Excavators are heavy construction equipment primarily consisting of a boom , dipper (or stick), bucket , and cab on a rotating platform known as the "house" .
41-594: Twinkle Toes is the largest excavator in the Southern Hemisphere. It was used in Christchurch to demolish tall buildings following the 2010 and 2011 earthquakes before moving to Wellington following the 2016 Kaikōura earthquake . The excavator is based on a 2008 Liebherr 984 that was heavily modified by Kocurek Excavators Ltd for the Birmingham -based demolition Coleman & Company. It
82-401: A crawler ) is a large, motorized machine equipped with a metal blade to the front for pushing material: soil , sand, snow, rubble, or rock during construction work. It travels most commonly on continuous tracks , though specialized models riding on large off-road tires are also produced. Its most popular accessory is a ripper , a large hook-like device mounted singly or in multiples in
123-399: A front-end loader designed for carrying rather than pushing material. The term originally referred only to the blade attachment but is now commonly applied to any crawler tractor with a front mounted blade. Typically, bulldozers are large and powerful tracked heavy equipment . The tracks give them excellent traction and mobility through very rough terrain. Wide tracks also help distribute
164-401: A tiltrotator which allows attachments rotate 360 degrees and tilt +/- 45 degrees, in order to increase the flexibility and precision of the excavator. Before the 1990s, all excavators had a long or conventional counterweight that hung off the rear of the machine to provide more digging force and lifting capacity. This became a nuisance when working in confined areas. In 1993 Yanmar launched
205-862: A backfill (or dozer) blade. This is a horizontal bulldozer-like blade attached to the undercarriage and is used for leveling and pushing removed material back into a hole. As of July 2021, current excavator manufacturers include: [REDACTED] Korea [REDACTED] China [REDACTED] France [REDACTED] United States [REDACTED] Denmark [REDACTED] Sweden [REDACTED] United Kingdom [REDACTED] India [REDACTED] Germany [REDACTED] Russia [REDACTED] [REDACTED] Switzerland-Germany [REDACTED] Iran [REDACTED] Algeria [REDACTED] [REDACTED] [REDACTED] Italy-USA-Netherlands [REDACTED] Indonesia [REDACTED] Turkey Bulldozer#Blade A bulldozer or dozer (also called
246-472: A brush rake for removing brush and roots. These attachments (home-built or built by small equipment manufacturers of attachments for wheeled and crawler tractors and trucks) appeared by 1929. Widespread acceptance of the bull-grader does not seem to appear before the mid-1930s. The addition of power down-force provided by hydraulic cylinders instead of just the weight of the blade made them the preferred excavation machine for large and small contractors alike by
287-464: A bucket as large as 52.0 m . Hydraulic excavators usually couple engine power to (commonly) three hydraulic pumps rather than to mechanical drivetrains . The two main pumps supply oil at high pressure (up to 5000 psi , 345 bar) for the arms , swing motor, track motors and accessories while the third is a lower pressure (≈700 psi , 48 bar) pump for pilot control of the spool valves ; this third circuit allows for reduced physical effort when operating
328-588: A dozer blade-equipped tank or armoured personnel carrier. Some bulldozers have been fitted with armor by civilian operators to prevent bystanders or police from interfering with the work performed by the bulldozer, as in the case of strikes or demolition of condemned buildings. This has also been done by civilians with a dispute with the authorities, such as Marvin Heemeyer , who outfitted his Komatsu D355A bulldozer with homemade composite armor to then demolish government buildings. In recent years, innovations in
369-501: A dragline rather than pushing them away to fill them the way the first powered shovels did. Excavators are also called diggers, scoopers, mechanical shovels, or 360-degree excavators (sometimes abbreviated simply to "360"). Tracked excavators are sometimes called "trackhoes" by analogy to the backhoe . In the UK , wheeled excavators are sometimes known as "rubber ducks". Excavators are used in many ways: Modern hydraulic excavators come in
410-500: A manual transmission, such as the early Euclid C-6 and TC-12 or Model C Tournadozer, blade movement controlled by hydraulic cylinders or electric motors instead of early models' cable winch/brake, and automatic grade control. Hydraulic cylinders enabled the application of down force, more precise manipulation of the blade, and automated controls. In the very snowy winter of 1946–47 in the United Kingdom , in at least one case
