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Imagine if you had a
giant Swiss Army knife with various types of blades, as well as
all the extras (nail clipper, screwdriver, toothpick, fire starter,
corkscrew, etc.). That’s a valuable tool—far more valuable
than just a simple knife blade—and it would be a lot less expensive
than purchasing individual tools to do all those jobs.
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Photo:
Horton
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That’s the basic
idea of construction-equipment attachments. Replace an excavator
bucket with a vibratory compactor, and a separate compaction machine
won’t be necessary. When equipped with a ripper, a standard
dozer can tackle hardpan soils and even soft rock. Replacing a dozer
blade with a rake allows the same piece of equipment to do both
earthmoving and debris clearing.
Types
of Attachments
There are about a dozen major categories of attachments, each with
multiple subtypes. The major categories include buckets, rakes,
grapples, clamshells, thumbs, compaction wheels and plate compactors,
forks, hydraulic hammers and concrete pulverizers, universal processors
and shears, stump splitters and other logging attachments, rippers,
and sticks and booms.
The following is a description
of these categories and a listing of the various attachment subtypes:
Buckets
Buckets are the part of the exactor that digs, lifts, and carries
dirt. Bucket edges are usually equipped with teeth to allow for
easier digging. Front-end loaders use wider buckets for material
handling and stockpile maintenance.
Excavator buckets
are standard attachments for backhoes, trenchers, and excavators.
They vary in size from a 9-inch bite width and a heaped capacity
of 0.02 cubic yard to a 79-inch bite width and a heaped capacity
of 1.15 cubic yards. Their functions include digging, general-purpose
excavation, ditching, utility installation, ditch cleaning, and
rock excavation. Specially made models allow for the direct cutting
of trapezoid-shaped channels.
Heavy-duty buckets are
exceptionally large and durable buckets used for severe operating
conditions (large loads and high productivity and/or extremely heavy
and hard material). Unlike standard excavator buckets, most heavy-duty
versions are specially made.
Excavator screening
buckets are similar to standard excavator buckets except that
their steel-plate bottoms are replaced by regularly spaced steel
bands. The bands are shaped to conform to the bottom curvature of
the bucket but create gaps of various widths that allow objects
of a given size to fall through. This screening action ensures that
only those objects larger than the opening remain in the bucket.
Pavement-removal buckets
are attached to excavators and are used to rip up and remove old
pavement. Pavement-removal buckets are designed to get under pavement
with long wedgelike teeth. This allows the operator to maximize
the hydraulic forces applied to the pavement. Pavement-removal buckets
have C-shaped profiles to efficiently remove broken concrete and
pavement slabs.
General-purpose loader
buckets are different from excavator buckets in that, instead
of being used to excavate or trench into natural soils, loader buckets
are used for stockpile maintenance and loading of pre-positioned,
loose materials.
Light-material loader
buckets are used for lightweight materials such as wood chips
and mulch, and the loading of coal. They tend to be larger than
standard buckets but of a lighter design. This combination of large
capacity and reduced weight increases the productivity of managing
lightweight materials.
Combination fork-loader
buckets convert lifting forks into loader buckets, often without
the need for a coupler. Many models allow for the bucket to slip
over the forks and be locked into place. They are designed for numerous
applications such as picking, loading, leveling, and grapple work.
Rock-loader buckets
are severe-duty attachments with capacities of 5 cubic yards and
up. These are used primarily for quarry mining operations and are
especially useful for removal and loading of blasted material.
Skeleton buckets
are designed for use by front-wheel loaders and are used for shifting
activities; collecting stones in riverbeds; removing debris without
the soil; and cement mixing, which is vital to the concrete finish.
The open tines of these buckets are designed to select materials
having the same dimensions. Objects larger than the openings (such
as building debris) are retained while smaller particles (like soil)
pass through.
Roll-out buckets
are used for operations requiring high dump clearance. The roll-out
bucket is specially hinged and powered by one or two hydraulic cylinders
to achieve higher dump height and avoid the need for a loader with
a greater reach.
Rakes
Rakes are blade-shaped attachments constructed of spaced tines.
They are useful for clearing debris without moving significant quantities
of dirt. Modified rakes can also be used for stockpile maintenance
excavation of demolition debris.
