Odd Mortar Question.

[Nerd King]

Guided mortar rounds are fairly rare, in my time in the Army I only shot them once, and only actually SAW them two or three times. Mortars are a low-tech weapon that will probably be eventually replaced when the Army begins using smart air munitions on a platoon or company based level. And I am fine with that, it means less weight for the infantry to carry and makes them more mobile. I doubt the Army will ever general issue a disposable mortar. I can think of several areas they might be useful for, but once again, there are aleady lighter multi-use, repeating weapons systems that can fill those functions.

[Drusus]

Mortars aren't propably going away, but they may not look much like regular mortars. Here is my favourite future mortar system, might have something to do with me being Finnish...: AMOS (defense-update.com)

If you combine AMOS (or some other advanced mortar system...) with these munitions you have a real killer: Advanced Mortar Munitions (defense-update.com)

[Peter Cairns]

Couple of points.

1) Single use LAWs have been around since WW2, and are issued to troops world wide, so the idea that antitank is the preroggitive of repeat weapons is false.

2) The charge in a mortar round is substantially lighter than an ATGM, because like a 155mm round compared to a MLRS in can be a small single charge over a long burn rocket, so weight per round is higher for rockets.

3) a large part of the weight of mortars comes from the need for a stable long range platform that can fire hundreds, indeed thousands of rounds. just compare a LAW with an RPG-7 for weight.

4) for seeker size, you are assuming universal diameter, as I recall an RPG-7 round has about a 90mm warhead, but a 30mm tube. Look at rifle grenades, they can be fired what 250mm are about 30mm in diameter, but are launched by a 6mm cartridge.

5) Multiuse direct fire weapons relay on staying in the line of fire to repeated use them which is fine in some circumstances but not in others. Which has the best chance of taking out four BMP-3's at 400m ( you can't always rely on getting use of the full 2,00om range), an eight man squad with a Javelin with six rounds, or an eight man squad with sixteen LAWs.

Peter.

[flamingknives]

Modern ATGMs tend to have the missile + tube as a single use round. The reusable bit is the electronic gubbins that the tube clips onto.

Regarding mortar wound weight;

An MLRS round may be a bit heavier than a 155mm shell with charge, but:

It goes further

It carries a significantly bigger warhead

The launching tube is a 5mm thick aluminium tube, compared to a 155mm ordnance.

[Drusus]

Please, tell me these things. 1) What material will the tube be made of. 2) Do you have something to prove that the material can withstand a 5kg grenade to be launched to 3000m. 3) How much will the tube weight? 4) Are you sure base plate is not needed? If it is needed, how much will it weight? 5) Can you point out some project that has been able to build a 5kg grenade that is both smart (I mean able to find and fly to its target without the help of laser or anything like that in a large area) and able to knock out MBT? 6) Are you sure that a dedicated mortar wouldn't be better?

If you are not able to answer these questions, then I have nothing more to add.

[Drusus]

Peter,

I said that I have nothing more to add, but I just have to add this (forgive me, I am a bit drunken). You say that we have 1) LAWs 2) Thermally guided 120mm rounds (10kg) 3) Light mortars (60mm mortar is 20kg) 4) We have a smart ATGM that only weighs about 20kg. Based on this you say that we should be able to build a weapon that can do all this and its weight is no more than 10 kg. I think that this logic is wrong.

You asked in an earlier post that how do I suppose new weapon systems are made. I think that first you have to imagine something. THEN you have to try to show that it is possible to build it in theory. And then you have to develope the weapon and test that it can do what you imagined. I would like to see the second step.

[shlitzzlipzz@hotmail.com]

I would design a large, disposable, hi-pressure-low-pressure, 'flying-claymore'.

Range is 50-200 meters. Device uses the principal of the US 40mm grenade launcher. It is stuck in the ground, angled for range, and fired.

The payload would have the effect of a 120mm mortar round. Detonation is a few feet off ground.

Device gives defending infantry a means to break up attacks before they can close in. It allows an infantry unit to quickly break contact and flee without needing to haul a heavy weapon with it. Total weight, 40 pounds.

One per squad. Allows infantry to quickly grab and contest ground.

