26
RIGGINGREVIEW
ACT
NOVEMBER2014
Wendy Armstrong
discusses how today’s
spreader beams offer
rigging solutions that are
safe and efficient.
THEAUTHOR
Wendy Armstrong
ismarketingmanager
atModulift.
Spreader
beam
technology
of units eachyear and stocking supplies
around theworld.
The fundamental engineeringprinciples
behind liftinghas remainedunchanged
for thousands of years. Liftingheavy
objectshas alwayshad an element of risk,
especially if the loadbecomesunstable. It
is essential that a lift is planned correctly
to ensure that the liftwill be executed
safely and that risks are eliminatedor
controlled. The liftmust bebalanced at
all times, otherwise the load could topple
over. Thepositionof the center of gravity
of the load is of paramount importance.
The lifting riggingmust bedesigned
in such away that itwill be stable
throughout the lift. Rigging arrangements
utilizingoneormore spreader beams is
an idealway to achieve a stable lift, rather
thanusing a liftingbeam.A triangular
distance is formed from thehook to the
spreader beam, and thisneeds tobe larger
than the trianglemade frombelow the
beam to the lifting load. Thedistance
madebetween thehook andbeam should
be as far apart aspossible.
A level load
The center of gravityof the loadwill
alwaysmove so that it isdirectlybelow the
cranehook, and therefore it is important
to lengthenor shorten slings in the rig
so that the center of gravity is below the
hook at the start,when the load is lifted
up. Thiswill ensure the load is asnear to
level as possible, andnot drastically tilting
toone side. Theother key consideration
ismaking sure the individual components
thatmake a
lifting righave the correct capacities.
Every element of the riggingwill be
experiencingdifferent forces, from
the spreader beam to the shackles that
connect everything together. The size
and capacities selected are crucial to
ensure a safe lift.
UnitedKingdom-basedModulift spotted
agap in themarket, recognizing therewas
aneed for amoreuniversal, cost-effective
style spreader beam thatwas also easier to
handle.
Withpioneering research and
development, amodular conceptwas born
–one single spreader beam that couldbe
re-used time and time again and easily
be adapted todifferent spans by altering
its length.Modulift’s smaller capacity
rangeup to24 tons is largelydurable for
manual handlingdue to its light freight
components.
Moduliftwas oneof the firstmodular
designs in existence. TheModulift design
stands out due to theuseof a separate
drop link at each end allowing thedrop
link topivot, thus being a truly ‘pin
ended’ designbecause there isno induced
bending along thebeam. Thishas enabled
Modulift to address the issueof heavy
andbulky spreader beams,which is an
inherent problem for ‘end cap’ systems.
Modulift’s streamlineddesignworks in
pure compression.Optimizing theweight
of the rigging is important as this can
mean a smaller capacity cranemaybe able
tobeused for the lift.
Modernheavy lifting safety concerns
has caused a rise inquality control
throughmanufacturing controls, testing,
inspection, regulations andprofessional
certifications that have standard
recognitionworldwide.
Various standards specify that below-
the-hook liftingdevicesneed to adhere
toOSHAASMEB30.20,which addresses
comprehensive solutionspertaining to
themarking, construction, installation,
inspection, testing,maintenance and
operationof equipment used for attaching
loads to ahoist,with theEuropean
equivalent beingEN13155.
As theworld’sdemands for “bigger
andbetter”progressively impacts the
heavy lifting industry, so the challenge to
produce the safest andmost cost-efficient
lifting solution increases. Inmany cases,
the standardoff-the-shelf spreader beam
doesn’t quitemeet the requirements of
these liftingprojects,whichoftendemand
Modulift’s spreaders are designed
with a separate drop link at each end
allowing the drop link to pivot, thus
being ‘pin ended.’ There is no induced
bending along the beam.
F
or over 70years the
improvements and standards
set in theheavy lifting industry
have fortified an ageof health and safety
for thoseusing specializedheavy lifting
equipment and for the loads themselves.
Developingdesigns and techniques
to reinforce these theories and reduce
risks are shownparticularly in theuse
ofmodern spreader beams. In the early
years, spreader beamswere largelybulky,
cumbersome andof fixed-length. This
meant efficiencywasn’t really at the topof
the agenda. Early spreader beams on the
marketwerenot usedveryoften. Some
wereonlyusedonce and then scrapped
or just sat collectingdust until a lift of a
similar spanbecame apparent.
Traditionally, fixed-length spreader
beamswouldneeddisproportionately
long lead-times as generally theywere
made toorder. Today, companies such
asModulift, haveproduceddesigns that
allow for theproductionof thousands
