Abstract: Excavating apparatus includes a vehicle having excavator in the form of a pivotal cutting boom pivotably mounted on the vehicle. The cutting boom has an endless cutting clain drivingly mounted thereon and the boom is pivoted relative to the vehicle so as to vary the depth to which a trench is current. In seeking to cut a trench having a level floor irrespective of any undulations in the surface upon which the vehicle travels, a sensor is associated with the apparatus and is arranged to receive a reference signal. Any variation in the location at which the reference signal impinges on the sensor, for instance due to the passage of the vehicle up an incline, serves to determine the angle at which the cutting boom extends from the vehicle and so varies the depth to which the trench is cut.

Abstract: A pipe laying machine comprises a vehicle carrying a trench excavator followed by a pipe laying box running in the trench. Pipe lengths are stored in the pipe laying box one above another and the lowermost pipe length is periodically released by movement of bars into the bottom of the pipe laying box and is pressed by a ram into the mouth of the last laid pipe length.

Abstract: Excavating apparatus includes a vehicle having excavating means in the form of a pivotal cutting boom pivotably mounted by way of mounting means on the vehicle. The cutting boom has an endless cutting clain drivingly mounted thereon and the boom is pivoted relative to the vehicle so as to vary the depth to which a trench is current. In seeking to cut a trench having a level floor irrespective of any undulations in the surface upon which the vehicle travels, a sensor is associated with the apparatus and is arranged to receive a reference signal. Any variation in the location at which the reference signal impinges on the sensor, for instance due to the passage of the vehicle up an incline, serves to determine the angle at which the cutting boom extends from the vehicle and so vary the depth to which the trench is cut.