[Dinger]

I think the consept of man-portable (maybe not one-man-portable...) fire-and-forget indirect fire system is going to happen. But I don't think it is going to be a one-shot-only mortar. If you want to have a system of this kind you want to get more than one shot out per platoon / squad. It just makes more sense to have a launcher and five grenades than five combined launcer/grenades. No matter how light the kevlar tube (if it is possible) plus some kind of base plate (I really think you need at least some kind of a plate), it is going to be quite heavy anyways. If I have understood correctly all the modern ATGMs have separated launchers and missiles.

That sounds like the M224 61mm mortar when fired in "handheld mode" with the baby baseplate.

the problem with the example given for the argument for organic guided mortars (OP spots 4 recon vehicles on reverse slope), is that it's not a situation where a squad needs to act quickly without relying on external resources. The OP is calling this in -- we're already assuming a reasonable-sized engagement.

The ideal infantry weapon would way 2 kilos, be able to penetrate 10m of Homogenous rolled steel, have a warhead of 50kg of compound B and be able to fire off 20 shots in a minute without reloading.It would have a MultiOption fuze with the settings: Airburst (VT), Graze, Impact, Delay, Sensor-Armor, Sensor-Soft, Sensor-AP, Sensor-POL/Ammo, GPS and Electronic Time. It could fire high and low angle and would require only one day of proficiency training.

AARs from Iraq have the infantry-carried 81mm M252 as already being too heavy to use effectively in mobile operations.

That being said, Anti-Armor rounds are going to be very interesting for spec fire on those pesky "sound contacts"

[Nerd King]

In my experience the M252 was light enough if carried by a humvee, or air assaulted in on the set-up site. Otherwise, too heavy to manpack, as the rounds are just too big and effective fire support would require too many of them.

[Drusus]

To fire for one minute continuosly, you need 20 grenades which means 100 kg. This is the reason that at least in Finnish doctirine mortars should be used only in places where there is road to the firing positions. I think 200m from road is maximum for optimal firing positions in the manuals. It is suprising how much work there is to prepare & carry the ammunition even if you fire small amounts of grenades.

[Nerd King]

Doctrine here is much the same, out of sight of the road in a defensable postion, but near a road, as ammo resupply is going to be constantly needed unless it is a fortified prepared position that can hold a good amount of rounds. Even then, if a few big fire missions come along resupplies will be needed.

Most fire missions I did in Iraq were 1-4 adjustment rounds, and a fire for effect of 20-30 rounds. These fire for effects might be repeated as well, not to mention multiple simaltaneous fire missions (Now THAT is a bitch to keep track when you are FDC!!!).

[flamingknives]

The M252 is essentially a modified L16 Mortar, as issued to the Parachute regiment and Royal Marines, both light infantry formations, so they manpack the things. AIUI, if no vehicles are available every man in the Battalion (81mm mortars are a battalion support weapon) carries a round and drops it off at the mortar battery when needed.

Actually, the L16 is significantly lighter (36kg to 56kg) than the German 81mm mortar of WWII, which was manpacked all over the place, plus ammunition, and was generally regarded as being pretty effective.

[Peter Cairns]

Dinger,

Firing on sound contact will be risky.

If they start setting off rounds by putting them in oildrums in school playgrounds and then setting them alight, it' their round that kills the kids, but if you counter fire we know who will get the blame.

Peter.

[Nerd King]

flamingnives,

Interesting idea having the other grunts carry more ammo, but what if the mortar team is seperated from the main body? Dunno about British doctrine, but we are usually out on our own when we deploy the system. No other infantry near us.

I could see that being very useful for a company or battalion sized move to contact, however.

[Drusus]

I have posted this information before, but the finnish system is to have marching order of 1st platoon, mortar platoon, 2nd platoon and then 3rd platoon. When the first platoon makes contact with the enemy, the mortar platoon begins firing with the ammo they carry. This is about 20 grenades per mortar. Then the 2nd and 3rd platoons deploy through the mortar platoons positions and drop (not literally) their ammo at the mortar platoons positions. If the mortar platoon is separated from the main body, then you want to have a road or fire just one fire mission which is pretty much useless. Carrying the rounds with only the men from mortar teams is going to be pretty much useless. BTW here is a nice picture about firing a 120mm mortar: 120mm mortar firing at Rovajärvi (irc-galleria)

Just for information there was yesterday an accident at Rovajärvi, one dead and 6 injured. It seems like a mortar round exploded at the firing positions of 120mm mortars. Propable reason is double loading. End result is the extremely fast burning of the grenades in tube (not explosion but a deflakration, it is possible that that word means nothing in english). This will cause breaking down of the tube and as you can see it is no wonder somebody might get injured as the men are all near the mortar.

