Auger Boring Is Back & Better than Ever
March 9, 2012There are numerous trenchless methods to install underground utilities, ranging from horizontal directional drilling (HDD) to pilot boring. Each has its advantages, but one technology — auger boring — has stood the test of time and continues to provide a cost-effective means of installing utilities under roads.
Modern-day auger boring began in the 1950s, and while the process is relatively the same, the technology has advanced. Today’s auger boring systems are much more advanced and allow the operator to control both grade and line, helping contractors complete more difficult and accurate bores.
“Auger boring is still one of the more cost-effective methods to install utilities ranging from 4 in. up to 72 in. in diameter under a road or railway,” says Mike Moore, vice president of sales for McLaughlin. “I think the heyday of auger machines was probably in the 1970s and early 1980s. Then, microtunneling became a buzzword in the industry. Now the industry realizes that auger boring is probably the most cost-efficient and practical way to complete a large diameter installation in many cases.”
Auger boring is a relatively simple process that features a rotating cutting head that bores a horizontal hole inside of a casing. As the cutting head cuts through the ground, the resulting spoil is moved by a flighted auger out of the casing and the steel casing is jacked into place. It’s a simple concept, but it’s also very effective.
As the need for oil, gas, water and sewer line installation grows, more contractors are evaluating trenchless installation methods and taking a closer look at auger boring. While the cost-savings of auger boring machines compared to other trenchless installation methods is a definite attraction, being able to install a steel casing while drilling the hole remains the No. 1 benefit. Not only is it more efficient, but it also helps create extremely stable bores.
“You’re not using any fluid to do the cutting,” Moore explains. “You may use some fluid to lubricate the outside of the casing and some fluid on the inside to help clean the auger, but you’re not actually using water or bentonite to help create the hole and hold it open. So you don’t have any subsidence of the ground.”
Another benefit of auger machines is that they can perform jobs in a relatively small footprint compared to other trenchless methods, meaning you need less work area.
“With an auger machine, you’re going to dig a pit on one side of the road, start there and go to the other side of the road and dig a pit to receive the casing.” Moore explains. “You don’t need a lot of room to set back and have a slow run-in for the pipe.”
Auger boring contractors are out there, but as the economy improves and infrastructure projects expand, the demand for these services will increase.
There are two types of auger boring contractors — a utility installer who wants to bring the work in house and the individual who decides that they just want to bore holes. A water, sewer or gas contractor may decide to purchase an auger boring machine for enhanced control over the entire installation process and develop more cost-effective bids. On the other hand, a person may want to specialize in boring holes as their primary business.
No matter your background, Moore wants to make sure contractors understand the business of auger boring before making the jump into auger boring.
“Patience is a virtue, but a requirement when it comes to auger boring,” says Moore. “The process, from pit preparation to the start of the actual bore, cannot be rushed. Contractors need to take time to correctly prepare the pit and ensure the machine is set properly before you rotate the auger. That first casing must be installed perfectly for the entire project to be a success. If you cut corners, it’s a recipe for failure.”
Moore also notes that it’s important to start small. In other words, don’t attempt to complete a 600-ft on-grade bore in poor soil conditions as your first project. Instead, tackle some 100- and 200-ft bores first and gradually move into more difficult projects.
“I know a lot of contractors who personally wouldn’t be good at auger boring,” says Moore. “However, they’ve hired the right people to operate the machine and they let those guys do their thing. Maintaining continuity on the crew is also important. The more experience the crew has, the better they will become.”
Success is also dependent on proper training. McLaughlin, like many manufacturers, will visit the jobsite and help the contractor with their first bore. Training will cover safety, machine operation, pit preparation, how to start the bore and how to effectively link the casing.
“We generally are on the jobsite and help install the first two casings, which are about 40 ft of drilling,” says Moore. “The first section is the most critical and must be installed square and on-line for the entire bore to be successful. Then we train the crew on how to link the casings together. Once that has been accomplished, everything else is repetitive.”
