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.

Medieval cranes
Cranes of the Middle Ages were used to build the
cathedrals of Europe. The crane was fixed on top
of a wall as it was being constructed and was
powered by men that ran inside of two large wheels
on each side. Cranes were also used in medieval ports
and in shipyards.

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.

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The skid loader is a rigid frame, engine powered
machine with lift arms that are used to attach a
wide variety of labor saving tools or attachments.
Skid loaders are normally four wheel drive with
left side drive wheels that are independent of
right side drive wheels. With each side being
independent to the other, the wheel speed and
direction of rotation of the wheels will determine
which direction the loader turns.

Skid loaders are capable of turning in their own
tracks, which makes them very maneuverable and
valuable for jobs that require the use of compact,
agile loader.

Unlike conventional front loaders, the lift arms
lay beside the driver with the major pivot points
located behind the shoulders of the operator. Due
to the operator being in close proximity to moving
booms and buckets, earlier models of skid loaders
weren’t as safe as conventional front loaders,
particularly during entering and exiting.

Skid loaders today have fully enclosed cabs and
other safety features that will protect the operator
from injury. Just like other front loaders,
the skid steer can scrape material from one
location to another, carry material in a bucket,
or load material on a truck or a trailer.

Operation
A skid loader can sometimes take the place of a
large excavator by digging a hole out from the
inside. The skid loader will first dig a ramp
that leads to the edge of the hole. Then, the
loader will use the ramp to carry material out
of the hole.

The skid loader will then reshape the ramp by
making it steeper and longer as the excavation
gets deeper. This method is very useful for
digging under an overhead structure where the
overhead clearance doesn’t allow for the boom of
a large excavator, such as those situations where
you are digging a basement under a house.

The bucket of most types of skid loaders can be
replaced with several specialized buckets or
attachments, many of which are powered by the
hydraulic system of the loader.

History
The first 3 wheeled front end loader was invented
by two brothers, Cyril and Louis Keller in their
machinist shop in Minnesota back in 1957. The
Kellers built the loader to help a nearby farmer
clean turkey manure from his two story barn. The
light and compact loader, with the rear caster
wheel, was able to turn around within the length
of itself, while performing the very same tasks as
conventional front end loaders.

Down the road, the Melroe manufacturing company
in Gwinner ND, purchased the rights to the Keller
loader in 1958 and hired the brothers to continue
their loader invention. Resulting from the
partnership, the M-200 self propelled loader was
introduced at the end of 1958.

The loader featured two independent front drive
wheels and a rear caster wheel, a 12.9 engine and
a 750 lb lift capacity. Two years later, they
ended up replacing the caster wheel with a rear
axle and introduced the M-400 loader, which was
the first four wheel skid steer loader in the
world.

In 1962, the Bobcat name was added to describe
the key features of the machine – touch, agile, and
quick. The M-440 was powered by a 15.5 HP engine
and offered a 1100 lb rated operating capacity.
In the mid 1960s, the skid steer loader progressed
with the introduction of the M600 loader.

Years later, the Bobcat skid steer loader experienced
quite a few changes, including the development of
a hydrostatic drive system, enforced cab structures,
radius and vertical lift arm configurations,
deluxe instrumentation, and even heating and air
conditioning.

In addition to the rubber tire skid loaders of today,
there are now all-wheel steer loaders and even
compact track loaders. Compact track loads offer
less ground disturbance and feature better traction
and control in soft, muddy, wet, and even sandy
ground conditions.

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The harvester is a type of heavy machinery that is
employed in cut to length logging operations for
felling, buckling, and cutting up trees. Normally,
a harvester is employed alongside a forward that
will haul the logs and trees to a roadside landing.

Harvesters were developed in Sweden and Finland,
and today they do nearly all of the commercial
felling in these countries. They work best for
less difficult terrain for the clear cutting area
of forest. For steep hills or removing individual
trees, chain saws are normally preferred. In
the nordic countries, small and agile harvesters
are used for thinning operations and manual cutting
is only used during extreme conditions or by self
employed owners of the forest or wooded area.

The leading manufacturers of harvesters include
Timberjack (which is owned by John Deere) and
Valmet, which is owned by Komatsu.

Normally, harvesters are built on a robust all
terrain vehicle, which can either be wheeled or
tracked. Sometimes, the vehicle can be articulated
to provide tight turning around obstacles. A
diesel engine will provide power for both the
vehicle and the harvesting mechanism through a
hydraulic drive.

