Although our Army loves mobility, the fact is, in any theater of operations, you simply have to have some fixed bases. Logistics, airfields, maintenance facilities require some sort of base. And in the nature of warfare, fixed installations are tempting targets for indirect fire.  For instance, in both the Iraq and Afghanistan wars, insurgents have targeted bases with a variety of indirect fire weapons. For the most part, these attacks have been primarily harassing fires.  They’re too small to destroy much of an installation, but they’re enough that work has to stop, people have to take cover, and occasionally the enemy gets lucky and causes casualties or hits an important piece of equipment.

In wars past, the tactic to counter these attacks was counter-battery fire. Special radars detect the incoming fire, and by tracking their trajectory, can locate their origin. That targeting in information is sent to the artillery (or helicopter gunships, or what have you), and fires placed on the attacker. But sometimes, that’s simply not possible. For instance, if the attack comes from a protected space such as a mosque, firing back might have worse consequences that simply riding out the attack. It’s hard to win hearts and minds when you’re shelling the locals village and their church.

With advances in technology, and some adaptation of existing technology, the Army has developed systems to actually intercept incoming fire. Under the term C0unter- Rockets, Artillery & Mortars, the Army is testing or actually fielding a family of weapons that defeat, well, rockets, artillery, and mortar shells in flight.

The first fielded system was a derivative of the US Navy’s Mk15 Phalanx Close In Weapon System, or CIWS.

[youtube https://www.youtube.com/watch?v=V2004nrHxa0]

A good start, but the Army is looking at other systems as well. For instance, lasers are maturing enough that a deployable system will soon be a reality.

In addition, the Army is realizing that its monopoly on cheap drones is coming to an end, and enemy forces, either state actors, nor non-state forces will be able to operate drones over our installations. Denying the enemy this intelligence is a critical task, and one that the C-RAM initiative is addressing. One interesting concept we noticed the other day is this mobile 50mm chain gun with guided ammunition.


While civilian countermeasures to combat malicious drones is moving toward UAV-freezing radio beams, the US Army is taking a more permanent approach. Under development by the U.S. Army Research, Development, and Engineering Center (ARDEC) at Picatinny Arsenal, New Jersey, the Enhanced Area Protection and Survivability (EAPS) system used steerable 50 mm smart rounds to shoot down two drones in recent tests.

The Army says that EAPS is a gun-based alternative to the missile-based Counter Rocket, Artillery, and Mortar (C-RAM) system currently favored by the US military. It was originally designed to counter rockets, artillery, and mortars (RAM), but due to the increasing threat from UAVs the system’s mission was expanded to include drones.

Using a 50 mm cannon, EAPS fires guided interceptor projectiles guided by a precision tracking radar interferometer and a fire control computer. The system tracks the projectile and the target and computes an ideal trajectory correction. A radio transceiver then beams an engagement “basket” at the target for the projectile to home in on. Thrusters on the projectile are used for course correction and as it nears the target a forward-fragmenting warhead with a tantalum-tungsten alloy liner detonates to deal with C-RAM targets, while steel body fragments take out unmanned drones.

As an aside, that’s one of the nifty things about the Chain Gun, it’s scaleability. The most common chain gun in use is the M242 25mm. But basic gun mechanism has also been used in 30mm (both the low velocity M230 of the Apache gunship, and the high velocity of the Mk46 intended for the canceled EFV) and even 7.62mm. There’s also a 35mm version. I’ll admit this was the first I’d heard of a 50mm variant. And I wonder if, given the fin stabilization of the guided ammo, is it a smoothbore gun? Heck, it would be fun to see a 60mm mortar version.

And having designed the basic architecture for a guided 50mm round, it should be quite simple to design various different warheads for the rounds, enabling it to be used for other roles beyond just C-RAM. For instance, might we see a variant tailored for ships as defense against cruise missiles or small boat attacks? That would be interesting, seeing the circle completed from the adoption of the sea based CIWS.

EFSS- Marine Mortars versus Army Mortars

A couple years ago, URR had a nice post on the Marine Corps shift to the 120mm rifled mortar system known as the Expeditionary Fire Support System. Basically, it is a rifled 120mm mortar, its associated ITV prime mover, and the associated ammunition caisson and its prime mover, another ITV. General Dynamics, the prime contractor for the system, put together a nice little marketing video. Lots of shooty, even some splodey.

