A Flexible Upgrade

Machine grading control systems have something in common with project delivery systems
By Don Talend, Contributing Editor | October 2009 Vol. 64 No. 10
A Haydon operator views a topographical layout of the AZ job site on a GX 60 monitor while digging with a Caterpillar 330 CL.

Excavating with precision
In early March 2009, with crews staking curb work for a winding entry road and masons constructing brick walls on the new maintenance facility, Fields walked over the buried pipe that had been installed three months earlier. Haydon had used a relatively new method of exposing the existing communications and water utilities, which would all be kept in service, before locating them with the X63. A Ditch Witch FX60 Vacuum Excavator was used for subsurface utility engineering, a nondestructive method of locating buried underground utilities that also improves worker safety. The vacuum excavator located utilities by forming clean cut, targeted potholes above the utilities without adversely affecting the surrounding soil stability.

After locating the utilities, Haydon had Dirt Pro LLC of Higley, AZ, build 3 D site models and loaded the models into the X63 system control box via a flash drive. A Caterpillar 330 CL excavator was equipped with Topcon’s X63 grade control system, which is specifically designed for excavators. The system consists of four temperature compensated, 360 degree CAN based tilt sensors that measure angles from the cab, boom, stick and bucket; a GX 60 color touch screen control box; two GPS+ antennae; and a GPS+ receiver.

While digging trenches, the excavator operator ensured the proper digging depth by viewing on the GX 60 the machine’s exact position on the site, in addition to the bucket’s constant position. The system eliminated the need for a grade checker to continuously monitor excavation depth. The depth for the potable water pipe and sewer force main was about 4 feet and the width about 2 feet. The depth for the gravity sewer was about 8 feet and the trench width about 3 feet.

“Basically, [GNSS] eliminates the need for a guy manually checking grade, whether he’s shooting it with an eye level or just simply putting a tape down or even a grade stake,” said Manny Tarazon, pipe superintendent for Haydon’s Heavy Civil Division. “You can also check the elevation on your pipe – if you put that bucket right on top of that pipe, you can actually take a shot. We were sloping the sides of the trenches, too, so the system even helped us to make sure we had our proper slope, which was 2:1.”

FOR MORE INFORMATION:

Topcon Positioning Systems Inc., (925) 245-8300, www.topconpositioning.com