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SH_MM

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Everything posted by SH_MM

  1. SH_MM
    Supposedly yes. For the new 120 mm gun.
  2. SH_MM
    Poland got a new tonk. Very stronk. PT-16.
  3. SH_MM
    I forgot the link Here is it. As for the mass efficiency and the thickness efficiency; in the original discussion on TankNet the ME was calculated from the TE. You just need to take into account the areal density for this. Ramlaen, on the Leclerc, Leopard 2 and similar designed tanks, the side skirts are meant to cover only the crew compartment (i.e. driver's place + turret ring section) along the 30° arc. The ammo would need to be stored behind the turret ring. While it is possible to extend the skirt armor, this would lead to an increase in weight or a decrease in frontal arc protection for the crew compartment (compare Leopard 2 and Leclerc with ~150 mm thick skirts to M1 Abrams with ~70 mm skirts). Each tank design is a trade-off between benefits and disadvantages.
  4. SH_MM
    There is a document on DTIC from 1987, where the probability of fuel fires after armor penetration was being investigated on the M2 Bradley, M113 and M1A1 Abrams tank (with diesel fuel, JP-08 was introduced in the Army later). The document is a technical report from the Ballistic Research Laboratory written by Antony E. Finnerty. It is noted that the automatic fire suppression system (AFSS) of the M1A1 is not capable of supressing engine fires. Depending on hit location and how much fuel is left inside the fuel tanks, the probability of incinerating the diesel stored in the Abrams with the first hit by a shaped charge is between 10% and 50%; the probabiltiy of a fire in the frontal fuel tanks was only 15% at 8°C ambient temperature and 25% at 24°C ambient temperature. These values are based on Soviet 125 mm HEAT rounds and might not be valid for more modern, larger calibre, HEAT warheads with tandem charges. The probability of a fuel fire after penetration by a 125 mm APFSDS projectile is between 50% and 60% (at 8°C and 24°C ambient temperature respectively). Again this represents Soviet technology from the 1980s and might not be valid for modern APFSDS rounds. The efficiency is determined by using a sample shaped charge against steel armor as reference (reference penetration is Pref), then using the same type of sample charge against the fuel tank (to determine the penetration into fuel Pfuel). The efficiency then is calculated using these factors. If the fuel tank includes 25 mm front and 20 mm back plates of steel, and this is included in Pfuel, the efficiency will be exaggerated depending on the reference penetration of the sample charge. Let's say (just for this argument) that the reference shaped charge penetrates 180 mm, but it can be stopped by 25 mm steel + 680 mm of fuel + 20 mm steel. Then 680 mm of fuel provides as much protection as 135 mm steel. Now if somebody forgets the fact that there is a 25 mm coverplate and a 20 mm back plate, the efficiency of fuel will be exaggerated by 33%.
  5. SH_MM
    When you penetrate a fuel tank, there are two holes from which oxygen can enter. One at the interior of the MBT, one at the place where the penetrator originally impacted. I am no expert for halon gases, but it seems somewhat unlikely that it is capable of exiting the tank through the penetration hole and is capable of completely blocking all air of entering. While Halon has a lower density than air, there still is Fick's law... this topic might need further research. I don't know your source, but a few years ago there was a discussion on the TankNet forums, where somebody claimed that fuel hat a ME of 3 vs HEAT. After he posted a link to a research paper, it became clear that this included the (relatively thick) steel walls of the fuel tanks. According to Israel Tal, fuel was found to be about 1/7 as efficient against HEAT as steel of the same thickness. This matches the expectations of the density law.
  6. SH_MM
    The further away from the front, the more exposed is the ammo. Traveling through more distance won't realistically affect the penetration power of an APFSDS/hollow charge jet or it's fragements. It will be enough to set the ammo on fire.
