There are many different opinions as to what machines should actually be classified as earth moving equipment. There are many different types of equipment that fall in this category, such as excavators, backhoe loaders, dump trucks, and even loaders.
The photo on the right is of just part of the largest excavator, earth mover, in the world.
See more here Large Excavator.
Other machinery that falls in between are articulated trucks, wheel and track tractors, and even scrapers. The thin line is normally drawn at motor grades, which are more than capable or light duty excavation, although they are mainly used to level lots and grade roads.
If you take a glance at any equipment literature from leading companies such as CAT, Komatsu, or Case, you’ll see right away that they believe the biggest and most important change over the last several years is increased productivity. This is normally followed by greater comfort and safety.
The increase in productivity is the result of many different advancements. CAT (Caterpillar) cites that more powerful engines with a faster rise in torque which allows machines to respond faster to increased power demands. Even though this new generation is far more powerful, it has a reduced impact on the environment as well.
Electronics
Most of the newer machines have electronic control systems that will optimize both engine and transmission performance, as well as fuel consumption and hydraulic system performance.
Take for example the CAT mid sized G series wheel loaders that feature electronically controlled powershift transmissions. Each and every transmission offers autoshift capabilities that ease the pressure on the operator, and an electronic clutch pressure control that smooth shifts the gears for longer life.
Comfort
In the industry, good operators are getting harder and harder to find. Manufacturers find themselves stressing that operator comfort and convenience need to be taken into account not only to make the job easier, but also more efficient and productive as well.
The new cab designs offer better visibility, reduced noise and vibration, and improved comfort as well. The new control systems will require low operator effort while also improving the control of the machine for both the experienced as well as the in-experienced operator.
Easier maintenance
Almost all new machinery offers electronic monitoring systems that will provide constant
information on the health of the machine for the operator. These types of systems provide information to technicians, including service modes that will help them to diagnose conditions quickly.
Now days, machines are designed to make routine maintenance easier. With CAT’s wheel loaders, regular service points are easy to access from ground level, with site gauges making it easier to check the fluid of the radiator, hydraulic oil, and transmission - without having to use dipsticks.
Changes for the better
If you compare the excavation equipment of today with the machines of the past, you’ll notice that the changes are better. The machines of the past relied more on operator skill and technique, as very few of them had electronic features.
Today, almost all types of heavy machinery offer electronic features. Electronics are a great thing, as they can make the life of an operator easier than ever. You don’t need to get out and check the fluids anymore, as all you need to do is take a look at your instrument panel, which can help to save you a lot of time.
Operators who have a lot of experience know first hand that machines of the past can’t begin to compete with machines of today. With technology always getting better, it just makes you wonder what is in the future for heavy machinery. Years from now, one can only begin to wonder just great heavy machinery will get - and what other features will make the life of an operator even easier than it is now.
Here a video of the massive truck built by CAT, the 797B dump truck. It is currently the biggest truck in the world and also carries the largest diesel engine in the world.
The compact hydraulic excavator is a tracked or wheeled excavating machine with an approximate operating weight of 13,300 pounds. Normally, it includes a standard backfill blade and features an independent boom swing. The compact hydraulic excavator is also known as a mini excavator.
A compact hydraulic excavator is different from other types of heavy machinery in the sense that all movement and functions of the machine are accomplished through the transfer of hydraulic fluid. The work group and blade are activated by hydraulic fluid acting upon hydraulic cylinders. The rotation and travel functions are also activated by hydraulic fluid powering hydraulic motors.
Most types of compact hydraulic excavators have three assemblies - house, undercarriage, and the work group.
House
The house structure contains the compartment for the operator, engine compartment, hydraulic pump and also the distribution components. The house structure is attached to the top of the undercarriage via swing bearing. Along with the work group, the house is able to rotate upon the undercarriage without limit due to a hydraulic distribution valve that supplies oil to the undercarriage components.
undercarriage
The undercarriage of compact excavators consists of rubber or steel tracks, drive sprockets, rollers, idlers, and associated components and structures. The undercarriage is also home to the house structure and the work group.