Stacking rakes
are used for land clearing and general stacking and stockpile maintenance.
They are attached to skid-steers and front-end loaders and consist
of a bottom set of fixed tines and a pair of upper, movable arms
located at each end of the rake.
Grapple rakes
are attached to front-end loaders and are used for loading logs,
picking up rocks and orchard prunings, and raking and piling brush
and other hard-to-handle material. During land-clearing operations,
they are used for picking up/piling cut trees and treetops. Attached
to skid-steers and front-end loaders, grapple rakes consist of a
bottom set of fixed tines and a set of top tines that can open and
close around an object.
Dozer rakes are
replacements to the blades normally attached to dozers. They consist
of a single set of fixed tines along the bottom where the dozer-blade
edge would be located. They are used for clearing operations instead
of earthmoving.
Excavator rakes
can turn your excavator into an efficient land-clearing machine
for a fraction of the cost. Attached to the end of the excavator’s
long arm, the excavator rake’s long tough teeth are built of
high-strength, heat-treated alloy steel. The teeth are typically
curved for maximum rolling and sifting action. They usually project
forward to improve the efficiency of loading the debris.
Grapples or Grippers
Grapples or grippers are clamshell-like buckets having two or more
jaws. The jaws hang vertically from a central cable with at least
one independently operated by mechanical, hydraulic, or electrical
power. Their main function is to grab and lift large, irregular
objects and materials. The jaws can be equipped with thin tines
for managing larger objects or with overlapping tines that seal
in smaller objects or granular material.
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Photo:
Barda
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Standard grapples have
numerous, relatively thin tines and are used to manage softer materials
such as cardboard, plastic, tires, and paper scrap.
Rotating grapples
can rotate on the axis of the central stick mounting. The rotational
movement is controlled by the operator either electronically or
hydraulically (cylinder or adjusting stiff arm). The rotation allows
for flexible orientation of the grapple and efficient management
of oddly oriented material handling such as stump removal, piling,
road building, or demolition.
Heavy-duty grapples
are specially made for severe operating conditions. They typically
have sheet steel connecting the tines, providing improved strength
and durability.
Orange-peel grapples
and tulip grapples (those that form a seal) are also referred
to as wide-tine grapples. They are operated by hydraulic, mechanical,
or electrical means. They can be mounted on excavators, truck-mounted
cranes, bridge cranes, gantry cranes, portal cranes, cables, and
ropes. Often used for scrap or trash handling, they can be equipped
with four, six, or eight tines. Versions with fully closed tines
allow for the management of sand and gravel.
Clamshells
Clamshells are shovel buckets with two jaws that clamp together
by their own weight when they are lifted by their closing line.
A shovel equipped with a clamshell bucket handles loose material
such as sand, gravel, crushed stone, or coal. Clamshells are also
used in dredging operations.
Hydraulic clamshells
differ from standard clamshells in that the closing action of the
clamshell is driven by hydraulic cylinders instead of the weight
of the jaws. This is especially useful in situations where increased
containment efficiency is required, such as managing wet materials
or contaminated soils.
Thumbs
Thumbs are attachments to excavator buckets that allow the buckets
to grab larger objects or improve the retention efficiency of the
buckets. Thumbs are equipped with one to four tines and a hydraulic
connection to the bucket arm. They are configured like a true thumb
to the bucket’s “fingers.” The tines mesh with the
bucket teeth for control, crushing power, and material retention.
Tines are often lined with teeth for improved gripping. Thumbs vary
in size from small, one-tined models to large, severe-duty models.
Compaction Wheels
and Plate Compactors
Compaction wheels and plate compactors are attachments to excavator
arms that allow for compaction of placed soil in relatively small
areas such as along a trench on either side of a utility alignment.
The wheels either self-vibrate to achieve compaction or transmit
pressure from the excavator arm.
Pad/sheepsfoot compactors
are equipped with pads similar to those of a sheep’s foot.
The pad lengths are equal to the thickness of the loose lift of
soil to be compacted.
Trench compactors
consist of one or two wheels (with or without pads) that are thin
enough to fit in a trench without touching the utility line in the
trench. Paired compactor wheels allow for consistent, simultaneous
compaction on either side of the utility.
Plate compactors
are attached to the ends of booms and are equipped with their own
hydraulically driven vibrator. The rapid vibration is transferred
to the bottom plate, generating compaction forces in the soil.