  7. SH_MM
    Come on, were are talking about something that is capable of penetrating the Abrams' hull armor; so essentially a tank round or some sort of modern anti-tank weaponry (RPG, ATGM, EFP). There shouldn't be much doubt about the JP-8 being incinerated in such a case. Btw. diesel has a higher flash point than JP-8 and is often set on fire during combat. As for the video of the burning T-80U; there are huge differences to our hypothetical scenario. First of all there are several hundred gallons of fuel in an Abrams (most of which is stored in the front), not just a tiny bit. The fuel tanks are not insulated from the interior, there would be only a small amount of steel and foam between the fire and the crew, while the T-80U has about two feet of composite armor including non-metallic materials (with much lower thermal conductivity than the Abrams' fuel tanks). The automatic fire extinguishers might work in some cases, but they most likely not designed to extingusih the fire of the main fuel tanks. The amount of halon seems to be more limited. I don't know; actually I was talking about the fuel being on fire without the crew compartment being penetrated. Yes and no. The turret armor is not thicker, if you take a look along the complete 60° frontal arc. But even if it was, there still is another difference: the turret is more likely being hit (depending on source, up to 75% of all hits occur on the turret). Moving the ammo to a place with lower likelyhood of it being hit, is the first step to make the tank more survivable. There is absolutely no need to become huffy and feel insulted. Everything I said is either based on a direct source or can be measured. I have read about and seen (although not in person) many cases of vehicles starting to burn after the fuel tanks were penetrated. This is why I wrote about this previously. I don't think the Leopard 2's hull design is a genius idea and the very optimal design; however I also don't think it is horrible and (a lot) worse than the Abrams hull design. In the end every design decision on an armored vehicle is a trade-off between multiple different factors. While people online are always very eager to praise the Abrams hull design, there is one major issue about it that bogs me: nobody cared about using the same design. The Leopard 2, the Leclerc, the Challengers, the K1, the Type 90, the Ariete, GM's XM1 design, hell even the brand new built-from-blueprint tanks such as the Type 10, K2 Black Panther and Altay have the same "dumb ammo storage" as the Leopard 2. So I cannot believe that it is inherently bad. What is the likelyhood of the frontal armor being penetrated and the ammo being incinerated without the crew dieing? Is there enough time to leave the tank before the ammo completely explodes (after initially being set on fire) for the crew to leave? Maybe these questions play a major role in tank designing; I don't have answers to them, but the people who should have access to such data (the people responsible for designing tanks) choose the dumb Leopard 2's layout. I'd personally love to see the same ammo storage layout, but fitted with blow-off panels and a proper isolated compartment.
  8. SH_MM
    Now it's Ariete bashing time. The Italian engineers had no knowledge of manufacturing proper tanks (even the OF-40 export tank was largley based on Leopard 1 components; in fact the original hull design was made by German companies), so the Ariete is a bit special. It's turret has extremely thin side armor, some say it's spaced armor, other people claim it's normal steel armor or composite. Judged by the thickness of the ammunition hatch, it's side armor might be 100-150 mm thick. Looks kind of like the Leopard 1A3's ammunition hatch. The hull side armor however is more than average, because it extends along the whole hull sides (whereas tanks like the Leopard 2 and Abrams have thin armor at the engine compartment). This might be ~60 mm armor at the engine compartment vs the Leopard 2's 40 mm and Abrams' 38 mm. Btw. did I forget to mention, that the ammunition in the Ariete's turret is stored like in the M48 tank? There are armor upgrades; a PSO package used in Iraq and a frontal turret armor upgrade, which apparently hasn't been purchased yet.
  9. SH_MM
    According to Steven Zaloga, the T-72 has 490 mm ground clearance; this about the same as the M1 Abrams (19 inches/482 mm according to Hunnicutt), but about two inches less than the frontal area of the Leopard 2 (550 mm). The upper section of the Leopard 2's hull nose (the one sloped at ~45°) has a line-of-sight thickness of more than 600 milimetres. The distance to the end of the special armor cavity is 600 mm, behind this is a further steel plate; I have commonly seen estimations in the range of 640-660 mm. This is essentially the same thickness as the armor cavity with backplate on the Abrams (estimated to be 600-700 mm). Also one should note that this is the same thickness as the M1A1 Abrams and Leopard 2A4 turret when attacked from 30° angle. The