
Apparently it went no further than drawing board, but still, that option existed.
BG6yF1r.jpg
Ovf82Xol.png
UPD: speaking about that turret - they were really struggling for money back than, searching for every customer they could get
1OY1BYJ.jpg

 

 

On 3/19/2019 at 9:12 AM, Collimatrix said:

At this point, you are basically using a T-55 shaped box that you're going to put modern systems into.  Is that meaningfully cheaper than an all-new tank?

I don't think it all that simple.

It seems to me that in order to make a new tank one needs much more advanced factory than to upgrade one.
And also one should not forget about politics and budgets and all that stuff. IIRC for example back in 1700s-1800s in British Royal Navy there was a situation when it was much easier to get money on ship's overhaul, than to get money from Parliament on making a new ship - so they systematically did just that, replaced so much during overhaul that sometimes one might say - with only little exaggeration - that all that's left from original ship was furniture from officer's mess and figurehead.


There is also another thing with all-new tank - one have to develop it all the way to serial production in the first place, which is not guaranteed. I mean - just look at US Army and its NGCV-OMFV for example, which is 4th Bradley replacement effort in last 35 years. Or Soviet/Russian army with its T-64, and its next proper clean-sheet design somewhat close to however limited serial production been T-14, some 5 decades later. Taking into account several tank design bureaus, it seems to me there are like a company or may be even two - worth of mockups which vere supposed to be next-generation replacements of T-64/72/80.
 

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13 hours ago, skylancer-3441 said:

Back in early 2000s there was a proposal from Omsk design bureau to do that with T-55.  They suggested to replace turret, and also suspension, roadwheels, tracks (using those 3 components from T-80U, I guess), and proposed to bolt on an addiional armour module at front - so big that it required additional roadwheel per side. I don't know about engine though.
Apparently it went no further than drawing board, but still, that option existed.

That was the T-55M6 project. They even built it.

It had longer hull thanks to additional armor at the front, but with T-72 roadwheels and the usual 580mm RMSh type tracks. Engine was probably a V-46-5M, maybe V-46-6, Im not sure. Turret was straight from a T-72B.

 

a0109941_498af0472a6b6.jpg

1_ZNLS.jpg

 

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16 hours ago, skylancer-3441 said:

It seems to me that in order to make a new tank one needs much more advanced factory than to upgrade one.
And also one should not forget about politics and budgets and all that stuff. IIRC for example back in 1700s-1800s in British Royal Navy there was a situation when it was much easier to get money on ship's overhaul, than to get money from Parliament on making a new ship - so they systematically did just that, replaced so much during overhaul that sometimes one might say - with only little exaggeration - that all that's left from original ship was furniture from officer's mess and figurehead.


There is also another thing with all-new tank - one have to develop it all the way to serial production in the first place, which is not guaranteed. I mean - just look at US Army and its NGCV-OMFV for example, which is 4th Bradley replacement effort in last 35 years. Or Soviet/Russian army with its T-64, and its next proper clean-sheet design somewhat close to however limited serial production been T-14, some 5 decades later. Taking into account several tank design bureaus, it seems to me there are like a company or may be even two - worth of mockups which vere supposed to be next-generation replacements of T-64/72/80.
 

 

I don't buy that upgrades of the depth you're talking about require any smaller a factory than just making a new tank.  You're stripping the tank down to the hull, pulling off the old suspension elements and putting new, high-performance ones on, potentially pulling the turret and replacing it with a new one, pulling the powerpack, etc.

So, aside from welding up a new chassis, you still need a facility with gantry cranes capable of handling the weight of the vehicle (if you want to get the upgrades done this century), you still need the ability to pull and install new powerpacks, etc.

 

You might be able to pull a quick one over the government, just because congresses and parliaments are filled with self-important know-nothings, but the bottom line is the only thing you're economizing on is the metal box that you put all the important stuff on.  Why is the T-14 taking so long?  I can guarantee you it's not problems with the underlying chassis itself.

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3 hours ago, Collimatrix said:

I don't buy that upgrades of the depth you're talking about require any smaller a factory than just making a new tank.  You're stripping the tank down to the hull, pulling off the old suspension elements and putting new, high-performance ones on, potentially pulling the turret and replacing it with a new one, pulling the powerpack, etc.
So, aside from welding up a new chassis, you still need a facility with gantry cranes capable of handling the weight of the vehicle (if you want to get the upgrades done this century), you still need the ability to pull and install new powerpacks, etc.

