How a mortar works?

[leonpoi]

Just out of interest, does anyone here know how a mortar works Is the round self contained, or do you have to have some kind of power charge (I'm talking 60mm, 81mm that type of thing) If so, is it possible to use smaller charges for shorter distances, or do you just use real high trajectories for that
Thanks in advance

[Fusilier]

AFAIK, all light and medium mortars are self-contained -- there is no separate charge.

Self contained, but there's more to it.

The internal charge is usually insufficient to provide enough power to propel the bomb any real distance. This is usually for all size mortars. Charges, which are often just semi-circle, plastic, ring shaped charges filled with propellant are added (or removed). An 81mm might have up to four. They are connected around the skinny part of the bomb near the bottom by the fins.

So in some situations not only do you need to figure out bearing and elevation, but also what charge setting to use.

[kato13]

AFAIK, all light and medium mortars are self-contained -- there is no separate charge.

I think most mortars can have their self contained propellant range increased via increment charges.

[leonpoi]

Self contained, but there's more to it.

The internal charge is usually insufficient to provide enough power to propel the bomb any real distance. This is usually for all size mortars. Charges, which are often just semi-circle, plastic, ring shaped charges filled with propellant are added (or removed). An 81mm might have up to four. They are connected around the skinny part of the bomb near the bottom by the fins.

So in some situations not only do you need to figure out bearing and elevation, but also what charge setting to use.

ok, thanks for that info. Do you know if these charges take much time to attach

I've found this on wiki, but it took me a while to find because I didn't know what I was looking for:
The charges on the 80mm rounds govern how far that particular round with travel. Each round that the M252 mortar fires has four semi-circle shaped charges that can be easily attached, or stripped by hand. While the rounds can fire without the aid of additional charges, to reach farther targets more charges must be applied.

[bigehauser]

Calling Paul Mulcahy! Or perhaps Gunner Law!

Paul, Law

Any insight, albeit your skill sets aren't specific to High Angle Hell

[Fusilier]

ok, thanks for that info. Do you know if these charges take much time to attach

No time. By the time the No.1 has laid the bearing and elevation, the No.3 will have the ammo ready (this includes setting the right charges as the Mortar Fire Controller indicated).

The charges come pre-connected, but taking them off or putting them back on, only requires a flick of a finger so yeah, no time. They are only loosely wrapped around - not tight or anything.

[pmulcahy11b]

Paul, Law

Any insight, albeit your skill sets aren't specific to High Angle Hell

Actually my first MOS was 11C (mortar gunner), but what the other minds on this board have said are right. I can add that the 4.2" mortar uses "cheese charges" -- these are about the size a color of a slice of cheese you might put on your bread, but made of nitroglycerin and beeswax. They have a hole in the middle to wrap around the tail of the charge. 4.2" mortar rounds don't have fins (the barrel is rifled), so there is a simple retaining ring to keep the charges in place. The rounds come with enough charges to propel the round to its maximum range, so the one of the ammo bearers (there are two on a 4.2" crew) "cuts charges" -- he tears off or detaches (they come in 5-"slice" increments as well as some single slices and one 10-pack) the parts of the charge not needed. A good charge cutter will be 2-3 rounds ahead of the round being fired. If you need to drop close, you can fire the mortar on charge 0 -- no propelling charges.

Then comes the best part of 4.2" mortar gunnery -- destroying the unused charges when you're done. You dig a bit pit, throw the charges in, then throw a burning book of matches or a stick on fire into it and run. Big fireworks display, and it sounds like a jet engine for a few seconds.

Older 81mm rounds have bagged charges -- 7 for an 81mm. The 60mm are similar, but only have three charges. You just unhook what's necessary.

[Adm.Lee]

Only thing I can add is some pedantry-- a mortar shoots "bombs," not "shells," according to many sources.

[rcaf_777]

I am qualifed on the 60mm mortar and have always wonder how far the basic round no extra charges would travel

[natehale1971]

I was wondering something.

