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.

[edwin hubble]

"Impeccable reasoning & calculation...shot down by an inconsiderate reality! *grin* "

Thanks.

It was a long time ago, but I have dropped rounds down the 4.2" mortar tube (Quantico, 1966).
I haven't ever seen a 120 round.
Semper Fi.

[RedlegCPT]

Plus Motars are not aprroved for overhead fire unlike the "KING"

[RedlegCPT]

Actually they do have MLRS now, in the form of HIMARS, they also have an agreement with the Army to provide them with MLRS support.

[RedlegCPT]

Still firing the heck out of Copperhead. By the way the way the only munition with a shelflife. I have no idea why.

[FreedomPoster]

Batteries in the terminal guidance units embedded in the rounds? Just a guess.

[300winmag]

Actually they do have MLRS now, in the form of HIMARS, they also have an agreement with the Army to provide them with MLRS support.

MLRS is nice, but nothing gives that warm feeling like hot steel out of a rifled tube.

[neverdem]

I'm sure the mortar crew, and possibly FDC, didn't expect a hole in one. I'm sure they only expected to get the tank to batten down the hatches and narrow the krauts' field of veiw to what they have from inside the vehicle. I know from the periscopes inside of a M113 APC, the field of view was pretty limited.

The points I was trying to make was that the rifled 4.2" mortar was fairly accurate for high angle fire, and that there is less probable error in direct fire gunnery than low angle, i.e. < 45 degrees elevation, indirect fire, which has less probable error than high angle indirect fire, i.e. 45 degrees or greater. The probable error is mostly a function of the length of the trajectories, note not range, and time of flight, not taking into account the accuracy of the tube and quality of the ammo.

I used to be a grunt that saw the projectiles of 175mm and 8" rounds fly to the NVA when we had firebase security. I certainly don't advocate getting rid of cannon artillery. Heavy mortars nicely fill the niche for infantry and armored battalions or task forces that may only have one artillery battery in direct support.

[Cannoneer No. 4]

I wonder if this wheeled SP twin 120mm AMOS wouldn't do more for a Stryker Brigade than an M198. 3/2 has 1-37 FA with M198's. Every once in a while they get to fire some counter-battery missions.

Mobility is pretty important. Being able to sling load and air drop howitzers is nice, but being able to move once you get them to the battlefield is critical.

[jpsb]

That is my recollection too. USMC 0849. Hope the Marine do not give up on the 105, and 155. Naval guns are not what they used to be, and they used to be awlsome weapons.

[Oztrich Boy]

17mmm -- probably all gone now, maybe some in the reserves or Guard - were very long range, tiny deflection probable error, large renge probable error, biggest problem was short barrel life.

Not the miniscule explosive bursting charge?

[neverdem]

He intended 175mm that was used most recently in a self-propelled(SP) gun. IIRC, the Army dumped them about 3 decades ago, keeping the 105mm(towed), 155mm(towed and SP) and 8"(SP) howitzers.

[Cannoneer No. 4]

They don't have Naval Gun Fire Support like this anymore.

[neverdem]

Plus Motars are not aprroved for overhead fire unlike the "KING"

What do you mean by "overhead fire", friendly units under the trajectory? What about danger close fire missions? It's been over two decades since I was junior enlisted FDC.

[Oztrich Boy]

I knew that

[fourdeuce82d]

"...nothing gives that warm feeling like hot steel out of a rifled tube."

All the more reason to keep the 4.2" w/longer barrel and beefed up base plate- some experiments had the old warhouse plunking rounds in at +10 klicks. It's jeep portable, packs a punch...and without fail that particular weapon system somehow attracts the best, the brightest, and the most handsome of all military personell. Don't why that's so...but it's true.

(creaking noises as a fat ex mortar maggot tries to pat himself on the back...)

[RedlegCPT]

You can not fire over the heads of friendly units with mortars. This is a training resriction, that may or may not be lifted during combat. I would have to defer to the gentlmen that hvae just come back from OIF. As far as DC I would much rather have 105mm howiters firing DC that ANY mortar.

I have placed steel on target with a 81mm and watch the next three rounds walk off the target. All 4 were from the same tube with absolutly no change in the data sent to the tubes.

BY the way OIF retaught all the crunchies and CDATS that Artillery is the "KING" when they found out that they could prep the objective and have very little left to fight them. This is coming out in AAR/Lessons Learned form OIF.

[neverdem]

I have placed steel on target with a 81mm and watch the next three rounds walk off the target. All 4 were from the same tube with absolutly no change in the data sent to the tubes.

Forgive me for asking, but did the gunner resight his aiming stake and relevel his bubbles after each round?

crunchies and CDATS

I need an update on the lingo, if you may, please.

[Redleg Duke]

Having been both 11C and 13A, I submit that the move is a smart one for the Corps. The 155mm is a fine weapon, but for the ranges that the Corps is dealing with in Littoral Warfare, combined with the reaction time and logistical consideration, it makes sense.

The Corps also is fielding a truck-mounted MRLS that also supports their needs. And remember, they have organic CAS.

[300winmag]

All the more reason to keep the 4.2" w/longer barrel and beefed up base plate- some experiments had the old warhouse plunking rounds in at +10 klicks. It's jeep portable, packs a punch...and without fail that particular weapon system somehow attracts the best, the brightest, and the most handsome of all military personell. Don't why that's so...but it's true.

By all means, give the infantry all the mortars they can take with them. But when things get busy, there's nothing like having some 155mm tube artillery to really take care of business.

[archy]

What's the advantage to breech loading mortars other than more control when the weapon is fired, i.e. the weapon is already loaded, waiting to fire?

Longer tubes are possible, offering better ballistic performance and longer range, since rounds don't have to be drop fired from the muzzle; longer barrels can also obviate the necessity for muzzle blast devices for crew hearing protection. Fire at lower angles of elevation is possible, including direct fire,[as with the improved US M19 60mm] making largebore mortars particularly useful in urban fighting/MOUT, and autoloaders are possible, as with the 4-shot Soviet 2B9 82-mm Vasilyek mortar found in both a towed/wheeled and MTLB tracked vehicle mounted version or can be mounted and transported in the cargo area of a modified GAZ-66 (4 x 4) 2000 kg truck.

There's also a similar 120mm MTLB tracked mortar carrier, not fitted with an autoloader- yet: