Wrong mortar or no mortar

[displayfireworks1]

I am trying to figure this one out. Is it the wrong mortar or no mortar?

http://www.youtube.com/watch?v=qn-JD8Cz0sA

[NOLApyro]

This looks like the wrong size mortar was used. If a mortar wasn't used at all it would've burst on the ground. That wasn't the case here, it looks like it burst about 10 feet (maybe more) above the ground.

[ClassCBexy]

Looks like the mortar might not have been sitting all the way at the bottom of the tube.

[tarkus4]

Also there is the possibility of not enough black powder in the lift cup.

[PyroJoeNEPA]

From the small break of the shell I would say it is definitely a 1.4g consumer shell. With that in mind, there are 1.25" & 1.5" consumer ball shells out there that need their own mortar tubes to launch properly. Drop one of those in a 1.75" tube & you have a very low lift like the video showed--if it even gets out of the pipe.... Also, it could have been damp lift powder--maybe rain in the gun & not dried out -- or it may have lost some of the lift powder like Tarkus said. lots of possibilities why it didn't go up.

[PuroJon]

Tube too small. Notice the spinning on launch?

[PGH_Pyro]

on a show i worked on this past summer, we had a 4" salute do that real close to the guy who was hand-lighting the rack it was in. i was 2 racks over and felt it like a punch on my chest . eek . low breaks are no fun .

[mguerra]

I had a low break like that once and every star started a small fire. I ran so hard and fast putting them out it nearly killed me. It could have set the whole county on fire. Scared the living sh.. out of me. Since then I have a new policy. I do a grass fire test before any shoot. I go out to the driest biggest clump of grass around and hit it with a MAPP torch. If it catches on fire, I don't shoot. Needless to say I have water or a fire extinguisher with me when I do the test.

[Engalwood]

Yeup what I was going to say. Tube to small

[Playingwithfire85]

The would be too large for the shell. If you look at the gas cloud above the tube there is no force built up to increase velocity almost like there was too much blowby. The spinning of the shell is likely due to the fact consumer ball shells are lopsided because of the lift tube. If the tube were too small the lift charge would have made a larger explosion and possible flowerpot rather than low break.