Abstract: A method of preparing a gassed water-in-oil emulsion explosives composition from a gasser solution of an inorganic nitrate, an ammonium species and an optional accelerator which is added to an emulsion explosive composition, reacts and forms gas bubbles is disclosed. The emulsion explosive composition is composed of a discontinuous aqueous phase, a continuous water immiscible organic phase, and an emulsifier. The reaction between the gasser solution and the emulsion explosive composition is such that the emulsifier does not undergo chemical attack.

Abstract: A method of preparing a gassed water-in-oil emulsion explosives composition from a gasser solution of an inorganic nitrate, an ammonium species and an optional accelerator which is added to an emulsion explosive composition, reacts and forms gas bubbles is disclosed. The emulsion explosive composition is composed of a discontinuous aqueous phase, a continuous water immiscible organic phase, and an emulsifier. The reaction between the gasser solution and the emulsion explosive composition is such that the emulsifier does not undergo chemical attack.

Abstract: A boring machine having a cutter head rotatably mounted on a hydrostatic bearing. High pressure water is supplied to passageways between confronting bearing surfaces which react axial and radial loads and which are capable of relative rotational movement. The flow of pressurized water discharges from the passageways to prevent contamination of the bearing by the ingress of material removed by the cutter head in operation.