ABSTRACT
Underwater or submarine blastings are used for various types of labor such as the deepening of harbors and channels, the excavation of trenches for the installation of oil and gas pipelines and communication cables, excavation for foundations in civil engineering, and exploitation of consolidated deposits. Underwater rock fragmentation can be performed with or without blastholes. In the first instance, the main inconveniences are: little information of the rock mass and lack of topographical precision; difficulty in maintaining the holes open for a length of time; and difficult control of collaring and blasthole deviation. Within the group, the principal operation methods are: drilling and blasting through rockfill; and drilling and blasting with divers. The initiation of each cord is done from the outside by placing an electric detonator after the drilling and charging of the whole round and always after removing the drilling pontoons.
