Cranes make life easier

The lifting was and is a key problem in the art history of mankind. A
big part of the cranes. Not that you could not build great buildings
without cranes. The Egyptian pyramids were all built without a crane
and are still over 100 m high. A lot of work would be spared but the
Egyptians, they were aware of cranes. Also, not sure 100,000 workers
in the construction of a pyramid would have been involved. The
technique of the cranes was already known to the Romans, but used
wisely it was not until the Middle Ages. Many churches and cathedrals
could only grow thanks cranes in the sky. Crane also brought great
relief in ports and mining. Meanwhile, the technology of the cranes is
considerably more sophisticated, but the principle is the same: loads
to be lifted and the work area of ​​the crane can be transported.
Roughly speaking, there are tower cranes and mobile cranes, which are
presented in more detail.
Tower cranes Mobile cranes
First Jib crane
Luffing jib crane

Trolley jib crane
Articulated boom crawler crane
Second Swing
Dreher notes below
Top slewing
Third Tower crane
4th Crane base
Tower cranes
Tower cranes consist of foundation, tower crane and jib. Tower and
boom are due to wind forces, who executed some very large radius and
height and weight reasons, mostly in timber construction. To prevent
the crane tips over, the crane needed to load a counter-jib and the
load attached. There are different types of tower cranes.
Distinguishing criteria are boom slewing, tower crane, crane
foundation.
First Boom
The boom is more or less horizontal part of a crane, which depend on
the loads. Sometimes the boom can be moved up and down, sometimes he
can bend and sometimes the cable can load on the boom back and forth.
Therefore, a distinction jib, trolley jib boom and articulated.
Luffing jib
When jib and luffing jib is mounted below the top of the tower at a
pivot point. By rolling over on top of the tower current boom
retaining rope is on the boom and swung away. Luffing jib have their
advantages where it is closely approaching on sites such as in the
inner city. The disadvantages of the jib, such as large dead space
around the crane tower, large space requirement for installation,
discontinuous load movement and the danger of slipping through the
boom brake for boom adjustment under load meant that he is now used
relatively infrequently. It is this type of crane slewing as well, as
well as top-slewing. The photo shows one of the manufacturer Liebherr
luffing jib.
Trolley jib
When the load trolley jib rope runs through a horizontally movable
trolley rope. The winds that moved the trolley sits on
Auflegerfußstück or counter jib. The swing can be above or below the
tower crane. The tower crane can be telescoped or be provided with a
free-standing or climbing equipment. If a trolley jib are used, all
these obstacles in the swing area of ​​project. Its advantages lie in
the horizontal load path that facilitates the operation of the crane
and, with relatively low performance overhead of fast procedures of
the trolley. The figure shows a trolley jib Zeppelin Construction of
the manufacturer.
Articulated boom
During the two-piece articulated boom boom cat driving by buckling in
a connecting joint is variable. For special applications, for example,
for the construction of cooling towers or television, these cranes
offer great advantages. The articulated boom in steep position at a
television tower, for example, brings a profit or saving additional
hook height of tower sections and supports. The larger the radius of
the boom, the less weight should be attached to the load cable.
Another disadvantage of the buckling boom is the high purchase price,
which is due to the extensive technical facilities. With this model
from Liebherr is the capacity at maximum forward reach two tons. The
maximum load capacity of twelve tons, however.
Second Swing
As already indicated, there are cranes, in which only the boom is
swung and cranes, where the tower is rotated. One speaks of
top-slewing and slewing.
Slewing
When slewing tower crane and ballast are (usually precast concrete) on
the swing mounted directly on the crane base. When swinging the boom
must be rotated along the whole tower. The winch for the lift and wind
rush from the boom and trolley are located in the tower base. Both are
luffing jib and trolley jib it in execution as slewing. Will the
construction of smaller buildings such as single-family homes used
cranes, then these are usually erecting cranes. Erecting cranes are
relatively easy to assemble and dismantle and maintain, however,
require a basic level with a relatively large space requirements.
Top slewing
The top of the tower Turner (also known as Tower Crane) is firmly
connected to the crane base. Only rotates on a turntable mounted on
the tower top part. Above rotating cranes adapt easily to the
different operating conditions and are designed for high altitude,
crowded or extended sites suitable. All three types of boom luffing
jib, trolley jib boom and bend it as the top movers. In comparison to
Below are the top Dreher Dreher construction and maintenance much more
complex, since all necessary facilities such as Swing, ballast and
crane winches are located in the upper range. However, can be placed
with the top-slewing tower crane significantly higher for the
construction of high buildings.
