We can design big drill rigs various from 100 ton to 500 ton according to our client's need. DDL4000 is showed in the picture. DDL4000 is integrated designation machine which makes it walk itself and suit for different work situation so that DDL4000 avoid the disadvantage of being difficult for transportation. The power system employed the permanent power and open-circuit hydraulic system. DDL4000 employed two engines but can work with one engine. When only one engine works the back drag force can reach to 150 ton. The advanced control ability is designed with the electric and hydraulic stick system which makes it easy to control and operate.