Heavy and medium tank design philosophies

I was engaged in a discussion at Think Defence, and want to salvage at least one part of the effort for my own blog:

SO define a modern heavy tank and a modern medium tank then?

A modern heavy tank was designed* with the ability to withstand all hits on its frontal (at least turret) armour and with the ability to penetrate all hostile front armour in mind. Mobility was a secondary development concern.

A modern medium tank was designed* with the ability to defeat all tanks and the ability to withstand almost all** hits on its frontal (at least turret) armour in mind. Substantial sacrifices were made to enhance mobility***.

*: Not necessarily with lasting success or even mere initial success.
**: Including common, but not the most powerful AT munitions.
***: This is rather about soft soil performance and choice of bridges than top speed.

These (unofficial) definitions show why I think mediums aren't at a major disadvantage: The heavies lose their edge to technological progress quickly, while the medium's advantages are more persistent.

S Ortmann

edit: These two definitions are concise descriptions of what I observed how others separate the two tank categories. Well, save for those people who only look at weight. I did not make this up by myself.

related: TK-X video (about the new Type 10 medium tank)



  1. I'm not sure I agree with your classification system.
    I think "Tank" is simply a bad designation.

    There are, in effect, three components to a tank.

    Taking a 45t tank, 15t of armour, 15t of firepower, and 15t of mobility, and calling it medium, and a 60t, with 20t of each and calling it heavy, is, uninspired.

    The weight is much less important than the capabilities.

    We already do it where we strip away armour for fire power, we call them self propelled guns.

    Why not a 60t tank, that prioritises mobility (range, speed and offroad) above armour and firepower?
    It would require a new way of fighting wars, it might not be best suited for the North German plains, but why bother even fighting enemy tanks, run around them and slaughter their logistics lines.
    Or keep just out of their 33% weapons range, wait for their 33% of fuel to run out, and then drive into your 25% weapons range with your 50% fuel and accept surrender

    But then that would require thought, rather than doing what we did yesterday, but bigger.

  2. Your 3 "effects" list is incomplete, the 4th pillar ought to be TC effectiveness - the most important and least obvious pillar.

    "(...)20t of each and calling it heavy, is, uninspired."
    ...which I don't do.

    "Why not a 60t tank, that prioritises mobility (range, speed and offroad) above armour and firepower?"

    Because the same can be had cheaper at 40 tons already. Such a balance at 60 tons would be wasteful and thus a poor design.

    Tanks have hit a ceiling of practical speed and acceleration. Much more ore than 80 km/h and 30 hp/t didn't prove to be worthwhile.
    This is why an emphasis on mobility isn't about such simple spec sheet figures, but about soft soil performance, reliability/maintenance issues and the ability to cross weaker bridges.
    So far there's not even much of a race in regard to road range.

  3. "So far there's not even much of a race in regard to road range."

    Which makes it quite an area to examine...

  4. Been there three years ago already.

  5. S O that doesn't really cover it all, does it?

    I think the people who made that stuff up in think defense were never in a tank. It does not make any sense in warfare. What they defined was the difference between a good tank and a poor one not the difference between a heavy and medium.

    I was a Cav Scout 19D 1/11th ACR US Army for a short stint so I know a little bit about this. I joined the Cav because I loved the idea of recon. I was miserably disappointed with the M113/M577/ITV and the Bradley that followed. Not to mention the lack of proper training. But that was a long time ago.

    What does it matter to put names on things. You can sit back and call this that and so on. What does the General do with it when it's the only thing he has to fight with. That's when it gets a truer name. Many get the name POS.

    To me there are two types of tanks. One that they have a really hard time destroying and one they don't. For instance take my favorite subject "the Vietnam war." There where two types of tanks, the M48A3(was a medium tank, the M103 was the heavy) which could take anything the enemy had and still fight. Than you had the M551 which was an Aluminum coffin and the ARVN M41 which was a steel coffin. All becuase of the RPG.

    All this became moot when the Russians started sending them the Sagger missle which could knock out the M48A3. Had we still been there the loses would have been unacceptable to the USA.

    To me a heavy tank is an M-1 Abrams, it can take just about anything there is. With the add on armor and continuous armor improvements it's a hard tank to kill. With it's superior optics and 120mm gun unless you're in a similar tank you're dead. There are a few tanks that can pretty much match the M-1 the enemies of the USA do not have them. Therefore they still maybe heavy tanks but not as good as an M-1 or similar, you can also call them heavy suicide machines.