composite armor at the lower nose section gets thinner; to some 200-300 mm-ish thickness until it ends. Something like this photo from SteelBeasts shows, but the lower armor cavity slopes back and is no straight. Overall it appears that the Leopard 2 has essentially the same armor thickness at the hull front as the M1 Abrams. The full thickness of the armor cavity might cover a slightly smaller area, but overall the Leopard 2 seems to have a slightly larger coverage of the front hull with composite armor., However the Leopard 2 has further armor packages for the hull available, such as IBD's MEXAS-H design (as adopted on Strv 122, Leopardo 2E, Leopard 2HEL, Leopard 2A5DK and Leopard 2A7 QAT), RUAG's SidePro armor aswell as the AMAP armor (as operational with Singapore and Indonesia). This armor packages add at least one foot thickness of composite armor to the tank. When the adoption of this armor package was tested on the M1A2 and Leclerc tanks for Sweden, the Swedish FMV noted a 50-100% increase in protection according to FMV's Richard Lindström. In Germany the armor package was originally ordered in 1995 for adoption within the KWS 3 upgrade (whole hull would require an overhaul for KWS 3, as this meant the adoption of a new turret with 140 mm gun), but the order was canceled shortly after. Currently Germany is trying to enhance the Leopard 2A7 design (enhanced tank currently codenamed Leopard 2A7V), which also includes the adoption of the further armor package. If you are talking about crew survivability, the frontal fuel tanks of the Abrams might be an advantage. On the other hand, once the fuel tanks are hit and the fuel is incinerated, the tank has be abandoned unless you want to eat fried Abrams tankers. The fuel tanks of the Abrams are more likely to be incinerated, because of the thinner side armor compared to the Leopard 2. The Leclerc might have the best hull armor design (at least as long as there is no AMAP/MEXAS-H armor), but it's lower front is not protected by composite armor. It is the safest place. All current tanks are optimized for anti-tank warfare, which means the armor of the tank is designed to protect the frontal 60° arc of the vehicle. By placing the ammo directly behind the hull armor, the largest amount of the frontal 60° arc of the the ammo is protected by the tank's thick frontal armor. Moving the ammunition away from the armor, means it is more exposed, as less of it is covered by the tank's frontal armor. It is possible to extend the ammo rack to the whole width of the bustle; Rheinmetall once proposed to fit a semi-automatic loader at the bustle containing all ammunition. However storing all ammunition in one place is not an ideal design decision, because this means you have to put enough armor at this place to survive anti-tank weapons; otherwise your ammo rack will be hit and the tank is useless. This is why the M1 Abrams' bustle has the same armor protection as the crew compartment. The 130 mm gun will need an autoloader. Rheinmetall claims that their Leopard 2 Revolution tank has a new "decoupled ammunition bunker". I am not sure if this also has a blow-out compartment or is just a fancy new term for ammo rack.
  10. SH_MM
    Rifled guns are more accurate than smoothbore guns Soviet monkey models had no composite armor The Assad Babil was produced in any noticeable numbers Leopard 1 could be penetrated by machine guns Chobham armor is ultra secret and even the armor for US tanks is manufactured in Britain without letting any US tank designer know it's composition
  11. SH_MM
    Leopard 2A6 is 2.64 metres tall with the additional bomblet protection at the turret roof, as operated by Greece and Spain; the height of the roof of a Leopard 2 without bomblet protection is 2.48 metres as you can read in Spielberger's books on the Leopard 2. The width of the Leopard 2 is greater because of it's thicker heavy ballistic skirts at the frontal hull; on the Leopard 2 to 2A4, the width was 3.70 metres. On the late batches of the Leopard 2A4 and follow up models (2A5, 2A6, 2A7), thicker heavy ballistic skirts increase the total width of the tank to 3.76 metres. Without any skirts, the Leopard 2's width is only 3.42 metres (Spielberger). Given The Leopard 2 has much thicker, but shorter heavy ballistic skirts. On the M1 Abrams, the frontal skirt elements have a thickness of supposedly 70 mm (claim made by a US tank crew member), while on the Leopard 2 the thickness is 110 mm (earlier versions) or 150 mm (later versions; skirts are mounted a bit closer to the tracks). This is why the Leopard 2's hull is actually not as wide as the hull of an Abrams tank. Excluding skirts and optional roof armor, the Leopard 2 is 30-40 mm taller (ground clearance 550 mm vs 482 mm), but the Abrams is 100 mm wider. That's why calling the Leopard 2 a giant compared to the Abrams is not justified.
  12. SH_MM
    The Leopard 2 is "needlessly giant"
  13. SH_MM
    Why do they store ammunition outside the semi-automatic rack in the Merkava 3 then?
