Precision Cuts

Professionals need a small machine with a good set of teeth. Shark, alligator, scorpion, rock, frost or cup — these are the names of the steel fangs you can fix to your pedestrian trencher to eat through dirt, roots and rock with velocity and accuracy.

Over the last 50 years, the pedestrian trencher has become an essential machine for digging on construction and landscape jobs, spearheading those quick cut-and-cover trenching operations.

Renting or purchasing the right chain, teeth and trencher combination allows professionals to roll onto the jobsite and saw through most types of soil, installing everything from fiber optics to water drainage. Since the first compact trenchers were unveiled, the machines have ridden the highs and lows of the housing industry. After a decline in residential construction in 2001, small trenchers were subject to the same roller coaster ride as nearly every other segment of the construction industry. So it is today, as the residential and financial markets wane in the fall of 2008. But even in tough times, there are still strong markets. When contractors aren’t buying, they’re typically renting, which is still good news for the walk-behind trencher industry.

“I would estimate over 60 percent of walk-behind trenchers go into the rental market,” says Jon Kuyers, utility products segment manager with Vermeer Corp. “But rental fleet purchasing has slowed too due to the housing slowdown. The walk-behind trencher market has remained stable over the last five years, but in 2008 overall sales in the marketplace have slowed due to the housing crunch and slowdown in new residential construction.”

When markets are soft, manufacturers need to push even further to innovate their products above the competition, appealing even more to a dwindling customer base. In the last two years, the trencher market has exploded with innovative new technologies — track systems instead of wheels, unique curved cutting paths, clever operational platforms and attachment systems for walk-behind trenchers (which are not considered compact utility loaders)

“Walk-behind trenchers have always been a staple for contractors. Dedicated walk-behind trenchers are one of the top five revenue-generating products in the general tool rental category — so the demand is there,” explains Greg Lawrence, marketing product manager for Sitework Systems with The Toro Co. “The added innovations incorporated into today’s trenchers have helped support steady sales, since rental stores and end-users understand the operating advantages innovative machines can bring to customers.”

Entrenched in History

It was realized long ago that there had to be an easier and more efficient way to dig those short, shallow trenches in confined areas. So in 1949 contractors had their first look at a compact trencher, called the Ditch Witch, combining the capabilities of a large trencher with the ease of use and maneuverability of an everyday lawnmower.

Ditch Witch founder Ed Malzahn was only 28 when the first production pedestrian trencher rolled off the assembly line. It was the first mechanized, compact service line trencher developed for laying underground water lines between the street main and the house. The invention paved the way for the creation of the compact trencher industry, which today produces all types of equipment for installing any type of underground utilities including water, sewer, gas lines, telecommunications, CATV and fiber-optic cables. Walk-behind trenchers have even expanded to other underground applications such as burying down spouts, installing drain tile and French drains, as well as digging footings and edging around landscaping beds.

“The innovation of the service line trencher started an industry trend that continues today. The pedestrian trencher will continue to evolve as customers need change,” says Greg Adkins, Ditch Witch trencher product manager.

The advantages of a pedestrian or walk-behind trencher becomes fairly evident as soon as you see one. They’re small, easy to get into tight spaces and relatively easy to maneuver and operate. Most walk-behinds utilize a 10- to 25-hp gasoline engine for power, digging depths ranging from 18 to 36 in. with widths from 4 to 6 in. And while a riding trencher will provide more horsepower and thus more capability than those numbers, they usually cater to a much more dedicated type of user and much bigger installations.

Pedestrians are mostly used for short, shallow service work, runs of 30 to 100 ft, laying pipe and cable up to a max of 6 in. in diameter and up to 48 in. deep. Ranging in price from $3,000 to $15,000, the walk-behind trencher category typically encompasses machines that weigh less than 1,500 lbs with boom sizes from 1 to 4 ft that you actually walk-behind (as opposed to ride-on trenchers or stand-on compact utility loaders). The major manufacturers today include Ditch Witch, Vermeer, Astec and Toro.