    It does not matter what gun it has, how much it weights and how far it goes. If it's all that army has to throw at you it's their heavy tank. Just ask the guys who hit the beaches of Normandy with their Shermans. Yes those heavy tanks that the DOD said were the best tanks in the world to the soldiers. Boy were they pissed off after the first battle with the Germans.

    The light and medium tank, one of my favorite subjects too. I really don't think anybody has defined exactly what it specificaly does as opposed to what it can do. The differences you described to me were completely off the mark.

    In fact the US DOD does not even have that name. You are not allowed to even call any tank anything other than a tank. If it's not a beast than it's not a tank period. I read this was done for political and pocurment reasons, having to deal with the houses. So as far as I know the US will never use that designation and has no use for one in it's arsenal.

    Yet the USA has the Stryker with a 105mm gun and the M3 Bradley which acts more like a ligth recce tank. Those sort of fill the light/medium tank role and can kill most tanks and all other vehicles plus provide support for ground troops.

    To me an analogy would be this; The light or medium tank is like a middle weight fighter. He has good punching power and could knockout a heavy weight with a good combination especially if the heavyweight is tired. He's light enough to move away from the heavy weight by circling around him away from his power punch. But if he is caught with a good one he is probably going down.

    The question is to define what the lighter tank's job is within your forces. As a tank destroyer or a fire support vehicle for infantry, or both. If the lighter tank or so called medium tank is your only real tank and it's the focal point of your armored troops, it's your heavy tank. That defines a heavy tank, it's that simple. At least to me and probably the troops that have to fight with it.

  6. Do you think TrT might find this old post of yours helpful (I did while looking into something awile ago), took me awhile to refind it:

    "Tanks - thoughts on a blank sheet of paper"


    a quote from it:
    I forgot to mention: The ability to negotiate obstacles gains importance once obstacles become the decisive tactical restraint. This means that fully tracked vehicles with good trench crossing ability, good power/weight ratio, low mean maximum ground pressure and possibly a dozer blade would completely outperform any of those fashionable 8x8 vehicles and probably also 55+ metric ton tanks."

    1. Exactly, one tank in one of the platoons must have a doer blade. It did wonders in the Vietnam war with M48A3 dozer tanks.

  7. bd,
    they didn't try to define heavy and medium,the discussion was about how decisive a strong front armour is.
    They were so fixated on a one-on-one head-on fight between tanks that all the complicated details that make the thin side armour so relevant were largely ignored by them. Their idea of tank combat is on a Tom Clancy level; below the imperfect field manuals.

    1. I actually laughed out loud.

      People just love to talk about things they don't understand.

      Everything on a piece of paper goes out the window when the bullets fly and the blood flows from your wounds. Although good training and discipline is so important as long as it is realistic.

      Had the Army told those poor tankers on the beaches of Normandy to use their nimbleness to get a rear shot. The lives saved, the loss of men and machines avoided. They let their ego and arrogance get in the way of reality. The combat leader must guard against that being done to his troops.

      I never said what the medium tank is to me. Although the boxer analogy summed it up pretty well. Big gun, really quick and maneuverable. The gun can be 105mm as long as it uses the new missile rounds. Maybe even smaller, super high velocity type.

      I like this Russian design that uses a 100mm gun with a 30mm auto cannon. Save the big ammo for a heavy tank and use the 30mm gun on everything else including helicopters.

      I must also add the .338 General Dynamics machine gun should replace ALL M240s in tanks and armored vehicles. Also the Mk19 should be added to tanks as a weapon to take out potential anti-tank positions, the Israelis use a 60mm mortar. And they are now using 50 cals as co-ax machine guns.

      And/or a version of the XM-25 like the ATK design. The idea of rounds going off over the position will help with the denial of these posistions. As well as the 50 cal for direct fire with the ability for high angle fire to take out snipers and overservation posts.

      The medium tank is invaluable in real combat. They can go places and do things heavy tanks cannot. One reason is that they should NOT need as much support from other units, especially engineers. Less need for preparing ground travel. Heavy tank units need so much support and are used in a way to be the focal point of an attack.

      The medium tank should be used as flanking and maneuver elements like Cav units. For Recon, fire support and flank protection for the heavy tanks. They should also be more integrated within other units that do not have heavy tanks.

      My idea of the perfect medium tank would be a scaled down version of the Merkava. The frontal armor is enhanced by having the engine in the front. A big powerful engine pack that can move the vehicle beyond even what a M-1 can do, use a similar suspension system. Give it an auto loading 105mm NATO type gun or develop a smaller one that can fire longer range anti tank missles. A low silhouette, long range and easy maintence.

