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Dump trucks
Dump trucks or production trucks are those
that are used for transporting loose material such as sand, dirt, and
gravel for construction. The typical dump truck is equipped with a
hydraulically operated open box bed hinged at the rear, with the front
being able to be lifted up to allow the contents to fall out on the
ground at the site of delivery.Dump trucks come in many different
configurations with each one specified to accomplish a specific task in
the construction chain.
Standard dump truck
The standard
dump truck is a full truck chassis with the dump body mounted onto the
frame. The dump body is raised by a hydraulic ram lift that is mounted
forward of the front bulkhead, normally between the truck cab and the
dump body. The standard dump truck also has one front axle, and one or
more rear axles which normally has dual wheels on each side. The common
configurations for standard dump trucks include the six wheeler and ten
wheeler.
Transfer dump truck
For the amount
of noise made when transferring, the transfer dump truck is easy to
recognize. It’s a standard dump truck that pulls a separate trailer
which can be loaded with sand, asphalt, gravel, dirt, etc. The B box or
aggregate container on the trailer is
powered by an electric motor
and rides on wheels and rolls off of the trailer and into the main dump
box. The biggest advantage with this configuration is to maximize
payload capacity without having to sacrifice the maneuverability of the
short and nimble dump truck standards.
Semi trailer end dump truck
The semi
end dump truck is a tractor trailer combination where the trailer
itself contains the hydraulic hoist. The average semi end dump truck has
a 3 axle tractor that pulls a 2 axle semi trailer. The advantage to
having a semi end dump truck is rapid unloading.
Semi trailer bottom dump truck
A
bottom dump truck is a 3 axle tractor that pulls a 2 axle trailer with a
clam shell type dump gate in the belly of the trailer. The biggest
advantage of a semi bottom dump truck is the ability to lay material in a
wind row. This type of truck is also maneuverable in reverse as well,
unlike the double and triple trailer configurations.
Double and triple trailer
The double
and triple bottom dump trucks consist of a 2 axle tractor pulling a
semi axle semi trailer and an additional trailer. These types of dump
trucks allow the driver to lay material in wind rows without having to
leave the cab or stop the truck. The biggest disadvantage is the
difficulty in going in reverse.
Side dump trucks
Side dump trucks
consist of a 3 axle trailer pulling a 2 axle semi trailer. It offers
hydraulic rams that tilt the dump body onto the side, which spills the
material to the left or right side of the trailer. The biggest
advantages with these types of dump trucks are that they allow rapid
unloading and carry more weight than other dump trucks.
In addition to this, side dump trucks are almost
impossible to tip over while dumping, unlike the semi end dump trucks
which are very prone to being upset or tipped over. The length of these
trucks impede maneuverability and limit versatility.
Off road dump trucks
Off road trucks
resemble heavy construction equipment more than they do highway dump
trucks. They are used strictly for off road mining and heavy dirt
hauling jobs, such as excavation work. They are very big in size, and
perfect for those time when you need to dig out roads and need something
to haul the massive amounts of dirt to another location.
Front loaders
Also known as a front end loader, bucket loader, scoop
loader, or shovel, the front 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 may be
a removable attachment or permanently mounted on the vehicle. Often
times, the bucket can be replaced with other devices or tools, such as
forks or a hydraulically operated bucket.
Larger style front loaders, such as 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 and called 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.
This article was submitted by Er. Ankush
Forklift
Sometimes called a forklift truck, the forklift is a
powerful industrial truck that is used to lift and transport material by
steel forks that are inserted under the load. Forklifts are commonly
used to move loads and equipment that is 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 with forklifts 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 you 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
forklift variation that is sometimes used in manufacturing facilities,
will utilize forklifts with a clamp attachment that you 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.
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. 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.
This article was submitted by – Er. Ankush
Various Types Of Cranes
A crane is a tower or derrick that is equipped with
cables and pulleys that are used to lift and lower material. They are
commonly used in the construction industry and in the manufacturing of
heavy equipment. Cranes for construction are normally temporary
structures,
either fixed to the ground or mounted on a purpose built vehicle.
