Equipment Notebook: March 2001, Trencher Trends

"Many installations out here are done along a curb or next to a house or building," Young explained. "In many cases, you can’t use trenchers because the lawns tend to be smaller and more detailed, garden layouts with curving or zigzag-shaped planter beds that make it more difficult to use mechanized trenching equipment. As a result, much of the digging is done by hand."

But in the past two years, Los Angeles’ school district administration has put more commercial projects out to bid, and Young has picked up much of this work, having replaced leaky irrigation systems on more than 50 sites.

In most cases, large amounts of irrigation piping needs to be replaced on these systems, Young said, and L.A. basin soil ranging from soft, loamy material to rock or slate can make digging challenging. Also, Young’s crews have to operate as efficiently as possible because deadlines for these replacements are very tight. For instance, one job at Jefferson High School had a six-week deadline for irrigation replacement, and some of these jobs, such as the one at Birmingham High School, require the installation of more than 2 miles of new irrigation piping, ranging in size from ¾- inch to 4-inches in diameter. Frequently, penalties are the result of any completion delays on these projects, excluding weather-related reasons, Young said.

"When you have large jobs such as replacement projects for schools, productivity is essential," Young pointed out. "The kinds of restrictions I’m under with these school contracts demand that the installer be able to open and close almost 2,000 trench feet a day. And all trenches must be closed by the end of the workday for school liability reasons."

As a result of this increased commercial work and his need for better productivity to meet deadlines, Young purchased a hydrostatic riding trencher. "Having this trencher allows me to have 10- to 12-man crews and get the needed amount of daily productivity," he said.

Like Young, many landscape contractors have specific needs when it comes to trenching equipment. Based on the application’s level of difficulty, manufacturers are offering many trencher options for the landscape market.

CHOOSE YOUR WEAPON WISELY. In the landscape market, trenchers are used for anything from soil and turf work to irrigation and drainage system installation or repair and replacement, pointed out Richard Greenwell, product manager of the compact line, Ditch Witch, Perry, Okla.

There are two types of dedicated trenchers available to landscape contractors: walk-behind/walk-beside trenchers and riding trenchers.

Walk-behind trenchers’ price tags are approximately one-third those of riding trenchers, costing between $7,000 and $10,000, pointed out Todd Roorda, rubber tire product specialist, Vermeer Manufacturing, Pella, Iowa.

"Walk-behind trenchers are great for residential properties with 36-inch backyard gates and other landscape elements, such as trees, contractors need to get through and around," Roorda said. "Although, due to the limited power of a walk-behind trencher when compared to a riding trencher, contractors lose the ability to dig deeper with a walk-behind and have less available power, particularly in tough soils."

Riding trenchers, on the other hand, cost between $23,000 and $37,000, according to Greenwell, and offer a greater variety as far as horsepower and add-on options are concerned.

Typical riding trenchers start with 43 horsepower and can go all the way up to 116 horsepower, but these riding trenchers cannot fit through 36-inch gates because they are too wide, Roorda said. But there are compact riding trenchers now available that are 35 inches wide and offer the same power options as traditional riding trenchers, Greenwell said.

In addition to a choice of horsepower and unit size, contractors can also choose to add different supplemental attachment options to their trenchers, such as a backhoe or vibratory plow.

"A backhoe is nice for contractors who dig many trenches," Greenwell said. "With a backhoe they don’t have to manually fill the hole back in themselves. They can use the backhoe to push the dirt back into the holes."

A vibratory plow, which is a blade that when put into the ground uses vibration to place irrigation piping or utility lines in a thin trench, is a popular add-on tool for contractors who use the chain teeth of trenchers to dig up to 4-inch-wide and 2-feet-deep holes for one application or renovation project, but who also need to dig narrower trenches for installing irrigation piping without disturbing clients’ lawns too much.

"When you’re trenching, you are digging as deep at 2 feet and as wide as 6 inches - there’s a lot of restoration that needs to be done to a lawn after that," Roorda said. "For all the dirt you dig out, you have to put it back in along with grass seed. For drainage problems, there’s a need to dig a wider hole as well. But if you’re only laying a 1-inch pipe, the vibratory plow works like a knife and you just pull irrigation piping in behind the machine. There are a lot less restoration costs involved this way.

"Ultimately, the choice depends on the project," Roorda continued. "If you’re in clay soil, you could use a vibratory plow to put in irrigation. If you are in an area where there is more cobble or rock, you’ll want to trench it in. If you tend to have both types of soil and a variety of projects in your business, you may need a machine that can do both."

RENTING OPTIONS. In the past, only about 10 percent of contractors rented equipment instead of buying equipment, according to Vermeer Manufacturing. But recent reports have shown that number to be closer to 25 percent, which means rental companies are reacting by putting larger numbers of construction equipment in their yards and by altering their fleet mix, Roorda reported.

"Contractors make a profit when they are able to use their capital equipment at a high rate of utilization," he said, explaining the reason for the increased interest in renting vs. buying. "Although 100 percent utilization is unrealistic, the higher the utilization rate, the less downtime, and the more work contractors can get done in a given amount of time. If contractors are between jobs, they don’t like to pay for new machinery that sits in their yards. As a result, many companies choose to pass this up-front investment onto the rental companies, lower their indebtedness and let the rental company take the ‘utilization risk’ gamble."

Desert Care Landscape, a division of TruGreen LandCare based in Phoenix, Ariz., was awarded the contract to install 7,800 feet of mainline irrigation along the right-of-ways for the roads that will wind their way through a 6,000-acre area. Thousands more feet of lateral water lines also will need to be installed. The company’s Project Supervisor, Patrick Franks, said he will rent trenchers to place the 1/5-inch diameter water lines under a minimum 2-feet of cover in the rocky, densely compacted soil in Phoenix.

"Every contractor on this project is using rental equipment," Franks explained. "The reason is the unpredictability of the ground conditions. Nobody wants the uncertainty of project completion dates that machine downtime would bring. We would rather rely on a rental company’s maintenance staff to keep us up and running when there is a problem."

The cost of renting can vary on a case-by-case basis, Roorda said, depending on if contractors are renting multiple, larger machines for one week or smaller machines for one day. "The average cost for renting a walk-behind trencher for one day is $150, depending on the region," he said. "Multiply that number by five and you have the average cost for one five-day week. This is a rough average, though, because many rental yards have different deals. For example, some rent machines for four days and that constitutes one week and others count a week as all five days."