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Posted: 10/8/2010 7:55:42 AM EDT
Excuse my ignorance on the subject.....I'm AF....we have some 81mm in our inventory but I've never personally seen them used. Just wandering how it works when a unit/F.O./Spotter in the field calls in 8/10 digit coordinate and how the crew calculates the info into a firing solution. Go easy if my terminology isn't correct......I'm especially interested in how the mortarmen calculate the trajectory etc. for a target behind a large terrain feature....mountains, hills, etc.
AF_K9 |
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I know just enough to make myself look like a douchebag to a real 0341, and I recommend googling for an FM or something.
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In for the info
A simple mind also want know if they really go PLUMPPP on fireing |
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Quoted: Huh????? 'Magnets' is a bad joke based on an even worse so-called 'band' called insane clown posse. As for your actual question.... The long-and-short of it, is that all the different 'call for fire' methods produce a math problem that when 'solved' gives you a set of coordinates that needs to be blown up... The mortarmen also have their own map coordinates, and that gives them what direction to shoot, and how far away the target is. Then, given how far the target is (and the weather conditions, etc), they can calculate (based on known round-ballistics data) what angle the tube needs to be set at, and how many charges (of propellant - think 'how much gunpowder' in easy terms) need to be on the round when they fire it.... Now, I'm oversimplifying by far - mixing FDC (fire direction center - I assume that one is used for mortars, just like arty) with mortar-crew actions, and so on - and I'm going to guess that the army has some sort of portable electronic device that does alot of the math these days... But that's about how it works... An 11C will probably be along to tell me everything I got wrong... |
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HS physics gives you the appropriate trajectory for a range or any obstacles in the way; the # of charges & elevation for a range, are already on a premade cheaters wheel.
If you're 120mm, the track will calculate & do most of the aiming for you...manual tuning is still required for us, Euro arty can be completely automated. I can IM you some manuals if you want. |
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Do they detonate on impact? standard HE has a variable fuze nowdays, with delayed, 3-5' high, 10-12' high, or impact settings. |
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Dave's on the money. The mortars know where they are. they know where the spotter is, they know (roughly, sometimes) where the target is. They set the direction the tube points to. They have charts and aids that tell them how much powder and at what angle to put the tube at to hit that range. They drop a round. Guy calling for fire corrects "Add 100, right 50" would mean another 100 meters from their perspective, and 50 m to the right. The mortar FDC guys have to take into consideration the perspective of the spotters in making their corrections. Been basically the same since WWI for mortars...
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Thanks guys......seems like fun job.....except for the math part....glad I'm just a dog handler.....haha
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Powder charges in a mortar round are variable? (Everything I know about mortars I learned through watching movies)>
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Tubes have firing solutions on a "whizz wheel" that gives them data for range, elevation, and deflection , it also calculates charge by way of the range, and can be adjusted for type of round.
FO radios in the target by grid, polar or shift and the tubes use his data for the calculation. |
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Quoted: Powder charges in a mortar round are variable? (Everything I know about mortars I learned through watching movies)> Yes. Some look like donuts, some come in small bags, and the old 4.2" mortar used "cheese charges". |
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Powder charges in a mortar round are variable? (Everything I know about mortars I learned through watching movies)> Yes, just like varying the bags of powder in an artillery piece. The propellant is wrapped around the base of the mortar round and you remove the appropriate amount of propellant for the shot your making. |
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how do mortars actually fire? I mean what is the sequence of event in the mortar tube when you drop the round? I don't understand how the charges that are wrapped around the fins propel the round.
