American Mortar Carriers

Mortars are awesome, and a bigger mortar means more range and explosive power per shell. But a bigger mortar is a lot harder for troops to carry. The biggest commonly in use today are the 120 mm mortars like the Soltam K6. This weighs 319 lbs, and breaks down into the following components:

  • M298 cannon assembly (110 lbs)
  • M190 bipod assembly (70 pounds)
  • M9 baseplate (136 pounds)

That’s not going to be easy for infantry to haul. And it’s pretty natural, especially for motorized or mechanized infantry, to want to put mortars in a carrier vehicle. Let’s look at a couple American options. The basic idea here is pretty straightforward: take an APC, fit a retractable roof, and mount the mortar in the back. Surprisingly simple for units in the US Army inventory.

Our first example is the M1064. It’s based on the classic M113 APC. While the M113, even with the A3 improvements, is pretty vulnerable to modern battlefield threats these days, in the artillery role it’s perfectly adequate. The mortar is the 120mm M121, an American licensed copy of the K6. The M1064 also has a ring mount for a machine gun, and usually has an M2 mounted. Ammunition capacity is 69 mortar shells and 600 rounds for the M2.

The Israelis operate a similar system to the M1064, the Keshet. The key difference is that it’s equipped with the CARDOM mortar system, which automates the aiming of the mortar using a computerized fire control system. I would expect the number of stowed shells carried to be similar to the M1064.

Next we have the M1129, based on the Stryker APC. Again, there’s a retractable roof exposing a 120 mm M121 mortar. Some versions are also equipped with an additional, smaller mortar for dismounted use. This may be a 60mm or an 81mm mortar. If the M1129 is only equipped with a 120mm mortar, it will carry 60 120mm mortar shells. If a dismountable mortar is also carried, the supply of 120mm shells is reduced to 48. If a 60mm mortar is carried, 77 shells for it will be carried as well. On the other hand, if an 81mm mortar is carried, a supply of 35 shells will be provided for it. Note that if a dismount mortar is provided, this mortar cannot replace the 120mm for mounted use, and the vehicle crew is sufficient to use only one of the two provided mortars.

Here’s a handy chart of ammo capacities. The designations M1129-60 and M1129-81 are my own, used here for convenience. What dismount mortar, if any, is carried on an M1129 is based on its tasking in the organization table (i.e. whether it belongs to a rifle company, rifle battalion, or RSTA1 squadron) and is not indicated in its designation.

VehicleM1064M1129M1129-60M1129-81
120mm shells69604848
81mm shells35
60mm shells77

In terms of deployment, each company in a Striker Brigade Combat Team has two M1129-60s and each battalion has four M1129-81s as an organic component. An RSTA squadron gets six M1129s. A mechanized infantry battalion will get 6 M1064s. In the future, an AMPV-based mortar carrier will replace the M1064.


  1. Reconnaissance, Surveillance, and Target Acquisition. They’re organized in the cavalry model (hence “squadron” instead of “battalion”). One RSTA squadron functions as the recon element for a brigade. 

9 thoughts on “American Mortar Carriers

  1. Steve

    The M1129 is alright, but it seems like an AMOS mounted on a CV90 does almost everything better. Far better protection, rate of fire, and rough terrain mobility combined with the ability to perform direct-fire missions make the AMOS CV90 a significantly more versatile vehicle. It seems like it also has more ammunition ( 90 rounds of 120mm ) and more modern electronics. A CV90 probably has a bit more fuel consumption and maintenance requirements as well as a slower road top speed, but the maximum range of the CV90 is actually higher.

    Reply
    1. parvusimperator Post author

      Yes, yes it does. I wholeheartedly agree with you. Turreted mortars are better, especially with regards to counterbattery fire protection. And AMOS’ fire control is pretty kick ass.

      Clearly the M1129 costs a lot less though, which is probably why the AMOS isn’t more popular. As usual for America and our NIH-itude, we had a future combat systems mortar vehicle (NLOS-M iirc), but that program died.

      (future article tease) I’d just go with the AMOS, myself…

    2. Steve

      Glad we agree on the superiority of AMOS.

