nesc39 Posted June 11, 2013 Posted June 11, 2013 I was just reading Shimzu FAST and I came across this sensitivity table of different burst charges. I'm interested in 3-4 inch shells and the consensus is that bp isn't going to break the shell hard enough. I've looked at the different options such as KP, h3 or using a booster like whistle or slow flash and they all make me nervous. I want nothing to do with whistle/flash so while looking at this table for the least sensitive, "safest" composition I was totally confused. If you look at table 1, it is a 2kg hammer drop test. Column "h" is the maximum height without explosion and column "n" is the number of times hammer was dropped at that height (at bottom of the page it describes method). So here is the confusion, looking under KP you will see heights ranging from 62cm to 25cm. So what the table is saying is that 10 times the hammer fell from 62cm and didn't explode? So when did it explode? 63? Then they went to 25cm and dropped it 10 times, did it explode then? Wouldnt you just start low and keep raising the height unril tou got a reaction and then record that height? ........ Idk I'm so confused. By looking at this chart what would everyone suggest is the least sensitive composition? KP, BP or No5
leedrill Posted June 11, 2013 Posted June 11, 2013 (edited) what i asked myself when reading that table was {as stated the first line shows the % of an oxidiser . e.g. 30% means 30% oxidiser 70% fuel and { * } means higher than 130cm and could not be determined it seems to me from the graph that on one of the runs all the oxidiser where tested by themselves with no fuel. i.e. 100% would mean 100% oxidiser with no fuel and all bar kno3 seem to be determined at 100% this confuses me also Edited June 11, 2013 by leedrill
nesc39 Posted June 11, 2013 Author Posted June 11, 2013 Leeds you just lost me.... There isn't anything that mentions the percent of oxidizer. What the table is showing at the top when it mentions "chlorate" is that H3 is a chlorate based comp. When it says perchlorate they are referring to KP being perchlorate based etc. On the left where it says not mixed with any other material they just mean that they tested the H3 by itself then they testes KP by itself etc. After they did those tests they next did tests with an extra 10% "s" (sulphur) added to the original comp and or whatever else it says. I assume they were trying to make the different comps more sensitive when they started adding the extras.
Mumbles Posted June 11, 2013 Posted June 11, 2013 Leedrill, there is a different table around where they are discussing bursts, where they do drop hammer tests. The one you're thinking of is the table of oxidizer with different levels of sensitizers. I know what table you're talking about nesc39, and it always confused me. Most of the heights he gives are maximum heights that give no ignition. Unless he is just showing all the tests they did, it confuses me too.
leedrill Posted June 12, 2013 Posted June 12, 2013 Ahh having a look through the book again I see which one you are talking about but still the question still stands for the other table did he test perc 100% with nothing else and get it to go off with a hammer test ?
nesc39 Posted June 12, 2013 Author Posted June 12, 2013 I must have screwed up my post because I actually included a picture of the table in talking about but obviously no one else is seeing it. I posted from my phone so I thought it worked, I'll check from my home computer later and fix it, thanks
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