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Quoted: What do they do with the left over charges? I've always wanted to know that.Quoted: Powder charges in a mortar round are variable? (Everything I know about mortars I learned through watching movies)> Yes, just like varying the bags of powder in an artillery piece. The propellant is wrapped around the base of the mortar round and you remove the appropriate amount of propellant for the shot your making. |
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What do they do with the left over charges? I've always wanted to know that.Quoted:
Powder charges in a mortar round are variable? (Everything I know about mortars I learned through watching movies)> Yes, just like varying the bags of powder in an artillery piece. The propellant is wrapped around the base of the mortar round and you remove the appropriate amount of propellant for the shot your making. Burn them, just like artillery burns all of the left over powder bags (at least this is what I've always seen) |
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Quoted: Quoted: What do they do with the left over charges? I've always wanted to know that.Quoted: Powder charges in a mortar round are variable? (Everything I know about mortars I learned through watching movies)> Yes, just like varying the bags of powder in an artillery piece. The propellant is wrapped around the base of the mortar round and you remove the appropriate amount of propellant for the shot your making. Big pile, throw in cigarette, run. Seriously. |
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Do they detonate on impact? standard HE has a variable fuze nowdays, with delayed, 3-5' high, 10-12' high, or impact settings. That's Nasty. |
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Do they detonate on impact? standard HE has a variable fuze nowdays, with delayed, 3-5' high, 10-12' high, or impact settings. That's Nasty. Thats the idea, high angle air bursting fire on exposed troops (or soft equipment) is not something I want to be on the recieving end of. |
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Cliff notes version:
FO observes target and calls grid to tactical operations center. TOC dertermines what wapon system is best to destroy the target and sends the firemission to the fire direction center at the gun line. FDC uses a mortar ballistic computer or an overlay on a map combined with ballistic tables to compute a firing solution which consists of azimtuh to target, elevation, and charge and sends the data to the gun line. typically the base gun will fire one round and adjust until the FO reports the rounds are close enough for all four guns to fire for effect. Each gun has a sight and aiming poles set out at a known azimuth from the gun. The deflection that the FDC calls is from the known azimuth. When the gun crew gets the data they set the sight to that data and then move the gun so that it aims at the poles again and use bubble levels to level the gun out. Gun up! Hang it. Fire! Posted Via AR15.Com Mobile ETA: some videos, just for fun: http://www.youtube.com/watch?v=oRFPNwaWWL4 http://www.youtube.com/watch?v=vbuAjCgyV9Y http://www.youtube.com/watch?v=Sbc1zFo1v3A Not mortars: http://www.youtube.com/watch?v=47MeVFZbZ5I |
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i was on a crew learning how to do this in afghanistan once with the mortar guys and we actually started to get incoming rounds. it was like a sick joke, the training became real and the crew dropped a shit ton of 81 and 120s on the position. we checked it next morning. 3 kills ive loved mortars ever since.
for the bad guys its real easy, point tube, guesstimate, drop rounds, run |
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Cliff notes version: FO observes target and calls grid to tactical operations center. TOC dertermines what wapon system is best to destroy the target and sends the firemission to the fire direction center at the gun line. FDC uses a mortar ballistic computer or an overlay on a map combined with ballistic tables to compute a firing solution which consists of azimtuh to target, elevation, and charge and sends the data to the gun line. typically the base gun will fire one round and adjust until the FO reports the rounds are close enough for all four guns to fire for effect. Each gun has a sight and aiming poles set out at a known azimuth from the gun. The deflection that the FDC calls is from the known azimuth. When the gun crew gets the data they set the sight to that data and then move the gun so that it aims at the poles again and use bubble levels to level the gun out. Gun up! Hang it. Fire! Posted Via AR15.Com Mobile "Hangin' on one!" |
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Quoted: Quoted: Quoted: Quoted: Do they detonate on impact? standard HE has a variable fuze nowdays, with delayed, 3-5' high, 10-12' high, or impact settings. That's Nasty. Thats the idea, high angle air bursting fire on exposed troops (or soft equipment) is not something I want to be on the recieving end of. And due to the lower stresses placed on mortar rounds vs. tube arty, they pack proportionately more HE than arty shells. |
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Huh????? 'Magnets' is a bad joke based on an even worse so-called 'band' called insane clown posse. As for your actual question.... The long-and-short of it, is that all the different 'call for fire' methods produce a math problem that when 'solved' gives you a set of coordinates that needs to be blown up... The mortarmen also have their own map coordinates, and that gives them what direction to shoot, and how far away the target is. Then, given how far the target is (and the weather conditions, etc), they can calculate (based on known round-ballistics data) what angle the tube needs to be set at, and how many charges (of propellant - think 'how much gunpowder' in easy terms) need to be on the round when they fire it.... Now, I'm oversimplifying by far - mixing FDC (fire direction center - I assume that one is used for mortars, just like arty) with mortar-crew actions, and so on - and I'm going to guess that the army has some sort of portable electronic device that does alot of the math these days... But that's about how it works... An 11C will probably be along to tell me everything I got wrong... AFATDS= Advanced Field Artillery Tactical Data System, pronounced A-FAY-TADS. Your portable electronic device. You, this is me. Adjust fire, over. |
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You want to see some real fun?