451-442: A remote cut-off village running out of food was supplied by a bulldozer towing a big sled carrying necessary supplies. A more recent innovation is the outfitting of bulldozers with GPS technology, such as manufactured by Topcon Positioning Systems, Inc., Trimble Inc , or Leica Geosystems , for precise grade control and (potentially) "stakeless" construction. As a response to the many, and often varying claims about these systems,
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#1732791248944492-568: A skilled operator to control all four functions simultaneously. The most popular configuration in the US is the SAE controls configuration while in other parts of the world, the ISO control configuration is more common. Some manufacturers such as Takeuchi have switches that allow the operator to select which control configuration to use. Hydraulic excavators now perform tasks well beyond bucket excavation. With
533-567: A wide variety of sizes. The smaller ones are called mini or compact excavators . For example, Caterpillar's smallest mini-excavator weighs 2,060 pounds (930 kg) and has 13 hp ; their largest model is the largest excavator available (developed and produced by the Orenstein & Koppel, Germany, until the takeover 2011 by Caterpillar, named »RH400«), the CAT 6090, which weighs in excess of 2,160,510 pounds (979,990 kg), has 4500 hp, and
574-399: Is also used. The undercarriage includes tracks, track frame, and final drives, which have a hydraulic motor and gearing providing the drive to the individual tracks. The undercarriage, especially frequently for a mini-excavator, can also have blade similar to that of a bulldozer. The house includes the operator cab, counterweight , engine, fuel and hydraulic oil tanks. The house attaches to
615-464: Is equipped with a replaceable tungsten steel alloy tip, known as a boot. Ripping can not only loosen soil (such as podzol hardpan) in agricultural and construction applications but break shaly rock or pavement into easily handled small rubble. A variant of the ripper is the stumpbuster, a single spike protruding horizontally used to split a tree stump. Bulldozers employed for combat-engineering roles are often fitted with armor to protect
656-537: Is generally smaller, stronger, and has hardened side cutters and teeth used to break through hard ground and rocks. Buckets have numerous shapes and sizes for various applications. There are also many other attachments that are available to be attached to the excavator for boring, ripping, crushing, cutting, lifting, etc. Attachments can be attached with pins similar to other parts of the arm or with some variety of quick coupler . Excavators in Scandinavia often feature
697-433: Is mono stick but there are also, for example, telescopic sticks. The largest form ever of an excavator, the dragline excavator , eliminated the dipper in favor of a line and winch . On the end of the stick is usually a bucket . A wide, large capacity (mud) bucket with a straight cutting edge is used for cleanup and levelling or where the material to be dug is soft, and teeth are not required. A general purpose (GP) bucket
738-471: Is the all-wheel-drive wheeled bulldozer, which generally has four large rubber-tired wheels, hydraulically operated articulated steering , and a hydraulically actuated blade mounted forward of the articulation joint. The bulldozer's primary tools are the blade and the ripper: Bulldozer blades come in three types: Blades can be fitted straight across the frame, or at an angle. All can be lifted, some, with additional hydraulic cylinders, can be tilted to vary
779-495: The Caterpillar D9 , was also used to clear mines and demolish enemy structures. Industry statistics based on 2010 production published by Off-Highway Research showed Shantui was the largest producer of bulldozers, making over 10,000 units that year or two in five crawler-type dozers made in the world. The next-largest producer by number of units is Caterpillar Inc., which produced 6,400 units. Komatsu introduced
820-473: The Type 73 or M8 tractor , to clear battlefield obstacles and prepare firing positions. Dozer blades may be mounted on main battle tanks to clear antitank obstacles or mines, and dig improvised shelters. A ripper is a long, claw-like shank that may be mounted singly or in multiples on the rear of a bulldozer to loosen hard and impacted materials. Usually a single shank is preferred for heavy ripping. The ripper
861-478: The steam shovel (which itself evolved into the power shovel when steam was replaced by diesel and electric power). All excavation-related movement and functions of a hydraulic excavator are accomplished through the use of hydraulic fluid , with hydraulic cylinders and hydraulic motors , which replaced winches, chains, and steel ropes . Another principle change was the direction of the digging action, with modern excavators pulling their buckets toward them like