      I can see smaller units filled with these pesky tanks showing up in a very stealthy manner. That is what Stryker unit do, but they cannot go cross country, tracks can. These may even carry a pair of scouts in the back. So a platoon can have 4 tanks with 3 crewmen each vehicle and a total of 8 scouts to dismount for the platoon. That sounds a lot better than using a mix of M1 and M3 vehicles in Cav units.

      Of course if the US DOD got a hold of it they would end up making it more expensive than a M-1. It would take 10 years to develop and be outdated before it got to the troops. Then after spending a few billion dollars on it they would cancel it.

  8. "Had the Army told those poor tankers on the beaches of Normandy to use their nimbleness to get a rear shot. The lives saved, the loss of men and machines avoided. They let their ego and arrogance get in the way of reality."

    Not sure what you mean there. Normandy's terrain didn't allow for much manoeuvre. Even attacking heavies would have been in huge problems.

    1. Yes the hedgerows very difficult, it was more when they got in open areas. I saw a video with the tankers talking about D-Day, all saying had if they known they would have changed their attack plans.

      They went into the battle head to head with Panthers and their rounds would just bounce off. The loses were just a horror.

      Had they been told you cannot go head to head with the German tanks this is what we have to do. They would have accepted that and drew up a better plan.

      First off the Allies had much more tanks, well over a 2:1 ratio. They could have used them in smaller groups to attack a single tank. Instead each tank commander thought he was on equal ground. They eventually figured it out but it was so unnecessary, the truth is best most times, not all times.

      Something like a 6-8 tank platoon operating always with either 2-3 tanks. Using hand singles to tell the other tank what to do, or flags. I had to learn what all the hand and flag singles meant in case our radios didn't work or we went silent. See a German tank split apart and move in a circle pattern around the tank. Use the 50cal, something they did not have to harass the TC and maybe destroy their optics. Take shots at the driver's hatch until one tank gets behind and unloads. Go after their tracks too as you maneuver.

      By then the other tanks would be there too all firing at the tanks rear. It would take skill and practice. But from what I understand that's what they ended up doing.

      It would have also been nice to tell the tankers that their gun signature could be see much easier than the German's because they used better power with less flash. Little things that would have helped them devise better battle plans.

      It was a terrible miscalculation by the allied Generals. But it was typical of all militarizes even now. Like telling the Russian soldiers their vests were bullet proof when all they were was a cotton vest. I remember in a magazine years ago the DOD finally got a Russian vest from Afghanistan and took it apart. It didn't even protect them from fragments.

      Or how about the Chinese who told their soldiers in Korea that they were in China. America had attacked them with nuclear weapons and their homes are all destroyed. No wonder they attacked in mass human waves.

    2. The real problem in Normandy was that they didn't manage to break out before the reserves arrived. The German defenders were entirely overstretched early on, with a low quality regiment defending more than what's usually a division sector.
      The Allies didn't use this opportunity to break out ASAP with quick vanguards.
      Same mistake as at Anzio earlier.

      The Soviet vest from Afghanistan story that I know is about a titanium plate-reinforced vest, and that one was unable to withstand 5.56 mm, but effective against pistol shot and most fragments (our kevlar vests only stop the majority of fragments as well).

    3. Yes that's what they were supposed to be until we got a few and found them to be nothing more than a vest. As usual the story went that the Russians have this great vest better than anything the West has, as usual. It was just a vest.

      They probably did have a titanium version given to special troops like Spetnaz. But the average troop did not get that one, he got the reasonable facsimile. Typical of Russia at the time.

      D-Day, what a mess. Same for Anzio. I was taught in school that the USA won the war in Europe. When I started to study on my own I found who really did the heavy lifting there, it was the USSR. We won the Pacific but it was the Russians that faced the German's best troops and so much more of them.

      They to this day make it seem like D-Day was this great military achievement. It wasn't, compared to what the Russians did when they attacked with millions of men and thousands of tanks at one time. Not to mention that 400,000 women fought on the front.

      Getting back to tanks I think the frontal armor is an important aspect but it does not define the tank. As an ex-anti-armor soldier I was taught to attack the side or rear. I worked with Dragon and TOW missiles. You just never attacked a tanks's front. Everybody knew the weakest point is the top of the turret or the engine compartment top. The turret top was what you aimed for if you could not get a side shot.

