48
ACT
MAY 2014
SC&RA
JOBSOF THE YEAR
M
cCarran International
Airport inLasVegaswill
enjoy the completionof a
new352-foot tall control tower in2015.
InFebruary2013, the general contractor,
ArcherWestern, calledBarnhart tohelp
with removingplatforms that hadbeen
installed to construct the control tower
cabon topof the tower.
The 10platforms on the tower – each
measuring16 feet longby19 feetwide
by10 feet tall andweighing12,000
pounds –were 230 feet in the air.With
the control cab inplace, the tower crane
on theproject couldn’t remove the
platforms. Theoutermost diameter of the
caboverhung thewalls by18 feet. Itwas
impossible toget the tower cranehook
above the center of gravity (CG) of the
platforms.
Theoriginal plan to remove the
platformswas to setwinches on the
concrete floor slab above, run the line
through ahole in the floor, rig the line
to theplatform, and lower it to the
ground. But it didn’t account for thenew
architectural façade.
Barnhart presented the tip stick,which
was designed to tipobjects. In this
application, themainquestionwas how to
secure theplatform to the tip stick.Also,
wherewould thepump sit so that the
operator could run thepumpwhilebeing
able to see thepick?Another questionwas
how toprevent thehoses formhanging
230 feet in the air?To assurehosesweren’t
just dangling, Barnhart installed lifting
eyes on the control pump and rigged it
to the tip stick, allowing thepump to
function as a counterweight aswell. To
assure theoperator could see the tip stick,
a remote controlwith100 feet of cordwas
installed. This allowed theoperator to
grab the remoteoff of the endof the tip
stick and standon the adjacent platform,
wherehewouldbe able to safely see and
make thepick.
The tip stick’s control pump allows
thepick locationon thebeam tobe
manipulated. After the connection is
made theoperator slowlymoves the
pickpointmore towards the center of
workwas stopped ifwinds exceeded20
mph. Two300 foot taglines controlled the
movement of the tip stick to counter the
wind.
Theworkplan addressed crane setup,
boom tipheight, tip stickposition,
swingpath, landing zone, platform
connection, FAA coordination, access
to theplatforms, fall protection, fallen
worker rescue and removing the last two
platforms behind the tower crane.
Theprojectwas a true team effort. The
platform companyprovided engineering
to ensure that the connectionwas safe,
andDielcoCrane Serviceprovided
theoperatedLinkBeltHC278.Archer
Westernprovidedvaluable input to the
connection, their carpenters performed
thedeckmodifications and connections,
and they also coordinatedwithother
operations and theFAA.
All said anddone the jobwas completed
in less than fiveworkingdayswith a
crewof eight. Itwas performed aheadof
schedule, under budget andwithout any
safety incidents.
■
thebeam,which is thenewCGof the
loadwith theplatform attached. The lift
director could than lift theplatformoff of
the support bolts and fly theplatform to
the ground.
Fall protection planning
Riggingwas a challengebecause itwasn’t
possible toplace the tip stickdirectly
above theCG.Amoment-resistant hard
connection to theplatformswas designed,
allowing theplatform tobepicked even if
theCGwasn’t below thebeam.Aportion
of thedeckwas removed andbeamswere
installedover the topof the tip stick.
Fall protection and a strong
communications planwere important,
especiallyworking at 230 feet in the air.
The safetyplan called for crews to access
theplatforms using ladders from the
level above.Workerswere required to tie
off prior to exiting the control cabusing
50-foot retractable lanyards secured to
an engineered anchor point. The lifts
were timed to ensureplaneswerenot on
the adjacent taxiway.Windwas an issue;
RIGGINGUNDER $150,000
Tip stick solution
Barnhart
Barnhart used its tip stick
to remove construction
platforms from the new
tower being built at
McCarran International
Airport in Las Vegas.
