Microtrenching Lets Utilities Keep Pace with Internet Demand
12 March 2018
It’s not exactly news that the demand for instantaneous, high-speed internet connections is growing by leaps and bounds with no sign of easing up any time soon. As a result, the number of fibre-optic installations is rapidly increasing as carriers scramble to bring fiber cable directly to homes, businesses, schools, and government facilities.
Fibre-optic cable is largely distributed underground in a protective conduit. Starting from a central location, the fiber network includes long-haul routes between cities and towns, backbone fibre lines, and the shared miles of fiber that multiple individual properties use when connecting to the backbone.
Although the type and size of equipment varies depending on whether a contractor is working on a long-haul project in open areas or doing backbone work closer to the city, plowing and horizontal directional drilling (HDD) are common on these jobsites. The exact machine or tool used largely depends on surface and soil conditions.
Plows are generally preferred where a long-haul jobsite has few surface and underground obstructions, said Rupp. This method is often the fastest and most efficient way for placing long-haul conduit in the ground in varied terrain. To improve maneuverability on level and uneven terrains, for example, he cited the Ditch Witch RT125 quad with a plow attachment that benefits from a quad-track ground drive system and is available with optional reel carrier attachments to hold conduit.
Long-haul jobsites that include rough terrain, wooded areas, water crossings, or other areas where plows cannot operate are best suited for directional drills. The units can help meet a project’s timeline by providing the capability to bore under obstacles. In tough soil conditions or rock, Ditch Witch All Terrain (AT) equipment is specifically designed for drilling precision, control and efficiency in solid rock, fractured rock or other hard, underground conditions.
Compact, last mile
Although plows and directional drills remain popular when connecting shared fiber lines, urban environments create unique issues for utility contractors, said Rupp. Utility placement beneath city streets is more congested, and unpredictable surface obstacles are more prevalent. In addition, these areas are often more compact, making equipment size an important factor in residential fiber drop-work.
Utility contractors are increasingly turning to microtrenching for fiber jobs in these congested urban environments that require a less-disruptive method of installation, he explained. Microtrenching is becoming a leading, cost-effective option for installing fibre-optic cable along paved rights-of-way. Unlike traditional installation methods, microtrenching cuts a narrow, shallower trench—deep enough to get under the upper layer of solid ground, but shallow enough not to interfere with existing utilities. Further, neighborhoods and businesses often are not built in a straight, easily-navigable line, so maneuverability has been a contributor to the popularity of microtrenching.
Equipment manufacturer Ditch Witch has invested in designs that reportedly bring out the best in microtrenching technology.
The MT16 is said to be a cost-effective microtrencher that creates an ideal trench in a single, quick and efficient pass when working with the company’s RT55 or RT80 ride-on trenchers, and the FX65 vacuum excavator.
The RT55, for example, has a 62-hp Deutz® diesel engine and powers the MT16 hydraulics. The RT55 has a hydrostatic ground drive with infinitely variable speed from zero to 5.5 mph. Attachments and trenchers also rely on a hydrostatic drive transmission. The ground drive pump runs at 32 gpm and 5,000 psi. Attachment pump capacity is 32 gpm and is rated at 5,450 psi. Two smaller auxiliary pumps, with 8 and 6 gpm flow capacities, are rated at 3,000 psi.
Designed to cut narrow trenches 0.5 to 2.0 in wide and up to 16 in deep, the MT16 decreases disruption to surrounding infrastructure during fiber deployments. An integrated hydraulic accumulator maintains constant pressure on the saw frame for sharper-edged cuts and improved spoils removal. In addition, an infinitely variable hydraulic-plunge feature eliminates manual adjustment of the microtrencher by providing variable depth control from zero to 16 in. For a tighter-cut radius, the unit’s frame swings up to 6° in each direction, letting operators efficiently cut on a street corner or around a cul-de-sac.
“Constrained time and unplanned expenses are the leading jobsite hurdles we hear from utility contractors,” said Steve Seabolt, Ditch Witch product manager, heavy-duty trenchers. “Our MT16 microtrencher is designed to help operators complete fiber jobs efficiently with less time and expense. Compared to traditional installation methods, the MT16 creates consistent trenches for faster fiber deployments, reducing the cost-per-foot on fiber jobsites.”
The MT16 is compatible with a complete lineup of Ditch Witch saw blades, from standard carbide-tipped blades to the Ditch Witch-exclusive Fibreblade, which combines the benefits of both diamond and carbide. The Fibreblade family of blades features a durable, maintenance-free design lasting up to 20 times longer than standard blades. All saw blades for the MT16 are easily changeable on a jobsite with standard hand tools. Similar to the MT16, the company’s MT9 microtrencher attachment is designed to improve productivity and reduce the cost-per-foot on small fiber jobsites. Developed to work in tandem with the Ditch Witch line of mini skid steers, the industry-first system is well suited for tight and confined residential areas, such as street crossings.
To reduce ground disruption, the MT9 creates clean, shallow trenches up to 9 in deep and 0.375 to 1.5 in wide. A patented blade plunge provides infinite variable depth control while the machine is in operation. Additionally, the microtrencher works with the FX65 vacuum excavator to ensure a clean trench in one pass by effectively removing spoils.
“Traditional fibre installation methods lack the speed and efficiency to be cost effective for contractors in many residential areas,” said Seabolt. “Our new MT9 minimizes the space required to operate, avoiding hurdles found in confined, tight and urban jobsites.”
Designed specifically for street crossings, an ability to push or pull the microtrencher keeps the saw in the ground for more efficient and accurate cuts, he added. By eliminating the need to realign during a cut, operators are able to complete the cut faster and produce a better looking finish.