Should Mortars always be used in pairs, or is a single mortar just as effective in a pinch Anti-Armor weapons like the SMAWS, Carl Gustav or PzF-3 seem to be good when used as single weapon team (Gunner, Asst. Gunner & Ammo bearer), but I was wondering about Mortars. Can a group that has a single mortar team work just as effectively Or a single gunner with two assistants be able to operate two mortars

[jester]

We operated guns with 2 man mortar crews. Gunner and A-Gunner with them prepping ammo before hand and the lone ammo man in the section and the corpsman and radioman and section leader lending a hand.

[Eddie]

I was wondering something.

Should Mortars always be used in pairs, or is a single mortar just as effective in a pinch Anti-Armor weapons like the SMAWS, Carl Gustav or PzF-3 seem to be good when used as single weapon team (Gunner, Asst. Gunner & Ammo bearer), but I was wondering about Mortars. Can a group that has a single mortar team work just as effectively Or a single gunner with two assistants be able to operate two mortars

Mortars (and artillery) are not necessarily best employed by firing the entire gun line, be it 2 guns or 20. It depends on the type of mission they're performing.

That said, you'll most likely not get the most bang for your buck when you go to FFE (Fire for Effect) if you're only using one tube.

((While I'm not an 11C, I am an Infantry Company Commander, graduate of the Infantry Mortar Leader's Course and own the Battalion's Mortar Platoon.))

[pmulcahy11b]

Only thing I can add is some pedantry-- a mortar shoots "bombs," not "shells," according to many sources.

That sort of depends on where you're from -- Americans and South Koreans call them shells, for example, while Brits and Germans call them bombs.

[Fusilier]

Should Mortars always be used in pairs, or is a single mortar just as effective in a pinch Can a group that has a single mortar team work just as effectively Or a single gunner with two assistants be able to operate two mortars

Not every army is the same of course, but I can say...

Part of keeping them in groups (of say 4 tubes) is due to the area effect of the bombardment (like Eddie said) with having a suitable FFE factor. However, another part is due to the limited number of personnel in your mortar platoon and the limitations of the crew...

Beyond 60mm, larger mortars are usually behind the FEBA so that they are indirect only. That means you need a MFC (mortar fire controller) to coordinate with fire controllers (spotters), and work out the calculations. There are only so many of these guys, so splitting up all you mortars up means you would have some tubes sitting idle (as in there isn't one MFC per tube). So one MFC can only do so much at a time.

So if a battalion has an eight 81mm mortar platoon, they are likely split into two 4-tube groups. Each group would have a one MFC team.

A single mortar is usually not able to preform indirect fire missions independently of a MFC. They have enough to do as it is without worrying about communicating with spotters and plotting. The MFC also will limit the number of rounds per fire mission, so you don't have gunners blowing off more than they should (or not enough).

I know I am not explaining this very well, its been a looong day here at work. But to summarize - they are grouped for the effects of firepower and due to how many MFCs you have.

For the question of 3 guys dividing their time on two mortars If they are mortar trained, then yeah, but their effectiveness would be obviously reduced. It would probably be best to just add a 4th guy and split 2 men each (instead of 3).

[pmulcahy11b]

I am qualifed on the 60mm mortar and have always wonder how far the basic round no extra charges would travel

Well...this is more geared towards the older mortars I'm familiar with, but the book minimum ranges for M-19 60mm mortar using the small M-2 baseplate is 40 meters. For the M-29 81mm mortar, the book minimum range 100 meters. For the M-30 4.2" mortar, it's 770 meters.

That said, if your gunner know a few tricks, like propping up the legs of an 81mm mortar or hand-holding a 60mm mortar without the bipod, you can literally drop the round right on top of your self, or very close to yourself. Those minimum ranges are for safety. A 4.2" mortar, on the other hand, has a definite elevation maximum; on charge 0 at max elevation (which is NOT recommended) you can expect that heavy round to travel no more than about 50 meters. For the 81mm on max elevation on charge 0, you can just about quarter the minimum range above (and the old M-29 can superelevate; don't know about the newer ones). For the 60mm, if you are using it handheld, you can almost use it as a grenade launcher; some countries make a HEAT round for their 60mm because of that. If you are using the bipod, you can expect about 20 meters on charge 0.

60mm mortars are the most difficult to quantify, since they can be used as indirect fire weapons and to an extent direct fire weapons, when they are handheld.