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#1732791248944902-754: The 1940s, by which time the term "bulldozer" referred to the entire machine and not just the attachment. Over the years, bulldozers got bigger and more powerful in response to the demand for equipment suited for ever larger earthworks . Firms such as Caterpillar , Komatsu , Clark Equipment Co , Case , Euclid , Allis Chalmers , Liebherr , LiuGong , Terex , Fiat-Allis , John Deere , Massey Ferguson , BEML , XGMA, and International Harvester manufactured large, tracked-type earthmoving machines. R.G. LeTourneau and Caterpillar manufactured large, rubber-tired bulldozers. Bulldozers grew more sophisticated as time passed. Improvements include drivetrains analogous to (in automobiles) an automatic transmission instead of
943-448: The 1940s. To dig canals , raise earthen dams , and do other earth-moving jobs, these tractors were equipped with a large, thick, metal plate in front. (The blade got its curved shape later). In some early models, the driver sat on top in the open without a cabin. The three main types of bulldozer blades are a U-blade for pushing and carrying soil relatively long distances, a straight blade for "knocking down" and spreading piles of soil, and
984-565: The D575A in 1981, the D757A-2 in 1991, and the D575A-3 in 2002, which the company touts as the biggest bulldozer in the world. These appeared as early as 1929, but were known as "bull grader" blades, and the term "bulldozer blade" did not appear to come into widespread use until the mid-1930s. "Bulldozer" now refers to the whole machine, not just the attachment. In contemporary usage, "bulldozer"
1025-574: The Kellogg Report published in 2010 a detailed comparison of all the manufacturers' systems, evaluating more than 200 features for dozers alone. The best-known maker of bulldozers is Caterpillar. Komatsu , Liebherr , Case , Hitachi , Volvo , and John Deere are present-day competitors. Although these machines began as modified farm tractors, they became the mainstay for big civil construction projects, and found their way into use by military construction units worldwide. The best-known model,
1066-494: The advent of hydraulic-powered attachments such as a breaker , a cutter, a grapple or an auger ,a crusher and screening buckets the excavator is frequently used in many applications other than excavation. Many excavators feature a quick coupler for simplified attachment mounting, increasing the machine's utilization on the jobsite. Excavators are usually employed together with loaders and bulldozers . Most wheeled, compact and some medium-sized (11 to 18-tonne) excavators have
1107-583: The angle up to one side. Sometimes, a bulldozer is used to push or pull another piece of earth-moving equipment known as a " scraper " to increase productivity. The towed Fresno Scraper , invented in 1883 by James Porteous , was the first design to enable this to be done economically, removing the soil from an area being cut and depositing where needed as fill . Dozer blades with a reinforced center section for pushing are known as "bull blades". Dozer blades are added to combat engineering vehicles and other military equipment, such as artillery tractors such as
1148-506: The bottom two storeys of a building. At full reach, a 2.5 tonnes (2.5 long tons; 2.8 short tons) demolition attachment can be fitted to the hydraulic boom. At 40 metres (130 ft) reach, the machine can handle a 6 tonnes (5.9 long tons; 6.6 short tons) concrete breaker . The excavator got its nickname following a naming competition on Christchurch radio station More FM . Excavator The modern excavator's house sits atop an undercarriage with tracks or wheels , being an evolution of
1189-482: The buffer zone. Some forces' engineer doctrines differentiate between a low-mobility armoured dozer (LMAD) and a high-mobility armoured dozer (HMAD). The LMAD is dependent on a flatbed to move it to its employment site, whereas the HMAD has a more robust engine and drive system designed to give it road mobility with a moderate range and speed. HMADs, however, normally lack the full cross-country mobility characteristics of
1230-412: The construction technology have made remote-controlled bulldozers a reality. Now, heavy machinery can be controlled from up to 1,000 feet away. This contributes to the safety of workers on the jobsite, keeping them at a secure distance from potentially dangerous jobs. The advancement and the ability to control the heavy machinery from afar provides workers with the sufficient control over the dozers to get