Have a misfire in a four duece.....talking about having your asshole wired tight. |
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Huh????? 'Magnets' is a bad joke based on an even worse so-called 'band' called insane clown posse. As for your actual question.... The long-and-short of it, is that all the different 'call for fire' methods produce a math problem that when 'solved' gives you a set of coordinates that needs to be blown up... The mortarmen also have their own map coordinates, and that gives them what direction to shoot, and how far away the target is. Then, given how far the target is (and the weather conditions, etc), they can calculate (based on known round-ballistics data) what angle the tube needs to be set at, and how many charges (of propellant - think 'how much gunpowder' in easy terms) need to be on the round when they fire it.... Now, I'm oversimplifying by far - mixing FDC (fire direction center - I assume that one is used for mortars, just like arty) with mortar-crew actions, and so on - and I'm going to guess that the army has some sort of portable electronic device that does alot of the math these days... But that's about how it works... An 11C will probably be along to tell me everything I got wrong... AFATDS= Advanced Field Artillery Tactical Data System, pronounced A-FAY-TADS. Your portable electronic device. You, this is me. Adjust fire, over. AFATDS only does technical fire direction for arty; it may do tactical fire direction for the FSE. But normally not. The MBC (PDA based application) is used for technical fire direction. |
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Do they detonate on impact? standard HE has a variable fuze nowdays, with delayed, 3-5' high, 10-12' high, or impact settings. That's Nasty. Thats the idea, high angle air bursting fire on exposed troops (or soft equipment) is not something I want to be on the recieving end of. And due to the lower stresses placed on mortar rounds vs. tube arty, they pack proportionately more HE than arty shells. True, but when you still have a round with more explosives than the whole of the other round weighs it makes up for a lower proportion of HE. |
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Huh????? 'Magnets' is a bad joke based on an even worse so-called 'band' called insane clown posse. As for your actual question.... The long-and-short of it, is that all the different 'call for fire' methods produce a math problem that when 'solved' gives you a set of coordinates that needs to be blown up... The mortarmen also have their own map coordinates, and that gives them what direction to shoot, and how far away the target is. Then, given how far the target is (and the weather conditions, etc), they can calculate (based on known round-ballistics data) what angle the tube needs to be set at, and how many charges (of propellant - think 'how much gunpowder' in easy terms) need to be on the round when they fire it.... Now, I'm oversimplifying by far - mixing FDC (fire direction center - I assume that one is used for mortars, just like arty) with mortar-crew actions, and so on - and I'm going to guess that the army has some sort of portable electronic device that does alot of the math these days... But that's about how it works... An 11C will probably be along to tell me everything I got wrong... AFATDS= Advanced Field Artillery Tactical Data System, pronounced A-FAY-TADS. Your portable electronic device. You, this is me. Adjust fire, over. AFATDS only does technical fire direction for arty; it may do tactical fire direction for the FSE. But normally not. The MBC (PDA based application) is used for technical fire direction. You learn something new everyday. I've always been on the AFATDS side and never down to the gun line. |
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Quoted: You want to see some real fun? Have a misfire in a four duece.....talking about having your asshole wired tight. <––-BTDT. It doesn't sound like a big deal to new 11C's but um...the four deuce was rifled. |
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Quoted: Quoted: Quoted: Huh????? An 11C will probably be along to tell me everything I got wrong... I was an 11C and no you aren't wrong, but like you said it's simplified. When I was in, and mind you this was nearly 20 years ago, we were still taught the plotting wheel and used charge books. Once you got that down we were trained with a Mortar Ballistic Computer, about the size of a telephone book that as you said, takes most of the math out and lets you add in all kinds of other information. I'm sure they have an iphone app for it now. Basically the mortar has a position on a map, the observer has a position on a map, and the target has a position on a map. You calculate the deflection needed to turn the mortar left or right and the elevation needed to get the round there. The charge and elevation go hand in hand so that you shoot at the lowest elevation to (try) avoid counter-battery radar. The mortar is aimed through a sight at posts a short distance away which are used as reference points. The sight also has leveling bubbles. Once the mortar is turned the right direction, the tube elevated, the bubbles leveled, you drop that bastard down the pipe and kaboom-off it goes (you hope anyway; nothing like a short round to wake everyone up). And unlike the movies they don't make a "bloop" noise. It's fucking loud. Here's one of my platoon's guns at NTC in 1994. I was in the FDC by then. These are old four-deuce mortars. We didn't get the Soltam 120mm until 1996. Thank you!!! I always wondered why there were direct sights on an indirect fire weapon. That makes sense that they would be sighted to a known reference allowing for smaller incremental adjustments to the target. ETA - interesting thread |
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Huh????? An 11C will probably be along to tell me everything I got wrong... I was an 11C and no you aren't wrong, but like you said it's simplified. When I was in, and mind you this was nearly 20 years ago, we were still taught the plotting wheel and used charge books. Once you got that down we were trained with a Mortar Ballistic Computer, about the size of a telephone book that as you said, takes most of the math out and lets you add in all kinds of other information. I'm sure they have an iphone app for it now. Basically the mortar has a position on a map, the observer has a position on a map, and the target has a position on a map. You calculate the deflection needed to turn the mortar left or right and the elevation needed to get the round there. The charge and elevation go hand in hand so that you shoot at the lowest elevation to (try) avoid counter-battery radar. The mortar is aimed through a sight at posts a short distance away which are used as reference points. The sight also has leveling bubbles. Once the mortar is turned the right direction, the tube elevated, the bubbles leveled, you drop that bastard down the pipe and kaboom-off it goes (you hope anyway; nothing like a short round to wake everyone up). And unlike the movies they don't make a "bloop" noise. It's fucking loud. Here's one of my platoon's guns at NTC in 1994. I was in the FDC by then. These are old four-deuce mortars. We didn't get the Soltam 120mm until 1996. Thank you!!! I always wondered why there were direct sights on an indirect fire weapon. That makes sense that they would be sighted to a known reference allowing for smaller incremental adjustments to the target. The FM 23-91 explains computational procedures. However, mortarmen normally skip many steps and used very simplified gunnery procedures. This is one reason in Marine infantry battalions the mortar platoon sgt is an artillery fire direction chief. |
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The fire coordinates are all around us. You can't see them, but they're there. Just there in the air.
