The Journal of Explosives Engineering - July/August 2022 - 31

High-pressure gas (up to 140,000 psi) is generated in a
deflagration process. The cartridges are typically oxygenbalanced
and do not produce significant quantities of toxic
fumes if initiated within a well- stemmed borehole. They are
available in weights from 3 g to over 1 kg and diameters from
9 mm to 90 mm, depending on brand and include electric
or NONEL initiators. The NXBurst products from NXCO Mining
tested ranged from 10-60 g and were cable of breaking
very large boulders and even in-situ rock. In the US, they are
classed as class 1.4S material and can be stored in a simple
type 4 magazine. They do not represent a significant hazard
when not confined in a borehole.
Investigation
In order to develop this idea into a real capability, several
questions needed to be answered about these technologies.
We interviewed professionals in the quarrying and trail building
professions, solicited samples of the materials and tools
involved and performed hands-on testing. The goal was to
determine if the methods outlined would actually be useful to
a rescue team. The study methods used were as follows:
1. Using manufacturers' catalogs and datasheets, we identified
tools and drill bit sizes available in the US commercial
trade that would be useful for portable rock breaking.
2. We performed field tests to determine if suitable blast
holes could be drilled by rescuers using only cordless
equipment. Test drilling took place using brushless SDS+
and SDS MAX drills and fully- charged Lithium Ion battery
packs.
A series of holes were drilled, with drill bits cooled off
after each 45 cm/18 inch of progress. Drilling continued
until a drill battery pack was no longer capable of powering
the drill. Both hard and medium rock types were
tested. Drill test results are summarized in table 1.
3. Using interviews and data supplied by manufacturers, we
determined that 1.4S products ranging in size from 1060
g would be best suited for rescue applications and we
procured samples for testing.
4. A variety of high explosive shaped charge configurations
from 100-400 g were tested for their potential to break
boulders or create holes into in-situ rock. Orica Powerditch
1000 dynamite was used.
5. Rock splitting with 50grain/foot (10.2g/m) PETN detonating
cord and small diameter holes was tested as a rescue
blasting technique.
6. Qualitative results and simple " rules of thumb " models
uncovered during testing were documented and prepared
as findings.
7. The micro-blaster and full-size 1.4S cartridges were safety-tested
by initiating them in open air to determine if
they represent a significant storage/transport hazard. All
products were initiated using a BTS-50 Handi-Blaster machine.
Bulk
Emulsion Manufacturing Unit
FRANCE - Zac des Sorbiers - 2 rue Joseph Cugnot 41350 Vineuil
+33 (0)2 54 42 90 30 I www.transmanut.com
Bulk Emulsion Manufacturing Unit
Mobile Explosives Manufacturing Unit
Mobile Explosives
Manufacturing Unit
Mobile Explosives Manufacturing Unit
Mobile Explosives Manufacturing Unit
Bulk Emulsion
Bulk Emulsion Manufacturing Unit
Manufacturing Unit
Bulk Emulsion Manufacturing Unit
Mobile Explosives Manufacturing Unit
July/August 2022
The Journal of Explosives Engineering
31
M
A
D
E
I
R
N
F
A
N
C
E
http://www.transmanut.com
The Journal of Explosives Engineering - July/August 2022

Table of Contents for the Digital Edition of The Journal of Explosives Engineering - July/August 2022
