dynamic forces between 10 and 20 t
act upon the crane. This effect is
responsible for the overloads, Port
Polnocny reported.
Solution
Liebherr conducted onsite research at
the port. In the first test run, both cranes
were tested without SmartGrip. The test
results revealed the moments of the
load cycle when the sticking grab breaks
out of the wet coal (Figures 4 and 5).
In the second test run, SmartGrip
was installed and activated. The results
were unmistakable. Both LPS 600s had
no overloads and there was no sticking
of the grab. Additionally, the grab filling
rates were above average
(Figures 6 and 7).
SmartGrip works as follows: the
system automatically controls and
synchronises both winches of the crane.
While one winch is closing the grab,
SmartGrip steadily adjusts the holding
winch to the weight of grab, including
load. This adaption avoids the
development of adhesive forces
between the grab and the rest of the coal
in the hedge. The grab does not get
stuck in the material and can be pulled
out of the coal more gently, which
avoids overloads.
Performance
After the installation of the SmartGrip
system, the first cycles have already
demonstrated the capability of the
intelligent grabbing technology.
“In our efforts to increase
productivity, the installation of
SmartGrip was a logical decision. Our
crane drivers are delighted with the
new system, which ensures that we do
not waste turnover caused by bad or
volatile grab filling rates. Moreover,
overloads are eliminated, which means
a longer crane life-time,” said
Adam Luczak, Port Polnocny’s Bulk
Terminal Manager.
This technology marks an
evolutionary step. SmartGrip is the
first self-learning system in the bulk
handling industry, using data mining
to power the machine control. In other
words, based on experience, the crane
handles bulk in an intelligent way.
The world’s largest mobile
harbour crane
Liebherr launched its new flagship
mobile harbour crane the LHM 800, in
March 2015. The dimensions and
capabilities of the LHM 800
outperform all existing mobile
harbour crane models in the market.
The LHM 800 provides a lifting
capacity of 308 t, exceeding the
maximum capacity of the so far
strongest mobile harbour crane, the
LHM 600, by 100 t. Equipped with
Liebherr’s Pactronic hybrid drive, the
giant masters up to 2300 tph, which is
a record in the mobile harbour crane
world. The intelligent grabbing
technology SmartGrip is also
available for the LHM 800.
Outlook
Recently introduced products and
technologies are expected to open up
new markets. In combination with
well filled order books,
Liebherr Maritime Cranes is
optimistic that 2015 will be another
successful year.
Figure 7. SmartGrip controls the filling of the grab to suit the
load curve of the crane.
Figure 6. SmartGrip avoids sticking of the grab and overloads.
Figure 5. High turnover variance when handling wet coal without
SmartGrip.
Figure 4. Forces on winches and crane while handling wet coal.
66
|
World Coal
|
June 2015