      I think the US is set to procure about 400 mortar carriers on the AMPV platform, but the BAE turretless bradley that won the competition doesn’t seem to be a huge step up from the M113/M1064 in capability, although I guess we might get more ammunition stowage and hopefully better fire control. Since BAE makes both the AMOS and the new AMPV, there should be some overlap.

  2. parvusimperator Post author

    You’re correct that the US is buying AMPV-mortar carriers. I don’t have too much specifics there. The biggest wins offhand are in the platform itself. The AMPV is Bradley-based, so it shares powertrain and suspension spares with the Bradley (and some of the parts on the M109A7, which has a Bradley power train). That should give it better mobility and speed, and it should be able to keep up with armored forces better.

    The AMPV can also mount quite a bit more armor than the M113A3, but that’s not all that helpful with a giant roof hatch.

    Do you recall where you read about the ammo capacity on the CV90-AMOS?

    Reply
    1. Steve

      My source for 90 rounds carried was here:
      http://www.deagel.com/Artillery-Systems/CV90-AMOS_a000589009.aspx

      That site didn’t provide a source for where they got 90 rounds, but from the sheer size of the CV90 it seems fairly plausible.

      I’m particularly impressed with the STRIX anti-armor precision mortar round used by the Swedes if it lives up to what the manufacturer claims it can do, although surely the Russians are working on ways to mask the infrared signatures of their vehicles to counter such capabilities.

  3. parvusimperator Post author

    Ok cool. Thanks. It’s better than a lot of what I found. Usually capacity for AMOS is given in a carry-platform agnostic way.

    Making STRIX work from a guidance/target discrimination perspective shouldn’t be too hard. As for signature reduction, I haven’t seen the Russians try anything like Saab’s Barracuda stuff, but that doesn’t mean it doesn’t exist. Also, T-14 has what appear to be upward-facing launchers for some kind of “masking” soft-kill APS. So perhaps they’re going to use those to try to break lock.

    Reply
    1. Steve

      If STRIX works the way Saab says it can, then it is a bit surprising that the technology in that round isn’t ubiquitous. The ability for a 120mm mortar battery to rapidly neutralize armored formations from range and behind cover seems like a game-changer of equal if not greater significance to the introduction of ATGMs in the 1970s. As far as I know, the US only has the XM395, which has a worse CEP and no fire-and-forget anti armor capability, although it is battle tested in Afghanistan.

      The T-14 might have some soft-kill system, but the vast majority of credible tank threats out there are older models without that capability. Perhaps the reason BAE helped put together Poland’s PL-01 sci-fi tank tech demonstrator is concern that the Russians might have their own anti-armor guided mortar round in the near future. It certainly would help them against Ukrainian T-64s in the Donbass.

  4. parvusimperator Post author

    Well, it was introduced in ’94, so there’s that whole “peace dividend” thing to contend with. The rounds are going to be expensive, of course, and 7 km is not really a ton of range.

    Anyway, you can get similar things with SMArt 155/SADARM/BONUS shells out of a 155 mm gun, which would give you a lot more range. Or DPICM, again for blanket coverage.

    Doing a little thinking/digging, how much STRIX can actually maneuver? If it’s not much, you’d need a good initial target location AND the target couldn’t move much at all. I can’t actually find tests against moving targets. It’s not going to go up all that high, which is rather less than ideal.

    OTOH, if you can find a moving target test, I’d be happy to be proven wrong.

    Reply
  5. Steve

    I didn’t find a moving target for STRIX, but I did find some material on the BAE Merlin 81mm guided round, which fills a similar niche.

    https://www.forecastinternational.com/archive/disp_old_pdf.cfm?ARC_ID=1486
    https://www.thefreelibrary.com/Anti-tank+guided+missile+developments.-a09046203

    Unfortunately, Merlin was never funded for cost reasons, but apparently it could cover 90,000 square meters of search area and was capable of hitting moving targets.

    And yeah, 155 mm guns can perform the same role, but mortars are cheap, fast firing,easily distributed among the infantry, and easier to hide from counter-battery fire.

    Reply

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