I think GMLRS might actually be the superior alternative here. At a bare minimum it's looking close to competitive, as a tradeoff between being (probably) more expensive than a 155mm shell of comparable range but also being larger and hitting harder.
The use cases seem different though.
If the aim is to hit a concentrated force out of cover and static, or field HQs, or fuel dumps, things that dont move quickly, yes, GMLRS excels at throwing knockout punches like that.
If the forces are moving, to the best of my knowledge GMLRS is not designed to hit moving targets, just spots on the map. Continuous shellfire can, on the other hand, recalibrate to keep up with a moving force, and maintain the drumbeat of bombardment for minutes or hours at a time, as long as the battery does not need to relocate immediately and have a supply of ammo.
And you really can't use GMLRS in danger close situations the way you can smart howitzer rounds.
I mean, you could, but it's really not a good idea if you are looking to avoid fratricide.
Yes, but note that I cited the mass-production cost per unit of 35k per round, not 800k per round. I was deliberately using the cost the manufacturers cited for "this is how much they'd cost if we weren't making an absurdly small production run."
Fair.
I will point out that the US Army (and the Norwegians, actually) seem to be pursuing this as a cheaper, more flexible alternative to a full launcher or battery ripple of GMLRS or ATACMS/PRSM tactical missiles. Which suggests the economics are worth it compared to GMLRS, and presumably closer to the theoretical LRLAP cost quote, or at worst the costs for Excalibur, than the actual limited run production cost.
Yes, it's the rocket engines and ramjets and so on that start raising the price significantly... but those are the features you're proposing to add to the
One GMLRS rocket has cost comparable to a dozen 155mm guided rounds fired from within the range of 'conventional' 155mm artillery. A dozen 155mm shells put together will probably make a bigger dent in the enemy, too.
But when you start putting rocket/ramjet sustainers on the 155mm shells, the equation changes, because the cost of the shells goes up dramatically and the warhead weight goes down a little. By the time you've upgraded the range of the 155mm artillery to the kind of "multiple divisions supporting each other, range >100 km" performance we're discussing, your costs are quite high.
That depends very much on the cost. We have no hard numbers yet, on that front.
As I understand it, with the ramjet shell we're looking at a boostglide weapon, where the shell is kicked into boostphase and supersonic speed out of the barrel, the ramjet takes over at altitude and burns for a minute or less, using propellant and air, and the round then goes ballistic or aeroglides the rest of the way, with a top range of 150km.
Modern manufacturing processes like 3d printing techniques as well as newer propellant formulations allegedly change the cost calculation for single use ramjets. Sorta like how grenade launcher launched drones are now cheap enough to be in production because we're mass producing GPS chips and small radar/lidar units today.
Wait until the full implications of cheap, high quality cellphone-camera sensors and image recognition software hits the downmarket segment of the smart weapon industry the way it's hitting the private drone and satellite imaging sector.
Individual MLRS rockets weigh around 300 kg. Individual 155mm shells weigh around 40-45 kg. The MLRS rockets are much bulkier than individual 155mm shells, but are, again, harder-hitting. If we're comparing one MLRS rocket to three or four extreme range boosted 155mm shells (comparable cost), the MLRS rocket is indeed heavier- but the difference in weight and bulk isn't entirely overwhelming.
An MLRS battery has nine launchers, so a reload for the battery is 108 rockets. If we have one salvo in the launchers, plus two reloads, that's 324 rockets, total weight of all ammunition around 100 metric tons (roughly)... and 36 rockets per launch vehicle.
Now, a 155mm artillery battery could carry 36 rounds per gun in a much smaller total space. 36 155mm rounds will weigh about one and a half metric tons, and I don't know how many guns there are per battery but it's only going to be six or eight guns, maximum. But if they want to carry more ammunition per firing vehicle, it starts to add up pretty fast... and each 155mm shell is less impactful against the enemy than a single MLRS rocket would be.
1)Not just weight, but compactness.
You can carry artillery shells in basically any vehicle with cargo space at need, from trucks and boats to oxcarts to bicycles. And they are relatively robust rounds to manhandle and store.I'm assuming ramjet shells are still shells, not mini-missiles. GMLRS rockets require rather more specialized transport , handling and storage equipment and procedures, both for moving the rockets, and loading them in the first place.
2) Each MLRS launcher has it's own reload vehicle(s)with it's reloads.
OTOH, an eight wheeler HEMTT truck has a payload of roughly 10 metric tons, which is enough to carry one set of 36 reloads for an entire battery of 6x 155mm howitzers. Not counting the MAC-propellant charges of course.