Work group
The work group consists of the boom, dipper or arm, and attachment. It is connected to the front of the house structure via a swinging frame that allows the work group to be hydraulically pivoted left or right in order to achieve offset digging for trenching parallel with the tracks.
Independent boom swing
The purpose of the boom swing is for offset digging around obstacles or along foundations, walls, and forms. Another use is for cycling in areas that are too narrow for cab rotation. Another major advantage of the compact excavator is the independent boom swing.
Backfill blade
The backfill blade on compact excavators are used for grading, leveling, backfilling, trenching, and general dozer work. The blade can also be used to increase the dumping height and digging depth depending on it’s position in relation to the workgroup.
The most common place you’ll find compact excavators is in residential dwellings. When digging phone lines or other things, these pieces of equipment are very common for getting between houses. Due to their small size, they can fit almost anywhere.
Over the years, the capabilities for compact excavators have expanded far beyond the tasks of excavation. With hydraulic powered attachments such as breakers, clamps, compactors and augers, the compact excavator is used with many other applications and serves as an effective attachment tool as well. Serving many purposes, the compact excavator is a great addition to any job that requires the use of machinery.
Picture above is a drag line excavator commonly used in strip mining and large excavation projects.
Drag line excavator systems are heavy machinery that is used in civil engineering, surface mining, and excavation. With civil engineering, the smaller types are used for road and port construction. The larger types of drag line excavators are used in strip mining operations to extract coal. These are among the largest types of mobile equipment and weigh upwards of 10,000 tons!
The drag line excavator bucket system consists of a large bucket that is suspended from a boom. The bucket is moved by a number of chains and ropes. The hoisting rope, which is powered by either a large diesel or electric motor, will support the bucket and hoist coupler assembly from the boom. The drag rope on the assembly is used to draw the bucket assembly horizontally. Through skillful maneuvering of the hoist and drag rope, the bucket can be controlled for many different types of operations.
Operating A DragLine Excavator
With a typical excavation cycle, the bucket is positioned high above the material that is being excavated. The bucket is then lowered down and the drag rope is drawn so that the bucket is dragged along the materials surface. Using the hoist rope, the bucket is then lifted. A swing operation is then performed in order to move the bucket to the place where the material is going to be dropped. The drag rope is then released which will cause the bucket to tilt, making the material in the bucket fall down, which is commonly known as a dump operation.
With smaller drag line excavators, the bucket is thrown by winding up the jib then releasing a clutch on the drag cable, which swings the bucket like a pendulum. Skillful operators can make the bucket land about 1/2 the length of the jib further away than if it had just been spun or dropped.
DragLine Excavator Limitations
The limitations of drag line excavators are the height and length of their boom, as this limits where the drag line can dump waste material. Being inherent with their construction, the drag line is most effective when excavating material below the level of their tracks. Drag lines aren’t suitable for loading piled up material.
Despite their limitations and high capital cost, drag line excavators remain very popular with several mines, due to their very low waste removal cost, performance, and reliability.
They also have different cutting sequences. The first is the side casting method which uses offest benches. This method involves throwing the overburden sideways onto blasted material to make a bench.
The second method is a key pass. This pass will cut a key at the toe of the new highwall and will also shift the bench further towards the low wall. This can also require a chopping pass if the wall is blocky. A chopping pass will involve the bucket being dropped down onto an angled highwall to scale the surface.
The next method is the slowest, known as the blocks pass. This method will however, move the most material. The blocks pass involves using the key to access the bottom of the material to lift it up to spoil or to an elevated bench level. If required, the final cut is a pull back, which pulls the material back further to the low wall side.
For construction, mining, or excavation, drag line excavators are great to have. They can move even the biggest of material, which is great for deep holes in the ground. If you’ve been looking for a great way to maximize mining or excavation productivity, the drag line excavator is just what you need.
Both of these machines are affordable, popular, highly productive, and they both have helped lay a lot of cable and pipe in the ground. While they both can do the work, there are differences as to how they perform when stacked up against each other in residential utility installations.
Compare Size and Price
The average dig depth for utility installations in residential applications is between 40 and 48 inches. The basic trencher that digs to the above depth will boast a 20 - 30 horsepower engine and cost around 40,000 dollars.
