THE KNOWLEDGE
uncommon) on a small footprint. The
small footprint causes less site disturbance
than a crane of equal capacity. The cost of
shipping strand jacks around the world is
small compared to a crane.
Another advantage of strand jacks
is that they are mechanically failsafe, at
any point during the lift the weight of
the loads can be transferred to the lower
wedges and is no longer suspended
by hydraulics.
To reach a capacity needed for a
strand jack lift, multiple units can be
Strand jacks in operation being
used for horizontal movement
rather than vertical lifting
combined. There is almost no limit to how
many strand jacks can be used on a lift.
Computerised monitoring systems have
unprecedented control over a lift and the
load can be positioned very precisely.
Strand jacks, however, also have some
disadvantages. The strands are generally
pre-cut to suit a particular job or project.
The likelihood that they can be used on
another project is small. Strands exiting
the top of a strand jack generally dangle
hanging down from the strand guide, they
don’t coil up neatly on a winch drum.
There is the risk of bird nesting or bird
caging in the lifting strands. Bird caging
happens when one or multiple strands
do not 'flow' right and buckle inside the
jack between the top and bottom jaw.
With the newest types of strand jack this
phenomenon is less likely to happen due
to telescopic tubes that do not allow the
strands to divert from their path.
They are generally slower than a
crane and they work at the same speed
regardless of the weight that they lift.
Cranes often increase their lifting or
hoisting speed with lighter loads, strand
jacks cannot do that.
■
NOTE:
Every effort is made to ensure the
accuracy of the contents of these articles. If
you find any mistakes, a brief notification and
explanation would be appreciated.
LOAD
RETRACT
OPEN
CLOSED
3
LOAD
RAISE
CLOSED
OPEN
4
Global technology leader
in the manufacture of wire and rope solutions for
the world’s most demanding applications.
Our superiority relies on continuous innovation,
quality assurance and technical expertise throughout
the organisation and along the supply chain.
Delivering lasting solutions
United Kingdom:
Tel: +44(0)1302 565100,
USA:
Tel: +1 800 521 5555,
Germany:
Tel: +49(0) 209 8001 0,
