Vaccume in the atmosphere and mortars

[flamingknives]

Originally posted by Wartgamer:

The impact velocity is greater than the launch velocity? Me thinks not.

GAAAAA! Good point.

Damn Excel and it's stupid erratic fill-down protocols!

*scurries off to fix it*

[flamingknives]

Spread sheet fixed.

Impact @58m/s, angle 85 degrees

Another object point on why you should check your answers, bought to you by flamingknives Inc.

[Wartgamer]

In any case, minimum range would be using the least propellant (cartridge only) and highest angle possible.

I have read +85 is the greatest angle. Thats about 91 meters or 98 yards or so (neglecting air resistance). You could probably take off 6% of that so around 90 yards.

[flamingknives]

Or 70m, which coincides with the officially stated minimum range. The launch angle is 85 degrees.

[Wartgamer]

http://www.stripes.com/ww2/stories/mortars.html

An interesting site. Detailed use of 81mm in combat.

In Holland, the platoon in several instances proved itself adept in using the 81-mm. mortar without base plate or bipod. That means firing without use of a sight and the gunner has got to be able to see his target. "My men have gotten on the target in two rounds at 200 yards," reports Lt. Cooper.

A gunner carrying a tube and two ammo carriers frequently went out with patrols and often the mortar was fired in this manner in close support of a company. "It's advisable to fire with no added increments when not using a base plate and biped because, if the charge is too great, your tube might sink in the ground," cautions Sgt. Woltz.

[SgtMuhammed]

The original quote is something I used to run into alot in the Army. Some new Lt. comes in with something that he read and didn't fully understand and proceeds to tell us all how it "really" is. I used to hang out with the 11C's (mortarmen) in my company and they stated quite explicitly that they could basically drop rounds on their own position, well at least danger close.

[flamingknives]

That sort of attitude isn't just related to the Army. People with zero real-world experience decide, on the basis of a possibly flawed calculation, that they know best.

Conversely, sometimes the upstarts are right, but the entrenched, 'way we've always done things' will never concede that it could be done any other way.

[Wartgamer]

Mortars can, and will, pound the baseplate into the ground. Especially large mortars or mortars firing with large charges. That is why you must watch the level bubble so that fire does not 'back-up'.

[Michael Emrys]

Originally posted by flamingknives:

That sort of attitude isn't just related to the Army. People with zero real-world experience decide, on the basis of a possibly flawed calculation, that they know best.

Conversely, sometimes the upstarts are right, but the entrenched, 'way we've always done things' will never concede that it could be done any other way.

I think what you are saying is that idiots come in all flavors. If so, it conforms to my own experience.

Michael

[flamingknives]

ISTR something about mortars skating backwards on hard ground sometimes causing the muzzle to drop below the level of the foxhole parapet.

[Michael Emrys]

Originally posted by flamingknives:

ISTR something about mortars skating backwards on hard ground sometimes causing the muzzle to drop below the level of the foxhole parapet.

Yike! That wouldn't be at all funny for a crew who failed to observe the change and make adjustment.

:eek:

Michael

[JonS]

Ballistics, vacuums, et al: http://armyapp.dnd.ca/ael/publications_ns.asp?series=370_e and in particular "371-006 - Ballistics and Ammunition". But it's from those odd Canadians, so they've probably got special factors for Maple Syrup viscosity and the number of beavers per sq meter. Or sumfink.

Strangely enough, it has this to say about blast:

3. Blast. Blast is the shock caused by the detonation of the HE filling and is accompanied by a flash and flame. The effects of both are very localized and if damage by either is to be expected a direct hit must be achieved. Blast can be effective if the projectile penetrates the surface before detonation, because the blast, being largely contained, causes a disruptive action. Such features are useful when engaging buildings or fortifications or when a cratering effect is required. Blast is effective against personnel at relatively short distances, whereas fragments (fragmentation) may travel great distances and cause casualties.

I guess they, too, can't have heard about all the magical-mystery properties of blast. Silly sods.

[ May 02, 2005, 02:19 PM: Message edited by: JonS ]

[Wartgamer]

Stranger still; what has that got to do with the thread?

[JonS]

As the master of the non-sequitur, I'm sure you know very well.

Then again if you'd, you know, read it before foaming at the mouth I'm sure that even you could figure out the relevance of the document. But never mind, you were probably confused by the link to the original document. It's a strange new fad you might want to emulate.

[ May 02, 2005, 04:56 PM: Message edited by: JonS ]

[Wartgamer]

yes I read your remark about blast. It has nothing to do with the thread.

[Wartgamer]

http://www.army.forces.gc.ca/ael/pubs/300-007/B-GL-371/006/FP-001/B-GL-371-006-FP-001.pdf

This is probably the link he wanted to post. It is also, like his inane blast remark, not that relevant to the discussion on mortars.