As with any business, there is an up-front cost. However, auger boring has a strong return on investment compared to other trenchless technologies. Most contractors can recoup their investment after five bores depending on the market in their area. However, a contractor needs to understand that they may complete five bores this week, and the machine may sit idle for a month before another project is available — it requires a long-term commitment.
The typical auger boring equipment investment depends on the contractor and the type of work they plan to complete. Most contractors will focus on a specified diameter range. So, if you focus on 12- to 24-in. projects, the estimated cost for an auger boring machine and a set of augers will be in the $50,000 range. Over time, the contractor may add additional auger sizes. Now a larger machine that can complete a 48-in. bore along with 400 ft of auger could cost upward of $250,000. The investment can be fairly minimal or substantial, depending on the project diameter range you select.
From a revenue perspective, most projects are bid based on the diameter of the pipe to be installed and the overall length of the bore. Let’s say you are installing a 20-in. pipe and plan to charge around $10 per inch, per foot. The contractor will take the $10 per inch fee times 20 (20-in. diameter project), which would equate to a fee of $200 per foot. So if the bore length is 100 ft then the project bid would be $20,000. Let’s say the auger boring machine and auger cost $50,000, then after three bores it’s possible to recoup your initial investment.
“Rates vary depending on the prevalent soil conditions,” says Moore. “I also encourage contractors to understand the bidding process. Don’t forget to include the cost of the steel casing, pit preparation costs and include a rock clause in the contract. If you hit unexpected areas of rock, you need to protect yourself. Do your research and understand the local market for auger boring.”
Not All Machines are Created Equal
So you’ve made the decision to purchase an auger boring machine, but not all brands are created equal. Each company offers unique features, and it’s important to take time to evaluate the options. Don’t hesitate to reach out to auger boring contractors for their perspective.
“Number one, I encourage contractors to determine what size diameter bores you want to complete,” says Moore. “If you want to go out and complete 24-in. diameter bores and that’s as small as you want to go, then don’t buy a 24-in. machine. You need to go up a size. Next, determine the maximum length of your bores. If you want to focus on 24-in. bores up to 400 ft in length, then you may need to purchase a 36- or 48-in. class machine.”
How can a contractor determine what’s the right diameter for your area? Talk to the water, sewer, gas and telecomm companies in your area and inquire about the type and size of projects completed in the past three years. Also explore upcoming projects. This information can be used to help you determine what diameter may be appropriate for your trade area.
Next, review the features of the auger boring machine. Look for a machine that groups the controls in one location within easy reach of the operator’s station. This will help make the machine easier to operate. Review the safety features of the machine; specifically, guards in place over moving parts and the clutching system. Inspect how the machine will attach and detach from the track. The process should be simple and quick as the unit ought to be pulled from the pit every night.
Finally, look at the pinhole positions on the track. This will determine how far you can stroke the cylinder before you have to bring it back up to catch the next ratchet position. The longer the distance between pinholes results in a shorter cylinder cycle time to begin the next push.
Moore also encourages contractors to select a drill head that matches the soil conditions in their area. For the most part, a cobble or combination head is the best option. Both have the ability to handle a variety of soil conditions. If rock is prevalent in your area, then purchasing a rock head up front is wise. You don’t want to get into a job and then wait two or three days for a rock head to show up on the jobsite.
It’s also important not to forget the supplemental equipment like an excavator and shoring equipment. The excavator will serve many roles on the jobsite — excavating the pit, installing the machine in the pit, lowering casing and removing spoil. Shoring equipment will be required to meet safety requirements, and remember welding and torch equipment to link the steel casing.
Don’t forget to spread the word about your services. You need to network with municipalities and utility contractors in the area to build up your business and secure bids. However, it all comes down to doing good work and being known as a quality contractor. That’s the best marketing tool you can have in your toolbox.
Greg Ehm is a technical writer for Two Rivers Marketing.