Xoon

My reason to mount the engine tranversly is to reduce the length of the vehicle. As we all know, the tank needs a turret ring of about 2000mm in diameter. By having the turret ring protrude into the sponsons we could optimistically reduce the internal hull width to about 1800mm. This means that the vehicle HAS to be at least 1800mm wide, regardless of how the engine is placed, since it is less then 1,8m in length. The crew capsule is also slimmer, so thereby we should use as much of this required width as possible. Since the engine is rectangular it makes sense to place it transversely, this reduces the length required by the engine by about 50%. Which means less side area needing heavy armoring, which means less weight. For example, let's say we use the MB 833, in a hull 1m tall with 80mm thick side armor. Let's say that 80mm plate goes 3 meters back from the front to the backside of the middle of the crew compartment, this would give it a weight of about 1,8 tonnes, 3,6 tonnes combined, By transversely mounting the engine we save off 620mm of length, and the plate would weight 1,435 tonnes, 2,87 tonnes combined, this saves you 730kg or a 20% weight reduction. This does not include the weight saved in roof or belly armor. Also, a driver located next to the engine would not work with a rear ramp or door, since the unmanned turret would be blocking the way. And if we do have the crew capsule mid mounted, then it would not reduce the overall size of the vehicle at all, since the turret still requires 1800mm of width, and 3 people can comfortably sit side by side with 1800mm width. And yes I do realize that that it is incredibly hard to find a transversely mounted engine in the front in a CAD, if not impossible. But remember, we are talking about MBTs, not IFVs like the Puma. I assumed you knew the voltage of the M1s subsystems. Since it makes zero sense for a APU to generate anything else, that would explain why I did not mention it. I know Ohm's law, it's my field. The size of the new APU was identical if I am not mistaken. But this discussion was not really about APUs, so we can discuss that later. But I am happy about the information you provided. According to what you are saying here, should we stop sloping the armor and extreme angles completely? If this is the case then hatch design has to be on a flat roof, or else they would either be insanely thick, or the frontal armor would be have to be heavily sloped. And making a hatch that can be 250mm thick not have weak spots is a hard feat, just look at the Merkava. By not having hatches, you could have the sloped of the armor reach almost all the way up to the turret ring, which would let the designers reduce the length of the vehicle compared to a conventional one with the same slope. The Armor would also work as roof armor here. By placing the crew in the back they will be protected from top attack munition by the turret and being longer away from the front, which takes the most amount of fire. If a missile aims for center mass, then it is more likely to hit the front hull than rear of the hull. The crew would still need about 200-250mm thick roof armor above them. But shouldn't the engine too? To stop bomblets from disabling the tank. Also, tanks that feature a flat hatch, instead of a sloped one, T-14, TTB and Leclerc prototype. To name a few. In the case of the CV90, this is a lie. The inside hull height at the troop compartment is around 980-1000mm from estimates. This is the same as the internal hull height of the Leopard 2 The CV90 is not close to as tall as other IFVs: Could you please explain how a door makes the hull higher? Does it impose any physical limitations or is just because a crew member needs to fit? Because a crew member can easily fit through a 900mm tall door. You know the Strv 2000 was supposed to use a front mounted engine right? And the RPG protection is only for the front half of the hull, and it only covers the front half of the crew compartment. It is also ERA. I know the turret is not right one, but the hull were almost identical between the different variants. The only thing that changed was the turret. I assume you know about this by reading about Prosjekt Stridsvagn 2000. For those that don't understand Swedish: Pil = APFSDS RSV = ATGM Buren PV = Handheld RPG or man portable RPG. Finkaliber up til 15mm= HMG Splitter och tungmetallkulor = Splinters and heavy metal balls.

