The hydraulic excavator began as a variation on the steam shovel, which employed cables and other mechanical systems to manipulate a digging bucket on the end of a boom. In England in the late 19th century, a manufacturer subbed a hydraulic cylinder for a cable and utilized water as the hydraulic fluid. Before the end of the century, steam began to power the hydraulics. By the middle of the 20th century, manufacturers of the excavators had settled on oil to transmit hydraulic pressure.
Early models were, of course, primitive. For example, a 1950s excavator was an ergonomic and comfort nightmare compared to modern excavators, with operators sitting on a bench and lifting out the front glass of the cab for ventilation. Development was relatively slow at first: Caterpillar didn’t introduce its first excavator until the 1970s. Today, the hydraulic excavator is an electronically sophisticated, powerful piece of equipment with application across numerous industries.
More than a dozen manufacturers produce mid-size and full-size hydraulic excavators for the North American market. In evaluating them, the primary consideration should be matching a machine to your situation. Some criteria to consider:
1) Digging, Demolishing or Denuding?
The question is, how will the machine be used? Most buyers will crank up an excavator to, yes, excavate. But others will employ it to load aggregate or tear down a brick building or cut away roadside brush and limbs. In addition, excavators frequently are called upon to lift materials. How many of these functions will happen on your job sites? Suggestion: Select a model with enough horsepower and hydraulic flow to accomplish the most demanding task without being way oversized for other jobs you’ll undertake.
2) What features and configuration will best-serve you?
All excavators are not created equally. Some have extra-long booms or sticks while others offer buyers a telescoping boom. Elevated operator cabs? You can get them. Will you be hauling a crawler excavator from job to job on a flatbed? Lots of choices. But if you prefer to drive a rubber-tired excavator across paved areas, you have that option, too. The variety of hydraulic excavator types in the market combines with their versatility to keep these machines a popular choice for contractors.
3) Brands and dealerships worth thinking about.
The reputations of iconic manufacturers of hydraulic excavators precede them. Newer brands — or new entrants in a marketplace — might require extra due diligence on the part of a buyer to really get a full backstory. Then there are dealers. Try to learn the level of satisfaction of current customers before becoming one yourself. Every machine needs solid dealer support.
4) Size matters.
If you are shopping for a midi or large excavator, you have dismissed consideration of mini and compact models. Even so, some attention to dimensions should be paid. For example, if a worksite is confined, a short-tail swing model might best fit your needs. If access to a working site is limited by height restrictions, a lower profile (telescopic boom) excavator might be best. Wheeled excavators sometimes are narrower than crawler equivalents and could mean the difference between entering a job site or not.
5) Will you transport it?
While a large hydraulic excavator seems a perfect choice, is your flatbed large enough to haul the machine to a job site — including attachments? Transporting heavy equipment means permits must be secured to ensure weight is appropriate for a road, escorts will be provided, routing is appropriate and the machine is properly secured on the trailer. Such regulations can vary from jurisdiction to jurisdiction. The larger the excavator, the more demanding transport becomes, so weigh all that before going large.
Renting an excavator is an excellent way to evaluate a machine model before buying it. It is a hands-on method of learning the difference between an excavator that’s a perfect match for your application and a so-so one. A mediocre match surely is not what you are after. Some pointers:
1) Look for a good fit before a good deal.
If renting an excavator for an extended project is your end-game — you have no plans to invest in one at the moment — don’t get hung up on an enticing rental rate. If you save a few thousand dollars over the course of a rental contract, but mutter daily about the performance of the rented machine, you’ll rue the day you rented it. So, look at your project site, your task, your production timetable and get the model you really need.
2) Look beyond immediate use.
Because the working end of a boom does more than dig, consider all the ways it might be used when fitted with attachments. Is there a barn on the back of the property you should demolish? A landscape berm to be shaped? Trenching needed for a foundation? Overgrown vegetation to clear away? If a rented excavator is too big, or small, for more than one task, consider upsizing or downsizing for better utilization of the machine.
As with any other investment, examine the condition of the excavator before signing papers. A visual check and mechanical test of the machine are in order.
1) First, examine the hydraulic components.