Forks
Forks consist of a pair of steel tines attached to and projecting
in front of a power-driven truck that can lift, travel with, and
stack heavy loads at a certain height. The loads are often lifted
on a pallet constructed to easily receive the forks. Forks are sometimes
used to carry the axles or rods of rolled materials. The fork’s
back frame can be designed with a low profile (maximizing operator
visibility) or with a reinforced frame to allow for heavy lifting.
Forklift tines are manually adjustable to allow for lifting of different-sized
objects and pallets.
Hydraulic Hammers
Hydraulic hammers are machine hammers driven by compressed air.
They are attached to excavators and loaders, and are used to break
up larger masses or thick slabs of concrete. The vibration generated
by air pressure is used to break pavement or rock.
Concrete pulverizers
are attached to excavators and use existing excavator hydraulics
to operate. Instead of the hardened point used by hydraulic hammers,
concrete pulverizers use a set of jaw clamps to break up concrete.
They consist of a movable front jaw, actuated by the bucket cylinder,
which closes in a stationary back jaw. The back jaw is pinned in
place with a position arm, which is pinned to a mounting pad welded
onto the end of the excavator arm. They are used for the demolition
of concrete pavements, bridge decks, walls, slabs culverts, beams,
columns, and pillars. The crushing action allows for easy separation
of rebar from concrete.
Shears and Universal
Processors
Typically loaded on skid-steers, loader-backhoes, and small excavators,
shears and universal processors are used primarily for building
and bridge demolition. They resemble a giant two-jawed pincer capable
of cutting through the hardest and thickest materials. There are
several different types of jaws.
Concrete-cracking
jaws have large openings useful for breaking large concrete
structures—parapets, pillars, beams, and high-productivity
projects where significant amounts of demolition are required.
Shear jaws are
designed for processing steel encountered on demolition sites, like.
Plate shear jaws
are specially designed for processing both aboveground and belowground
storage tanks.
Demolition jaws
are general-purpose processors that combine features of the shear
jaw and concrete-cracking jaw.
Wood shear jaws
are used on all types of wood materials including those involved
in logging operations.
Stump Splitters and
Logging Attachments
Stump splitters and logging attachments are utilized by specialized
equipment in the logging industry. Also included in this category
are cutters that clear brush and cut down trees.
Tree shear jaws
are similar to wood shear jaws but are designed to cut standing
trees. Their jaws therefore have a horizontal orientation to cut
tree trunks.
Brush cutters
are used in a variety of applications including power-line rights
of way, seismic lines, regrowth, and oilfields—anyplace brush
is a problem.
Feller bunchers
cut and stack tree trunks and are used in logging applications where
the trees are to be salvaged.
Loader brush blades
are designed for ease of use in efficient handling of brush, stumps,
waste material, and rocks. The blade has multiple box sections with
under-extending teeth of varying length and curvature.
Rippers
Rippers are towed machines equipped with teeth designed to loosen
hard soil and soft rock. They are typically attached to the rear
of the equipment (usually a dozer) and pulled behind as the equipment
moves.
Heavy-duty rippers have
excessively large teeth at the ends of reinforced tines.
Sticks and Booms
In a dipper shovel or pull shovel, a stick is a rigid bar hinged
to the boom and fastened to the bucket. Part of a revolving shovel,
a boom is a beam hinged to the deck front, supported by cables,
and carrying a weight-lifting device at the other end. It is the
upper arm to the stick’s forearm.
Attachment
Suppliers and Products
Barda Equipment’s Davco brush cutters are its main attachment,
as are some selective logging feller bunchers. All products are
designed for skid-steers, Posi-Tracks, and excavators. Barda produces
only Davco industrial-strength attachments.
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Photo:
Barda
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CEAttachments Inc.
provides a wide range of attachments for use on compact excavators,
skid-steers, and compact utility tractors. The attachment product
line includes about 50 different categories for skid-steer loaders
alone. Currently CEAttachments sells exclusively to equipment dealers
and rental centers (the company does not sell directly to contractors).
Its product line includes products considered “core” (augers,
pallet forks, buckets), and extremely unique products like culvert
cleaners and sand bag filling attachments.
