R. Meyer J. Köhler A. Homburg Explosives

Stemming
Stemming
Besatz; bourrage
In mining, “stemming” refers to the inert material used to plug up a
borehole into which the explosive charge has been loaded. The “classical”
stemming materials are mud or clay noodles. Stemming brings
about more economical utilization of the explosive charge, provided
the explosive columns employed are short and the detonation is
effected at the mouth of the borehole. Stemming is mandatory if there
is any danger of firedamp. The strongest stemming is not necessarily
the best; if the stemming is too strong, deflagration may take place. In
coal mining water stemming cartridges proved to be the best; they are
plastic tubes filled with water or water gel and closed at both ends,
which are easily inserted into the borehole, do not stem too strongly,
and make a significant contribution to the settling of dust and fumes.
W also Confinement.
Storage
Lagerung; magasinage
The safe keeping of explosive materials, usually in specially designed
structures called Magazines.
Stray Current Protection
Streustromsicherheit; protection contre les courants vagabonds
The increasingly large consumption of electric current has resulted in
intensified stray currents. The stray current safety of an electric primer
is the maximum current intensity at which the glowing wire just fails to
attain the ignition temperature of the charge in the primer. To improve
protection against stray currents, the “A” bridgewire detonators, which
were formerly used in Germany have now been replaced by the less
sensitive “U” detonators (W Bridgewire Detonators).
Strength
296
Arbeitsvermögen; force
Also W Bulk Strength, Weight Strength.
The performance potential of an explosive cannot be described by a
single parameter. It is determined by the amount of gas liberated per
unit weight, the energy evolved in the process (W Heat of Explosion),
and by the propagation rate of the explosive (detonation velocity
W Detonation). If an explosive is to be detonated in a borehole, the