They can either be controlled from an operator in a cab
that travels along with the crane, by a push button pendant control
station, or by radio type controls. The crane operator is ultimately
responsible for the safety of the crews and the crane.
Mobile Cranes
The most basic type of crane consists of a steel truss
or telescopic boom mounted on a mobile platform, which could be a rail,
wheeled, or even on a cat truck. The boom is hinged at the bottom and
can be either raised or lowered by cables or hydraulic cylinders.
Telescopic Crane
This type of crane
offers a boom that consists of a number of tubes fitted one inside of
the other. A hydraulic mechanism extends or retracts the tubes to
increase or decrease the length of the boom.
Tower Crane
The tower crane is a
modern form of a balance crane. When fixed to the ground, tower cranes
will often give the best combination of height and lifting capacity and
are also used when constructing tall buildings.
Truck Mounted Crane
Cranes
mounted on a rubber tire truck will provide great mobility. Outriggers
that extend vertically or horizontally are used to level and stabilize
the crane during hoisting.
Rough Terrain Crane
A crane that is
mounted on an undercarriage with four rubber tires, designed for
operations off road. The outriggers extend vertically and horizontally
to level and stabilize the crane when hoisting. These types of cranes
are single engine machines where the same engine is used for powering
the undercarriage as it is for powering the crane. In these types of
cranes, the engine is normally mounted in the undercarriage rather than
in
the upper portion.
Loader Crane
A loader crane is a
hydraulically powered articulated arm fitted to a trailer, used to load
equipment onto a trailer. The numerous sections can be folded into a
small space when the crane isn’t in use.
Overhead Crane
Also refered to as a
suspended crane, this type is normally used in a factory, with some of
them being able to lift very heavy loads. The hoist is set on a trolley
which will move in one direction along one or two beams, which move at
angles to that direction along elevated or ground level tracks, often
mounted along the side of an assembly area.
In the excavation world, cranes are used to move
equipment or machinery. Cranes can quickly and easily move machinery
into trenches or down steep hills, or even pipe. There are many types of
cranes available, serving everything from excavation to road work.
Cranes are also beneficial to building bridges or
construction. For many years, cranes have proven to be an asset to the
industry of construction and excavating. Crane operators make really
good money, no matter what type of crane they are operating.
This article was submitted by Er. Vikrant
Compact Excavator
The compact hydraulic excavator can be a tracked or
wheeled vehicle 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, them 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.
This article is submitted by – Er. Vikrant
Bulldozer
The bulldozer is a very powerful crawler that is
equipped with a blade. The term bulldozer is often used to mean any type
of heavy machinery, although the term actually refers to a tractor that
is fitted with a dozer blade. Often times, bulldozers are large and
extremely powerful tracked vehicles. The tracks give them amazing ground
mobility and hold through very rough terrain. Wide tracks on the other
hand, help to distribute the weight of the dozer over large areas,
therefore preventing it from sinking into sandy or muddy ground.
Bulldozers
have great ground hold and a torque divider that’s designed to convert
the power of the engine into dragging ability, which allows it to use
its own weight to push heavy objects and even remove things from the
ground. Take the Caterpillar D9 for example, it can easily tow tanks
that weight more than 70 tons. Due to these attributes,bulldozers are
used to clear obstacles, shrubbery and remains of structures and
buildings.
The blade on a bulldozer is the heavy piece of metal
plate that is installed on the front. The
blade pushes things around.
Normally, the blade comes in 3 varieties:
1. A straight blade that is short and has no lateral
curve, no side wings, and can be used
only for fine grading.
2. A
universal blade, or U blade, which is tall and very curved, and features
large side wings to carry more material around.
3. A combination
blade that is shorter,offers less curvature, and smaller side wings.