You are fully allowed to do so, this is a discussion after all. I was talking about a tranverse mounted engine, not a conventionally mounted engine as seen in the picture. Imagine the picture, but now remove the drivers compartment, and rotate that engine 90 degrees, do you see all that extra space that is freed up? First, I was talking about 1500HP engines only. I should have specified this and it is entirely my fault. For a bigger engine, a front mounted setup would most likely not work out. Second, APUs are compact, and they already produce a large amount of power, the Abrams is going to get a upgraded APU too: http://www.scout.com/military/warrior/story/1728632-army-builds-new-abrams-tank-variant-for-2020s (Shown by Damian in his thread on AW) The APU shown here has a claimed max output of 1KA. That is A LOT of power, and should be more than sufficient to power a APS, cameras, turret traverse, FCS, computers and sub systems. At least in the case of the Leopard 2, the APU is separate from the engine compartment right? The main reason I see for placing the APU in the back of the sponsons is because it does not take up any space inside the hull, and because it is the tallest part of the sponsons, also it helps that it can have it's exhaust going out the back. When it comes to complexity, yes , it would be more complex, but not by much, a longer power cable, and since the MBT would most likely have fuel mounted in it's sponsons, the a longer fuel line would not be needed. I was saying that front mounted engines made more sense now, not that all MBT designs are going to use them. If you are refering to my last bit of line, that was spelling error, I meant "I could see front mounted powerpacks in the future". As in, they might have some potential. My list was more food for thought honestly. And I was simply listing everything I could think of. So of course I overlooked some mayor drawbacks, this is why I post here, to get other peoples opinion. How true they are is up to you to decide, they are just theories. The idea was that electromagnetic sensitive, pressure sensitive, laser, thermal mines and IEDs are most likely to explode under the front of the vehicle, and with the crew in the back they would physical be as fast away as possible, for example the explosion would not be as strong as at the epicenter, and it cause of hull breach, the crew would be further away. Drivers are the most likely crew member to die of mines or IEDs after all. If the IED or mine is timed, programmed or remote operated this would make little of a difference, that is true. But those are more expensive, newer or more risky. And of course it would be easily countered, it is not a mayor advantage, more a minor one. A common trick in tank design to reduce the frontal area that needs protection is to slope the roof at a high angle, about 82-83 degrees. In the case of a crew capsule, the crew needs hatches, which usually needs the plain, flat surface. This minimizes the potential to slope the roof, which increases the frontal area needing protection. You can slope the hatches too, but most designers have moved away from this practice. Also, turret armor and the gun barrel blocks these hatches, this can be seen on the Leo 2A5, or any T-series. Without the hatches the designers can freely create a overhand without worrying about trapping the crew. I already explained how we could accomplish the same height as a crew capsule, and if you wondering about the cooling system, just create it is the same way the Puma did, by letting it fill the space between the slope and the engine. Example one: ' Example 2: As you can see (with writing that could kill) in this example, the front mounted powerpack has a frontal height 50mm smaller than the crew capsule. And if you are wondering what the length of that flat is, it is 450mm. Regarding optical vision, I think I stated that in the pros and cons. As you have to entirely rely on cameras. And, how does a rear door in itself increase the height of the vehicle? This is true, but it can have the same thickness. But not without a few drawbacks. See CV90. Front mounted engine, rear mounted exhaust. And a rear door/ramp. And about the sideskirts, depends on the country. Swedish requirements were 65 degrees coverage of the front, not the crew. 1. This is not a issue as stated earlier, cameras, which are becoming widespread. 2. With my proposed layout, you might even gain gun depression. It is unfair to compare it to the Merkava, which has a huge conventionally mounted engine. 3. Could you rephrase this one, I did not quite get this one. "Though very uneven engine"? You are correct that a two-man crew capsule can provide better protection per weight than a front mounted engine pack, simply because you have more room to play with. But in my opinion vs a 3-man crew capsule, I think it would actually tip in my proposals favor. Anyways, thanks for commenting, and I am very tankful that you provided so much great information. Huh, thanks for letting me know that! huh, thanks for the information! Another thing brought to my attention from tank-net is hybrid electric drivetrains. It seems to be two viable solutions: 1. Soft hybrid parallel.:The soft hybrid parallel would be the same system as already used in tanks, but with a small electric motor added to the axle between the engine and the gearbox, as well as a electric motor coupled to the turbochargers axle. And a battery of course. How the system would work is that the electric motor coupled to the turbocharger would spool it up when starting, effectively eliminating turbolag and the need for a second turbo. This same engine would be used as a generator to harvest excess energy from the turbocharger too. The small electric motor between the engine and the gearbox would work as a regenerative break when the tank is breaking, reclaiming some energy, and optionally adding power when driving and using excess energy stored in the batteries is available. This could increase acceleration and fuel economy and performance in general. Of course, this system would be take more space then a conventional drive train, and also be a bit heavier. 2. Full serial hybrid:Here the engine would get the same aid as said earlier, but instead of sending it's power to the gearbox, it sends it to a generator. This would allow the engine to run at optimal RPM. This generator would then feed into a rectifier, and then into the main battery, which would feed into two Speed controllers that would control two electric motors. These electric motors would also work as regenerative breaks. To avoid de-synchronization, you simply make the engines communicate and adjust to each other. This system allows the engine(s) to be moved away from the "transmission" and placed anywhere, like the sponsons, or even the turret. The battery would have a capacity to allow the tank to run in silent mode, and to recapture as much energy as possible while breaking. This way the tank could also do a cold start and heat up the engine while it moves away. Alternatively, you could go turbine electric. Maybe you could attach a electric motor to the main shaft to spool up the turbine faster? Anyhow, if I am not mistaken, turbines run quite efficiently when they are at their optimal RPM, which should help greatly on fuel usage. The tank would also be able to start immediately, and spooling up the engine while running on battery power. This would remove the 30 second spool up time of the turbine. Also hilariously, the tank could still technically be charged from a house socket, if it carried a charger with it, or be charged by the APU, in case of engine failure. Batteries would have to be stored in the sponsons with blow out panels most likely, since lithium batteries have a tendency to explode when hit.