Fuckin' magic, man. |
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Mortars are pretty much old technology for most part, there is nothing really new out there them or that is not know by the rest of the world.
In the next couple of years when PERM comes on line for 120s than much of that data will either be FOUO or secret. |
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Quoted: True, but when you still have a round with more explosives than the whole of the other round weighs it makes up for a lower proportion of HE. I wonder what the casualty radius is on this big bastard: http://en.wikipedia.org/wiki/2S4_Tyulpan |
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Quoted: Dave's on the money. The mortars know where they are. they know where the spotter is, they know (roughly, sometimes) where the target is. They set the direction the tube points to. They have charts and aids that tell them how much powder and at what angle to put the tube at to hit that range. They drop a round. Guy calling for fire corrects "Add 100, right 50" would mean another 100 meters from their perspective, and 50 m to the right. The mortar FDC guys have to take into consideration the perspective of the spotters in making their corrections. Been basically the same since WWI for mortars... Well, good to know I at least have some idea... Coming from the 'point-and-shoot' side of 'making stuff explode'... 'It puts the reticle on the target, lases the range, and fires... BOOM, dead target' |
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Quoted: Quoted: True, but when you still have a round with more explosives than the whole of the other round weighs it makes up for a lower proportion of HE. I wonder what the casualty radius is on this big bastard: http://en.wikipedia.org/wiki/2S4_Tyulpan I wonder how many rounds actually function... Standard Soviet solution to quality control on explosive ordnance... 'Make it BIGGER, so the ones that work can make up for the ones that don't'.... |
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Quoted: Mortars are pretty much old technology for most part, there is nothing really new out there them or that is not know by the rest of the world. Yeah, but there's always that one guy here. |
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I had no idea how cool mortars were until I became an ammo-man for a LAV 25 mortar variant. My tube ended up being the most fired gun in the battalion during the invasion of Iraq.
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Do they detonate on impact? standard HE has a variable fuze nowdays, with delayed, 3-5' high, 10-12' high, or impact settings. That's Nasty. Thats the idea, high angle air bursting fire on exposed troops (or soft equipment) is not something I want to be on the recieving end of. And due to the lower stresses placed on mortar rounds vs. tube arty, they pack proportionately more HE than arty shells. True, but I still don't want to be down range when a 155mm shell comes in. It packs plenty of bang to mess your day up. |
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Quoted: Quoted: Dave's on the money. The mortars know where they are. they know where the spotter is, they know (roughly, sometimes) where the target is. They set the direction the tube points to. They have charts and aids that tell them how much powder and at what angle to put the tube at to hit that range. They drop a round. Guy calling for fire corrects "Add 100, right 50" would mean another 100 meters from their perspective, and 50 m to the right. The mortar FDC guys have to take into consideration the perspective of the spotters in making their corrections. Been basically the same since WWI for mortars... Well, good to know I at least have some idea... Coming from the 'point-and-shoot' side of 'making stuff explode'... 'It puts the reticle on the target, lases the range, and fires... BOOM, dead target' 11C puts reticle on red and white stick...boom boom boom, etc....grid square: gone. |
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I've learnt a lot in this thread..thanks...
I remember reading a story once, about the IRA, who would set mortars up in the back of vans and fire them off. That must have been loud. |
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Quoted: Quoted: Powder charges in a mortar round are variable? (Everything I know about mortars I learned through watching movies)> Yes, just like varying the bags of powder in an artillery piece. The propellant is wrapped around the base of the mortar round and you remove the appropriate amount of propellant for the shot your making. Aha! I always thought the charges were the same, out of the transportation tubes into the mortar tube. Makes sense! |
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Didn't expect this much info when I posted this....Thanks guys!
AF_K9 |
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You want to see some real fun? Have a misfire in a four duece.....talking about having your asshole wired tight. <-BTDT. It doesn't sound like a big deal to new 11C's but um...the four deuce was rifled. That sucks. Do you use an extractor like with the 120mm? Posted Via AR15.Com Mobile |
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