These aren’t electric excavators or steam shovels. The excavator’s hydraulic system defines its power and responsiveness. So, look first to the machine’s hydraulics to determine condition. Is there evidence of consistent leaking from pump, hoses, lines or cylinders? This suggests poor condition, but also indicates poor maintenance.
2) A lot rests on the undercarriage.
Rotating an excavator’s upper structure puts tremendous stress on the slewing ring that connects superstructure to undercarriage. To determine if wear is occurring in the ring, look for metal particles in lubricant and excessive play. Operate the machine and try to discern wobbly movement and grating sounds. A failing ring can be a costly fix.
3) Know signs of wear and abuse.
Cracks are worrisome, especially in metal structures and welds. If the boom or stick of an excavator has cracks in connecting-point welds, it strongly suggests the integrity of the mechanism is at risk. If the cracks in a machine are compounded with denting and possible twisting of the framework, a potential buyer probably should not proceed.
4) Don’t get attached to attachments.
You are buying an excavator, not the tools fitted onto the boom, so concentrate on the base machine. Still, any attachments coming with the excavator deserve some attention. Is the leading edge of a bucket scalloped (worn down)? Does a breaker show evidence of hydraulic leaks? Is a rotary cutter dented and rattling? Don’t count on them working well.
Hydraulic excavators continue to evolve and become more sophisticated, yet their effectiveness and reliability are proven. New and used models are widely available at widely ranging prices.
Prices for new models depend on brand, power and capacity, optional features and general market demand, which varies by region. Looking at prices from dealer to dealer or region to region is worth the trouble. Hereafter are some categories of pricing:
For used machines, comparing value is more difficult because of additional variables including the year of manufacture, number of engine hours and general condition. Hereafter are some general pricing guidelines for conventionally outfitted second-hand crawler excavators with 2,500-4,000 operating hours:
Prices are determined by size of machine, local demand and the volume of rental competition in an area — with coastal areas of the United States generally charging more. An online survey suggests the rental price for a mid-size crawler excavator ranges widely — from $800 to $1,500 a day, $1,800 to $3,100 a week, and $5,200 to $7,000 a month. Some rental companies give corporate and fleet customers a lower rate. Equipment rental sources include independent and national rental houses as well as equipment dealerships.
Some Financing Options
Buying a piece of heavy equipment usually involves financing the investment. Leasing a machine with an option to buy can lower upfront costs for customers wanting eventual ownership of an excavator. If owning a hydraulic excavator outright is your choice, companies have structured programs to make it happen.
1) Weight and horsepower
Machine weight and engine size are wide-ranging in the midi-to-full size category of excavators. The manufacturing industry includes machines weighing from six tons to almost 100 tons and with power units rated as small as 50 hp and as large as 530 hp. Somewhere along that spectrum is a hydraulic excavator for every buyer. Example: If a machine mostly will excavate, get one with the power (and base weight) to provide sufficient breakout force, reach and digging depth. If it mostly will be lifting, calculate how much it will be able to lift and how high. Match weight and horsepower to function.
2) Hydraulic flow/pressure
Along with horsepower and weight, hydraulic capacity is a major consideration. A hydraulic excavator can accomplish wide-ranging tasks when fitted with one attachment or another, but only if hydraulic fluid flow and pressure are up to it. For example, a brush cutter attachment capable of cutting a 42-in. swath needs 10-20 gpm of flow to perform up to speed, whereas a cutter with a 60-inch swath may require 30 gpm. While a shears attachment can do a job with relatively low flow, if the host machine’s PSI is too low, shearing force is reduced. Match attachments to hydraulic capacity.
3) Strength and reach
A buyer deciding on an excavator with a boom and stick — as opposed to one with a telescopic boom — still has decisions to make. Boom assemblies can be heavy-duty, extra-heavy-duty and extra-long and are sized for digging, carrying particularly heavy attachments, or extreme reach. The sticks attached to the boom are similarly sized for function. So, a buyer should know if breakout force is more important than reach or vice versa and the weight of a preferred attachment. The size of a bucket, for example, must be considered in tandem with the sturdiness and length of boom and stick.
4) Tracks or tires?
