ARTILLERY: Marine Mortar Replaces Howitzer

StrategyPage.com ^ | January 16, 2004

[Cannoneer No. 4]

January 16, 2004: The U.S. Marine Corps has, as is their custom, taken an innovative approach to developing a new lightweight, self-propelled artillery system (the Expeditionary Fire Support System, or EFSS). They have combined an existing commercial vehicle, the Supacat HMT (High Mobility Transport) with an Israeli 120 mm mortar system. The HMT is a seven ton, four wheel cross country vehicle with a capacity for 3.2 tons. It has a 180 horsepower engine and a 4x4 drive optimized for cross country work. The cab is being modified to hold the five man gun crew. The Israeli mortar system weighs 1.6 tons and is mounted on a computer controlled turntable. The mortar can fire regular 120mm shells 8.2 kilometers, or rocket assisted ones 13 kilometers. The breech loading mortar system allows for rapid fire and the turntable system takes data directly from forward observers and quickly positions the 120mm tube to put the shells on the target. The EFSS can put shells on the target within minutes of a request. The system can fire 20 rounds in two minutes and uses a GPS assisted fire control system to provide accuracy comparable to any other artillery system. The EFSS is light enough to be moved by helicopter or Osprey tilt-wing transport.

The system can fire several types of cluster bomb shells. One of these, for example, will destroy most armored vehicles, and kill or wound most troops in a 100x100 meter area. Each of the 32 bomblets can penetrate four inches of armor, but will be hitting the thinner top armor on armored vehicles.

The marines went after the 120mm mortar, instead of another 155mm howitzer, because the mortar is lighter, faster firing and uses a shell that does damage equivalent to 155mm types.

[archy]

2nd,2nd Mech. had a 4.2 mortor section in their battalion over 30 years ago. They were mounted in the back of M113's, the old tin box we used as mechanized infantry. They went everywhere they were needed.

And the M113-based M106 4.2-inch mortar carrier [and similar current M1064 120mm Mortar vehicle] was amphibious. With the gun tube aboard, it could only carry 10 rounds while fording rivers or lakes, but one answer to that was to have one vehicle in a 4-vehicle battery dismount their mortar tube and baseplate and set up their tube and baseplate for covering fire from the near bank, while the vehicle hauled additional ammunition for the other vehicles with their tubes ready for firing. I've heard different stories about the advisability of actually firing the mortar while amphibious, but in any event, I'd expect accuracy would be pretty spotty. It might be useful for firing illumination rounds during nighttime river crossings, however.

-archy-/-

[archy]

I wonder how accurate the RAP rounds are?

Think laser guidance, as with the British Merlin 81mm mortar projectiles, or the SAAB/Bofers Strix 120mm projectile.

[Ringman]

While doing military service (sweden) my platoon had a chance to fire off a few STRIX rounds. While the accuracy is impressive for a mortar round, I wouldn't use it against for example a moving target. Still any armored vehicle hit by one of these will be little more that scrap metal.

IIRC it took 6 STRIX (2 salvos * 3) mortars to hit 3 static targets at 3-4 kilometers. Two of them were hit with the first salvo.

[archy]

I don't know if you've ever had the pleasure of horsing 155mm ammunition around, but it comes in 800-pound pallets and if you don't happen to have a 4,000 pound forklift with you, it's going to take a long time to move that ammo!

The Russians have come up with a very neat little ATV-type forklift for use with their 152mm gun-howitzer ammo. And it can double as a prime mover for the wheeled guns for short local movement, as well.

The US built Groundhog ATV forklift [or bucket blade] is similar, and could likely be arranged to work with a skid-steer tracked Bobcat Model 864 vehicle instead, or besides. About $2500 for the Groundhog ATV, and $379.00 for the forklift option.

[Calvin Locke]

Attach some sort of GPS guidance package...

I believe the first of the new generation of bunker buster bombs was an 8" cannon barrel, filled with liquid HE, and given a laser guidance package.

That was in the waning days of Gulf War I. The bombs were still cooling from the HE when loaded for transport.

Final delivery was by FB111's.

[Darksheare]

That last pic: Digging out the spades after a fire mission prep to a move.
*ugh*

Yes, mobility is a good thing.

[archy]

While doing military service (sweden) my platoon had a chance to fire off a few STRIX rounds. While the accuracy is impressive for a mortar round, I wouldn't use it against for example a moving target. Still any armored vehicle hit by one of these will be little more that scrap metal. IIRC it took 6 STRIX (2 salvos * 3) mortars to hit 3 static targets at 3-4 kilometers. Two of them were hit with the first salvo.

Catching a unit of armored vehicles refueling or receiving an ammo resupply would be ideal....

[Ringman]

Exactly, I belive they are intended to be used with the AMOS system. One AMOS-vehicle could put 12 of those at the same coordinates simultaneously, and a battery would be even more lethal.

[Robert A Cook PE]

Nothing ignorant about being a civilian at all ..

You just have a different background, and know more about your field than you do about big guns. 8<)

There are actually a few other subtle changes that this allows the Marines too.