      The whole idea of the ITV was to hide and raise the missile launcher then fire. You had the higher ground so the missile would hit the top of the tank. With TOW it didn't matter they would knock out any Soviet tank no matter were they hit it as far as I know. If it wasn't a dud that is.

      I also have read that the quality of the Russian steel varied. A lot of the exported tanks did not have as good a quality to their armor. I lean toward believing this knowing a bit about Soviet quality control. They where all about quantity during the cold war.

      I wasn't in the Army long but I did study about armor tactics. With that I say why did the Army even accept the M3 Bradley for the Cav? We needed a medium recon tank, not a mix of M3s and M1s.

      They turned the Cav into a heavy armor unit which defeated the whole purpose. The failure of the Sheridan caused it I guess. I read about the Horrordan or Sheridan and talked to some Scouts who used them. What a POS.

      I still can't believe they were OKed for Nam. When I read about the Sheridan I lost a lot of respect for Patton and General Abrams who sent them to Vietnam. To use men as guinea pigs?

  9. My 2 cents, the webcam can have a major impact on the whole tank design issue. The another major effect related to the webcam is improved remote controll fighting platforms, possibly wired and over short distances, (Goliath was a German experiment with this idea) and reduce overall system complexity of current combined arms.

    The whole current tank design derives from a tradition of handling a gun on an all-terrain chassis with enough armour for a crew compartment in which humans can survive that idea. You need a large manned turret with an armoured exterior that does include lots of dangerous explosives. If you reduce the manned space to zero you need to armour much less space and have correspodingly less armour weight (significant if you look at turrets and the necessary armoured chassis).
    Modern developments in information&energy transfer, sensors and information processing would allow to create an unmanned vehicle with a tank gun&turret on a self-moving capable chassis that is wired and can be interlocked (for better energy transfer during cruising) to another vehicle (for example an IFV or scout). You can steer the unmanned wired(no radio interference or SIGINT) and remote controlled platform forward to face danger from a safe distance behind. The combination can be cheaper and lighter than a current tank while providing similar degrees of protected firepower.

    Take an old idea from WWII and pull another gun behind the central vehicle, this can be for example a mortar, able to fire while being pulled, that at the same time offers rear protection, leaving just the central section of the modular bandwagon open to attack.

    I suggested an IFV or scout for the center of this combination with a very shallow siluette and a high raising angle for all guns (translates into range with indirect fire).
    An increase in the internal volume for more humans on board has only a minor effect on overall armour requirements, because most explosive material is in better shielded unmanned compartments.
    Scouts will be capable to use extendable multi-spectrum surveillance antennas to see enemies while still being turret down. IFV and scouts will likely merge because of economies of sclae and because both need constant information flow and descending infantry.

    One weakness of this combination will be shooting enemies to the rear that requires the tank part to disconnect and move sidewards to the central vehicle behind. Doing a weight/protection comparison with current systems will be difficult and could be judged disadvantagous. If you look at things as a system then the fuel costs and expenditure, including replacement of losses, will be lower than for the current tank and other armoured vehicle designs that date from pre-webcam days.

    A major advantage of these modules will be mission specific modifications and faster upgrades of the system. Maintenance leads to higher availability because complexity of entities gets reduced by separating them into different entities that can be combined as available.

    As for size, if you turn it into a light powered self-stabilizing wheel-barrow design pulled, not pushed, by an infantryman that can unload all suitable sizes of field artillery and even remote controlled move them forward to take up exposed positions, you get the complete range of this concept from replacing heaviest tanks to upgrading infantry (and providing them with sonme transport to ease their load). The wheelbarrow has an old military application for this purpose as it requires the least available transport network. http://www.lowtechmagazine.com/2011/12/the-chinese-wheelbarrow.html
    Current ideas to just pull extra weight fall short of what weight I would like to have. Which other infantry squad has a personal artillery piece and machine guns around?


    1. If the interior volume gets reduced by 50-66% the weight goes down to 60-46% for the same degree of armour. That's one of the reasons a small tank carries much less armour and why tanks were developed to such large sizes with little worry about additional armour due to increased internal space. These considerations didn't take the weight limits on mobility into account. If the heavy manned prototype weighs about 60tons the unmanned versions go down to 40-28tons with a corresponding increase in mobility.
      An unmanned system allows armour features a crew couldn't stand and thus further reduced weight due to different conceptualization of armour.
      Overall weight reduction could be 60%, resulting in a 24tons unmanned tank version from the 60tons manned version. This would have three major impacts, reduced fuel requirements, a wider spectrum of useable terrain and easier deployment via air transport.