Wegener also noted that the continents move up and down to maintain equilibrium in a process called isostasy. As an example he cited the sinking of Northern Hemisphere lands under the weight of continental ice sheets in the last ice age, and their rise since the ice melted some 10,000 years ago.
Drill that is fitted with a Pipe provides effective connection to the rig surface equipment or application with the bit and the bottom hole assembly for the purpose of pumping the Drill fluid to the bit.
Typical Cordless Hammer Drill. A hammer drill/driver is a drill with a specialized âhammerâ mode that is used when drilling into masonry such as brick, cement, and similar materials. The hammer mode can often be turned off so that the drill can be used as an ordinary drill/driver. The hammer drill capabilities do add a little to the weight.