So first of I got a question about hydropeumatic suspension. When used as a active suspension you have to have a pump, valve and reservoir to increase and decrease the pressure in the cylinders right? If this is the case, it would take up extra volume and require two pipes going to each suspension arm. Considering this, would be electromagnetic suspension be more space efficient? I assume it would use electricity to regulate it's height. If this is the case, then much thinner cables could be used instead of pipes. Also the system would be powered most likely by a APU, which seems like it is becoming a standard in most tanks. Next question is whether or not front mounted engines make more sense now then ever. Considering how much the powerpacks have shrunk, would be front mounted setup be more compact than a crew capsule? When I took some measures of myself I found out I could comfortably fit with a height of 900mm, 80-100mm extra for seats and helmets, and 170mm extra for head space against IED explosions, if we are to thrust the Swedes. When it came to width I ended up with something like 600mm, but I do know 500mm is considered roomy, so for the benefit of the crew capsule, we will use that. And by multiplying this by 3, we get a total width of 1500mm. And for length, I ended up with 1350mm, when sitting straight. The length may be longer if you want a lower capsule or more leg room. This would be us the dimensions: 1350x1500x1150mm for the crew capsule. The powerpack is more rough measurements, but from what I understand, the MTU 890 V12 is 700mm wide, 550mm tall, and while the length is not given, it could be the same as the 883, which is 1480mm wide. The newer RENK transmissions seems to be about 500mm long, about 1500mm wide, and 500-600mm tall. So by placing the MTU 890 in a tranverse mount, the combined length would be about 1200mm, with a width of around 1600 when including the mechanical linkages between the engine and the transmission, and 550mm tall. The dimensions of the powerpack would thus be: 1200x1600x550mm. This does not include the cooling, or piping or smaller systems that might add more volume, so adding 1-200mm here and there should be expected. The overall height would not really be much more when the cooling is installed, since it can be placed on top of the engine, so unless you want a 45 degree slope, there should be enough space. Next we about the pros and cons of this setup: Front Mounted Crew Capsule: Pro: -The main armor protection is placed around the crew. -The Periscopes are positioned in such a way that the driver can drive even when all cameras and electronics fail. -Smaller frontal heat signature. -Less likely to suffer a mission kill. -Smaller front sprocket -Less Likely to throw a track. Cons: -When the armor is penetrated from the front, the crew is highly likely to be injured, since nothing can stop the shrapnel of projectiles. -The crew hatches forces the roof to extend forward to avoid shells hitting the hatches, which cause the frontal area needed to be protected to be larger, this also may cause a reduction in gun depression, or a higher turret. Also the hatches may be blocked by special armor or the gun barrel. Lastly, if the hatch is angled, it will have a notch weak spot if the front is up armored. -Crew has to be evacuated through their hatches, which is not the easiest thing is the world. -Crew is exposed to enemy fire while evacuating from the tank. -Crew is more likely to be wounded or killed by a mine or IED. Front mounted powerpack: Pros: -Potentially smaller frontal area needing protection. -A door, or ramp, which would make crew evacuation easy, and wounded crew member could simply be dragged straight on to a stretcher from their seats. -Crew is protected by the tank when evacuating. -The powerpack and potentially the internals of the tank would protect the crew from shrapnel and the projectile during a penetration. -Crew is less likely to be wounded or killed by a mine or IED. Cons: -More likely to suffer a mobility kill. -More likely to throw a track. -Larger thermal signature. -Less ideal crew protection. -No back up in case of failure. So with the introduction of unmanned turret, and smaller powerpacks. I see frontally mounted powerpacks. Or maybe sponsons mounted engines, which would make the tank shorter.

