Against All Odds - Nozzleless BP SBR

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Date: 2006-01-12


This little Super Bottle Rocket started out as the boost stage of a BP to Whistle SBR staged pair. I had made two of these conventional nozzled BP SBRs based on an especially hot batch of 6:1:1 BP. Fortunately I had decided to use the second unit as a test for that propellant. It catoed rather spectacularly leaving my ears ringing.

The staged unit was then ignored for fear of a repeat performance and a detonated whistle upper stage just to add to the report. This evening I dismantled the staged rocket and decided to try the boost stage nozzleless. Chipping out the clay with a scalpel was delicate, time consuming work, but eventually the rocket was re-fused with blackmatch and prepared for testing.


Worked great.

Needless to say I had my fingers in my ears, expecting a cato from a grain crack, or a lawn dart. Instead it really performed well, about the same as an conventional BP SBR using my usual propellant.

It seemed to take slightly longer to come up to pressure, as can be seen in the animated gif above, but once accelerating it left the frame faster than usual.


title type size
Test Video video/x-msvideo 1.260 Mbytes
Its Twin CATO Video video/x-msvideo 1.215 Mbytes
Pre-Dismantlement Picture image/jpeg 33.079 kbytes
CATO Frame image/jpeg 6.452 kbytes