[QUOTE=jjimm]
Much favoured by the IRA
[/QUOTE]
I got an early day home from school when the IRA couldn’t decide whether to point their mortars at the school or the church next door (the police were next door to the houses that were next door to the church :rolleyes: )
chowder, I seem to be remembering less and less of “Saving Private Ryan”, were they mortar rounds or rifle grenades that were thrown?
Mortar rounds
[QUOTE=chowder]
In Saving Private Ryan Capt Miller and Ryan threw mortar rounds at the Germans after striking them against some hard metal plate.
Possible or just film stuff?
[/QUOTE]
Not only possible, but it happened:
From Beauford T. Anderson Medal of Honor citation:
I was just watch that Future Weapons show on the Military Channel the other day. Seems like they are working on guided shells for howitzers. The shell is given a set of gps coordinates and then launched out the tube. It then can correct for as much as a 20° deflection to still hit the target within a few meters. The actual challenge up to this point was gettting the onboard electronics to survive the launch.
[QUOTE=RickJay]
(…)
Small rocket weapons don’t serve the same purpose; they’re generally line-pf-sight or close to it, and serve the purpose of destroying specific types of target; bazookas and their precedessor, the panzerfaust, were armor penetration weapons, used to destroy tanks or bunkers.
[/QUOTE]
Uh, two minor nitpicks:
Panzerfaust is not precedessor of bazooka. When G.I. started happily blasting german tanks with bazookas (in 1942), panzerfausts were in early development stage and had to wait until middle 1943 to enter first, small scale production.
Panzerfaust is not rocket weapon. It’s recoilless one.
We have some small errors in previous posts to clear up.
Current US mortars are 60mm (not 61mm), 81mm, and 120mm. The 4.2" (107mm) has been retired. The 120mm is available in a ground mount M120 and mortar carrier M121. The 60mm mortar can be employed in direct fire mode (direct fire = you can see what you are shooting at.)
Blast overpressure is a factor for the 120mm in particular. There is a certain model of the 120mm mortar that is restricted from firing from the mortar carrier but is okay from the ground mount. (less confined space around the open mortar pit.)
US military terminology: Fuse refers to a chemical burning fuse such as time fuse used to set off demolition material via a nonelectric blasting cap. Also appears in some old mortar fuses which have a black powder time train controlling the time of burst or function. Fuze refers to mechanical or electronic fuzes used on projectiles, mines, other munitions.
Most modern fuzes for mortars are multi-optioned. One variety has settings for PD (point detonation) or delay (allows penetration into a structure). Another variety has an opening at the tip allowing wind to drive a turbine generator. The electric charge powers a transmitter/receiver that measures remaining distance to the ground to get an airburst. Effectively spreads shrapnel down into trenches and foxholes from above. This fuze also has the PD and delay function. A standard mechanical time fuze is used for illumination rounds that are dispensed at altitude. This round has a flare suspended from a parachute that illuminates the bad guys. It can be visible light or infra-red.
Current propellant charges are donut shaped with a bite taken out of them, like a big puffy “C”. They come 4 per round and some number is removed depending on range desired. All can be removed and the mortar round launched with just the ignition cartridge (very short range). The body of the propellant charge can be treated felt or nitrocellulose (a propellant itself); both with propellant grains inside. The propellant grains can be spherical or cylindrical in shape. There are some other types of charges as well. The US Army still has a number of older rounds of all types with propellant bags or wafers as propellant charges.
Pvt Ryan indeed did show accurate employment of mortar rounds. The type of fuze had a pull pin for safety that was removed and the slamming down on the base released the other safety in the fuze that depended on setback (the reverse acceleration normally given when the propellant charge function in the base of the tube.) the older type fuze function on impact. The propellant and ignition cartridge did not function because the fins have a small projection at the base that protect the primer/ignition cartridge from functioning in case of an accidental drop.
The 155mm Excaliber projectile is the latest guided example being fielded. The round has both inertial and GPS guidance. The projectile has small fins that deploy after launch for guidance and some gliding capability. The same guidance system is used in the Guided Multiple Launch Rocket System.
Any specific question? I do ammunition for a living for the past 28 years. I’m in Jalalabad, Afghanistan even as we exchange electrons.
Just one Q:
in Pvt. Ryan the mortar rounds were passed to the thrower but I cannot recall any pin-pulling action such as you describe.
Could be that my memory of the film is a bit hazy
And stay safe
It’s a quick action, you could hide it in your hand. On some fuzes; it’s a wire that runs between two pins; just yank the wire and they are out. Happens when I’m inspecting them too if the wire hooks something. Pins are a straight pull, the wire is usually spring steel and it’s shape conforms to the fuze body and keeps the pins in place.
Pvt Ryan probably passed on the wires/pins thing - easier when it’s a movie.
Thanks. I was imagining a pin along the lines of that in a grenade, y’know the ones you yank out with yer teeth
IIRC the Vietcong used them with great effect, particularly during the Tet offensive.
Regarding pins: it depends on the weapon. I’ve fired both 52mm and 60mm mortars; the 60 shells had pins, the 52 shells didn’t.
[QUOTE=RickJay]
bazookas and their precedessor, the panzerfaust
[/QUOTE]
Nitpick: although the development process of both weapons was convoluted, it looks like each made its battlefield debut in 1942, so I’d be hard-pressed to call either a “predecessor.”
