Tank Battles

I’m feeling poorly today, so here a “best of..” post from way back in the very early days of the blog.

I wrote earlier about bringing enough gun to the fight, but not too much. A prime example of this was the M-1 Abrams tank.

When this tank debuted, people were aghast at the cost. What they didn’t realize was it was acutally the result of an extreme cost cutting program. For 20 years, the Army had been cooperating with Germany to develop a sucessor to the M-60 series of tanks, but each iteration had become too complex and too costly. The Army finally decided that they would develop a tank using technology shared with the Germans rather than develop a tank to be used by both countries.

One of the sticking points was the main gun. The standard US tank gun was the 105mm M68. The Army thought this was sufficient to defeat current and projected Soviet armor (and were pretty much right).

The Germans had developed the excellent 120mm smoothbore, and wanted both countries tanks to use it. Our Army resisted for a couple of reasons. The biggest was cost. The new gun would have to be license produced here, with associated setup costs. Even more expensive would be providing stocks of ammunition for the gun. The Army had a huge stockpile of 105mm ammunition already. Buying an entirely new stockpile in the tight budgets of the 1970s wasn’t an attractive option.

In the end, the 105mm won-sort of. The decision was to place the M-1 into production with the 105mm, but make provision to add the 120mm in the future. As it turned out, for various reasons, this was a lot harder than anyone expected. Still, partly as a sop to our German allies, and partly over concern about the ability of the 105mm to defeat future Soviet armor, the 120mm was adopted for the M1A1 that entered service in 1988.

One disadvantage of the 120mm was a reduced ammo load. An M-1 with the 105mm carries 55 main gun rounds. An M-1A1 carries 40. As it turns out, however, few tanks will shoot their entire basic load in a single battle. In fact, not a single tank in Desert Storm fired its entire basic load.

Tankers, ever wonder why the coax on your tank has that massive 4000 round load? Because that’s where the designers originally wanted to put the 25mm M242. The only reason it didn’t make it into the final design was cost. Leaving the 25mm out saved about $100,000 just for the gun, and made the fire-control system simpler, and hence cheaper. 

8 thoughts on “Tank Battles”

  1. Minor quibble, but Abrams carry about 11000 rounds of 7.62mm, not 4000. Also about 1k .50 cal.
    In addition to the early plan for the M242 25mm, they also considered putting a MK19 grenade launcher on top.
    In the book “King of the Killing zone” which is the story of the development of the Abrams, there is a great story of “the army” showing off the tank to an Israeli tanker general officer, who is not impressed with the speed, but takes it back through the course at the speed that the Isrealis fought their tanks in urban environments (i.e. slow and deliberate), and bemoans the lack of machine guns at that time in development. Very illustrative.

    1. King of the Killing Zone was the basis for this post. But your memory is in error. The old general was a US guy from WWII, talking about how they fought in Europe.

    2. Last time I read that, I think I was still a young infantryman. It was one of the 2-3 things that made me decide to switch to armor. Might have to review it. I notice you are silent on the 7.62 though…

    3. I believe xbrad is referring to the massive coax ready box, not the total 7.62 capacity of the monster.

      As for machine guns, having two pintle (or one pintle and one cupola weapons station, as on my old ride) and a coax machine gun puts the M1 series ahead of almost every other tank’s secondary firepower. I believe that the commander’s CROWS installed on the recent TUSK upgrades can accommodate a MK19 as well as the venerable M2, but I may be mistaken; I only have experience with CROWS on the MRAP vehicles.

      I have seen photos of Merkavas with a .50 over the main gun, an attempt to give the gunner a 2000m weapon that doesn’t flatten buildings. As I am now converted to M3 CFV’s, I do not know if any TUSK M1’s have this added as well.

    4. Furthermore, being a Brad guy now, I have no idea how I would be able to dis-assemble that 25mm gun in the loader’s area. I’m glad they went M240 and not M242.

    5. You are correct, I was indeed referring to the ready ammo box. To be honest, I had no idea the total 7.62mm on board. I just know I’ve had barracks rooms smaller than the ready box.

    6. There is a mount that TKR Terror refers to called a Counter Sniper/Anti Material Mount for the M1 that mounts an M2HB .50 cal on the main gun, and allows you to use the Gunner’s Primary Sight to fire it with precision gunnery techniques. We fielded it in 2007. Pretty good system, though I am not sure if they used it to any effect on my last two rotations, since I rode an M3 myself on one, and a desk on the other…. With regards to the 7.62 stowage, if only 4k go in the ready box, I have no idea where the remaining 7k go. That equates to 35 more cans and there is no other place in an M1 for that other than the coax box. We don’t have that big garage in back like the brad…. I just checked my 24th ID tank load plan from my younger days and it doesn’t depict CL V stowage. I guess we weren’t serious about it back then! Anyone want to pull up the -10 you can settle it, but I am going to sleep…

  2. The Wehrmacht tried to cut back on machine guns on tanks and paid for it at Kursk. That wasn’t the only thing that went wrong there (being suckered into prepared positions was the highest on the list), but it was a serious lack for the Panzers.

    Our WW2 tankers also knew the importance of auto weapons on armor.

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