Modifications
Over
time, bulldozers have been modified to evolve into new machines that are
capable of things the original bulldozers weren’t. A good example is
that loader tractors were created by removing the blade and substituting
a large volume bucket and hydraulic arms which will raise and lower the
bucket, therefore making it useful for scooping up the earth and
loading it into trucks.Other modifications to the original bulldozer
include making it smaller to where it can operate in small working areas
where movement is very limited, such as mining caves and tunnels. Very
small bulldozers are known as calfdozers.
History
The
first types of bulldozers were adapted from farm tractors that were
used to plough fields. In order to dig canals, raise earth dams, and
partake in earthmoving jobs, the tractors were equipped with a thick
metal plate in the front. Later on, this thick metal plate earned the
name blade.
The blade of the bulldozer peels layers of soil and
pushes it forward as the tractor advances.The blade is the heart and
soul of the bulldozer, as it was the first accessory to make full use
for excavation type jobs. As the years went by, when engineers needed
equipment to complete larger jobs, companies such as CAT, Komatsu, John
Deere, Case, and JCB started to manufacture large tracked earthmoving
equipment.They were very loud, very large, and very powerful and
therefore earned the nickname “bulldozer”.Over the years, the bulldozers
got bigger, more powerful, and even more sophisticated. The important
improvements include better engines,more reliable drive trains, better
tracks, and even hydraulic arms that will enable more precise
manipulation of the blade and automated controls.As an added option,
bulldozers can come equipped with a rear ripping claw to break up
pavement or loosen rocky soil.The best known manufacturer of bulldozer
is CAT,which has earned a vast reputation for making
tough and
durable, yet reliable machines.Even though the bulldozer started off a
modified farmtractor, it rapidly became one of the most useful pieces of
equipment with excavating and construction.
Backhoe loader
Also referred to as a loader backhoe, the backhoe loader
is an engineering and excavation vehicle that consists of a tractor,
front shovel and bucket and a small backhoe in the rear end. Due to the
small size and versatility, backhoe loaders are common with small
construction projects and excavation type work.Originally invented in
Burlington Iowa back in 1857, the backhoe loader is the most common
variation of the classic farm tractor.As the name implies, it has a
loader assembly on the front and a backhoe attachment on the back.
Anytime the loader and backhoe are attached it is never
referred to as a tractor, as it is not normally used for towing and
doesn’t normally have a PTO.When the backhoe is permanently attached,
the machine will normally have a seat that can swivel to the rear to
face the backhoe controls.Any type of removable backhoe attachments will
normally have a seperate seat on the attachment itself.Backhoe loaders
are common and can be used for many tasks, which include construction,
light transportation of materials, powering building equipment, digging
holes and excavating, breaking asphalt, and even paving roads.You can
often replace the backhoe bucket with other tools such as a breaker for
breaking and smashing concrete and rock. There are some loader buckets
that offer a retractable bottom, which enable it to empty the load more
quickly and efficiently.
The retractable bottom loader buckets are often times
used for grading and scratching off sand.The front assembly on a backhoe
may be either removable or permanently attached. Often times,the bucket
can be replaced with other tools or devices. In order to mount
different attachments to the loader, it must be equipped with a tool
coupler. The coupler consists of two hydraulic cylinders on the end of
the arm assembly, which can expand and retract to allow different tools
to be attached to the unit. There are several types of backhoe loader
brands,including New Holland, John Deere, and Case. Some will offer you
cabs, while others won’t. The newer types of backhoe loaders even offer
you air conditioning, radios, and other accessories that make you feel
like you are working with luxury.Common with excavating jobs, the
backhoe can serve many purposes. It can haul equipment and supplies in
the loader bucket.Another great use is to cover up dirt when filling in
trench lines or covering up pipe that was just put in the ground.The
backhoe attachment at the rear is ideal for digging water pipes and
sewer pipes.The best thing about the backhoe loader is the fact that
they are easy to operate. You don’t need to be a rocket scientist to
fully operate this nifty piece of equipment.
Submitted By : Er. Vikrant
منبع : http://4-engineer.blogfa.com/category/45/
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