Brochures From Hagglunds
Describe Computerized
Cargo Handling Systems
Efficient cargo handling plays a major role in
the overall economy of cargo vessels. When
working with slewing cranes, a large portion of
the total crane cycle time is accounted for by
spotting of the cargo. In container handling, for
example, spotting may take as much as 40 per-
cent of the cycle time. The Swedish crane manu-
facturer Hagglunds Marine & Offshore AB has
utilized a microcomputer to achieve appreciable
reductions in spotting time.
The first of Hagglunds new cargo spotting
aids, named Steadyline, was introduced in late
1985. It was followed during 1986 by a comple-
mentary system, known as Swing Defeater.
These tools constitute a major advance in cargo
handling technology.
High-performance, high precision cranes are
the basic requirement for fast, effective cargo
handling. However, the attainment of maximum
output is dependent on the skill of the crane
The multipurpose cargo ship Pauwgracht, built by Miho
Shipyard in Japan for the Dutch company Spliethoff's Bev-
rachtningskantoor BV, is fitted with two Hagglunds G type
cranes.
operator. Even for the skilled operator it is diffi-
cult to compensate for the torque introduced
into the crane during slewing and the unpredict-
able movements of the load caused by wind, heel
or collisions with other cargo or the ship struc-
tures. With Steadyline, the microcomputer has
been harnessed to solve these difficult dynamic
control problems. The microcomputer, located
in the crane housing, is linked with sensors and
electronic transducers in the electrohydraulic
power swivel at the hook or spreader. When
picking up a cargo unit, the operator sets his
control lever to the required final alignment rel-
ative to the ship. Steadyline speedily adjusts the
unit to the alignment and maintains it regard-
less of crane movements and external distur-
bances.
Unless the cargo is perfectly plumb when the
load is lifted, swinging is inevitably introduced.
This pendulum effect is a leading time-wasting
factor in cargo spotting. With Swing Defeater a
microcomputer is used to analyze signals from a
number of sensors which indicate the origin of
the pendulum effects. By modifying the orders
given by the crane driver, Swing Defeater coun-
ters pendulum effects before they arise.
Steadyline and Swing Defeater greatly im-
prove the speed and safety of cargo handling, as
well as reducing the risk of damage to the cargo,
the gear and the ship.
As one of the premier builders of marine and
offshore cranes, Hagglunds offers a wide range
of products, from the smaller L type cranes,
suitable for fast cargo handling, to the larger G
type units for bulk and unit care goes.
In fact, since their introduction in 1974, more
than 1,000 G type cranes have been ordered or
delivered. The rugged G type, with capacities up
to 50 tons in single mode, is a general purpose
crane which can operate in some of the most
severe environmental conditions.
For example, G type cranes have been fitted
aboard several U.S. Coast Guard Polar icebreak-
ers. A number of G cranes have also been fitted
on Arctic bulkers and will be installed aboard
Soviet nuclear icebreakers currently under con-
struction.
For free copies of a full-color descriptive bro-
chure from Hagglunds on Steadyline,
Circle 50 on Reader Service Card
For free copies of the full-color brochure on
the complementary system, Swing Defeater,
Circle 51 on Reader Service Card
For a free 12-page, full-color descriptive bro-
chure on cargo cranes from Hagglunds,
Circle 52 on Reader Service Card
MARINE PRODUCTS DIVi TELEX 277709 / T1UR FAX (714) 894-3927
15301 Transistor Lane Huntington Beach, California 92649 (714) 894-5566
Circle 140 on Reader Service Card
November, 1988 89
Circle 204 on Reader Service Card
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