That is a prototype of BAE/Sweden's SEP-AMV/AMV 8x8 universal platform. Projekt SEP was a project to unify all the different armored platforms under a single platform: The plaform would be divided into 3 sub catagories: The tracked version also came in two types, the T1: And the T2: And it was designed to be modular: And appears to use a hybrid electric system as we can see here, with the side sponsons mounted exhaust, which hint sponsons mounted engines: And the drivers station here: More info here: http://www.ointres.se/projekt_sep.htm

What about a raise-able mast with the Radar/sensors on it?

Does the K1 totally lack any kind of turret mounted ammunition or ready rack? And does it have any composite side armor on the turret? The shape seems kinda curious, even though it makes sense, it does not leave a lot of room.

A few quick questions for the folks here: Considering how modern naval combat works, with close to no armor, and heavily relying on stealth, APS and missiles. Could a entire navy composed of submarines be possible? Wouldn't the water help protect the ships against radar, as well as hiding them from visual spotting? I know that you can't just have a submarine carrier and helicarrier as well as landing crafts, but what about the other ships, what stops them from becoming submerged? Is it because of cost? or any other reason? Just some food for thought.

Very interesting MM, But just a few things: A easy way of tracking the position of the lens would be to hook it up to a variable resistor. The further out the lens moved, the higher resistance would be created. The resistance can then be converted to a analogue electric signal, which could vary from 4-20mA. Usually, you can have 255 states from a analogue signal. 256 being 0 or or 0m in this case. So if each state equals 100m the analogue signal could in theory contain measurements up to 25 500 m. Are you referring a analog electric signal here? And if so, did you mean a digital electric signal when you said electronic signal? Mvh Xoon.

Does anyone have any pictures of the other prototypes or some info?

So two spaced 12,7mm plates to protect accomplish STANAG IV then? To avoid overmatch.

So considering you need 18mm of RHA to stop AP 7,62mm, does this mean that we only need 9mm of nano-ceramics for the same protection? Considering this, would it be possible to use 5/500/5 (Cermics/Air/Ceramic) setup to provide STANAG IV protection? And I guess the two times thickness efficiency figure is not taking the containers into the equation right? So For example a AFV would need a 3mm thick steel walled container to contain the ceramics.

I see the old heavy ballistic sideskirts are still fitted, couldn't they be replaced by a lighter alternative? Like ceramics or a AMAP module without increasing the weight? As far as I know, those side sideskirts are simply a 50/10/50 mm of steel, so it could easily be exchanged for something lighter right? The reason they did not up armor the hull was because the suspension would not support a much higher weight, so why not replace some of the old components with lighter ones?

It appears yes to be a K1, look at the engine deck. The K1 has two circular intakes and two round "hatches" on the sponsons, and altogether looks clean: While the K2 has square intakes and a more detailed engine deck: Edit: Ninja'ed lol Oh and a quick question: Does anyone know the thickness of the composite armor on the front of the hull on the Strv 122B? By comparing the thickness of the add on armor with the base armor I got around 410mm for the add on armor, which means a combined thickness of around 1050mm.

Are you referring to the ammo rack up in the front, or that the engine has fuel on each side of it?

They did indeed cheat on the numbers. You should never fully trust a advertisement. With fuel, it is closer to 400mm of saved space, if the hull inside is 2m and the required fuel capacity is 1200L. You could cut it down the amount of fuel because of the engines higher fuel efficiency, and then you would save 460mm. Does anyone know what the sponsons of the Leopard 2 are used for?

Here you have your suggested layout, in a high and low capacity variant. I find the high capacity variant the most logical, considering the fact that you have enormous space for fuel. Maybe even a ultra high capacity variant would make more sense, which would come out with something like 66 rounds. However, the ultra high capacity and maybe the high capacity version depending on hull width would need a frontal layout like the M1 series or fuel in the sponsons. But since you are talking about using fuel as armor here is the estimated protection the fuel tanks would provide in a hull which is 1,8m wide on the inside: For the high capacity version: 32mm of RHAe at 0 degrees, 64mm at 60 degrees. For the high capacity version: 75mm of RHAe at 0 degrees, 150mm at 60 degrees. This is estimated with the claim that a fuel tank is 1/7 as effective as RHS, which supposedly comes from the designer of the Merkava series. Feel free to correct me if I am wrong. If we take the Leopard 2A4 are a basis here, the estimated protection on each side of the ammunition rack would be: For the high capacity version: At 0 degrees: 13+40+32= 85mm of RHAe. At 60 degrees: 23+80+64= 167mm of RHAe. For the low capacity version: At 0 degrees: 13+40+75= 128mm of RHAe. At 60 degrees: 23+80+150= 253mm of RHAe. This does not however take into consideration the spacing or the armor the roadwheels would provide. Or a steeper angle for that matter. And with this layout, would it be possible to quickly reload the ammo rack by lower the rack though the roof with a crane? Like a quick reload method.

