With all this news about DPICMs going to Ukraine, I’m trying to understand:
Is the idea of cluster munitions that you basically have a shell or a bomb that contains the equivalent of many small hand grenades, and the idea is that if you can fling the grenades over a wide area, equally spaced, that each grenade (a submunition) will catch an enemy soldier within its kill radius and thus you kill everyone in that kill field, whereas if you used a single bomb or shell, that would amount to only one, medium-sized kill radius and thus harm fewer enemy troops?
And also that you might get a few lucky submunitions falling into trenches here and there?
The DPICM element is significant, because not only are the submunitions dispersed over a larger area than unitary warhead blast or fragmentation can cover, but the submunitions include a shaped-charge anti-armor design to defeat light armor in the beaten area.
The primary downside, and a large reason there are treaties restricting or banning their use, is that you get a lot of duds, plus many cluster weapons explicitly include delayed-fuse munitions, so they become a hazard like a scattered minefield.
But the US isn’t party to those treaties and actually uses (or plans to use) air-dropped and artillery-scatteres mines, as well as cluster munitions.
You’ve pretty much got it, but it’s a lot more than a few lucky submunitions landing in trenches here and there. The entire area is saturated, and as @gnoitall notes DPICM is very effective against armored targets as well, particularly lightly armored targets, meaning anything with less armor than a full-fledged MBT, but even they are vulnerable as the submunitions are likely to hit the top of the tank, where the armor is at its thinnest. Even lacking a catastrophic kill, it can still damage or destroy important things like sights, the gun tube, etc. By still current US Army Field Manuals, DPICM is the preferred ammunition for servicing targets such as groups of massed armored vehicles.
Perun put out a video on the topic last week, revisiting his year-old video on the topic of artillery and ammunition in the war in Ukraine. It’s chaptered, the chapter starting at 32:17 ‘Cluster Munitions and the Debate’ covers the topic with his usual thoroughness. The diagram at ~33:18 demonstrates the differences in effect between a DPICM shell and a unitary warhead shell.
A couple or three interesting points he makes are that 1) The fact that the M30A1 Alternative Warhead which fills the area with 160,000 high velocity pre-formed tungsten fragments is considered the ‘toned down and more humane’ alternative to DPICM should tell you something about the capabilities of DPICM, 2) while over 100 nations have bans on cluster munitions, and this is a ‘majority’ of countries, it is actually very much the minority of nations with large artillery parks and a % of the total worlds artillery. Essentially everyone who seriously plans their defense using large artillery parks and/or feels actually threatened by their neighbors has not signed the cluster munitions ban. Notable nations that haven’t signed the ban apart from the US, Russia and Ukraine are both Koreas, India, China (People’s Republic of and Taiwan), Pakistan, Poland, Finland, Romania, Estonia, Latvia, Turkey, Greece, Iran and Belarus. Note that means every NATO country that shares a border with Russia or Belarus with the exception of Lithuania hasn’t signed the ban. Finally, 3) the areas where DPICM is going to be used is already extremely heavily mined and is going to need extensive unexploded ordnance cleanup once the war is over.
At a layman’s guess, any given mass of explosives will give you about the same volume of effect… but human battlefields are mostly two-dimensional, not three. And so you can get a greater AREA of effect on the battlefield by making the volume flatter. And cluster munitions are an easy way to do that.
Cluster munitions should be more effective than conventional artillery shells against the Russian trench networks. Being in a trench provides good protection from an artillery shell explosion, unless the shell lands in the trench, and even then the trench will limit the radius of effect. So lots of smaller explosions increases the likelihood of some of them landing directly in trenches.
Mostly true. And definitely on exactly the right track.
An explosion of even a handful of modern explosive is way more powerful than necessary to maim people or wreck equipment right at the core of the explosion and out for a few feet. Beyond that range the effects drop off at the square of the distance.
The net effect, and nukes are the limit case of this, is that any chunk of explosive “overkills” its immediate surroundings, lesser-overkills further out, then just barely kills, then wounds / damages, and finally just disturbs / shakes up / annoys / scares.
Ideally you could spray explosive (and the shrapnel it drives) out onto a target area at the optimal density so that everywhere gets just enough and neither too much or too little. Said another way, given a particular weight of available explosive, you’d like to spread it just thick enough to cover the largest possible area.
Cluster munitions, like shotguns, are a way to spread the same mass of destructive energy over a larger area. Which can both cover for some lack of aiming accuracy, and can also just increase the area affected and hence the total quantity of damage done. Which is, after all, the idea of warfare. Inflict damage with reasonable economy of effort.
The Russians have been adding a lot of cope cages to their armored vehicles to counter Ukrainian drones. While a cope cage isn’t going to do diddley squat against a modern anti-tank round (that’s why military folks like to call them “cope cages”), I have to wonder if a cope cage would at least prevent cluster munitions from directly hitting the top of a tank or other armored vehicle.
These are artillery weapons, and there is a psychological effect from these weapons as well. Being on the receiving end of MLRS rockets for a couple of days takes a pretty good mental toll on the enemy.
It’s worth noting that nukes have followed the same path. Whereas the ones dropped on Japan in WW2 had yields in the range of 15-20 kilotons, within 6 years we were testing bombs of 10+ megatons - and since then, we’ve figured out that instead of putting one multi-megaton bomb on a launch vehicle, it’s better to put about a dozen warheads on that launch vehicle instead, each one with a yield of just a few hundred kilotons.