DTH RIG (down to hole)
A down-the-hole drill,is basically a mini jackhammer screwed on the bottom of a drill string.The fast hammer action breaks hard rock into small flakes and dust and hammer.The DTH is hammer is one of the fastest ways to drill hard rock.Drilling mounting remains fit in large trucks and trucks have to be driven to the drilling point.There should be space to park the truck to drill with such a machine.Currently most of the bore is done by there machines because they are able to fast drilling on hard rock.It can drill deeper than other machine So it is more popular than other RIG.
ROTARY RIG
ROTART RIG IN places where thick layer of marshy sand is found in the top surface,rock found in very deep and there is a collapse formation of soil.There is drilling by rotary rig.
PORTABLE/INWELL RIG
The portable rig is commonly called the inwell rig.It also works on DTH technology But it is portable type and can be drilled indoors.The truck is at a great distance from the drill point and carries the compressed air from the pipe to the drilling point,so it is drilled indoors narrow and small place.But it has its limitations without sabotage.But it has limitations.It cannot drill more than 200 feet.