1271-402: The controls. Generally, the 3 pumps used in excavators consist of 2 variable displacement piston pumps and a gear pump. The arrangement of the pumps in the excavator unit changes with different manufacturers using different formats. The three main sections of an excavator are the undercarriage , the house and the arm. The boom, the front part that is attached to the cab itself and holds the arm,
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1312-564: The driver from firearms and debris, enabling bulldozers to operate in combat zones. The most widely documented use is the Israeli Military militarized Caterpillar D9 , for earth moving, clearing terrain obstacles, opening routes, and detonating explosive charges. The IDF used armoured bulldozers extensively during Operation Rainbow where they were used to uproot Gaza Strip smuggling tunnels and destroy residential neighbourhoods, water wells and pipes, and agricultural land to expand
1353-534: The first designs for the bulldozer. A replica is on display at the city park in Morrowville, Kansas , where the two built the first bulldozer. On December 18, 1923, Cummings and McLeod filed U.S. patent #1,522,378 that was later issued on January 6, 1925, for an "Attachment for Tractors." By the 1920s, tracked vehicles became common, particularly the Caterpillar 60 . Rubber-tired vehicles came into use in
1394-411: The house. The boom attaches to the house and provides the up-and-down movement. It can be one of several different configurations: Attached to the end of the boom is the stick (or dipper arm). The stick provides the digging movement needed to pull the bucket through the ground. The stick length is optional depending whether reach (longer stick) or break-out power (shorter stick) is required. Most common
1435-488: The job done. Though these machines are still in their early stages, many construction companies are using them successfully. The first bulldozers were adapted from Holt farm tractors that were used to plough fields. The versatility of tractors in soft ground for logging and road building contributed to the development of the armored tank in World War I . In 1923, farmer James Cummings and draftsman J. Earl McLeod made
1476-648: The military buffer zone along the Philadelphi Route . This use drew criticism against both the use and the suppliers of armoured bulldozers from human-rights organizations such as the EWASH-coalition and Human Rights Watch , the latter of whom urged Caterpillar to cease their sale of bulldozers to the IDF. The use of bulldozers was seen as necessary by Israeli authorities to uproot smuggling tunnels, destroy houses used by Palestinian gunmen, and expand
1517-415: The rear to loosen dense materials. Bulldozers are used heavily in large and small scale construction, road building, minings and quarrying , on farms, in heavy industry factories, and in military applications in both peace and wartime. The word "bulldozer" refers only to a motorized unit fitted with a blade designed for pushing. The word is sometimes used inaccurately for other heavy equipment such as
1558-422: The undercarriage by way of a center pin. High-pressure oil is supplied to the tracks' hydraulic motors through a hydraulic swivel at the axis of the pin, allowing the machine to slew 360° unhindered and thus provides the left-and-right movement. The arm provides the up-and-down and closer-and-further (or digging movement) movements. Arms typically consist of a boom, stick and bucket with three joints between them and
1599-588: The vehicle's weight over a large area (decreasing ground pressure ), thus preventing it from sinking in sandy or muddy ground. Extra-wide tracks are known as swamp tracks or low ground pressure (lgp) tracks. Bulldozers have transmission systems designed to take advantage of the track system and provide excellent tractive force . These traits allow bulldozers to excel in road building , construction , mining , forestry , land clearing , infrastructure development, and any other projects requiring highly mobile, powerful, and stable earth-moving equipment. A variant
1640-455: The world's first Zero Tail Swing excavator, which allows the counterweight to stay inside the width of the tracks as it slews, thus being safer and more user friendly when used in a confined space. This type of machine is now widely used throughout the world. There are two main types of control configuration used in excavators to control the boom and bucket, each distributing the four primary digging functions across two x-y joysticks. This allows
1681-524: Was bought for around NZ$ 4m and imported to New Zealand by Auckland-based demolition firm Nikau Contractors, and arrived in the Port of Lyttelton in September 2011. The tracked excavator weighs 220 tonnes (220 long tons; 240 short tons) and has a maximum reach of 65 metres (213 ft). When the telescoping arm is not extended, the reach is 25 metres (82 ft). The excavator is not suited for demolishing