Saying “hydraulic excavator” usually conjures up a mental image of the ubiquitous digger on steel trucks. That is the most common configuration, but not an exclusive one. Crawler excavators are a first choice for good reasons: They can function in soft or wet ground conditions, hug the ground stably, and ride smoother on rough terrain than wheeled excavators. On the other hand, excavators on tires can be driven on pavement without damaging it and are easily maneuvered in tight spots. Outriggers give them working stability. Contractors have good reason to consider a wheeled excavator.
Most excavators excavate. Yet attachments have been developed to take advantage of the machine’s reach and robustness so they can be employed for other tasks. Some attachments require higher hydraulic flow to power them. Other attachments — thumbs and shears, to name two — require a third-function hydraulic circuit to operate. A buyer should know if an excavator’s hydraulic capacity and versatility will be sufficient for a desired attachment. Here are some popular attaching tools:
Auger — Drilling holes for fence posts, pilings or other structural members is made easier when the auger is fitted to the end of an excavator boom-stick. Hard-to-reach drill spots are easily reached and several holes can be drilled without moving the excavator.
Breaker-Hammer — These are the tools that pound a hardened bit through hard materials to split or rubblize them. They do this with downward force applied by the excavator and an internal reciprocating ram that delivers hundreds of blows per minute.
Bucket and Thumb — A bucket is the workhorse, the fundamental attachment. It comes in narrow, general purpose and broad widths as needed. When a moveable “thumb” is added, it gives an operator means to scoop up and grasp oversized or ungainly material.
Vibratory Compactor — This boxy attachment with a flat bottom is employed to firm loose soil or aggregate. It rapidly delivers short, vibratory blows. Example: On a 15-ton excavator, a 2,000-lb model delivers 2,200 cpm with a vibrating force of 16,000 pounds.
Coupler — This attachment connects an excavator to tools. Hydraulic quick-couplers are hands-free. Mechanical models can require an operator to climb from a cab. Tilt-rotating couplers give a tool wrist-like dexterity in handling material or for slope-sided digs.
Crusher-Screener — Buckets scoop up material, but some also crush or screen the material. Bucket screeners and crushers process aggregate and debris. The buckets often employ hydraulic-driven churning shafts that chew up concrete and brick.
Demolition Tools — Hydraulic excavators can dismantle structures and reduce scrap. With attachments, they snatch brick, rip welded material and shear steel beams. Example: The jaws of a steel-cutting shear on a 20-ton excavator have 280,000 lbs of cutting force.
Drum Cutter — Grinding through rock or concrete material is easy (if loud) with this attachment. Torque, weight and RPMs do the trick. A 150-hp excavator needs at least 55 gpm of flow to spin a 3,000-lb cutter’s hardened fingers and carve a 46-in. wide path.
Forestry Tools — Various excavator attachments have been developed to speed the harvesting and handling of timber products. Attachments include shears and saws, wood splitters/sectioners, and stump grinders and stump extractors.
Grapple — This is a relatively simple tool used in a host of applications from forestry to demolition to construction. Two moving jaws reach out like thumb and finger and clamp together. In larger models, the jaws are wider and can resemble buckets.
Magnet — Putting magnetism to work, this attachment is commonly used in scrap yards for moving irregularly shaped steel material. It also is employed on demolition and construction sites for clean-up. A midsized round magnet is about 40 inches in diameter.
Mulcher — These chewing tools can reduce a 30-ft.-tall tree to a stump in less than a minute as the mulcher rides down on the upright trunk, shredding it. The tool can be six feet in width, with larger models requiring 70 gpm hydraulic flow or more.
Pile Driver — Mounting this attachment on an excavator gives it the ability to sink and extract piles, girders, casings and similar permanent or temporary structures. High-speed vibrations help propel a pile into the ground and also help loosen it during extraction.
Rock Saw — A vertical rock saw dangling from the end of a boom-stick is a formidable tool. It can slice through asphalt, concrete, and granite, among other materials. A 100-hp machine with 75 gpm flow can spin a 5-ft. blade and cut 25 in. deep.
Bobcat — This legacy American equipment-maker is known for its compact equipment including skid steers (which it invented) and CTLs, but also for compact excavators. It continues to grow the size of its excavator line - and the size of its equipment.
