Digging trenches is a process required to bury everything from a single, thin wire to large or multiple pipes. Many trench-digging tools are designed for maximum efficiency, or to remove only the bare minimum soil required to establish the necessary trench. You can find several power trenching machines and hand tools that make trenches with varying efficiencies, costs and labor.
A chain trencher operates similarly to a chainsaw; it drives a chain around a blade to excavate the soil. A chain trencher, costly to hire and move, is most useful for large commercial irrigation projects with hard soil issues. It may also reduce labor costs and physical labor.
Disc or Blade Trencher
Disc trenchers are small, motor-driven machines specifically designed to dig small trenches. These machines work quickly. They are easy to transport but blades can wear out quickly and may need frequent replacing, depending on soil conditions.
An excavator is a track-driven machine most useful for large commercial projects calling for a trench for large or multiple pipes. It scoops soil and deposits it beside the trench. A long-reaching boom arm can dig holes quickly but the cost is usually determined by an hour rate. To these, add transportation costs.
Skid Steer Machines
Skid steer machines, or bobcats, are generally not used to dig trenches but can be adapted to do so. They are useful for leveling and general earthworks. The machine weight can help to compact filled-in trenches and can work quickly. A clumsy operator could damage irrigation systems. Your costs will include hiring the machine.
A turf cutter is a small, motor-driven machine with a V-shaped blade attached for cutting turf. It removes the turf sod while trenching, which is useful in returning the sod to its original place for quick site recovery. The turf cutter is not suitable for deep trenches and can be cumbersome to operate, particularly in corners.
A trenching shovel features a square mouth to help keep a flat bed for the pipe to lie in and a handle. The handle should be light and long for easy digging with minimum back strain. You can find one at most hardware stores, but it is only suitable for digging small trenches.
A spade can be the most useful hand tool to cut trenches in existing, established sod. It has a sharp edge that can penetrate top soil and is widely available -- but it's is not suitable for lifting soil.
Shovels suitable for trench work are generally available in two types: the wide mouth and the pointed mouth. They are both readily available and useful for lifting and moving small amounts of soil or sand.
Pick Axes and Mattocks
Pick axes and mattocks are useful hand tools for penetrating hard ground and breaking it up for removal with shovels. A mattock is handy for many jobs, but the heads of either tool may be prone to coming loose.
"Combi" Tool and Hoes
The combination, or "combi," tool is a military entrenching tool with a long handle. It resembles a shovel with a single tooth extending forward off the shovel head. It serves as a light-duty shovel and scraper. Different hoes, including the adze, grub and hazel hoes, can break up sod clumps, level the bottom of a trench, and can be useful in heavy duff.