Third Tower crane
When the tower crane must be distinguished whether it is a slewing or slewing.
When top-slewing tower crane is the free-standing, but at larger
heights and arm lengths from struts anchored to the building or be
braced by ropes. A special case is the tower crane with climbing
equipment. With a climbing facility, the tower can be hydraulically
raised or lowered.
Slewing tower crane at the lower height and is often telescoped (eg
fast-erecting cranes) has. Fast-erecting cranes can relatively quickly
by a hydraulic or to be mined and implemented.
4th Crane base
Tower cranes are built either fixed in one place or they have a track
or tire or tracked chassis.
The stationary crane will be placed on foundation blocks of concrete
in the foundation slab of the building or clamped in a building shaft,
such as the elevator shaft.
The crane has a track chassis, it can be moved under load. This is the
tire and crawler chassis is not the case. Here is the conversion of
the crane, however, not be moved under load. Tower cranes on railway
carriages must carry ballast so much that the wheels under heavy load
does not leave the ground. Cranes landing gear tires on a low
stability. Therefore, they need during the transportation of an
additional hydraulic load support. For crawler cranes can be dispensed
on the jib because of their high weight, unless they are designed as
slewing.
Mobile cranes
Mobile cranes are lifting devices have road vehicles, the rotatable
telescopic and lattice boom. The vehicles are driven almost
exclusively by diesel engines. Power is transmitted mostly through
hydrostatic hydraulic pumps, less than mechanical transmission.
Hydraulic pumps can be operated more easily and the operating speed
can be regulated better. In some cases, mixed systems are used for
power transmission. In this example, the lifting is going on and
turning mechanically, hydraulically luffing and driving the crane. A
distinction cranes, mobile cranes, truck cranes and crawler cranes,
where the terms "mobile crane" and "mobile crane" in general usage
will not be used unambiguously. Mobile cranes are then often used when
no fixed cranes can be used, for example, when no power is available.
Or it's not worth it, because the crane is needed for a very short
time. With some mobile cranes can lift even heavier loads than with
tower cranes. Will help build a mobile crane must, however,
particularly care that he is tipping over.
Crane
The crane is mounted behind the cab or the rear of a truck's. He is
fully hydraulically operated and can be swiveled. The foldable and
telescopically extendable and retractable boom allowing the waiver of
a hoist. With claws or hooks can be bulk or general cargo unloaded
there, too, where no crane systems are available. For larger loads
laterally extendible and hydraulically adjustable restraints are used,
which increase the stability of the vehicle while the crane is
working.
Mobile Crane
Mobile cranes have a two-to four-axle chassis with pneumatic tires or
solid rubber tires. In contrast to the mobile crane truck crane has
only one motor for driving and crane driving movement. Mobile cranes
can be equipped both with lattice booms and telescopic with solid wall
brackets (see photo of Sennebogen). Outriggers at the base of the
crane to increase its stability at work. A mobile crane is usually
mounted on an excavator chassis and features a crane cab and an
engine. Since most mobile cranes are very slow and do not street
legal, they must be transported by trailer to the next site. The
advantage over the crane is its compact design and stout. This gives
the crane a versatile use in harbor, storage, construction and
installation work.
Auto Crane
A crane usually has two drive motors, one in the chassis for movement
and one for the crane movements. Unlike the mobile crane truck crane
also has the two cabs, so that there can be two separate assemblies.
The structure with its jib is mounted via a swing bearing on the base.
The number of vehicle axles is determined by the dead load of the
crane and the legally permissible axle loads. The model on the picture
of Liebherr example, has eight axes. The maximum capacity is 800 tons.
If you want to lift this weight, the overhang must not exceed 3
meters. However, the maximum radius is 126 m and 146 m. ​​The maximum
lift height The crane is used mainly in construction and installation
work in buildings and bridges. Cranes, there is both a lattice
structure with lattice boom as well as multiple telescopic box section
boom. Lattice boom are mainly used for high lifts are used to reduce
the wind load and dead weight.
Crawler crane
Vehicle with crawler cranes come in rough, especially soft terrain and
in particular stresses are used. For example, sheet piling will be
drawn with the crawler crane. Crawler cranes have a lifting capacity
of up to 1,200 tons. Accordingly high is their own weight and
therefore they can move around slowly. Over longer distances, they
must therefore by special vehicles such as a flatbed truck to be
transported. In general crawler cranes are equipped with lattice
booms.