Weird choice of imagery there when talking about the MTU MT890, considering that is a MB883 engine. But they are very close in size, but I do believe the 890 was 668mm high, and 700mm wide. The length I was unable to find. This is a clean MTU MT890 V10 engine:

1. The powerplant intended here would be the MTU MB 883 V12 or 890 V12. The MB 830 dimensions are about 1488x972x742mm (LxWxH). For a transmission the standard RENK would do. The with of the inside of the hull is usually around 1,8-2m wide on the inside, which leaves 820-1020mm of space left, 410-510mm on each side. Two rounds wide, and 3 high, which gives 12 rounds actually, ops, a miss calculation earlier. But for a 1892mm wide inside of the hull, it would still be 36 rounds Here you can see the old engine, MB 873 was it? As you can see, at each side of the engine you have fuel tanks, by removing these you should be able to fit some rounds in there. I don't remember the dimensions of the older engine, but it was a bit bigger. Obviously, if you are already going to upgrade the Leopard 2, then you might as well change the powerpack while you are at it. 2. Yes, the radiators would be on top of the transmission since it is a bit shorter than the engine, and because of the extra space the raised engine deck gives. Here is a example: 3. There is NO WAY you can fit the 120x570mm NATO into a carousel autoloader without using two piece. Well you can, if all the rounds are standing, with a unmanned turret. So it's a no go for a manned turret. I have literally messes around for hours to see if I could make a 120x570mm carousel autoloader, but it didn't worked out without making mayor comprises. Sorry about that one, I should have been more specific, if 125mm shells were used, then it would be possible. And for those that wonder where the fuel went, it would probably be moved to the sponsons, or you could remove the front rack on the Leopard 2 and install a fuel tank there. Do you think it is possible to fit a APU there too?

So while I was tinkering with the engine compartment layout I came up with these three layouts inspired by Soviet design: Layout 1: This layout has the advantage of being the shortest of the three. This is because the rounds lie along the length of the engine on each side. The total ammunition count here was about 36 rounds when using the 120x570mm NATO shell, with the entire engine compartment being 1,8m wide and about 1m tall. One potential I see with this design is that it could possibly be retrofitted on a Leopard 2. By shrinking the fuel tanks on each side of the engine, and isolating the ammunition and modifying the engine deck, this should be possible. This layout also works with the 130mm without being any longer, at the cost of even smaller fuel tanks in the engine compartment. Layout 2 and 3: Layout 1 here is just for almost for the fun of it. Put simply, it is longer than layout 1, but gives you a ludicrous ammunition capacity. You can fit about 72 shells of 120x570mm NATO ammunition in there! Any tanker that thinks that a tank with over 72 rounds of ammunition has to little ammunition deserves a slap. Layout 2 here is a bit more realistic, sacrificing ammunition capacity for space for fuel and/or a APU or whatever you want to fit there. With identical length to layout 1 by the way. However, this layout still sports a pretty solid amount of ammunition, around 54 rounds in fact! Of course, all of these layouts use isolated ammunition with blowout panels and a blast door, so in case of a penetration the crew will survive. Also, if I am not mistaken, tanks with all of their ammunition in the hull experienced less cook offs after penetration. And of course, this design allows for smaller turret, with either a 16 rounds ready rack bustle, a Leclerc style autoloader with 16 rounds, or the glories Soviet carousel autoloader. Any questions?

Thanks!

Quick question about the M1A2s AGT-1500 turbine engine and transmission: Can the turbine engine be set up in a tranverse setup? Or is it too long? Just thinking about how much more compact the tranverse setup is compared to a conventional one. And how the turbine always looks so long in the drawings. Mvh Xoon.

Oh, so it has a MG.

They could slap a RCWS on top to give it hunter/killer capability. The rest would be programming. It also lacks any type of MG, which may pose a problem.

True, but optimally you don't want to lose it. Wouldn't it make more sense to have it above the side of the turret bustle that lacks a blowout panels?

One question about that RCWS, is it mounted above the blowout panels? Isn't it mounted right above the panels?