“I would say the 13-hp machine is the most popular size today,” notes Bob Wren training manager at Astec Underground. “It is small, narrow and can go through a yard gate, and with today’s machines having hydrostatic ground drive and hydraulic trencher drive, they are very easy to operate.”

There are really three popular groups of pedestrian trenchers — 12-in., 24-in. and 36-in. digging depths. Those depths have a tendency to match up to the horsepower class that is available. Those horsepower categories tend to fall in the 6- to 9-hp class, 10- to 15-hp class and 18- to 25-hp class. The most popular is usually the 10- to 15-hp range, which offers an excellent size to power ratio. Those 10- to 15-hp pedestrian trenchers typically dig 24 in. deep and that’s often a minimum depth requirement for many utility contractors to install product safely. It’s also a trencher in a category that’s relatively inexpensive — $7,000 to $10,000. With those prices, pedestrian trencher sales have been steady for decades.

Drives, Teeth, Chains and Things

In the beginning, walk-behind trenchers were relatively simple machines — a boom, digging chain, wheels, operating levers, metal frame and a mechanical ground drive, which used gear boxes, shafts, pulleys, chains and sprockets to drive the digging chain. For decades, mechanical drives offered the most power and efficiency in a wide range of ground conditions, but since hydrostatics came out in 1979, years of improvements, superior reliability and lower maintenance have closed the gap in the market considerably.

“Mechanically-driven trenchers do not offer reverse chain operation for dislodging debris from the chain and boom,” explains Lawrence. “Mechanical trenchers are typically belt driven, which can have a high maintenance cost due to wear and tear on the belt. Manufacturers now offer a hydrostatic chain drive, which offers reverse chain capability and improves trenching performance by reducing belt slipping, while also reducing maintenance due to lack of a belt drive. Toro’s hydrostatic traction drive delivers variable transport speed that’s easily regulated versus a mechanical or hydraulic drive that is strictly on/off. Hydrostatic drive also allows for improved steering and increased maneuverability over a hydraulic or mechanical drive.”

When an operator comes across a tree root or a large rock in the ground with a mechanical drive, the options become relatively limited. A hydraulic drive, on the other hand, allows the operators to reverse the digger chain and either cut their way through or resort to hand digging. Hydrostatic drives offer a lower operating cost, more reliability, infinite variability with ground drive control and a price tag that’s about 10 to 15 percent more expensive. But mechanicals still have their place.

“As far as the components to manufacture it, it’s less expensive to manufacture a mechanical machine versus a hydraulic machine. It’s also the most efficient way to get the engine horsepower to the digging chain, so you’re going to have a more productive machine with a mechanical unit,” says Adkins. “The two main benefits of a hydraulic machine are reduced maintenance and a reversible chain for novice users.”

Other factors for your purchasing decision formula will most likely revolve around a good dealer and the exact features offered by the manufacturer. Extras like trench depth levers, loading handles, comfortable and steady handlebars, color-coded and user-friendly controls, digging chain operator presence control switches and a well-balanced, brawny construction will always sweeten the deal.

“Improved hydrostatic pumps and motors, improved digging chains such as the new EarthPro Raptor Series and more reliable operator presence systems for safety are all big options and features,” says Wren. “And almost all walk-behind trenchers are hydrostatic these days.”

The biggest options will be in boom and chain configurations (and occasionally an engine or tire choice). The tiny Vermeer RT60 mini-trenchers, for example, offer a 5.5-hp Honda engine with a choice of boom sizes from 4, 8 or 12 in. The popular 13-hp Astec 60 trencher is perfect for light trenching jobs with either a 24- or a 36-in., heavy-duty boom (the choice is yours), and the Ditch Witch 1230 offers both mechanical and hydrostatic drives (one of the only companies to offer both) with the option of a 24-, 30- or 36-in. big dig boom. And now Toro offers its TRX 15 and TRX 19 with boom sizes of 24 and 36 in. — not to mention the only walk-behind trencher on a dedicated track system in the industry.

