TRENCHLESS TECHNOLOGY
Working in their place is a funny looking contraption that is installing the bright yellow plastic pipe by boring tunnels under roadways. There are no driveways to close, limited noise, and less confusion.
In 1993 A.M. Ortega was the first in San Diego County, and only the second in the state, to use the Vermeer D-24 directional bore unit. This machine, which resembles a cannon on treads, relies on state-of-the-art technology developed in the oil fields of Oklahoma and Texas.
Instead of drilling vertically, it bores a horizontal tunnel 500 feet or longer at a time, and can maneuver around sewer mains, tree roots and other subterranean obstacles.
Crews have used this machine installing thousands of feet of yellow pipeline for San Diego Gas & Electric Co., and the Southern California Gas Co. Similar tunneling projects are fairly common in other parts of the country, but have seldom been tried in California because of the rocky, sandy soil.
The machine is fairly easy to run, said Maurice Ortega. Simply put, it pushes a spinning, arrow-shaped bit through the ground at a specified depth using a series of flexible, 10 foot long metal rods. Inside the bit is a transmitter that relays its depth and direction, and allows operators above to adjust it accordingly.
When the bit reaches its destination 500 feet away, workers remove the boring head and replace it with a reaming tool. The pipe is then attached and pulled back through the newly excavated tunnel. The only real digging required is a small access hole on each end. Besides being less disruptive, the drilling operation is better for the environment because far less asphalt and concrete must be torn up and dumped in a landfill.