An articulated, extensible boom that is similiar
to that of an excavator, will reach out from the
vehicle to carry the head of the harvester. There
are even some commercial harvesters that are
adaptations of excavators with a new harvester
head, while the others are purpose built vehicles.

The normal harvester head may consist of:
1. A chain saw to cut the tree at the
base and also to cut it to length. The saw is
hydraulically powered rather than using a 2 stroke
engine of a portable version. It offers a more
robust chain and a higher output power than any
saw carried by man.
2. Two curved de-limbing knives that can
reach around the trunk to remove branches.
3. Two feed rollers to reach out and grasp
the tree. The wheels will pivot apart to allow
the tree to be embraced by the head of the harvester,
and pivot together to hug the tree tight.
4. Two more curved knives for de-limbing.

All of this is controlled by an operator who sits
in the cab of the vehicle. A control computer is
used to simplify mechanical movements and keep the
length and diameter of trees that have been cut.

The length is computed by counting the rotations
of the gripping wheels. The diameter is computed
from the pivot angle of the gripping wheels that
hug the tree.

Harvesters are normally available for cutting trees
up to 900 mm in diameter, built on vehicles that
weight up to 20 t, with a boom that reaches up to
a 10m radius. The larger, more heavier vehicles
do more damage to the forest, although a longer
reach will help by allowing more trees to be
harvested with less movements required by the
vehicle.

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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.

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Site prep is the best term that is used to describe
the operations necessary to make raw land ready
to accept improvements such as buildings, parking
lots, roads, and other amenities. Once the project
has been completed, the site prep is invisible.

The term site prep is a broad term that can include
several different tasks, such as clearing and
grubbing, soil erosion, sediment control, storm
drains, water and sewer pipes, topsoil stripping,
rock removal, underground utility, and several
other tasks.

Soil erosion and management
To protect the quality of the water, soil erosion
and sediment control measures are vital. With
most locations, storm water permitting is
required. All erosion and sediment control
measures and devices must be in place and inspected
before the first tree drops or first shovel full
of dirt is removed.

The designs for storm water management systems
are becoming more and more complex. The detension
basins have complex and spiraling side slopes
and bottoms that have almost flat grades.

Clearing
The limits of clearing can be marked with a GPS
dozer. By following the outline of the display
in the cab, the bulldozer can cut a path through
the wooded area so other equipment will have a
clear line to go by.

The traditional method used to clear debris, such
as burning, is rapidly fading away. The air
pollution standards will prevent any type of
burning of most areas across the United States.

Site prep made easy
Depending on the job site, what you have to do will
vary greatly. With excavation, what is needed to
complete a job is as different as night and day. No
matter what type of work you are doing, it will
almost always require the use of heavy machinery.

Clearing lots for houses, grading roads, laying
pipe, fixing water leaks, and digging foundations
are just some of the most common tasks found with
the art of excavation. To do this type of work,
it takes a special individual as work is outdoors
year round, meaning that you freeze in the winter
and burn up in the summer.

Laying pipe is a task that takes skill. You first
must dig the trench for the pipe, making sure that
the elevation is right, and that the pipe will meet
the specifications listed in the blueprints. There
are several different types of pipe that needs to
be layed, including water, sewer, and storm drains.

When you first begin your job, you’ll need to have
the proper permits from the area that you are going
to be disturbing the ground in. Once you have
the proper permits, you can begin your work. With
some jobs, you’ll need to document on paper just
how much land you disturb each day.

Sometimes with excavation, the job site and plans
will call for ponds or temporary ponds. This can
be fun to do, although you have to be careful as
well. Very common with sub divisions, ponds are
something that take a lot of skill to dig right.

Manholes are something else that you will encounter
as well. You can use machinery to set them in place,
although they will need to go a certain way. The
easiest way to put them in place is by using an
excavator, as you can lower it down and have a
couple of workers set it in place.

Anytime you are working on an excavation site, you
should always be careful and make sure you do things
by the book. There are always rules and regulations
that you need to follow. Excavation is a very fun
trade, although you’ll need to be well versed with
following plans, running machinery, and having fun
outdoors.

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As you may know, the CX330 is the upgrade to the
9050B model from Case. The CX330 is quite an upgrade,
being much bigger than the 9050B.

In standard form, the CX330 is almost 5,000 pounds
heavier than the 9050B. This added weight comes
from a larger counterweight and from a redesigned
carbody that will now completely enclose the swing
system.

These added pounds will also contribute to the boost
in the CX330s over-front capacity, and in combination
with higher hydraulic pressures the travel circuit,
give the excavator a very impressive 16% boost in
draw bar pull, which means more power for negotiating
poor underfoot conditions and very steep grades.

