Selecting the right trencher
Published in: Landscape & Irrigation
Date: 9/1/2002
By: Bolay, Brent
Trenchers were the driving force that initiated the under-ground construction boom that began more than 40 years ago. In the years since then, trenchers have buried much of the world’s utility infrastructure.
The development of several effective trenchless technologies permits pipe and cable to be placed underground with minimal excavation, yet trenchers continue to be responsible for much of today’s underground utility construction workload.
Trenchless procedures are best suited for jobs where surface improvements, existing underground utilities, and restoration costs make excavation impractical or impossible. But because many utility construction projects continue to be in open country where these factors are not issues, trenching often is the most efficient and cost-effective method of installing underground cable and pipe.
Choosing the right trencher — or the best combination of trencher models for an equipment fleet — involves several important considerations.
Equipment buyers should consider several factors in order to select trenchers best suited to their needs:
How will the machine be used?
What kinds of installations will the trencher be expected to make?
Which model is best?
The sizes of products to be placed in the ground determines how deep and how wide trench needs to be. What kinds of soils will the machine work in? Equipping a trencher with the digging assembly, chain, and teeth best suited for soil conditions in which it will be working will enhance productivity and eliminate unnecessary wear of digging components and stress on the machine. Will the trencher be used every day, or occasionally? Is production speed important? Will the machine only be used to dig trench, or should attachments be considered?
Carefully analyzing how equipment will be used enables realistic decisions about model selection. Compact, pedestrian machines are least expensive and are adequate for many jobs. Small and medium-size riding models handle larger jobs, and some models can be equipped with attachments to expand their capabilities. Powerful, multi-purpose machines with a wide assortment of available attachments can be equipped to do a wide range of utility work. Big trenchers and plows have the capability of installing cross-country installations of cable, pipe, and duct and conduit in diameters to 24 inches.
Many models offer a variety of options. Most compact trenchers have air-cooled gasoline engines. Riders often are available with either gasoline or diesel power. Thrbo-charged engines can boost production capabilities. Large machines are equipped with liquid-cooled diesel engines.
All models can be equipped with teeth and chain suited to specific digging conditions. A variety of trenching component options are available for larger models, including center-line and multi-position digging assemblies, disk trenchers for cutting through paved surfaces and frozen ground, and teeth-and-chain combinations for cutting through rock and other difficult conditions.
Mechanical or hydrostatic drive?
Equipment buyers have a choice between machines with mechanical and hydrostatic trenching drive systems.
Some trencher owners consider mechanical drive systems the most productive and believe that hydraulic drives are easier to maintain. Mechanical trenching drives generally transmit a greater percentage of engine horsepower to the digging component, but mechanical systems require belt and chain adjustments and lubrication, and the operator must use a clutch and shift lever to change digging chain speeds. Hydrostatic machines are easier to operate; the operator can adjust digging speeds without shifting gears, and hydrostatic models require less regular maintenance.
Improvements to both types of systems have narrowed performance differences; both are efficient and productive, and the choice of which to use has become largely a matter of personal preference.
Are attachments needed?
Trenching is the only function of pedestrian models. Riding models usually come with a standard backfill blade, but most riding machines today are designed to accommodate a variety of attachments which convert a basic trencher into a multi-purpose underground construction machine. A utility backhoe is one of the most popular trencher attachments. Others are the vibratory plow, combo (combination vibratory plow and offset trencher), and hydraulic boring attachment. Medium-range models can be equipped with attachments to do as many as six different underground jobs. Equipping a trencher with one or more attachments often can eliminate the need to bring another piece of equipment to a job. A careful analysis of how a machine is to be used will help buyers decide whether the extended capabilities offered by attachments will justify the added investment costs.
Easy to operate, maintain?
The easier a trencher is to use, the more efficient and productive its operator can be. Machine functions should be easy to understand, controls clearly identified and arranged for easy, natural operation. Even on compact pedestrian models, trenching components are raised and lowered hydraulically, and attachments also are operated off the machine’s hydraulic system. Comfort is not a feature customarily associated with construction equipment, but ergonomic design considerations can make a long work day less tiring and stressful.
For example, the operator station of the new Ditch Witch RT family of tractors makes effective use of available space to provide as much leg room as possible. The padded seat can be adjusted for height, slides forward and backward, rotates 90 degrees, and has adjustable arm rests. A tilting column permits the steering wheel to be adjusted to individual operator preferences.
The easier a machine is to maintain, the less likely regular service will be neglected. Wear parts must be replaced and regular maintenance and occasional repairs are necessary to keep machines in top running condition. Look for equipment with extended maintenance periods, fewer daily maintenance points, and convenient access to service points – all features that make a trencher simpler to maintain and repair.