[youtube https://www.youtube.com/watch?v=1ZsAAIczQeg]

There’s a major, major difference between the Marine EFSS and the Army’s own 120mm smoothbore mortar systems. And it’s not really so much the  guns themselves.  It’s the organization of fire support assets.

A Marine Division has three infantry regiments, and an artillery regiment.  The Marines have elected to replace their light 105mm howitzers in the artillery regiment with the EFSS. That means the division’s artillery will lose significant range, but will also gain a much greater ability to land early via vertical envelopment using the MV-22 Osprey, and that the small size and light weight of the EFSS will allow battalions and batteries of fire support to move quickly right behind the supported infantry regiments and battalions. It is a fairly bold shift, but the Marines probably know better than I what their fire support requirements are. One other major impetus for shifting to EFSS is that space on amphibious shipping for artillery is incredibly tight. EFSS has a very small footprint, which makes finding space for it much easier. Or rather, not taking up as much space as a conventional 105mm artillery battery frees up space for other vehicles and equipment the Marines really want to bring along, but previously had no footprint for.

The Army, by contrast, doesn’t have the same shipping and footprint constraints. Further, the Marines have, historically, only operated in division or larger sized formations since World War II. The Army, by contrast, has always had (at least theoretically) the ability to field corps and field armies. And each of those formations had their own artillery to reinforce the  fires of divisional artillery.  For instance, today, each Brigade Combat Team has its own Field Artillery Battalion, to support its maneuver battalions. The division headquarters controlling the BCT might well have a Fires Brigade attached to effectively double the artillery available.  In the Marines, there simply isn’t any artillery above the division level.

In the Army, 120mm mortars belong to the infantry and combined arms* battalion commander, in the form of a mortar platoon organic to each battalion. That is, they are not an artillery weapon, but an infantry weapon, one of many supporting weapons organic to the maneuver unit.

Both the Army and the Marines have smaller mortars, 60mm and 81mm, that are infantry weapons, belonging to the rifle company or the infantry battalion, though how they are distributed differs in detail, if not in effect.


*Combined Arms Battalions are the maneuver battalions of Armored Brigade Combat Teams, and consist of a battalion with two tank companies, and two Bradley mechanized infantry companies.

Mortar Monday (I meant to post this yesterday)

So, 5/20IN hosted the Japanese Ground Self Defense Force to a mortar live fire at Yakima Firing Center recently. Lots of 120mm goodness going on.

Here’s the short PAO take.


And here’s the extended version. I love that piiiiiing! that 120mm mortars make when firing. Gives me a warm fuzzy.


And while I tend to think of the 120mm as a big mortar, the Soviets and the Israelis have used 160mm mortars. And then… there’s this:


Warheads on Foreheads…

You have to love it when your readers do your research for you. Makes blogging a lot easier. Frequent reader Vmaximus pointed this little gem out to us via the comments:

I found this at Theo’s,
I do not know anything about mortars, but is this how a mortar team works?
It does not look like they even aim till about 7 min in. Then they are slinging that tube around like there is no tomorrow. Do you know anything about Mortars?

Why yes, Vmax, I do know a little about mortars. But just a little. I suspect that the Infantry School, where mortarmen train (mortarmen are infantrymen, 11C’s to be specific) might not approve of their firing drill. But that doesn’t mean they don’t know what they are doing.

NSFW language.

[vodpod id=Groupvideo.1787189&w=425&h=350&fv=]

The mortar crew is obviously in a well prepared defensive position. They are at an outpost, likely very much like the one pictured here. They have had time to figure out likely enemy avenues of approach. In addition to digging in, they figured out where they would most likely be shooting, and are prepared to do it with minimal preparation.

The other thing is this- they are only throwing the rounds a fairly short distance. The gunner can see what he’s shooting at. He’s shot mortars enough that at short ranges, he can eyeball it. You see him pop up to see where the rounds are striking, then dropping down to shift the rounds a little bit to spread the coverage over the target.

One other interesting bit. Towards the end, the last round he fires? You see him take it out of the packing, then pull some light colored stuff off the base of the round? That’s propellant. Mortar rounds carry their powder on the outside of the case. By varying the number of these “charges” you change how far the round will go.

You also hear troops talking about “107s coming in!” That’s the 107mm Chinese Type 63 bombardment rocket. Taliban troops love shooting these things, usually from a crude homemade launcher. They are wildly inaccurate, but big enough that they only have to get lucky once.