The   HR 420-800  is our largest model, which has been specially designed and built for carrying out works requiring large bore diameters at great depths. 
This one of a kind drilling rig can be equipped with different rotaries with different torque values ​​depending on your job requirements. The rotary can also be set up with the MCS (MAIT Casing System) or torque multiplier which can exert a maximum nominal torque of 800 KNm for insertion and extraction on the casing tubes up to a maximum diameter of 3000 mm. 
The HR 420-800 is not limited to the conventional kelly bar drilling system, but it is able to utilize Casing Oscillators, Continuous Flight Auger (CFA), Diaphragm Walls by kelly bar system, and Driven piles with hydraulic hammers. The HR 420-800 is also available with a crowd winch system (THD), which allows a longer stroke along the length of the mast, therefore longer casing sections may be used when drilling.