In addition to the new features, the CX330s digging
linkage has been enhanced in many ways. The boom
and arm, deeper in cross section to accommodate
higher digging forces, now incorporate V-groove
type welds that are placed by robots and 100 percent
ultra sound inspected.

The boom foot and boom to arm pivots use improved
bushings, new plated pins, and new dust seals that
combine to make a more durable and easier to take
care of assembly. The newly hardened chrome pins
will also contribute to the overall digging linkage
durability.

Even though the basic 6 cylinder, 8.3 liter engine
in the CX330 has been used in Case products since
1985, continual refinement over the years has
changed nearly 85% of the original engine’s part
numbers. The CX330 features 259 net HP with an
air to air intercooler and a free breathing 24 valve
cylinder head.

The electronic logic that controls the new engine’s
fuel system tracks the machine’s operating parameters
and keeps the system continually armed to respond
instantly and precisely to the fuel requirements of
each individual cylinder. The total electronic
design of the engine will also eliminate cable
and step motor controls from the fuel system, with
a large gain in reliability.

Even though modest changes in the CX330s digging
linkage geometry will contribute to the higher
forces of digging, the big guns here are the
refinement of the trench with it’s open center
hydraulic system. The main pressure in the
implement circuit is up almost 8%, with the hydraulic
cylinder diameter up 7% as well.

Hydraulic power
The increase in hydraulic power combines with the
more efficient linkage geometry to yield almost
20% more bucket digging force and 15% more arm
force. With 19 more HP, the CX330 can drive it’s
main hydraulic pumps with much better force. In
addition, the new pumps will produce about 6% more
flow for increased hydraulic speed at much lower
system pressures.

The new PCS (Pro Control System) will manage the
hydraulic system and interface with the 6TAA-830
engine, and does it with more electronic genious
than the 9050B did. Similar to the 9050B, the
CX330 does have manually selected working modes,
although it departs from previous designs by adding
a new automatic work mode. By working in the
new automatic mode, the CX330 can analyze load
demands and operator input at the joystick, then
adjust the engine and hydraulic pumps to balance
power and speed with efficiency and even with the
economy.

Other PCS features include a high speed assistance
system, which will speed up boom and arm functions,
and an automatic power boost system as well. The
power boost system will increase main pressure by
10% for 8 seconds if the implement system reaches
the standard relief pressure for more than 1 second
in tough digging conditions.

With everything the CX330 from Case offers, it’s
truly the best excavtor in years. Case has outdone
themselves this time, doing their part to make
excavating both fun and exciting. If you’ve been
looking for the perfect upgrade from the 9050B, the
CX330 is all that and a bag of chips.

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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.

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Digging trenches is one of the oldest types of work
with both construction and excavating. Prior to World
War 2, trenches were dug by hand. As workers dug the
trenches deeper, the sides needed to be shored or
supported, to keep the walls of the trench from caving
in.

Following the World War, several innovations were made
in backhoes, and trench digging seemed to fade away
as a profession. By 1950, hydraulically actuated
backhoes were developed, which make it possible to
rapidly dig very deep trenches. Resulting from the
innovations with backhoes, and because there were no
workers inside digging the trenches, the walls no
longer needed to be shored.

All types of trenches have what’s known as a stand up
time. This time is the amount of time that elapses
from the time the ditch is dug until the time the
trench walls start to collapse. The stand up time
is dependant on many factors, which include the type
of soil, water content, trench depth, weather
conditions, and whether or not the soil has been
disturbed.

The stand up time can be as short as zero seconds
or as long as several months, as they are very
difficult to predict. Before the trench can be dug,
someone must take soil samples as way of estimating
the stand up time. Keep in mind that the soil
conditions can be dramatically different only a
few feet from where the sample of the soil was taken.

After the trench has been dug, workers will go down
into the trench, and perform whatever work is
needed, such as laying pipe or installing telephone
lines, welding pipe, or installing valves. If the
trench walls aren’t supported, there is the possibility
of the walls collapsing and trapping the workers in
the trench. Throughout history, there have been
100 – 300 people killed in the U.S. each year
due to trenches collapsing.

The public has become very aware that industrial
progress will often have negative side effects as
well. The place of engineers protecting the
public from these types of side effects is a very
controversial issue. The use of trench boxes on
the site, will help to ease this debate.

The trench box, also called a trench shield, may
be placed in the trench to prevent failures from
injuring workers. The trench box consists of two
large plates, normally made from steel, which are
parallel to the walls of the trench, and horizontal
cross members which will hold the two plates
apart.

