Contractor's aim is true with trenchless technology

June 1, 1998
Do the job right the first time so you don't have to do it again. That's one of Deuy Hoffman's favorite sayings. Deuy credits his dad for the saying, which has become a cornerstone of his firm's success. His brother Dave agrees. Hoffman and Hoffman, a Waterloo, Iowa-based contractor, was born in February 1976 with just five employees, a combo plow, and a couple of trucks.In the beginning, the Hoffman

Do the job right the first time so you don't have to do it again. That's one of Deuy Hoffman's favorite sayings. Deuy credits his dad for the saying, which has become a cornerstone of his firm's success. His brother Dave agrees. Hoffman and Hoffman, a Waterloo, Iowa-based contractor, was born in February 1976 with just five employees, a combo plow, and a couple of trucks.

In the beginning, the Hoffman brothers mainly installed telephone lines. In 1979 when the cable television industry started taking off, a large part of their work became cable installation. After several years, the Hoffmans focused on geothermal heating-unit installations. When the fiber-optic boom began in the early 1990s, the Hoffmans decided to move back to cable installations. Cabling kept them and their 25-man crew closer to home.

Since then, the lines dividing electrical construction and datacom work have blurred. "While 80% of our work remains in the telephone and cable industries, we are also involved in putting a lot of their lines underground for some of the small towns that now supply their own electrical distribution. That has increased more in the last 3 years than ever before," Dave said.

Trenchless technology

The Hoffmans have been using trenchless equipment, specifically pneumatic boring tools, since 1976. In those days boring tool accuracy and reliability didn't measure up to today's capabilities. "We didn't like to send boring tools more than 50-ft deep because we could never depend on the depth of the tool. It would end up being too deep or too shallow and we'd end up hunting for it." The Hoffman brothers first saw a pneumatic piercing tool with a reciprocating head in the summer of 1993 in Kalona, Iowa. "We had about a 100 ft bore. We launched the tool at 7-ft deep. When it showed up between 7-ft and 7 1/2 ft deep on the other side, I was sold."

The piercing tool has a reciprocating head. The chisel head assembly moves independently of the main casing, creating a pilot bore for the rest of the tool body to follow, which ultimately leads to greater bore accuracy.

With long bores and accuracy no longer a problem, the Hoffmans became confident enough in their boring tool to expand their trenchless applications. They then purchased another piercing tool to do shorter distance bores under sidewalks and driveways for service lines.

Accuracy is the key

As more and more lines go underground, accuracy becomes vital. In 1996, the Hoffman brothers were contracted to replace failing 30-year-old underground street light lines for the city of Aplington, Iowa. "The city strung temporary lines above ground between the street light poles along U.S. Highway 20, which runs directly through downtown Aplington," said Dave. "It was very unsightly."

The Hoffmans needed to install new conduit underground for those lines. In residential areas, the crews bored under driveways and sidewalks in sandy loam. Twelve bores, as long as 65-ft, were successfully completed, but the hardest part of the job was yet to come. Downtown, the Hoffmans needed to bore from light pole to light pole underneath sidewalks and next to buildings.

Dave and Deuy each headed a crew, took opposite sides of the street with 3-inch diameter piercing tools, and got ready to bore. They were working in very tight quarters. The city had cut launch and exit pits at the base of each light pole. The pits were 24-inches deep, 5-ft long, but only 15-inches wide. The Hoffman crews also had to contend with abandoned underground coal cellars.

To ensure accuracy, each crew used a telescopic aiming frame and surveyor stakes. With the exception of one bore that hit a coal cellar, each of the 75-ft to 85-ft bores was successfully completed on the first try. Deuy's crew finished first. That portion of the job was wrapped up in one day, with each crew boring 390 ft. The entire Aplington electrical job was completed in two and a half days.

Trenchless lighting

Accuracy was also needed in the fall of 1997 when the Hoffmans were contracted by a Waterloo hospital to replace electrical conduit between two light poles in their parking lot. The hospital's security department had been trying to get the problem fixed for some time, but no one wanted to trench the parking lot. The Hoffmans were hesitant about sending a piercing tool because of the length of job-130 ft. They never sent a piercing tool more than 100 ft before.

After much debate, they decided to try it. The bore needed to be made within a depth of 18 inches to 26 inches in order to avoid two storm sewers and an unwanted speed bump in the asphalt of the parking lot. After digging launch and exit pits, the Hoffmans again used a telescopic aiming frame and surveyor stakes from TT Technologies. They determined that there was a 4.5-inch-grade difference between the poles and launched the tool from the lower pit.

One hour and 18 minutes later, it emerged on the other side, just 2 inches right of center and 20 inches below the surface. A small crowd that gathered watched in amazement. The 1.25 inch conduit was installed. The launch and exit pits were backfilled and the asphalt replaced. The entire job took just 4.5 hours.

Through industry and technology changes, the Hoffman Brothers have survived and prospered for 22 years. Why? According to Deuy it goes back to lessons learned from their dad. For the Hoffmans, doing it right the first time now means using trenchless technology.

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