GROEFTEPLOG OG FREMGANGSMAATE VED LEGGING AV EN ROERLEDNING I HOVEDSAKEN UNDER VANN UNDER UTNYTTELSE AV EN GROEFTEPLOG

A trenching plow and technique for its use, especially for forming a trench under water for receipt of pipe. The plow includes a frame with a tandem set of wheels at the front, and a share with mould boards mounted at the back of the frame. During trenching the frame always makes a positive angle with respect to the horizontal, and a soil furrow splitter is formed on the bottom of the frame. A pair of coulters are mounted to the frame in front of the share, each of the coulters raking forward at an angle of about 60 DEG -70 DEG to the horizontal, and the coulters being staggered along the length of the frame. The coulters also have a positive clearance angle with the trench side wall, and they extend to a depth about two-thirds the depth of the share. A trench having a depth of about 1.1 meters with side walls at an angle of about 60 DEG to the horizontal may be formed at a towing speed of about two knots, the trench being formed having constant cross-section and constant depth.