The most popular type of compact excavator is the 2.5 metric ton size class, and it uses a 30 HP engine and costs around the same price. The biggest difference in the two surfaces when you need the trencher to dig deeper. The 2.5 metric ton excavator has no trouble at all digging to 8 feet or more, although a trencher that can dig that deep will require an engine with around 100 horsepower and cost upwards of 90,000 dollars!
Compare Life Costs
Not counting the bucket teeth and the replacement of the rubber tracks at 2,000 hours, fuel and routine maintenance are your only daily costs with a compact excavator. The digging chain, teeth, and sprockets on the trenchers are considered wear items and need to be replaced often. Even with the high consumable costs of trenchers, the differences will tend to even out when productivity is taken into effect.
Compare Productivity
For straight line trenching at an average depth, trenchers will flat out lead compact excavators. Under reasonable conditions, a trencher can work three to four times faster than that of a compact excavator. Another area where trenchers really excel is wooded areas, where tree roots and logs can make for slow and sloppy digging when using a bucket.
Compare Versatility
When it comes down to it, compact excavators can do a lot of things that trenchers can’t, especially when they have attachments on hand. If you are digging with a compact excavator, you can’t go anywhere near as fast as you can with a good quality trencher.
Keep in mind that a trencher isn’t a single minded machine either. Most styles of trenchers can be outfitted with a backhoe attachment that attaches to the front end. Whenever concrete, rocks, or asphalt stands in the way, the boom and chain can be replaced with rock teeth and a wheel. In soft soils, you can set up a trencher with a plow attachment and plow in cables faster than using any other available method.
When it comes down to choosing, keep in mind that it all depends on your needs. There are some cases where the compact excavator is best to choose, while there will also be jobs in which the trencher is going to do the best work.
The definition of excavation. Excavation is commonly and best known for a technique within the science of archaeology. The individual types of excavation are known simply as digs to those who participate, with this being an over literal description of the process. An excavation concerns itself with a specific archaeological site or connected series of sites, and may be carried on over a number of years, since the work is normally seasonal.
Within the industry of excavation, many more techniques may be utilized, with each dig having its own particular features that may necessitate differences of approach. Resources and other practical issues don’t allow archaeologists to carry out excavations whenever and wherever they choose, as many known sites have been deliberately left alone and non excavated.
Initially, excavation involves the removal of any topsoil that is uncovered by machine. What is dug up may be examined by a metal detector for stray finds but unless the excavation site has remained untouched for a long period of time, there is a small layer of modern material on the surface that is of limited archaeological interest.
In rural areas, any type of archaeological features should be visible beneath the surface. With urban areas, they may be thick layers of human deposits and only the uppermost will be visible to the naked eye. With either case, the first task is drawing a scaled site plan that will show the edges of the excavation.
This plan can be composed using tape measures, or as it is more common these days, an electronic total station. A grid is normally set up, to divide the site.
Excavation is also useful for digging out houses and trenches. When clearing dirt out for roads or sub divisions, excavation is what takes care of things. Even though there are a few means, the term excavation is used anytime that the earth or dirt is disturbed.
Heavy machinery is also very common with excavation, such as excavators or backhoes. Excavating crews run the equipment and dig up soil and rocks for whatever the purpose may be. Excavators are the most used machinery, as they can move a lot of dirt in a little bit of time.
Anytime you are taking part in excavation, you should always use common sense and be safe. If you plan to get down into a hole or trench, you should always use a trench box. Even though the hole may not be that deep, excavation sites can always cave in and at that point - things are very dangerous and possibly even deadly.
For digging up rare artifacts or putting in houses or roads, excavation is something that has been around for years and years. There is a lot to learn with excavation, as you’ll need to know how to run machinery, shoot grade, and how to properly dig holes and trenches so they won’t cave in.
Forklifts are ometimes called a forklift truck. The forklift is a powerful industrial truck that is used to lift and transport any heavy materials using steel forks that are inserted under the load. Forklifts are commonly used to move loads and equipment that are stored on pallets. The forklift was developed in 1920, and has since become a valuable piece of equipment in many manufacturing and warehousing operations.
