Soft recoil artillery, and electronics-coined artillery in general

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"Soft recoil" mechanics have been one of the no-breakthrough evergreens for generations. Again and again developers looked at it, trying to make it work competitively.

Soft recoil lets the bolt (in a rifle) or entire barrel slide forward at the moment of ignition, so the forward momentum cancels much of the recoil. This allows for more controllable fully automatic fire (as in the Singaporean Ultimax 100 light machinegun) or allows for a much lighter carriage, maybe a much lighter platform vehicle.

The first notable and till today probably most successful soft recoil artillery piece was a pre-First World War 65 mm mountain gun. It was evidently useful, for it was still being used post-WW2.

A much more modern attempt was the American XM204:

A German arms museum (WTS Koblenz IIRC) has one XM204 prototype and its plate is rather dismissive, pointing out that it failed the very same way other soft recoil gun designs failed as well; timing the ignition. Range dispersion was intolerable.

Now fast forward to 21st century, and range dispersion is curable. Trajectory correcting munitions are fired at a point behind the target, and the munition deploys a brake (not real steering) at the correct time to correct the range. This doesn't change the left/right dispersion (I keep forgetting the terminology for this).

One method to determine the correct timing for the brake is to track the munition by radar and initiate the brake with radio command - this has been done with multiple rocket launchers. Another way is to use shock-hardened, very compact inertial sensors or satellite/radio navigation. This kind of trajectory correction can nowadays be compact enough to be built into a standard fuse (patent example here; I've seen even simpler-looking, actually-built devices). This leaves no room for great fuse functionalities, but it works apparently.

Maybe in combination with this the newest attempt to revive soft recoil artillery may actually make sense:

(0:43 sec; the forward movement of the barrel prior to firing.)

edit: Additional video, explaining it a bit more

As of today, the latter video had 1,528 views after almost ten months on Youtube. That's a rare case of an American company developing some gun and (almost) nobody paying attention. More videos here and here.

They also look at a 155 mm soft recoil howitzer for a 5-ton truck.

The accuracy of the launcher becomes less important if not irrelevant if electronics and movable surfaces have the last say on external ballistics. This is a bit reminiscent of fighter agility becoming less important since missiles have become very, very agile (ever since the R-73 innovation).

The possibility of using lightweight platforms for artillery ordnance is but one consequence of many. The electronics revolution in artillery is bound to change artillery a lot in comparison to 1980's hardware. This has so far not really happened, as 1980's and older equipment has been maintained and upgraded or new equipment based on late Cold War requirements has been introduced. The great fashion of the post-Cold War era was air-deployability and wheeled platforms. Neither aimed primarily at exploiting electronics advances, but at suiting better for occupation and intervention warfare.

Vertical launcher and fibre-optic guidance artillery haven't made it into service so far, both are apparently much sexier than superior in practical employment. 

Some artillery requirements which do deserve much greater attention and emphasis are in my opinion

 

(1) Super-quick reaction. A firing mission sent by radio to a computer needs to be executed within seconds, as many targets are fleeting. A howitzer of traditional design with only 50 or 60 degree traverse is too slow if the firing mission isn't within this traverse. The 1960's D-30 was superior in this regard. Most self-propelled howitzers have 360° traverse, but some -notably most on wheeled vehicles- don't.

(2) Ability to hide behind concealments such as buildings without great impediment of capability. Traditionally this has been an issue about maximum elevation angle; the upper angle group (45-70°) that's now standard for howitzers was early on in part a requirement for enabling fire from within woodland (clearances, from woodland roads et cetera). Nowadays we could have a simple camera sensor looking all-round and determining the actual horizon (such as 3,600 traverse/minimum elevation combinations) and transfer the info to artillery fire control centre so it can have all SPGs hidden, but also arrange for sufficient area coverage of the fields of fire. This is behind the scenes stuff, of course.

(3) Covert, camouflaged AND deceptive modes.

covert - looking like a mobile civilian object, such as an abandoned long ISO container

camouflaged - classic approach, but not necessarily woodland camo. Settlement environments should be considered for camo pattern. A reduced radar cross section might also help against aerial ground moving target indicator radars.

deceptive - look like a stationary object (such as a hut), and on road marches even tracked SPGs should not be identified as tracked vehicles by ground moving target indicator radars (which can usually tell tracked from wheeled).

Some old requirements such as NBC protection (air filter and internal overpressure compressor) may be unnecessary now, but it shouldn't hurt too much to keep an upgrade option for it ("equipped for, but not with").

I mentioned before that the ban on most cluster munitions in most countries is a powerful argument for going back to smaller calibres, such as 105-122 mm (more efficient in terms of fragmentation-saturated area to HE shell weight).

S O

related: 2011-10 "An article about artillery",

Defence and Freedom's general arty blog post

edit 2015: http://www.mandusgroup.com/downloads/Hawkeye_105mm_Brochure.pdf

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