* * *
His first day on the job, Garver lowered his new machine into a shaft, aimed it, and started digging. The tunneler ran off into the dirt and stalled, wedged tight. Garver dug a new shaft down from the surface to reach it. When he hit metal, he loosened the machine and pointed it once more. Again it jammed. His vendor's technical consultants were baffled. The machine had worked fine in Japan. The vendor offered to return his money and take the machine back. It was an honorable gesture, but Garver was in no position to accept it. Returning the machine would have left him sitting around watching a $10,000-a-day late-penalty clause eat up his new business.
Garver had a hunch that the water-saturated silts, sands, and clays of Houston must be imposing different forces on the operating cycle of the machine than the rocky, heterogeneous sands of Japan did. So he used a cutting torch to reshape the face of the mole. He eventually got the machine going, but clearly there had been some major miscommunication with the vendor regarding tab A and slot B. "River Oaks was a real baptism by fire," he says.
Microtunnelers take a mix of systems (hydraulic, electrical, electronic, mechanical, optic, even video) down into an environment that is dirty, wet, unpredictable, inaccessible, largely unobservable -- and characterized by extreme pressures. If anything goes wrong with any of the subsystems, the whole cycle stops and doesn't restart until the failure is fixed. One wrong touch on the steering knobs (the machines are guided remotely from a control console on the surface) and the tunneler can start "porpoising": oscillating back and forth across an axis instead of running straight down it. Too little pressure on the jack and the machine will stick -- and the longer it stays stuck, the more tightly the surrounding ground will settle around it. Too much pressure from the jack and the pipes will crack, in a way that may not be obvious until later. The exact value separating too much pressure from too little varies with the soil type, and the soil is unobservable until the tailings start coming out of the shaft.
Those and other constraints mean that microtunneling jobs must be planned in much greater detail than cut-and-cover trenching jobs. Hundreds of connections need to be monitored and maintained. One slipup can lead to trouble: if a cable breaks when the machine is underground, for instance, as much as a week's production -- and tens of thousands of dollars -- can be lost. A large parts inventory has to be kept on-site for preventive maintenance, and a versatile equipment-repair shop must be established in the home office. The workforce needs to be trained to high skill levels and evaluated constantly to make sure it shows an obsessive attention to detail. How fast an employee can be trained is a critical factor in planning work assignments. "A worker who doesn't like to learn isn't going to be very happy doing this work," says Garver.
Amazingly, the River Oaks project was completed on time, though just barely, and Garver even made a profit. From the perspective of many of the local contractors, however, that was not good news. The Houston rebuild, which was coming in at more than a billion dollars, could have kept the whole community of cut-and-cover contractors in steak for years; now Garver was threatening to grab most of it with his Buck Rogers technology. Contractors lobbied the city council, arguing that it was unfair to the taxpayer for city engineers to specify tools. They should just define the job, the contractors insisted, and let the lowest bidder win. Several jobs were, in fact, announced that way, but Garver kept winning the contracts, because while trenching gets more expensive with depth, the cost of microtunneling stays pretty much the same. Today BRH-Garver does roughly $35 million worth of business a year, about half of which comes from microtunneling projects across the country.
River Oaks made believers out of Houston Public Works, but the rest of the country stayed unconverted. The skepticism could have turned into a long-term problem for Garver, who knew the Houston work would end in a few years. So he searched for ways to expand his market. "We decided to let our light out of the basket," says Clifford Tubbs, Garver's vice-president in charge of estimating and project management.
Going against all the instincts of contractor culture, Garver began inviting competition into the business, knowing it was the only way to build market. In 1990 in cooperation with a microtunneling trade magazine, he sponsored the first U.S. conference on the technology. He set up a microtunneling field demonstration (and barbecue) on his company grounds and ran in busloads of engineers, contractors, and clients from the conference to see working demonstrations. In 1992 he helped organize the Gulf Coast Trenchless Association, a promotional group that supports lectures, technology demonstrations, and conferences in underground construction. "He's the leader," says Professor Tom Iseley, of the Purdue University School of Engineering and Technology, in Indianapolis. "There's been nobody else with that kind of vision."
The vision has spawned opportunities. The number of feet dug with micro-tunneling has begun to edge up: 300,000 feet in 1994 compared with 90,000 in 1989. Tim Coss, who does microtunneling research at the Colorado School of Mines, in Golden, Colo., estimates that there are about 40 machines in the country now, which is impressive, given that there were only a half dozen or so here five years ago. (The impressiveness fades somewhat when the number is compared with the thousands of machines currently being used in Japan.) Today Garver can't lose for losing. For a recent job he bid on in Amarillo, Tex., eight microtunnelers bid against him. That he lost is just another measure of his success.
* * *
Fred Hapgood (fhapgood@world.std.com) is a freelance writer based in Boston.
