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Setting mortar angle


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#1 Merlin

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Posted 10 July 2019 - 01:03 PM

I bury my mortars just to be safe. That said is there a rule or procedure to get the right angle? Year before last they were low but this year they were too vertical. Not good though I never have had a failure to burst. This time I had an angle but they went too vertical. Most of the end disc were in front of the firing area but that may have been wind. There was no noticeable wind that night on the ground. Just wondering how angles are set These were all cylinders. If there is no way prescribed to set mortar angle I suppose next time it will require firing dummy shells the day before. Thanks

#2 BetICouldMake1

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Posted 10 July 2019 - 04:26 PM

For the most part I think mortars are just set up vertically unless you are trying to angle them away from a hazard or the audience, or trying to shoot your shells out over something, like a lake. Are you talking about setting angles for creating a fan effect?



#3 pyrokid

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Posted 10 July 2019 - 10:04 PM

Standard spectator distances specified in code of law in the U.S. (70' per inch of shell Dia.) pertain to mortars fired vertically. Mortars are allowed to be angled away from the audience if adequate setback distances are available, and this allows for larger shells to be fired. A "safe" shoot site is one that prevents spectators from coming into contact with ANY hazardous debris. Keep in mind that spin imparted to shells can significantly affect their trajectory. In my opinion, angling of mortars isn't required under normal circumstances. Merlin, where are you coming from with this?

#4 Merlin

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Posted 11 July 2019 - 10:33 AM

Ok fair question. You fire a shell weighing 900 grams. It fails for some reason to explode so you have a returning object with enough velocity and mass to kill you. Just seems to me mortars should be fired at an angle to ensure the rte doesnt kill the person firing the shell. The safe distance radius refers to debris from an exploding shell not an unexploded shell returning. Correct me if my concern is unwarranted but I thought mortars should be fired so that a dud would fall in a safe area. If it is fired vertically it would fall back into the firing area. I have fire cylinder and round shells. The cylinders seem relatively predictable but round shells seem to fly in the direction of the spin imparted by the smooth bore of the mortar.
Anyway I was very conscious that since my shells were going vertical in the event of failure to explode I would have a few seconds to take cover. It seems that the mortar should be set so the shell travels away from the firing area and attain an altitude of 100 feet per inch of shell diameter plus an additional 100 feet meaning the lift charge would be sufficient to attain proper altitude plus some horizontal travel. Just seems to me everyone should be in a safe zone. Maybe duds are unheard of- Ive never had one but there must be a reason that mortar racks are angled. I dont use racks but I bury the mortars but I still think they should be angled or aimed so an unexploded shell falls away from anything or anyone.

Edited by Merlin, 11 July 2019 - 10:50 AM.


#5 jakespeed

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Posted 11 July 2019 - 12:05 PM

i screw my mortars to a wood platform with a 10 degree angle & point it away from me.  10 degrees has always kept shells safely away from me.  have never fired in heavy wind.



#6 Merlin

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Posted 11 July 2019 - 01:53 PM

Sounds reasonable Jakespeed. The wind just determines where the debris like paper and end disks fall. I just feel anything 4 or more is best buried. Ill just have to fire a couple test shells to get the angle. A couple years back I had a married crossette blow in the tube 1.75 and it split the tube and blew 2 halves 75 feet in two directions. Yes a PE black tube. The crossette contained 70:30 of course and though I use Spanish 5:3:2 in cylinders its much more- thats the reason I use a PHD. Post hole digger in case of flower pot.

Edited by Merlin, 11 July 2019 - 01:59 PM.


#7 Arthur

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Posted 13 July 2019 - 01:15 AM

In the UK hand firing of shells is now considered sub standard except for really small ones (2" and 3") most shells are electrically fired. For a small show mainly of cakes then a small wireless control unit may be used to launch a final volley of shells. We do use fan racks to make fan angles look right so some racks may contain 5 upright tubes and a rack the same size may contain two or three tubes at preset and fixed fan angles. We also have a couple of makers of rack systems where whole racks can be angled in a rigid frame. 






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