[Drusus]

The reason was a double loading. That means you load the mortar when there is already one grenade in the tube. This can happen suprisingly easily when there are 3 mortars firing the simultaneous first shot of a fire mission. You think that the mortar fired but actually only the two others did. It doesn't help that when you are in Rovajärvi, you usually can sleep only 1-3 hours per night. I have been able to sleep 10m from a firing mortar for a fire mission of 8 grenades and not wake up. But I was ammusmies 2. Direct translation is ammoman 2, indirect translation is that he is the guy who doesn't need brains, and in the army you don't use your brains simply because you have them, only if you are ordered to...

[flamingknives]

not explosion but a deflakration, it is possible that that word means nothing in english

If you switched the 'k' for a 'g' you'd be spot on

'deflagration'

[shlitzzlipzz@hotmail.com]

I don't think 50 years is needed.

A weapon system that can fire a disposable 'mortar' launch (to gain altitude), deploy 'glide' type fins (conventional mortar rounds can do something like this already) and then have some sort of auto-target selection (based on heat sensing, etc.)

The main attraction to this type of weapon is portability and covering large areas of front. Its a dispersed system unlike a conventional mortar that is a fixed weapon site.

The weapon would have top attack capability, target priority selection (go for armor first... if not detected.. other vehicles or groups of infantry, etc). A dual purpose warhead (small HEAT round in front, thermobaric/fragmentation in rear) gives lethality against most battlefield targets.

The firer would just have a simple folding bipod that allows the weapon to be roughed in for direction and range. Its basically fire and forget.

The initial launch could be high-pressure/low-pressure followed by a rocket stage that gets it up to altitude. Its then a glide bomb till it reaches the target.

It can be fired from behind cover (small hills, large buildings, trees) and bleeds the enemy. Its a weapon for use in conventional situations rather than urban counter-insurgency.

[ December 03, 2005, 01:27 PM: Message edited by: shlitzzlipzz@hotmail.com ]

[flamingknives]

The trouble with an autonomous AT weapon that is fired blind is that there is no operator in the loop. As such, it is no more discriminating than a land mine.

[shlitzzlipzz@hotmail.com]

It isn't autonomous since the operator does sight it in to target an area.

[Peter Cairns]

If it uses a hellfire type seeker that can discriminate a T-72 from a tractor then it's Okay. A basic heat or EM sensor isn't.

The other option is optical, via Fibre optics, but that's not fire and forget.

Peter.

[cassh]

[edit] typos...

Dinger - you said that in the scenario I gave "it's not a situation where a squad needs to act quickly without relying on external resources The OP is calling this in"

Actually it is. The whole purpose of the example given is that if the recce vehicles come over the slope the squad/section/platoon's position may be compromised and they get seriously biffed with arty or worse wake up the next morning to an assaulting enemy who know their dispositions accurately. To say they can get on the blower and get instant anti-armour support from afar isn't how the real world works. Best case - if you've got a switched-on FOO and well trained and oil fire-control-centre then you might get arty on the target in a minute. Otherwise it could take much longer, especially so if there's no FOO/FAC to hand. An armoured recce troop could be in LOS of the reverse slope defence in two-shakes.

Additionally, fire-support is not dished out willy-nilly. You have to have the guns in position setup and in support before you can call in their fire - not always possible in the confusion of battle - friction as Clausewitz points out is omnipresent in war. So to have weapon systems that lets the man on the spot deal with the threat is really very sensible.

A fire-and-forget indirect-anti-armour round would be a lot more of an assurance to any platoon commander in that situation.

Flammingknives - it's two 81mm mortar bombs per tom/jock/bod/squaddie - they come as a brace in a lovely green plastic handbag.

[ December 06, 2005, 12:41 PM: Message edited by: cassh ]