Dependent and Independent HolesWhere hole B requires hole A to have fired to provide the necessary relief then hole B is dependent on Hole A.
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Detonating CordA flexible cord with a solid core of high explosives, commonly PETN.
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detonating cord union |
DetonationA shockwave driven reaction at a velocity great than the speed of sound in the medium.
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DetonatorA detonator is a device used to trigger an explosive device. Detonators can be chemically, mechanically, or electrically initiated, the latter two being the most common. The commercial use of explosives uses non-electric or electric detonators. Many detonators' primary explosive is a material called Lead Azide pressed into place above the base charge, usually PETN. Delay detonators have a pyrotechnic delay train above the primary charge. This provides a time delay between the firing of the downline and the detonation of the base charge.
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Detonator (or cap) SensitiveA term applied to any explosive which can be reliably initiated in the unconfined state by a number 8 detonator. |
Dewatered HoleA blast hole which has had water removed using an in-hole pump or other mechanical means.
Typical dewatering truck fitted with submersible pump. |
Direct SupervisionDirect supervision is a term that is used to refer to situations in which a supervisor is present at all times. The supervisor oversees activities as they occur and provides constant direction, feedback, and assistance. For some types of workplaces, direct supervision is required for safety and health reasons.
A test for direct supervision is that the supervisor is constantly aware of what the supervised person is doing and is able to immediately communicate direction (such as Stop That Now!!) |
Direction of MovementThe preferred direction in which the blasted rock mass moves under influence of the blast – at right angles to the ‘angle of initiation’. |
Dislocation FailureA form of misfire in which some explosive is left undetonated as a result of an adjacent explosion, eg. separation of charge by ground movement or severance of the initiating line. |