  14. SH_MM
    The upper photographs are a bit misleading. The tanks were photographed from different distances; you can see that by comparing the size of the measuring pole: each square is about 9-10 pixels high on the Leopard 2 photo and only 7 pixels on the T-72 photograph. Correcting this shows that the Leopard 2's hull is about 160 mm higher; however the Leopard 2 has a ground-clearance of 550 mm (reduces to 500-520 mm at the engine compartment), while the T-72 has a ground-clearance of only 490 mm. As such, the hull height difference at the turret ring might be only 100 mm. German author Rolf Hilmes wrote a chapter in one of books solely to compare the T-72(A) to the Leopard 2. This is based on the official evaluation of ex-GDR tanks analyzed by the Bundeswehr after the reunification of Germany. According to him, the difference in hull height is 188 mm, but he didn't write at which exact position (other than comparing the total height). Comparing other photographs of the T-72M1 and M1 Abrams, there seems to be a similar-sized hull height different, if we take into account ground-clearance (Abrams and T-72 have essentially same ground-clearance). Note that the ARAT reactive armor covers only the side skirts, the tank hull actually extends over these skirts though. In so far I would be careful with claiming that the hull height of the Leopard 2 is much greater and the tank thus has a greater internal volume. Should I measure scale drawings or photograhs to come up with a mililmetre value? Not the exact same, but very close. Given that more of the Leopard 2's frontal turret profile is covered by the sloped roof armor, the Abrams might actually have more vertical thickness at the front. It is however not the case. The scale measurements have some margin of error, but the roof section excluding the armor is at most 20 mm larger on the Leopard 2. If you take into account that the M1's turret is much longer (see previous posts) and it's width increases downwards (from ~2.5 to ~3.3 metres), it will have a quite larger internal volume. This was the case of the old Leopard 2 (2A4).
  15. SH_MM
    The Merkava 3 also has some ammunition stored in the turret, despite not having such a semi-automatic ready-rack.
  16. SH_MM
    In reference to what statement? How thick is this composite armor? Is this only the 30 mm gun shield or also the armor at the gun mount? How much area does it cover? And how did Froggy "discover" this? The Abrams is not shorter. It has a longer hull (7.92 metres vs 7.672 metres) and a longer turret (at the turret centerline, the Abrams' turret has a length of 4.77 metres, where as the Leopard 2's turret has a length of only 3.99 metres). The only difference is the location of the unarmored external storage boxes, which in case of the Leopard 2 are all located behind the turret, increasing the visible turret length without affecting the internal volume. On the Abrams, external storage boxes are not only located at the turret rear, but also at the rear side section. I think it is obvious why I am not including the storage boxes: As for the hatches, them being closer together means nothing. If you have a sheet of paper and draw to circles with a distance of X, putting two larger circles onto another sheet of paper at the same position will reduce the distance to less than X. The commander's cupola has a diameter of 31.75 inches (806 mm; slightly more if you include it's "turret ring"), which is a lot more than the 500-550 mm diameter of normal hatches as found on the Leopard 2 and for the M1 Abrams' loader.
  17. SH_MM
    The spall cone created by shaped charges can be larger than 90°, in such a case there is quite some danger of the crew being injured. Fragments of the projectile/shaped charge jet might also damage the internals of the tank, rendering it useless. I wouldn't assume that hitting this place or the gunner's sight won't cause harm to the crew. Based on photographs, the side armor of the M1 Abrams is not thicker than the side armor of the Leopard 2 or the Challenger 2. The M1 Abrams just has a very large commander's cupola, which creates the illusion of the hatches being located closer. The Abrams turret has about 10% more frontal surface and has about 40% more side armor volume (at the ammo racks), so I'd expect it to have less frontal armor at the same weight. The problem of the mantlet-less design of Challenger 1 and Chieftain, is that it had a negative impact on too many other aspects. For example replacing the gun barrel took about 24 hours, while the same task can be done within half an hour with proper equipment on the Abrams and Leopard 2 tank. The lack of a proper gun mantlet also meant lower protection; while the size of the weakspot is smaller, the armor still gets thinner at the gun mount.