Paladin Brands (ATI)
is a supplier of attachments from Badger, Bradco, C&P, Genesis,
JRB, McMillan, Pengo, and Major. In addition to its standard line
of excavator and loader buckets, Paladin supplies specialty attachments
for landscaping, demolition, auguring, forks, and sand-blasting.
Specialty buckets include rock buckets and grappling buckets.
C&P Attachments
manufactures various productivity-enhancing attachments. In addition
to standard excavator buckets, C&P also supplies specialized
trapezoidal channel buckets and sand buckets suitable for loose
material excavation. It also provides four types of thumbs: welded-on
stiff-armed thumbs that are manually adjusted; welded-on hydraulic
thumbs, which allow for hydraulic opening and closing by the operator;
non-linked hydraulic thumbs that allow for up to 140-degree rotation;
and linked hydraulic thumbs that allow for 180 degrees of rotation.
Construction Attachments
has a unique product line of attachments and accessories, including
breakers and shears mounted on tractor-loader backhoes, compact
excavators, skid-steer loaders, and large excavators. The breakers
are hydraulically powered and used for concrete and rock demolition,
asphalt removal, quarry work, and compaction work. The shears are
also hydraulically powered and used for demolition work involving
concrete and rebar destruction. Multipurpose buckets and specialized
buckets mounted on skid-steers are also available. These specialized
buckets include industrial buckets, low-profile buckets (designed
for material handling and leveling), high-capacity light-material
buckets, grapple buckets, and root grapples, as well as nursery
buckets (for the transportation of nursery stock). Forks are also
available for use on agricultural and industrial tractors. The company’s
line of specialty attachments includes boom polls and bale spears
(for the transport of large agricultural bales).
Pemberton Inc.
manufactures a variety of grapples, buckets, rakes, forks, crushers,
and shears. These attachments are designed for use by wheel loaders
and excavators, in applications where loaders and excavators are
also used in bulk-loading, sorting, and processing applications.
Pemberton’s line of grapples includes those specifically designed
to manage bulk tires and pipe or poles, as well as a lone tine grapple
suitable for working white goods and general scrap. Pemberton provides
a line of specialized buckets for wheel loaders that includes light-material
and wood chip buckets (2- to 16-yard capacity), a heavy-duty spade-nosed
rock bucket (3 to 8 yards), general-purpose buckets (2 to 12 yards),
trash buckets with optional heavy-duty rubber-opening stop-to-cushion
dumps, high-reach roll-out buckets, heavy-duty multipurpose buckets
with bolt-on teeth or edges, and a skeleton open-tined rock bucket
(3 to 8 yards). In addition to its standard loader rakes Pemberton
has a line of citrus rakes, some of which are equipped with saddle
clamps to secure uneven loads, specially designed to move trees.
Its line of forks includes designs for mill feeding, carrying pipes,
and moving logs. Its MDG series of rock crushers and shears uses
the same mounting bracket (allowing for interchangeability) and
varies in size from 2,700 to 8,200 pounds.
Werk-Brau Co.
manufactures specialized bucket attachments for excavators, backhoes,
loaders, and skid-steers. In addition to its standard line of excavator
buckets (rated for general purpose, heavy duty, extra heavy duty,
and severe duty), Werk-Brau has a list of specialized buckets designed
for ditch cleaning, frost and rock rippers, coral excavation, sand
buckets, coal buckets, pavement-removal buckets, and trapezoidal
ditch cutters. The company also makes matching thumbs designed to
aid in handling large objects, irregularly shaped objects, rocks,
and debris that cannot be handled by the bucket alone. Its line
of backhoe attachments includes wheel compactors, solid tine grapples,
material handlers, and various types of couplers. The grapples allow
for effective clearing of debris, rock, and brush. Its loader attachments
include booms, rakes, adjustable forks, and various buckets. The
wishbone grapple fork is a specialized attachment designed for moving
logs or large pipes with a high productivity rate.
American Compaction
Equipment supplies a series of Diamond brand trench compaction
wheels. They can be mounted on excavators, backhoes, and skid-steers
and come in hex pad, wedge pad, or sheepsfoot styles. Hex pad and
wedge pad wheels measure 3 inches in diameter smaller than sheepsfoot
pads. All compaction wheels include a removable mount with pins
and a soil-leveling plate. Tight corner compaction is provided by
American Compaction Equipment’s SK series of wheels for mini
excavators.
