Compact Machines for Erosion Control Projects
Compact machines are often ideal for erosion control projects. They access wooded areas. They cross wetlands and golf courses, leaving little compaction of the soil. The small size and light weight of compact machines—track loaders, excavators, and skid steers—make these vehicles ideal for work in limited spaces and sensitive areas that need to be protected from damage. They maneuver along the shores of waterways and beside busy roadways. And, they’re easy to haul.
When these little machines are combined with the dozens of attachments that are available, they can handle virtually every erosion control task: blazing paths through underbrush, installing silt fence, land clearing, digging ditches, sculpting detention ponds, laying permeable pavers, planting vegetation, sweeping, and mowing.
Although their engines are smaller than those of standard machines, and provide less strength and horsepower, manufacturers continue to increase their pushing and lifting forces and their horsepower with engineering techniques that include direct-drive motors and hydraulic power capacities.
Compact loaders and skid steers can be connected to a wide variety of attachments for erosion control. They each have advantages in performing different operations.
Skid steers are typically shorter than compact loaders and can turn in place, a big advantage in limited spaces. They’re faster, and better for driving on hard surfaces as well as on aggregate, rocks, and debris.
Compact loaders are typically larger, heavier, and more stable than skid steers. They’re better on slopes and uneven terrain, and, because their tracks provide more flotation, on soft and wet ground.
Assessing the costs to own and operate one of these machines depends on many factors, including its purchase price, operational costs, and efficiency. It’s important to choose the machine that’s most suitable for the required erosion control operations.
Excavators come in two types: tail swing and zero-tail swing. Both provide comparable levels of performance when it comes to dig depth, reach, cutting height, and dump height.
Tail swing models have a rear counterweight that offsets the weight of the material in the bucket and stabilizes the excavator during operation. The counterweight provides more lifting capacity as well as greater bucket and arm breakout force than zero-tail-swing excavators, but because it extends 6 inches or more beyond the width of the tracks during operation, the design is less suited for work in limited areas.
Zero-tail-swing models have a counterweight that rotates within the width of the excavator’s tracks. They’re much easier to drive in limited spaces, such as along walls and other obstacles, and they need less space to operate but they have less lift capability.
Wheels are commonly used on skid steers. Because wheels need a lower amount of torque—the tendency of a force to rotate an object around an axis, fulcrum, or pivot—than tracks do, wheeled machines are more nimble and agile. They excel where the ground conditions are firm and higher travel speed is required.
Solid and pneumatic tires provide the same traction. Solid tires cost more than pneumatic ones to purchase, but they wear longer than pneumatic tires and withstand punctures and debris, so there’s less downtime for repairs. On the other hand, pneumatic tires cushion the unevenness of bumpy terrain, so the ride is smoother and the machine may be used at higher speeds.
Tracks increase the traction of compact machines on soft ground. They also increase flotation, which causes less compaction and damage to the soil, by spreading the weight of the machines more evenly and over a larger area than tires do. Flotation is especially important on grass or on wet, muddy, or sandy ground, and where good soil drainage will be important.
There are two lift paths for booms for track loaders and skid steers: a vertical lift path and a radius lift path. Their performance is virtually identical when the loader arms are not raised.
A vertical lift path follows a straight pathway in front of the machine. It keeps the load closer to the machine throughout much of the lift cycle, which increases the machine’s stability, making it better for heavy loads such as blocks or sod. A vertical lift path also provides higher lift capacity and greater overall lift height, which is better for loading dump trucks.
A radius lift path follows an arc. It has more reach at around the mid-height of the machine and is better for jobs at this working height, such as backfilling or loading and unloading flatbed trucks, because the machine doesn’t have to get as close.
Some of the more recent innovations in compact machines and attachments are detailed below.