Abstract: The invention provides for a drill unit for drilling and charge laying operations and is suitable for operation on land or underwater. The drill unit comprises a rock drill mounted on a frame structure on a gantry and drill steels and casing members located in a drill magazine where they can be moved into register with the drilling machine for drilling a hole below the gantry, the casing member being put down the hole to line it and a charge magazine containing explosive cartridges also mounted on the gantry provided with means for bringing a cartridge into register with a casing member put down a hole to charge the casing member. The operation being remotely controlled.