Re: the OP…the “rocket’s red glare” you hear sung at sporting events refers to the Congreve rocket, which debuted in 1804, and was origninally inspired by infantry rockets used by the Indian state of Mysore.
Sailboat
[QUOTE=Sailboat]
Nitpick: although the development process of both weapons was convoluted, it looks like each made its battlefield debut in 1942, so I’d be hard-pressed to call either a “predecessor.”
Sailboat
[/QUOTE]
Already nitpicked 
Here’s quick and dirty timeline:
Bottom line:
Bazookas were predecessors of panzerschrecks and panzerfausts were developed independently at around the same time.
[QUOTE=puppygod]
Already nitpicked
[/QUOTE]
Nit noted now. 
I skimmed through the mortar discussion a bit too fast.
Sailboat
[QUOTE=smithsb]
We have some small errors in previous posts to clear up.
Current US mortars are 60mm (not 61mm), 81mm, and 120mm. The 4.2" (107mm) has been retired. The 120mm is available in a ground mount M120 and mortar carrier M121. The 60mm mortar can be employed in direct fire mode (direct fire = you can see what you are shooting at.)
Blast overpressure is a factor for the 120mm in particular. There is a certain model of the 120mm mortar that is restricted from firing from the mortar carrier but is okay from the ground mount. (less confined space around the open mortar pit.)
US military terminology: Fuse refers to a chemical burning fuse such as time fuse used to set off demolition material via a nonelectric blasting cap. Also appears in some old mortar fuses which have a black powder time train controlling the time of burst or function. Fuze refers to mechanical or electronic fuzes used on projectiles, mines, other munitions.
Most modern fuzes for mortars are multi-optioned. One variety has settings for PD (point detonation) or delay (allows penetration into a structure). Another variety has an opening at the tip allowing wind to drive a turbine generator. The electric charge powers a transmitter/receiver that measures remaining distance to the ground to get an airburst. Effectively spreads shrapnel down into trenches and foxholes from above. This fuze also has the PD and delay function. A standard mechanical time fuze is used for illumination rounds that are dispensed at altitude. This round has a flare suspended from a parachute that illuminates the bad guys. It can be visible light or infra-red.
Current propellant charges are donut shaped with a bite taken out of them, like a big puffy “C”. They come 4 per round and some number is removed depending on range desired. All can be removed and the mortar round launched with just the ignition cartridge (very short range). The body of the propellant charge can be treated felt or nitrocellulose (a propellant itself); both with propellant grains inside. The propellant grains can be spherical or cylindrical in shape. There are some other types of charges as well. The US Army still has a number of older rounds of all types with propellant bags or wafers as propellant charges.
Pvt Ryan indeed did show accurate employment of mortar rounds. The type of fuze had a pull pin for safety that was removed and the slamming down on the base released the other safety in the fuze that depended on setback (the reverse acceleration normally given when the propellant charge function in the base of the tube.) the older type fuze function on impact. The propellant and ignition cartridge did not function because the fins have a small projection at the base that protect the primer/ignition cartridge from functioning in case of an accidental drop.
The 155mm Excaliber projectile is the latest guided example being fielded. The round has both inertial and GPS guidance. The projectile has small fins that deploy after launch for guidance and some gliding capability. The same guidance system is used in the Guided Multiple Launch Rocket System.
Any specific question? I do ammunition for a living for the past 28 years. I’m in Jalalabad, Afghanistan even as we exchange electrons.
[/QUOTE]
Thanks!
stay safe.
One question: Circular Error Probable of a mortar round? That is, how accurate are they in practice?
Accuracy? It’s still an indirect fire weapon targeting an area. A lot of factors are now being input to the ballistic computer. Model of round fired, distance, altitude at firing site, difference in altitude between firing site and target, wind, temperature, humidity (runs in to density calculations) - you need a weather station to operate one of these things! Talked to a 120mm crew and they said about 25 meters circular around a pre-surveyed target. With a two-tube section, they’d send two rounds each and wait for feedback from an observer. Best I’ve got for you.
Rounds are prohibited from firing over the heads of friendly troops during training even on highly controlled ranges. Factors like wet propellant, aged propellant, fin breakage, and changing weather still happen along with human error.
The rounds are still requested by supported troops and range adjustments are radioed back to the firing site in many cases. On exception is fire returned on the basis of anti-mortar FireFinder radar. The radar will supply coordinates to return fire at and also can estimate accuracy of returned fire and adjust. Still, to do this, the crews must have an accurate map of surrounding area so not to target near schools, mosques, or other sensitive areas. One story from my last time in Iraq: Incoming fire was traced back to the street outside the town mayor’s home. He was considered friendly to the Americans so no fire was returned. A Bradley patrol in the area caught the bad guys firing from the back of a truck ostensibly hauling garbage.
[QUOTE=KlondikeGeoff]
My question is, now that portable missiles are so prevalent, does the Army still have any use for mortars. Any military Dopers know about this?
[/QUOTE]
Not only does their high trajectory make them great for putting hurt in well shrouded places but it also can make it difficult to pinpoint where they are coming from.
Mini hijack:
I have always been of the opinion that if you wanted a serious weapon for domestic terror, a small/medium mortar concealed in a high sided truck/van would be one of the most effective tools out there. Out of sight, minimal flash and noise at firing end, plenty of bang on the recieving end…