Quick thought on tank design balance

Traditional tank design has to balance firepower, protection and mobility. There is usually a trade-off between these three, as two increase weight and the third deteriorates somewhat with weight.
Good reliability and durability, low supply demands, good range, low maintenance and quick repair are important hidden values which require little trade-off.

T-34: It was the first properly balanced tank, but weak on 'hidden' values.
Many Chobham-generation main battle tanks (beginning with Leopard 2, ending with Merkava IV and Leclerq) got the balance about right, as "Chobham"-like armour finally offered good protection at acceptable weight.

The German 1990's upgrades to Leopard 2 increased frontal turret protection and firepower, whereas later upgrades increased mine protection. Other countries limited their upgrades even more, increasing firepower only through improved munitions.
Much money was also spent on better sensors and electronics.

The 1999 Kosovo Air War and subsequent U.S.Army panic about "relevance" and "deployability" pushed deployability (low weight) to the foreground and AFV development focused on this frantically for a few years. The Iraq War 2003+ shifted the emphasis to electronic countermeasures, roadside and underbelly blast (and EFP) mine protection, but most AFV projects were still relatively modest-weight wheeled vehicles because tracked vehicles couldn't run the same thousands of kilometres every year, much less at the same cruise speed.

Now - after a decade of occupations - the emphasis still seems to be on protection, with very little emphasis on firepower (especially not high-end anti-armour firepower) and mobility concerns are still about cruising on highways or air lift rather than off-road manoeuvres.
The confusion about the American FCS and GCV projects with radically changing protection and mobility demands suggests a certain cluelessness or maybe rather uncertainty:
The meaning of "balanced" is in question. What's a balanced tank (or AFV) design in regard to firepower, protection and mobility nowadays?

Judging by military history, I guess a later generation may find the present emphasis on protection and road mobility exaggerated and may complain about (anti-tank) firepower and offroad (soft soil) mobility shortcomings.



  1. Put a 35mm on top of a Namer and you got my choice.

    1. Yup, psychology of soldier confidence. Namer got it...

  2. When you speak of balance and how firepower is not growing, you also need to look at the most recent developments. In the current iteration of US kinetic energy penetrators you are actually seeing an increase in mass and a slight decrease in velocity, this may be in reaction to the extensive use of explosive reactive armor, or what I believe is happening is that we are seeing a "wall" for the speed we can currently send KE projectiles downrange accurately. In short we cannot at this time go faster due to hypersonic instability issues, therefore we can only increase mass. Going with slower hollow charge or sensor fuzed EFP type weapons of sufficient diameter will lead to counters by active and passive defenses which with cheaper and faster computing power are now available (think Trophy), so raw speed is still seen as the best counter to defenses. We will see the next generation of tanks when the the hypersonic flight issues have been worked out.

    1. The trophy marketing team surely was good.

      Improvements of firepower are possible (proximity-fuzed EFP precursor, for example).

      The really neglected part of the triangle is mobility. There weren't even mere powerpack upgrades for the tanks after all those heavy protection upgrades. We moved from a balanced tank philosophy to a heavy tank philosophy. Those heavies have difficulties with bridges and wet soil and we could have much higher road march tank mobility by now.

  3. Current EFP only punches approximately 1 times charge diameter, so frontal defeat is right out. Going for thinner armour locations exposes the charge ( or more precisely, the sensor controlling the charge) to hard/soft defeat, this can be by barrage or deception jamming: stealth application ( soft defeat) or a point defense system ( hard defeat). Where we end up is looking closer to peer naval warfare today, indeed I little difference other than the scale.

    1. EFPs vary with the liner angle. The M72A6 ( 66 mm) has an EFP warhead with 150 mm RHAeq penetration.

      More importantly, EFPs trigger heavy reactive armour and a proximity- or electronic time-fuzed EFP precursor charge could clear the path for the long rod tungsten penetrator. Precursor shaped charges have been used in front of bunker busting penetrators for generations (and have become widely used for it during the 90's).
      Additionally, total penetration may be increased if no heavy ERA was encountered.

    2. M72A6 is a hollow charge designed for punching less armour and bigger behind armour effect, it is a hollow charge not an EFP ( Misznay–Schardin ), Hollow charges designed to punch heavy armour will on average punch 7 times charge diameter or greater (tungsten copper liners) in RHAe.

      To go back a bit to the mobility portion of this...that path was looked at with the American FCS project...and so far has been found wanting in regards to in occupation type scenarios against non peer opponents. In a peer versus peer confrontation where both sides have similar sensor capability, first shot will rule as tactical speed is less relevant with precision munitions or even simple ballistic projectiles with today's fire control apparatus, heavy armour will be downgraded as defensive countermeasures will take up a larger fraction of mass as defeating the sensor will predominate the future peer versus peer battlefield.

    3. An EFP warhead IS a hollow charge. Shaped / hollow charges with a liner cone of more than about 110° are being called "EFP" because the slug becomes more important than the fast tip at such angles. The cone of the M72A6 is near 110°, and its halved penetration stems from this fact.

      "The warhead is the same as
      the M72A4, but has a copper explosively formed penetrator (EFP) liner for penetration with larger diameter holes and greater spallation effects."
      source: TM3-23-25 "Shoulder Launched Munitions"

      The FCS base vehicle was kept light for air transportation; that's not what's generally meant by "mobility" in the mobility-firepower-protection triangle for tanks.