 

Well, exactly that explanation which i gave earlier - was given on why in late 80s Israelys choose to make Achzarits using T-55 hull, instead of going straight to Merkava-based vehicle.

 

 

3 hours ago, Collimatrix said:

Why is the T-14 taking so long?  I can guarantee you it's not problems with the underlying chassis itself.

It took some time do develop all those different chassis during that 5-decade period, too.
It's like every single time they start a contest on some clean-sheet designs, or even if they go with one single design - it turns out there are several opinions on every part of it. And the fact that one of them was able to win and got implemented into design - does not guarantee at all that by the time this project moves closer to production noone would strike back claiming this allmost-ready-design obsolete, and trying to win again.


Just look at weight of US Army IFV developments of last 40 years. 
Around 1977 with TBAT-II Bradley was 21.4 metric tonnes, and it sucesfully dodged a 50-60 metric tonnes SAIFV proposal during Creizer study. And then it dodged another SAIFV proposal in another study. So it goes into production and weights around 22.5 metric tonnes.
By late 80s US Army has it first next-generation-IFV program, part of larger ASM program, and even though they looked at all sorts of designs, including those close to 28 metric tonnes, what they - apparently - choose - was a continuation of that SAIFV idea, based on tank chassis, with weight of some 60+ metric tonnes. Which dies in early 90s,
and by mid-90s another concept emerges, which was also studied in mid-80s. It becomes second program on next-generation-IFV after Bradley, by early 2000s - or FCS as we know it, much lighter vehicle which had to fit in AMT and C-130 - so, around 18 metric tonnes. Well, sort of. By late 2000s it was clear that it would not fit into C-130 at all, with options on increasing weight limit up to 24.5, or 27, or 30 metric tonnes on the table.
Then they have another program, GCV, with famous figure of 84 short tons (76 metric) including future upgrades, and later with design-after-trades of like 45-51 metric tones in configurations stripped for transportability on aircraft.
And now there is an NGCV-OMFV with nothhing so far going beyond 50 metric tonnes, and requirement of 2 on C-17.

 

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Can a snake break its spine? Yes, if it tries to follow the general line of the Party

 

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On 3/19/2019 at 2:12 AM, Collimatrix said:

 

The extra useless steel certainly doesn't help, but it is far from the most serious problem.

...

Even modern tanks are made of steel.  Maybe even mostly of steel.  The underlying hull needs to be made of something that can withstand the automotive stresses and provide a firm backing for the composite armor packages that are welded/bolted to them.

 

Steel is cheap, and RHA-grade armor steel has enough toughness that it can work as a structural material while doubling as an additional layer of protection.

 

Furthermore, ERA doesn't _completely_ stop HEAT warheads.  The tip of the shaped charge jet, also called the jet precursor typically punches through the ERA without being disrupted very much.  So there needs to be some sort of armor behind the ERA element to stop the jet precursor.

With these factors in mind, what is the appropriate thickness of steel for a modern MBT?

 

How does the steel thickness of the T-55 and M-60 compare to that? 

 

I'm curious to know how bad the "excess steel armor" problem is on the older tanks. 

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  • 2 weeks later...

"Enough to retain structural integrity for the rest of the tank that isn't (N)ERA, with frontal arc also functioning as a backstop for HEAT's remaining penetration"

 

The "excess steel armor" problem came around due to increasingly powerful HEAT shells and ATGMs, their relative inaccuracy asides. If one of those connected, they would probably go through a lot more steel than you could reasonably fit on a tank.

 

The Germans and French responded with the Leopard 1 and AMX-30, which were intended to trade armor for speed to get out of the line of fire with. The British had Chieftain, which relied on sloping to hopefully deflect was fired at them (this didn't work, hence Stilbrew). The Americans had the M60, which was designed for fused silica that would probably be pretty effective against period HEAT, but was never built with it.

 

Leo 1 and the AMX-30 don't have much of an excess steel problem, but they don't have the growth space for significant upgrades due to how light they are. Chieftain... well, eventually a version of the design shorn of most steel armor and replaced with Chobham, and with hydropneumatic suspension became Challenger. M60s soldiered on for far longer than they should have in US service no thanks to MBT-70. Marine Corps M60A1s eventually got an ERA kit (apparently not Blazer) in time for Desert Storm, but remaining stocks were rapidly sold off afterwards. Israeli M60s (Magachs) got very extensive (N)ERA upgrades following the agonizing experiences of Yom Kippur. Sabra is a further evolution of late Magach design principles, but it's really close to the absolute maximum you can do with an M60, assuming it's not already there.