Teeth (also called cutters and bits) options can be either welded or bolted onto the chain. The most widely used teeth are cupped cutters, which are designed with a front-cutting edge that’s shaped to actually dig and move spoil out of the ditch. But cup cutters are not designed for hard ground. For serious soil conditions, buyers can equip chains with gnarly teeth that have cool descriptors like shark, alligator, mining or rock and frost cutters. Reference the digging chain chart below for more information.

Innovation of an Industry

In the past, small pedestrian trenchers have had a reputation for their occasional obtuse operation. Contractors would have to muscle a machine to get the exact angle and path they wanted. Hydrostatic drive helped improve handling, but today customers have even more options when it comes to innovative features and operation.

Top of the list is Ditch Witch’s new Zahn. Three different Zahn units break the mold of traditional trenchers, allowing operators to dig both straight and curved trenches, as well as take different front-end attachments. Ditch Witch has a line of three Zahn power utility units with one as a dedicated trencher. But some of the new Zahn’s were engineered to be mobile power units with the ability to attach to a set of compatible front-ends — trencher, plow, backhoe and a tool carrier that can drive more than 70 quick-change attachments (from the company’s mini skid steer line).

“We have introduced several new front-ends to go along with the Zahn family — we’ve added the dumper line, stump grinder and tiller,” says Adkins. “We have recently released those into our dealer organization to reach new markets. The stump grinder for instance is a product that was upgraded to a dedicated stump grinder and built with contractors in mind.”

With an eye on easy-to-maneuver performance, Vermeer will be introducing a new machine in November 2008 called the RTX100. “It has an intuitive and easy-to-operate steering system called VZ steer, which allows the operator to steer the machine by moving the directional control bar [handlebars] to the desired amount they would like to turn the unit,” says Kuyers. “This feature makes it even easier for the rental customer to operate the unit. It is also the only unit in its class that can interchange between tires and tracks and does not require the customer to purchase another platform to meet this need.”

Speaking of track options, the new Toro TRX Series of walk-behind trenchers work faster and straighter than you would ever expect from a walk-behind trencher, says the company, because of the unit’s dedicated track undercarriage. The track drive design provides a low center of gravity and large footprint offering stability and increased maneuverability — without causing damage to existing turf.

“Unlike other trenchers on the market, Toro’s new TRX trenchers are designed with tracks rather than wheels, which allow the machines to easily handle cross trenching and effectively work on wet, rainy days or in sandy, loose soils where wheeled trenchers would struggle. The tracks disperse the weight of the machine, providing high flotation while delivering the necessary traction in any ground condition,” says Lawrence.

With added versatility in mind, Astec released its RT160 Plus tool carrier last year — a machine created to specifically appeal to the rental industry. Based on the company’s popular RT160 walk-behind trencher, the RT160 Plus can take a set of select attachments — like brooms, snow blowers, landscape rakes, dozer blades, stump grinders and (you guessed it) trenchers to maximum versatility. The attachment lift is controlled by a hydraulic cylinder, and the hydraulic drive is capable of running attachments up to 13 gpm.

“In 2007 we released the RT160 Plus which has a quick-attach system to accept different attachments such as a power rake, snow blower, snow blade and trencher,” notes Wren. “But I believe there will always be a dedicated walk-behind trencher market.”

And that’s the sentiment shared by all four major manufacturers that CE interviewed. The simplicity and durability of a pedestrian trencher is what makes these tough cutters so appealing to customers, rental houses and end-users. And although innovative technologies from tracks to curved digging paths are bringing walk-behind trenchers to another level, most professionals just want an easy-to-use unit that’s efficient, fast and simple to maintain. Luckily, manufacturers are offering that and more to the landscape and construction pros of today.

Keith Gribbins is managing editor of Compact Equipment, based in Peninsula, Ohio.