The lower edge of the trench box rests at the
bottom of the trench, with the top edge of the
box extending above the top of the trench. The
workers will stay between the plates of the trench
box, so that if the trench does collapse, the dirt
will be stopped by the outside of the trench box.
As the work progresses, the trench box is pulled
along in the trench with a backhoe or other machine.

When a project calls for a large excavation such
as digging the foundation for a tall building, the
supporting structure for the excavated walls will
be specified in the plans. The big problem with
not using trench boxes occurs in cities, when
water or sewer lines are being installed or
repaired. The engineer doesn’t specify for the
trench box in the plans, but instead leaves it
up to the contractor.

Anytime you are going to be digging trenches or
working in them, you should always use common sense
and take your time. Trenches can be very deadly,
especially if trench boxes aren’t used. To be on
the safe side, you should always use a trench box
if you need to be in the trench. If you don’t
need to be in the trench – do the smart thing
and let the machines do all of the work.

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Carpentry Career Training

Carpentry career training may be a bit different from the usual courses that one takes in order to find a good paying job. For one, carpentry training taken at vocational schools and community colleges do not usually lead to degree courses. What a student will get after finishing a carpentry course would be a certificate of completion signifying that he or she has finished through and has completed the requirements of the course. This certificate would aid students in finding entry level carpentry jobs later on.

But in the most usual career path for most future carpenters, education and training are almost always picked up their skills while on the job. This is aside from the many others who learn about the craft from institutions and vocational schools or even apprenticeships. Each method has its own way of enriching and teaching interested participants of the essential knowledge of carpentry.

In today’s construction industry, a majority of employers try to ensure that the carpenters they hire are well adept and proficient in the craft. Such employers prefer carpenters undergo an apprenticeship program since it provides the most extensive training that can cover all aspects of carpentry. Most local and nationally recognized organizations for carpenters and the construction industry usually sponsor apprenticeships or run programs for the development and training of would be carpenters.

What makes apprenticeships so appealing to employers as well as for most other carpenters in training is that they provide practical experience in a real work setting. Apprentices do not just learn about carpentry in the classroom, they get to learn the craft the practical way- while on the job.

It is easier for apprentices to learn and understand basic design principles and familiarize with the work of carpenters like framing, structure finishing, and layout on an actual workplace setting. What they see what is being done alongside experienced carpenters doing real work can gain them more valuable and practical knowledge about the job that no classroom can ever provide. Through actual work, they gain actual experience in using the various carpentry tools, equipment as well as the proper techniques and methods in using them. Through apprenticeships, they learn about the scope and range of tasks as well as how carpenters work with other kinds of construction jobs.

In looking for people qualified for carpentry apprenticeships, qualified candidates should at least be eighteen and above. Other programs may also require candidates to undergo testing to gauge their ability to learn. The duration for most carpentry apprenticeships can last from three to four years. This will depend on the apprentice’s skill level and ability to learn.

Aside from apprenticeships, other carpenters can also gain their skills elsewhere and through other means. There are also employers that provide additional training for their employees, especially entry level carpenters. The nature and thoroughness of that training usually depends on the size and capacity of the employer company. Sometimes, entry level carpenters would gain and receive instruction from small residential contractors.

In this case, knowledge and experience for their carpentry career may be pretty limited only to the scope of the work projects that contractors may have during the said training and instruction.

Original post by Article Info

Carpentry Career History

Carpentry career is one of the oldest professions. Carpentry dates back to the early days of man using crude tools. Ancient Greeks showed the skills in carpentry through the temples that they have built to show reverence for their gods and goddesses. While in Asia, ancient Japanese also showed their skill in carpentry through the buildings they have constructed. These buildings dates back to 7th century and some of these buildings are still standing up to this day.

We can trace the history of carpentry back to 8000 B.C. During this time, early people are using stone axes to construct their shelters. Several studies and researches showed that early Stone Age Europeans were building rectangular timber houses more than 100 feet long.

Egyptians were already using copper woodworking tools as early as 4000 B.C. These copper made tools evolved into bronze tools used in 2000 B.C. Egyptians were very proficient in drilling, dovetailing, mitering, and mortising wood.

The word carpenter was derived from the Latin word carpentarius. Carpentarius is the person who build the two- wheeled chariots called carpentum in Latin. Roman carpenters were already using adzes, saws, rasps, awls, gouges and planes.

In the Middle Ages, carpenters found work in large towns. They would travel along with their tools to other villages where a major construction project is ongoing. During this age, steel-edged hand tools were already part of the carpenter

Original post by Article Info