 

magach-7-latrun-2.jpg

 

You may have noticed that I didn't mention Soviet tanks. Starting from the T-64 on, all of them had NERA protection on the frontal arc. BDD kits with similar (if not identical) working principles to Chobham were made available for T-54/55s and T-62s as well, although never for export.

 

EDIT: General Dynamics actually did propose your suggestion of putting a new turret on an old tank with the M60-2000, an M60 hull with an M1A1 turret. Nobody bought it.

 

Edited by Krieger22
M60-2000 says hi
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On 4/9/2019 at 9:48 AM, Krieger22 said:

Leo 1 and the AMX-30 don't have much of an excess steel problem, but they don't have the growth space for significant upgrades due to how light they are. Chieftain... well, eventually a version of the design shorn of most steel armor and replaced with Chobham, and with hydropneumatic suspension became Challenger. 

The Leopard 1 and AMX-30 lack the growth space for what? Later iterations of the Leopard 1 had 120mm cannons. And surely, both tanks could have been upgraded over time with better engines. 

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The hardest limit to these sorts of upgrades is the ground pressure.  Engines could be developed that are more powerful, but fit into the old engine bay (the original Leo 1 engine wasn't even turbocharged, so there's probably lots of room for improvement there).  New transmissions that can handle the power could reasonably be developed.  New torsion bars that can handle the weight could be installed.

 

But there's not really any practical way to make the track contact area bigger.

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One could simply redefine allowed trafficability levels, while doing nothing about ground pressure, just making statements that it's worth the increase in survivability.
I mean - back in late 70s XM2 had ground pressure of about 0.5kgf/cm2, and now with Bradley M2A3 w/ BUSK its like what, more than 0.8? It was accompanied with change of Go/No-Go terrain in German Wet scenario from 98/2 percent to 92/8 percent, and they were ready for much worse - while looking for AMPV, US Army was ready to accept 85/15 percent.

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    • By Beer
      I haven't found an appropriate thread where to put some interesting rare stuff related to WW2 development, be it industrial one or makeshift field modifications. 
       
      Let's start with two things. The first one is a relatively recently found rarity from Swedish archives - a drawing of ČKD/BMM V8H-Sv tank. The drawing and a letter was found by WoT enthusiasts in Swedish archives in 2014 (the original announcement and the drawing source is here). The drawing is from a message dated 8th September 1941. One of the reasons why this drawing was not known before may be that the Czech archives were partially destroyed by floods in 2002. Anyway it is an export modification of the V-8-H tank accepted into Czechoslovak service as ST vz.39 but never produced due to the cancelation of all orders after Münich 1938 (for the same reason negotiations about licence production in Britain failed). Also later attempt to sell the tank to Romania failed due to BMM being fully busy with Wehrmacht priority orders. The negotiations with Sweden about licence production of V8H-Sv lasted till 1942, at least in May 1942 Swedish commission was present in Prague for negotiations. The tank differed compared to the base ST vz.39 in thicker armor with different front hull shape (armor 60 mm @ 30° on the hull front and also 60 mm on the turret; all sides were 40 mm thick). The tank was heavier (20 tons) and had the LT vz.38 style suspension with probably even larger wheels. The engine was still the same Praga NR V8 (240-250 Hp per source). The armament was unchanged with 47 mm Škoda A11 gun and two vz.37 HMG. The commander's cupola was of the simple small rotating type similar to those used on AH-IV-Sv tankettes. It is known that the Swedes officially asked to arm the tank with 75 mm gun, replace the engine with Volvo V12 and adding third HMG to the back of the turret. In the end the Swedes decided to prefer their own Strv/m42. 

      Source of the drawing
       
      The second is makeshift field modification found on Balkans. It appears Ustasha forces (and possibly some SS anti-partizan units) used several Italian M15/42 medium tanks with turrets from Pz.38(t). There are several photos of such hybrids but little more is known. On one photo it is possible to see Ustasha registration number U.O. 139.

      Few more photos of such hybrid.
       
      It appears that the source of all those photos to be found on the internet is this book, Armoured units of the Axis forces in southeastern Europe in WW2 by Dinko Predoevic. 
       
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