What about product support?
Surveys document that many owners and operators of construction equipment consider product support to be just as important as the quality of the equipment they purchase. Product support begins with ready access to replacement parts and availability of professional service when repairs are necessary. Terms of a machine’s warranty is an extremely important consideration. What does it include? How long does coverage last?
The best product support programs don’t end with parts and service and a good warranty.
It doesn’t much matter how good equipment is if it is impossible to get parts in a timely manner or training in its operation isn’t readily available.
Training is an important element of total support. Operational and maintenance training is important, both from factories and from dealers.
What about brand name, value?
The true value of any piece of construction equipment is determined by many factors: purchase price, operating costs, maintenance and repairs, productivity, and resale value. Buyers want to invest in a trencher that will produce the greatest amount of trench at the lowest per-foot cost. Experienced equipment owners understand that purchase price often is the least significant factor in overall equipment value. The complete picture of a machine’s lifetime value is documented when total income the machine generated and final sale price are deducted from the initial purchase price and operating and maintenance costs. Owning quality, brand-name equipment also is important, and at no time is that more evident than on the day the machine is sold or traded in on a new model.
RELATED ARTICLE: Hitch and trench
A 3-point-hitch-mounted trencher is available for Kubota’s B Series tractors that has “Top Link,” a quick attach-detach feature.
It has a 3-ft. boom and is pre-assembled for 8-inch trenches, but 10- and 12-inch digging chains are included. The units can trench up to 600 ft. per hour, depending on depth and soil conditions.
A hydraulic valve with an integral check valve ensures trenching depth remains constant and prevents acidental lowering of boom when the tractor engine is stopped.
Kubota Tractor
Phone: (888) 458-2682
Circle 125 on Reader Service Card or www.OneRS.net/209li-125
Tiny to humongous
Case Construction Equipment offers a full line of trenchers suited for a wide range of applications. The Case line ranges from the 13-hp walk-behind Case 60 with maximum dig depth of 36 inches to the ride-on Case 960 with 99.5-hp engine and maximum dig depth of 84 inches.
Other case models include:
* the TF300B offering dig depths up to 45 inches;
* the Maxi-Sneaker drop-cable plow with trencher attachment;
* heavy-duty 360, 460 and 560 units with dig depths up to 72 inches; and
* the high-production 660 model, with a 60-hp engine and maximum dig depth of 72 inches.
Most of these trenchers can be fitted with attachments including backhoes, rock-wheels, backfill blades, vibratory cable plows, reel carriers and the Case Hydra-Borer boring unit.
Case Construction
Circle 126 on Reader Service Card or www.OneRS.net/209li-126
Trenchers with disc blades
Elite trenchers are small push-type trenchers with disc blades. Four models are available:
* DD6 – digs 5.5 inches deep, 3/8-inch wide; 5- or 5.5-hp engine.
* DD8 – digs 8 inches deep, 2 or 3 inches wide; 5- or 5.5-hp engine.
* DD10 – digs 10 inches deep, 2 or 3 inches wide; 6- or 6.5-hp engine.
* DD12 – digs 12 inches deep, 2 to 4 inches wide; 7.5- or 8-hp engine.
Elite trenchers can dig 20 to 30 ft. per minute, the company says, and are constructed of heavy-wall square tubing.
Elite Trenchers
Phone: (800) 223-5468
Circle 127 on Reader Service Card or www.OneRS.net/209li-127
New walk-behinds
Vermeer has launched a new family of walk-behind trenchers starting with the introduction of the RT60, its first mini-trencher in the under-10-hp class. The RT60 can trench 4, 8 or 12 inches deep and 3 inches wide. The RT60 comes standard with the patent-pending ground drive assist.
Also:
* The fully-hydrostatic RT100, with a 13-hp Honda or Kohler engine, has the capability of trenching depths down to 36 inches with 4- to 6-inch widths. Its hydrostatic ground drive equipped with twin wheel motors makes it one of two new Vermeer machines that are the first fully-hydrostatic pedestrian trenchers offered to the market today.
* The other is the RT200, with the capability of trenching depths down to 48 inches with 4- to 8-inch widths. The RT200’s hydrostatic ground drive is equipped with twin wheel motors and powered by a 23-hp Kohler engine.
Vermeer Manufacturing
Phone: (888) 837-6337
Circle 128 on Reader Service Card or www.OneRS.net/209li-128
Brent Bolay is product manager at The Charles Machine Works, Inc., Perry, Okla. The company manufactures Ditch Witch equipment, horizontal directional drilling equipment, subsite electronic tracking equipment and utility locators, and related underground construction products.
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