The logistics equation is thus much easier to solve for howitzers.
And I say this as someone who thinks MLRS are an essential part of the artillery arm, and is looking forward to being able to nail VAF aircraft on the ground with naval- and MLRS-launched M31 rockets and PRSM missiles.
Yes- but by the same token the M31 rocket is carrying roughly 90 kg of explosives to the M107's seven or eight. It may not have proportionately as high a weight of shrapnel, but it's a much heavier category of munition.
Point of order: 90kg
warhead.
There's one version with a unitary warhead for killing point targets like HQs, and an alternative warhead with preformed fragments for attacking area targets like infantry and light vehicles with an airburst detonation.
The explosive fraction of the M31's alternative warhead isn't stated, just that a significant fraction of the warhead is formed by about 180,000 preformed tungsten fragments. If it's anything like, say, the Mark 82 500 pound bomb, only 30-40% by weight would be explosives. If it's more like the LRLAP round, IIRC, you're looking at maybe 11% explosive fraction.
Forum poster on another website said the 90kg warhead only has 22kg explosive content(
LINK), but I can't swear to it.
And I certainly dont have the foggiest idea of how the explosive payload compares in effectiveness; I doubt the difference between shell and missile is linear, but that's more gut feel than anything solid.
It's definitely a project and they're definitely working on it, but a lot of things get worked on that don't pay off. Developing a new artillery shell is relatively cheap, since you don't have to build entire new weapon systems to use it; it's the kind of thing I'm unsurprised to see a company that specifically makes artillery doing. Their militaries may or may not ever actually adopt the extended-range rounds, depending on the exact balance of cost and capability the extended-range shells have relative to missiles. Plus European militaries- I can't comment on South Africa's- are all in that same situation of wanting to be able to cover very large areas with very few actual gun batteries, due to manpower restrictions. We're not operating under quite the same paradigm, even if it'd be lovely to have divisions 100 km apart able to "scratch one another's backs," so to speak.
-True.
But ramjets are not new tech. They're not even new weapons; some of the first US missiles in the 1960s like the Bomarc SAM were ramjets, as were British SAMs like the Sea Dart and Bloodhound. There was even a 1950s ramjet engine that weighed about 13 pounds and was used in a prototype helicopter (Hiller Hornet, if you are interested in looking it up).
They just havent been economical at this size and configuration(solid propellant ramjet) before.
-Nammo is part owned by the Norwegian government(50%) with the other half owned by Patria, a Finnish company that is itself part owned by the Finnish govt(50.1%) and the Norwegian defense company Kongsberg Gruppen.
The incentives here seem to be very different from those on US private defence contractors.
-Less a manpower shortage as I understand it, and more that Russia has been acting up again.
And the Russian borders are close enough for the Scandinavians to count the bear's teeth when it yawns. Indirect fires that dont require sending expensive pilots and aircraft into the teeth of heavy SAM defense are back in fashion.
And since there is a practical limit to how much firepower you can maintain in peacetime, squeezing as much (economic) capability as you can out of them is probably a good idea.
-The South Africans just make really good arty, and have since apartheid times. Dunno why.
The Denel G6 155mm remains the longest ranged active service self-propelled howitzer in the world, and has held that record for almost two decades by this point.
This is the most public source information I have on the Norwegian round anyway.
There's a US one called the XM1113 rocket assisted projectile, which extends range to ~60+km, but I have insufficient knowledge of it.
It is not the first time that a company decides to add jet propulsion to artillery rounds.
www.edrmagazine.eu
The technology chosen by Nammo, dubbed ExR for extreme range, will bring the range in the three-digit dimension, the Mach 3 velocity being maintained for around 50 seconds, a ramjet being inherently self-regulating maintaining a constant Mach number independently of altitude, allowing the round to hit a target at over 100 km; this means that one single artillery system will be able to cover an area of over 31,000 km2 compared to the 5,000 km2 covered by a current 155/52 mm artillery tube with extended range rounds.
The round is being designed to be fully compatible with the JBMOU L52 155, in order to allow it to be fired by any current system developed in accordance with that standard. The presence of the ramjet inevitably reduces the amount of explosive, Nammo declaring an amount of "HE explosive with similar weight as 120 mm round", which should mean between 3 and 3.5 kg. The warhead will be designed to neutralise soft targets, such as light armoured vehicles, radars, ground-based air defence systems, thus an HE-FRAG solution is foreseen, while no anti-armour effect is being considered. Nammo's 155 mm ExR is expected to have its first ballistic flight test in 2019/2020, probably without guidance, the company looking forward to have it operational in 2023-2024.