  18. SH_MM
    Well, if you include TUSK as armor kit for the Abrams, then you also have to include the different Theatre Entry Standards (TES) armor kits (three versions at least) of the Challenger 2. The base armor however was most likely not upgraded. The Leclerc is not geometrically more efficient. It could have been, if it's armor layout wasn't designed so badly. The Leclerc trades a smaller frontal profile for a larger number of weakspots. It uses a bulge-type turret (no idea about the proper English term), because otherwise a low-profile turret would mean reduced gun depression (breech block hits the roof when firing). There is bulge/box on the Leclerc turret roof, which is about one feet tall and located in the centerline of the turret. It is connected to the interior of the tank, as it serves as space for the breech block to travel when the gun is depressed. With this bulge the diffence between the Leopard 2's and Leclerc's roof height is about 20 milimetres. The problem with this bulge is, that it is essentially un-armored (maybe 40-50 mm steel armor); otherwise the Leclerc wouldn't save any weight. While the bulge is hidden from direct head-on attacks, it is exposed when the tank is attacked from an angle. Given that modern APFSDS usually do not riccochet at impact angles larger than 10-15° and most RPGs are able to fuze at such an angle, the Leclerc has a very weakly armored section that can be hit from half to two-thirds of the frontal arc and will always be penetrated. The next issue is the result of the gunner's sight layout. While it is somewhat reminiscent of the Leopard 2's original gunner's sight placement for some people, it is actually designed differently. The Leopard 2's original sight layout has armor in front and behind the gunner's sight, the sight also doesn't extend to the bottom of the turret. On the Leclerc things are very different, the sight is placed in front of the armor and this reduces overall thickness. This problem has been reduced by installing another armor block in front of the guner's sight, but it doesn't cover the entire crew. The biggest issue of the Leclerc is however the gun shield. It's tiny, only 30 mm thick! Compared to that the Leopard 2 had a 420 mm gun shield already in 1979. The French engineers went with having pretty much the largest gun mantlet of all contemporary tanks, but decided to add the thinnest gun shield for protection. They decided to instead go for a thicker armor (steel) block at the gun trunnions. Still the protection of the gun mantlet seems to be sub-par compared to the Leopard 2 (420 mm armor block + 200-250 mm steel for the gun trunion mount on the original tank) and even upgraded Leopard 2 tanks. The Abrams has a comparable weak protected gun mantlet, but it has a much smaller surface. The Challenger 2 seems to have thicker armor at the gun, comparable to the Leopard 2. Also, the Leclerc has longer (not thicker) turret side armor compared to the Leopard 2 and Challenger 2, because the armor needs to protect the autoloader. On the other tanks, the thick armor at the end of the crew compartment and only thinner, spaced armor/storage boxes protect the rest of the turret. So I'd say: Challenger 2: a few weakspots, but no armor upgrades to the main armor Leclerc: a lot of weakspots, but lower weight and a smaller profile when approached directly from the turret front M1 Abrams: upgraded armor with less weakspots, but less efficient design (large turret profile and armor covers whole turret sides) So if you look for a tank that is well protected, has upgraded armor and uses the armor efficiently, the current Leopard 2 should be called best protected tank.
  19. SH_MM
    Let's germanize the bad British tank!
  20. SH_MM
    According to Russian Defence-Blog.com, this is the wheeled Barys IFV. It is claimed to be a new development and not directly related to the Bismarck. It is developed by the Paramount Group of South Africa. Their websites calls it the "Mbombe 8". Given the poor armor (ballistic protection according to STANAG 4569 level 3) and low maximum (gross vehicle) weight of only 28 tonnes according to the press release, I would assume that there is no relation to the Bismarck "wheeled tank". The current Boxer A2 as Combat Reconnaisance Vehicle has a maximum gross vehicle weight of 38.5 tonnes and ballistic protection according to level 6 of STANAG 4569.
  21. SH_MM
    Very "rare" such an internal view... it's not like there are hundreds of photographs of the internals of the Leopard 1 (including cut-through tanks) available.
  22. SH_MM
    Time to get some more Wiesels in here: Wiesel eDK2 prototype with new running gear and suspension. Source: flickr Wiesel DIOK prototype with stretched hull, new shock dampeners and track spanners. Turret is mock-up. Might be fitted with the hydropneutic suspension units in the left of this picture (?). Source: flickr Wiesel with experimental hybrid drive (iirc. diesel-electrical) and fibre-composite roadwheels (weight reduction 45% to 55% compared to the oriuginal roadwheels). Source: flickr Wiesel 2 WITCH prototype. Can be remotely controlled as a UGV, but in general the German Army is still waiting for an official NATO standard for (UGV) software architecture.
  23. SH_MM
    I thought Bumerang has no APS?
  24. SH_MM
    I don't see any ERA boxes. I see very thin armor plates bolted on the main armor of the hull (a very, very, very, very, very common armor design). The sponsons look average, comparable to Boxer, AMV, VBCI etc. Only the fact that the outer section is used as storage box is new. The side armor of the Eitan doesn't seem to be any thicker as the armor of the aforementioned vehicles. The distance from driver's hatch to hull side (as one can see in this video) is virtually identical to the Patria AMV. I don't see any ERA box neither do I see any double layers. I'd would be interesting though to hear about the source of this claims.
  25. SH_MM
    "Wheeled death traps" is a joke/meme. I don't see any ERA on the Eitan.
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