Mortar Rack Design
#16
Posted 15 May 2009 - 07:03 PM
I have seen pics of steel racks with a matrix of tubes supported, but usually for larger tubes where weight of timber is greater, I've never seen a real one though.
Keep mannequins and watermelons away from fireworks..they always get hurt..
#17 Guest_PyroPDC_*
Posted 21 May 2009 - 09:42 PM
from what i read a gap of 1/2 the diameter of the mortar showed it was 90% less chance to damaging other mortars around it in a mortar failure) but is this just being to safe.
should i leave a gap or not (im not one for saving money over safety but iv seen so many mortar designs without any gap it cant be that bad.)
#18
Posted 21 May 2009 - 10:34 PM
Keep mannequins and watermelons away from fireworks..they always get hurt..
#19
Posted 22 May 2009 - 07:58 AM
however
- isn't that what should be paramount in a mortar rack design?but is this just being to safe.
Edited by Starsky72, 22 May 2009 - 08:00 AM.
#20
Posted 22 May 2009 - 08:27 AM
thegreenman
#21
Posted 22 May 2009 - 12:05 PM
#22
Posted 22 May 2009 - 06:17 PM
We did extensive testing on our racks where the glass fibre tubes touch each other.
In a 6" rack, the tube with a shell in upside down would destroy the tube, and neighbouring tube, which in turn damaged the next tube, and so on... resulting in the whole rack failing almost instantly.
No shells, no danger...
In this situation us moving the tubes further apart would actually increase the danger, so there is a point between whereby damage can be done without damaging the shell enough to explode in the tube. Past this point the rack becomes safe again.
If I had the option - I'd rather all my shells explode together in a failure... to remove further risk.
We also found that our steel racks can take the force of all 8 6" tubes exploding, you could even use the rack again if you really had to, but of course you wouldn't.
Mat
www.mlepyro.co.uk www.firebywire.co.uk
#23
Posted 22 May 2009 - 07:59 PM
#24
Posted 22 May 2009 - 08:26 PM
#25 Guest_PyroPDC_*
Posted 23 May 2009 - 03:45 PM
i think if i was making the rack out of wood, I would definitely space them. But as Steel i think i could get away with it as mat says its better off damaging all off in one go including the shell I suppose if i was really worried i could just make smaller racks so instead of 4x4 mortars with spaces I could do 3x3 mortars without spaces that way worse case only 9 would go off in one go.
Edited by PyroPDC, 23 May 2009 - 03:46 PM.
#26
Posted 23 May 2009 - 03:57 PM
I have assisted with shows at a nice venue where the firing site is a 100 yard walk through a single personnel gate. The hand cart just goes through, then you can pass the load through.
If you build racks bigger than you can lift with one hand, then you need power tools on the firing site. If you make big steel racks then you may need truck access and possibly a hiab.
If you are firing off big concrete flats like docksides big things and cranes are part of the job. If you are across the lawns at a nice hotel and they don't let the truck round then with big racks you are stuck.
Keep mannequins and watermelons away from fireworks..they always get hurt..
#27
Posted 24 May 2009 - 10:24 AM
Metal racks are more convenient than wooden ones in my opinion. In terms of carrying them, it requires 2 people to carry any of our metal racks - but would take a minimum of 2 trips to carry the same number tubes in wooden versions.
Some disadvantages of metal racks...
1) heavy
2) you can hurt yourself with them if you trap your hands when stacking without gloves on
3) very expensive compared to wood
Mat
www.mlepyro.co.uk www.firebywire.co.uk
#28
Posted 24 May 2009 - 12:37 PM
#29
Posted 24 May 2009 - 05:07 PM
There is also something nice about them being heavy... in that they gain support from being able to freestand (not that I'd encourage that!).
Mat
www.mlepyro.co.uk www.firebywire.co.uk
#30
Posted 24 May 2009 - 06:24 PM
Is there a sketch or picture of the steel racks available in public webspace? The one design I've seen was like a milk crate but 6ft x 6ft x 4ft high. It had about 80 - 100 tubes inside and was a challenge to assemble form barely luggable parts.
Keep mannequins and watermelons away from fireworks..they always get hurt..
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