Types of Forklifts
The most common type of design for a forklift is the counter balance. Other types of designs include the reach truck and side loader, both of which are used in environments where the space is at a minimum.
Control and capability
Forklifts are available in many types and different load capacities. In the average warehouse setting, most forklifts have load capacities of around five tons.
Along with the control to raise and lower the forks, you can also tilt the mast to compensate for the tendency of the load to angle the blades towards the ground and risk slipping it off the forks. The tilt will also provide a limited ability to operate on ground that isn’t level.
There are some variations that allow forklift operators to move the forks and backrest laterally, which allows easier placement of a load. In addition to this, there are some machines that offer hydraulic control to move the forks together or further apart, which removes the need for you to get out of the cab to manually adjust for a different size
load.
Another variation of the forklift that is sometimes used in manufacturing facilities, will utilize forklifts with a clamp attachment that operators can open and close around a load, instead of having to use forks. Products such as boxes, cartons, etc., can be moved with the clamp attachment.
Forklift Safety
Forklifts are rated for loads at a specified maximum weight and a specified forward type center of gravity. All of this information is located
on a nameplate that is provided by the manufacturer and the loads cannot exceed these specifications.
One of the most important aspects of operating a forklift is the rear wheel steering. Even though this helps to increase maneuverability in tight cornering situations, it differs from the traditional experience of a driver with other wheeled vehicles as there is no caster action. Forklift drivers should be certified.
Another critical aspect of the forklift is the instability. Both the forklift and the load must be considered a unit, with a varying center of gravity with every movement of the load. You must never negotiate a turn with a forklift at full speed with a raised load, as this can easily tip the forklift over.
Normally, to drive a forklift, you’ll need to pass a basic test to be certified. They aren’t difficult to operate, although you’ll need to be safe when you operate them. Once you have operated one for a while, you’ll have no problems being safe.
Front loaders are also commonly known as bucket loaders, scoop loaders, or shovels, the front end loader is a type of tractor that is normally wheeled and uses a wide square tilting bucket on the end of movable arms to lift and move material around.
The loader assembly can be a removable attachment or permanently mounted on the machine. Often times, the bucket can be replaced with other attachments or tools, such as forks or a bucket that is hydraulically operated.
Large style front loaders, like the Caterpillar 950G or the Volvo L120E, normally have only a front bucket and are known as front loaders, where the small front loaders are often times equipped with a small backhoe as well. They are referred to as backhoe loaders or loader backhoes.
Loaders are primarily used for loading materials into trucks, laying pipe, clearing rubble, and also digging. Loaders aren’t the most efficient machines for digging, as they can’t dig very deep below the level of their wheels, like the backhoe can.
The deep bucket on the front loader can normally store around 3 - 6 cubic meters of dirt, as the bucket capacity of the loader is much bigger than the bucket capacity of a backhoe loader. Loaders aren’t classified as excavating machinery, as their primary purpose is other than moving dirt.
In construction areas, mainly when fixing roads in the middle of the city, front loaders are used to transport building materials such as pipe, bricks, metal bars, and digging tools.
Front loaders are also very useful for snow removal as well, as you can use their bucket or as a snow plow. They can clear snow from the streets and highways, even parking lots. They will sometimes load the snow into dump trucks which will then haul it away.
Unlike the bulldozer, most loaders are wheeled and not tracked. The wheels will provide better mobility and speed and won’t damage paved roads near as much as tracks, although this will come at the cost of reduced traction.
Unlike backhoes or tractors fitted with a steel bucket, large loaders don’t use automotive steering mechanisms, as they instead steer by a hydraulically actuated pivot point set exactly between the front and rear axles. This is known as articulated steering and will allow the front axle to be solid, therefore allowing it to carry a heavier weight.
Articulated steering will also give a reduced turn in radius for a given wheelbase. With the front wheels and attachment rotating on the same axis, the operator is able to steer his load in an arc after positioning the machine, which can come in quite handy. The problem is that when the machine is twisted to one side and a heavy load is lifted high in the air, it has a bigger risk of turning over.
