SoonerKid
October 7th, 2005, 08:08 AM
Table from the 1123 nfpa:
27
27
View Full Version : Minimum distances from tubes to spectators!
JoeRatman
October 7th, 2005, 08:46 AM
Very useful table, but I wish the text was a bit bigger. It is hard for my old eyes to read.
;)
;)
SoonerKid
October 7th, 2005, 09:19 AM
There you go Joe!
Tennespeedy
April 10th, 2006, 08:39 PM
We get 150-200 ft away from spectators. Estimated the better 2" shells were going 135+ feet in the air. That was in the cold winter though. I think a little less in the heat of summer?? I like 200 feet myself.
pyrocasto
April 10th, 2006, 09:39 PM
We get 150-200 ft away from spectators. Estimated the better 2" shells were going 135+ feet in the air. That was in the cold winter though. I think a little less in the heat of summer?? I like 200 feet myself.
Why? I thought cold air was more dense therefore more air resistance.:redface:
Why? I thought cold air was more dense therefore more air resistance.:redface:
MNPyro
April 11th, 2006, 12:49 AM
Depending on where you are you can argue over different factors of the air.
For instance in a highly humid environment, you could say that the water in the air provides resistance to shells as well, in which case, the cold air would give you less resistance in comparison as it is not as "water heavy".
And so to say, the desert, being dry and hot, would provide least amount of resistance in terms of "air quality".
But, for how small the shells are (at least for class C) I don't think the cold nor the humid weather is going to affect the height of a shells projectory. I think it would have to be raining quite hard for it to influence it much at all.
MNPyro
For instance in a highly humid environment, you could say that the water in the air provides resistance to shells as well, in which case, the cold air would give you less resistance in comparison as it is not as "water heavy".
And so to say, the desert, being dry and hot, would provide least amount of resistance in terms of "air quality".
But, for how small the shells are (at least for class C) I don't think the cold nor the humid weather is going to affect the height of a shells projectory. I think it would have to be raining quite hard for it to influence it much at all.
MNPyro
DennyMo
April 11th, 2006, 04:24 AM
I'm not sure what the columns for Vertical Mortars and Angled Mortars are supposed to be telling me. Interpretation, please?
pyroholic
April 11th, 2006, 04:36 AM
Hi Guys; Are the tables above for class 'C' cakes as well as mortars. "PH"
MNPyro
April 11th, 2006, 05:05 AM
Hi Guys; Are the tables above for class 'C' cakes as well as mortars. "PH"
Technically, yes, as the >1" would be for smaller cakes and so on.
So if you have a 9 shot cake, has probably 1.5"-2" "shells" then you would give it the minimum distance accordingly.
Generally, I think, most cakes have smaller shells than regular packages shells, so you can put them ahead of your racks of shells several feet.
Really all you have to do is measure the I.D. of the biggest tube in the cake, and set it the appropriate distance according to NFPA 1123.
MNPyro
Technically, yes, as the >1" would be for smaller cakes and so on.
So if you have a 9 shot cake, has probably 1.5"-2" "shells" then you would give it the minimum distance accordingly.
Generally, I think, most cakes have smaller shells than regular packages shells, so you can put them ahead of your racks of shells several feet.
Really all you have to do is measure the I.D. of the biggest tube in the cake, and set it the appropriate distance according to NFPA 1123.
MNPyro
carp
April 11th, 2006, 05:18 AM
What edition of 1123 is that from. Appears to say DRAFT.
carp
April 11th, 2006, 05:34 AM
I'm not sure what the columns for Vertical Mortars and Angled Mortars are supposed to be telling me. Interpretation, please?
Vertical mortars column is the location of the mortars within the site. So for 2" the mortars are at the center of the display site if 2" is the biggest shell.
Angled Mortars is the position of the mortars from the main spectator area when mortars are angled to compensate for wind and to direct fallout away from the spectators. The minimum is 1/6 the radius and the max is 1/3 from the center of the site.
Mortars to special hazards. Form some hazards like buildings within the display area, this is the minimum distance that that shell size has to be from the hazard.
For health and correctional facilities double the distances in the table.
Vertical mortars column is the location of the mortars within the site. So for 2" the mortars are at the center of the display site if 2" is the biggest shell.
Angled Mortars is the position of the mortars from the main spectator area when mortars are angled to compensate for wind and to direct fallout away from the spectators. The minimum is 1/6 the radius and the max is 1/3 from the center of the site.
Mortars to special hazards. Form some hazards like buildings within the display area, this is the minimum distance that that shell size has to be from the hazard.
For health and correctional facilities double the distances in the table.
jman
April 11th, 2006, 08:59 AM
Keep in mind guys that the table above is based on a still night. IF there is any wind at all, it has to be taken into consideration, how strong, which direction and so on. In 1.3g shows, wind can make the difference between firing the show or shutting her down. Same considerations should be taken with 1.4g. The last thing any of us want it to start firing and have lots of debris falling on the spectators. No fun and someone could get hurt. Please consider wind and weather when calculating fall-out areas. And dont be afraid to re-locate your audience or just hold off all together until conditions allow you to proceed. Better safe than sorry.
JoeRatman
April 11th, 2006, 07:45 PM
I am on a trip, so I can't consult my NFPA 1123, but there is a 125' minimum distance of separation for multishot cakes, roman candles, etc. as long as the I.D. of the biggest tube of the device does not exceed 2". In that case you then have to use the 70' per inch I.D. rule.
You also have to 125' for large wheels and saxons.
Its 75' for other ground devices (fountains, I presume, I wish I had my 1123 with me now).
You also have to 125' for large wheels and saxons.
Its 75' for other ground devices (fountains, I presume, I wish I had my 1123 with me now).
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