A mortar (traditionally) is a local support weapon under local control. It fires "up" and the shell comes down relatively slowly and vertically. Good against trenches and against people hiding behind walls. But it is smaller, often man-portable, so doesn't do much damage. Man-portable means it can move faster when the enemy shoots back, but not as far. And it's heavy! Its shells are heavy! A mortar can't fire "level" directly at attacking troops - and this was needed in Vietnam many times when the enemy ran directly at the perimeter of a camp.

A howitzer can fire "flat" directly at the enemy, or "up" and at long range. It's bigger, but you need a truck, ammo truck, (or two or three) and have to wait to set the thing up. Once you fire, since it takes a while to dismantle and move it, the enemy can "reverse fire" and kill your cannon crew.

So a self-propelled mortar-howitzer solves several problems. Particularly since it has a self-contained GPS system so survey points aren't needed. Stop, fire, move, stop, fire again, move.

Also, the artillery are usually under a higher-level staff command, and so the local commander has to relay fire request up his chain of command, then they go back down to the artillery crew down that chain of command. This can take a while. If somebody else has a competing request for fire, then the first troops have to wait.

As a mortar, weapon seems to be designed to give the local commander local control over a BIG gun.

And local commanders like that. In WWII against the German forts and bunkhouses in the forests, 8" Long Tom cannon crews would drive up outside of machine gun range of a stubborn outpost, literally sight directly up the cannon barrel at the bunker (if no enemy tanks were around!) and "ask" the Germans to surrender. Local fire control away from the division's commanders made that possible.

[johnb838]

It said it is GPS guided and as accurate as as a tube. I would ask, what would we do if anybody ever found a way to destroy our satellites?

[Robert A Cook PE]

Short barrels require the crew lift the round "up" to the top of the barrel, and drop it down.

Real hard with a heavy round.

If you do this with a big barrel, you have to make a platform or stand or crane to lift it. Hard to be portable. Standing up high on a platform or using a crane exposes you to fire, if the enemy is close. Or then you dig down, but that takes time.

The real big coastal mortars (12" and 14") used against ships early in the century required crews of 12-16 men and permanent concrete "forts" ... They worked well against the Japanese at Corregidor in the nearby hills for a while, but enemy artillery eventually destroyed all the fixed mortars, the mounts, and killed many exposed troops trying to fire back.

[Robert A Cook PE]

True, but isnt the baseplate settling into the dirt.

Moving the bottom of a weapon 1/4-3/8" makes the round as inaccurate as re-aiming the tube 4 degrees.

[Darksheare]

MLRS can't pop illume.
Illume is useful as a psyche attack on the opfor, nothing makes one feel so visible and vulnerable as having bright light on you.
Don't think MLRS has WP rounds either.
MLRS is useful, and instead of the rivalry between the disciplines that I ran into during my stay in uniform- the two disciplines, MLRS and tube artillery, should be used together for max effect destruction and psyche impact.

But, we aren't the ones writing policy.
*snort*

[Robert A Cook PE]

that's what I mean!

Direct fire with antipersonnel rounds (fleshettes, (or canister rounds any more, shotgun-style balls ?) isn't really possible over the troops heads against somebody assaulting the perimeter.

Direct fire seems advertised with this thing. And it's needed. Sometimes.

Sure, our recent wars have been "chases" across deserts inside trucks and APC's/M-2's against a retreating enemy.

The Vietnamese did use direct assault though, and just because no recent enemy has been good enough to attack camps and trenches doesn't mean we won't be attacked in the future.

[XJarhead]

Mortars are useful when you don't have artillery, but for accuracy, true all-weather capability, quantity of steel on target over time, and availability of appropriate munitions, give me tube artillery.

I don't think anyone disputes that in-place tube artillery is generally a superior weapons system to mortars. The specific advantage that mortars give you is mobility, which is why infantry companies and battalions have organic mortars rather than artillery.

I'm an M198 guy, but I think moving it or its successor to a GS role and using a light, SP 120mm mortar for DS makes a lot of sense.

[XJarhead]

Direct fire seems advertised with this thing. And it's needed. Sometimes. Sure, our recent wars have been "chases" across deserts inside trucks and APC's/M-2's against a retreating enemy.

My battery in the Gulf War got in a direct fire shootout with some Iraqi armored cars and MLRS, so its not entire out of fashion yet.

[American in Israel]

If it only fires high angle, what's the reason to abandon traditional muzzle loading mortars?

Automation?

[Robert A Cook PE]

Bet the MLRS vehicles, their troops, and their supply carriers were a lot of help in that direct fire event.... 8<)

[XJarhead]

Heh -- they were more targets than active participants for obvious reasons. But they also had some tanks in support that were a bit more of a problem, so we asked for and received some help from Cobras and TOW's. Quite happy when they made their appearance, because the tanks didn't seem to impressed by us.

[neverdem]

"If it only fires high angle, what's the reason to abandon traditional muzzle loading mortars?"

Automation?

Thinking about the problem after viewing some of picures and your and archy's comments, it seems to me that by having breech loading mortars you could put the crew under armor, automate the cannon, and with the proper mount, use it for direct fire and low angle indirect fire as well as high angle indirect fire. In effect, it's no longer a self-propelled(SP) mortar. It's a SP howitzer.

Nothing wrong with that per se, except with the weight, which is the main part of the original problem, transporting it to the theatre of operations, and then having ease of mobility to keep up with the maneuver battalions so they can provide direct support.