Action Equipment Systems
supplies a series of open-rimmed, sheepsfoot, and padded compaction
wheels. They can achieve standard densities in normal soil conditions
with six to 10 passes. They are mounted on rubber-tire backhoes
or mini excavators and vary in size from the 17-inch-wide, 835-pound
model 183 LBWL to the 23-inch-wide, 850-pound model 243 LBWL. The
compaction wheels can be mounted in three different configurations.
Bucket-mounted wheels are mounted on the underside of the excavator
bucket, allowing one dedicated machine to pull material back into
the trench and then compact it in place by reversing the orientation
of the bucket. Mount-bracketed wheels are mounted directly onto
the excavator arm, improving compaction productivity. Bucket clamps
allow for temporary mouthing of the compaction wheel on the edge
of the bucket. This provides versatility, allowing the operator
to mount the wheel on many different machines.
Tech Hydraulic Inc.
is a 25-year-old company that manufactures a line of Rockblaster
hydraulic hammers, breaker attachments, and associated tool bits.
Tech Hydraulics’ hydraulic hammers range from the 424-pound
RB50SSG (delivering 550 to 950 blows per minute at an operating
pressure of 1,280 to 1,700 psi) to the heavy-duty 9,600-pound RB2000
(delivering 230 to 320 blows per minute at an operating pressure
of 2,600 psi). Operations of the hydraulic breakers require the
installation of dedicated hydraulic pipelines. The nature of these
pipelines depends on the operating characteristics of the base machine
(usually an excavator).
MBW Inc. has been
supplying vibratory equipment since the 1970s. Though primarily
a supplier of hand-operated compactors and air hammers, MBW also
offers boom-mounted vibratory rollers and skid-steer roller attachments.
Its roller designs are patented and replace its older, walk-behind
models. Available in three working widths—18 inches (46 centimeters),
24 inches (61 centimeters), and 30 inches (76 centimeters)—MBW’s
EXA boom-mounted vibratory roller exerts both static and vibratory
pressure and is suitable for backhoes and excavators up to 60,000
pounds (27,216 kilograms). MBW’s ATS/ATP series of skid-steer-mounted
rollers is available in 73- and 84-inch working widths in both smooth-
and padded-drum. These models feature hydraulic-drive systems with
no intermediate mechanical transmission.
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Photo:
Horton
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The Helac Corporation
manufactures a Power Tilt that greatly increases the flexibility
of standard excavators. Allowing a 180-degree swing, the Power Tilt
greatly increases the dexterity of a standard excavator bucket.
Combined with a grading bucket, it is very competitive in quality
and speed on small to medium-size work sites to a dozer. It also
allows for accurate cutting of subgrades to specified slopes. The
company’s Power Grip attachment for backhoes or excavator buckets
can be used as a trenching, grading, or clamshell bucket, or as
a grapple or hydraulic thumb.
Kenco is an attachment
supplier with over 20 years of experience, offering a wide variety
of attachments for excavators, lifters, skid-steers, backhoes, and
wheel loaders. Kenco’s product line ranges from excavators
as large as 200,000 pounds to wheel loaders with a 1- to 2-cubic-yard
capacity. Kenco has specialized lifting attachments for concrete
barrier placement, pipes (replacing slings and cables), and a pipe
hook for placing and pushing together pipe segments. Its skid-mounted
attachments include a Slab Crab pavement bucket for removal of small
concrete slabs and sidewalks (there is also a version for backhoes),
and steer buckets for digging and grading. For wheel loaders, Kenco
has general-purpose buckets, moldboard rakes, and brush/debris rakes.
Leading Edge Attachments
(LEA) Inc. is a designer and provider of unique high-productivity
attachments and couplers for use on excavators and backhoes. Although
LEA Inc. designs specialized products like the patented 2-Way Bucket
and the Multi-Scaler, the products that currently have the fastest-growing
sales are its lines of the patent-pending Multi-Ripper Bucket and
three-stage Multi-Ripper for all sizes of excavators and backhoes.
Daniel P. Duffy, P.E.,
is an environmental engineer for Rumpke Waste Inc. in Cincinnati,
OH.
GEC
- January/February 2005
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