A water cartridge for stemming shotholes in coal or rock. The ampul consists of
a plastic (polyvinylchloride) bag, 1-1/4 in (3.2 cm) in diameter and 18 in
(45.7 cm) in length. When filled with water and the neck of the bag tied off,
the filled ampul is about 15 in (38.1 cm) in length and holds slightly over 1/2
pint (0.24 L) of water. Compared with dry clay or sand, the use of water ampuls
for stemming effects substantial reductions in both the airborne dust and the
nitrous fumes produced by shot firing. This applies to both coal and rock
blasting. Also called a water dummy. Syn: cushion
firing
Source:
Dictionary of Mining, Mineral, and Related Terms