Length of 3 inch mortar

[displayfireworks1]

Can someone help me answer this question I received.
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Hi Dave, What length mortar tube would you recommend for 3 inch shells. I see 15, 18, 20 and 24 inch lengths

[Bigjohnson]

18 seems to be the industry standard and is what I have

[djsmurf]

The ones I have are 450mm or 17.71" so I agree with 18"

[Bigjohnson]

Most the 1.3 suppliers I've looked at sell the tubes in 18" length as well

[PyroJoeNEPA]

General rule of thumb for ball shells is 6 x the diameter of the shell, so a 3" is 18", 4" is 24", 5" is 30", etc.
The exception you may see is using tubes longer than the 3X rule for multibreak cylinder shells...at least here in the USA. In Italy & Malta some of those 5" 10 break shells are about the same length as the mortar tubes!!!

[displayfireworks1]

PyroJoe, that is great information to pass along. Something similar and not that it is an industry standard . I always remembered the number 10 from the Zambelli racks. The mortar size plus the number of mortars per rack would equal 10. It seemed to work pretty well, designed like that. Example 4 inch mortars are 6 mortars per rack. 5 inch mortars are 5 per rack and 6 inch mortars are 4 per rack. 4+6 , 5+5 or 6+4 all equal 10. In the middle of a display or possible reload during a display, I always kept this in mind as a quick way to identify the size of the product.
I have to admit now that I have been around to different display companies, there are some real odd built racks out there. Maybe it is just me, but I always thought the Zambelli racks were a good design for setup, lifting, loading , finale etc. A display company needs this consistency to match up the electrical rails and choreography software.
Can anyone else comment about a variation on the size and number of mortars they are seeing out there?

[Bigjohnson]

I'm building my 3" racks with 10 mortars and 4" with 6. Most the 3" racks I see are 10 but I have seen some finally chains that are 12 shells. Which wouldn't go good with 10 shot racks

[displayfireworks1]

I never really understood the three inch racks that were twelve instead of ten. It has to be confusing counting out say a 280 or 300 shot finale. When unloading the truck, ex. Hey Joe how big is the finale, 300 shot. How many racks should I unload? I don't know let me get my phone calculator. LOL
There are all these presumptive theories out there, that state something along the lines of the longer the mortar the higher the shell goes. You hear this particularly with consumer artillery shells. I never known anyone to demonstrate and/or prove any of it.

[PyroJoeNEPA]

There are all these presumptive theories out there, that state something along the lines of the longer the mortar the higher the shell goes. You hear this particularly with consumer artillery shells. I never known anyone to demonstrate and/or prove any of it.
There has been lots of speculation and "hype" about this over the years. No one has ever-to the best of my knowledge-been able to supply any verifiable data that the tube length increases the height in any way. There is a difference when you are shooting a mine, though, Shorter tubes [I am talking 6"-8" ] will give you a wide fan compared to using a 12" tube....this has been documented.

The Zambelli "10 count" does make a lot of sense & I see the benefit of it. It might not be a standard with companies here in the states, but it should be!
I shot several shows with a company over the last few years [whom I won't name] that has 2 1/2" finale racks with 24 tubes in each rack!!!! Talk about a hard to manage rack! Their logic is 24 tubes x 3 racks = 72 shells---the shells they use are packed 72 in a case..

[displayfireworks1]

I guess the question is, is there an industry standard? There is none that I know of. I wish I could remember all the details , back in the 90's Zambelli had these Pyro-Magic rails that may have been 28 count , then when FireOne came along continuing to make use of the existing PyroMagic pin board rails it caused some weird error on the FireOne software that you had to be aware of. FireOne may have been designed for 25 shot rails. I may be wrong on these numbers. When pyro-musicals were setup on a pinboard Zambelli also had a rack I though was a good design. Five mortars in the rack, setup as 4-5-6-5-4 . I liked those also. I have a weird custom made rack I rarely use, it is combination of 3-4-5-6. But you have to reload when using it. I have a setup video where I detail how the Zambelli racks and rails are setup to accommodate the PyroMagic rails and E-matching using a PyroMagic firing system. Once you see it laid out you can see how the design came to be.
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Here is the video from 2008. Wow that seem so long ago. LOL
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https://www.youtube.com/watch?v=R6xSfwX1Qy4

[jknepp1954]

I think ours was 3" 24" tubes. and the 4" same - 10 per rack. Yes the 4" were heavy SOBs!

[jr99svt]

NFPA 1123 Table A 4.3.8
Mortar ID Single Break Two Break Up To Four Break

3" Mortar 15" 18" 21"
4" Mortar 20" 23" 27"
5" Mortar 24" 28" 32"
6" Mortar 28" 32" 37"
8" Mortar 34" 40" 46"

[Melp]

Most of the racks that I built were 18 in guns. One of the companies that I shoot for all the 3" and 4" tubes are 24" tall. I now know why, with the length of the fuse on the shorter tubes you have to bend over a lot lower to lite the fuse if your hand firing. After 500 shells thats a lot of bending over.I know that some one will say you can't bend over a little further!!!!!