Case — This Wisconsin equipment manufacturer dates from 1842. It introduced its first excavator in 1967. Today, its full-size crawler excavators range from a 102-hp 15-ton model to a 532-hp 90-ton model. Its “intelligent” hydraulic system maximizes efficiency.
Caterpillar — The Illinois company was formed in 1925 and is an icon in the heavy construction equipment industry. Cat offers eight mid-size and six full-size hydraulic excavators as well as seven wheeled excavators, the largest a 169-hp model.
Doosan — The South Korean firm began manufacturing heavy machinery in 1937, turning out its first crawler excavator in 1978. Today, Doosan builds 12 crawler models and three wheeled models. Its largest excavator on wheels is a 24-ton unit boasting 186 hp.
Gradall — In 1944, this Ohio company introduced an innovative wheeled excavator with a telescoping rigid boom. The unique rotating-boom engineering has been translated into highway speed, rough terrain, crawler and railway models, powered by Volvo engines.
JCB — For 66 years, this British manufacturer has marketed finely engineered machinery. It offers seven full-size crawler and seven wheeled excavators. It classifies its hydraulic excavators as high-reach demolition, long-reach, mass excavation, and extra heavy duty.
John Deere — This Illinois company, founded in 1837, markets 14 mid-size excavators and three full-size, the largest a 512-hp model. One example: Model 300G LC is a 15-ton, 223-hp unit that digs 25 ft. deep and boasts several operational efficiency systems.
Hitachi — The Japanese firm built its first excavator in 1957. Its products available in the U.S. include four mid-size models and six large (mining) excavators, the largest with paired 1,900-hp engines. The smallest mid-size unit has 100 hp and digs 19 ft. deep.
Hyundai — A South Korean company established after World War II, Hyundai builds both wheeled and crawler mid-size excavators with Perkins, Cummins or Scania engines. A 150-hp wheeled model can whip along on pavement at 24 mph.
Kubota — The Japanese company started as a foundry in 1890 and continues to expand its product line. Its excavator models now are small but are expected to grow as the line matures. One of Kubota’s strengths as a manufacturer is the popularity of its engines.
Komatsu — The Japanese firm’s roots go back 99 years. It builds hydraulic excavators, from compact to mining machines, including a dozen mid-size crawler models and a half dozen wheeled. The units incorporate numerous “intelligent” automated control systems.
Kobelco — The company formed in 1930 and built its first excavator in 1963, a tri-cycle rubber-tired model. Today it manufactures a full range of crawler excavators - compact to large - plus three long-reach and four “high and wide” specialty models.
Liebherr — The German company, begun in 1949, markets seven wheeled excavators, 10 crawler models and five pontoon units engineered for dredging operations. In addition, the company is launching a new “8th-generation” series of hydraulic excavators.
Link-Belt — This company with American roots dates to 1880, but it didn’t build its first excavator until the 1980s. It now offers 11 full-size or mid-size hydraulic excavators, 13 forestry-oriented models and four designated for material handling.
LiuGong — A Chinese firm started in 1958, LiuGong introduced its first hydraulic excavator in 2001. Though it is a fairly recent addition to the excavator-manufacturing industry, the company now offers eight mid-to-full-size crawler models in the U.S.
SANY — Formed in 1989 in China, SANY entered the U.S. market in 2006. Three years later, it built the largest excavator in China, a 200-ton model. It offers two mid-size and two large excavators in the U.S., the biggest a 400-hp unit that can dig down 27 feet.
Takeuchi — Founded in 1973, the Japanese company introduced the first compact excavator eight years later. It continues to grow the line and today has a true mid-size excavator, the TB2150, which weighs 17 tons and is powered by a 114-hp diesel engine.
Volvo — Founded in 1906, the Swedish firm began to offer hydraulic excavators in 1991. Today, the manufacturer’s product line-up for North America includes eight large crawler excavators (the biggest a 600-hp model), six mid-size units and six wheeled excavators.
The secret of hydraulic excavators’ global popularity is in its variable reach, its hydraulically powered digging and lifting capacity and its swiveling base. Together, these engineering features are the basis for efficient excavation, construction, material-handling, demolition, and logging operations. Specialty models and attachments extend the excavator’s versatility across numerous markets. To call them “excavators” is something of a misnomer. They are everything-ors.