40
ACT
NOVEMBER2014
SITE REPORT
LIFTING
Dismantling two Potain tower cranes that were
working on the TilikumCrossing Bridge in Portland
required precision planning, flawless rigging and
expert cranework.
mounted cranes. Butwhen it came to
taking themdown, a larger cranewas
required. Kiewit calledonNess and
CampbellCranes, based inPortland, to
manage the take-down.
“Kiewit came touswith their
requirements as far aswhereour crane
couldbepositioned, the amount of room
wewouldhave for assemblyof our crane,
for thedisassemblyof the tower cranes
and the capacities thatwouldbeneeded
toget the tower crane counterweights and
jibs down,” saidBill Chapman, project
manager,Ness andCampbellCranes. “We
cameupwith aplan that gave them the
capacities theyneeded andusing a crane
that didn’t exceed the ground-bearing
pressures on theirworkingplatform and
on thedeckof thebridge [for the second
tower crane].NorthwestTowerCrane
Servicewas instrumental inperforming
the taskof assembly anddisassembly
of the tower cranes and the logistics of
organizing the trucking schedule and load
outs.”
For takingdown the first craneon the
west endof the crossing, Kiewit had
constructed aworkplatform thatwas 20
feet below thebridgedeck surface. The
platformwas used to feed the tower crane
supplies andmaterials tobuild thebridge.
“Weused that sameplatform to set up
ournew600-ton capacityLiebherr LTM
1500-8.1 all-terrain crane tohoist down
the components of the first tower crane,”
saidChapman.
Having touse a luffing jib attachment
on a crane set up in such a small areawas
a challenge, Chapman said.
“Wenever exceededwhat thebridge
could support in terms of outrigger and
ground-bearingpressure in the assembly
of the 600-ton crane,”he said.
Theheaviest liftwas about 32,000
pounds, comingdown from aheight of
254 feet.
“Heightwasn’t an issuebecause the 600-
ABOUTTHETILIKUM
CROSSING
Known as the TilikumCrossing,
Bridge of the People, the bridge
spans across theWillamette River
in Portland, OR.
Total length:
1,720 feet
Height:
180 feet
Bridge type:
Hybrid cable stayed
suspension bridge
Construction start date:
June
2011
Owner:
TriMet, Portland
Metropolitan’s regional transit
authority
General Contractor:
Kiewit
Opening:
Fall 2015
Cost:
$134.6million
Traffic:
Light rail, buses, cyclists,
pedestrians, street cars and
EMS vehicles in the event of an
emergency
Tedious
take-down
T
henewTilikumCrossing
Bridge inPortlandwill cater to
pedestrians, bicyclists, buses and
light rail.What youwon’t seeon thenew
trestle is cars and trucks.However, for a
short time, abigLiebherr all-terrain crane
was allowedon thebridge. Its taskwas to
takedown two tower cranes that helped
build the structure across theWillamette
River.
The twoPotain485 tower cranes, one
ownedbyKiewit andoneon rent from
CoastCrane, wereon the jobsite for about
twoyears. Kiewit, general contractor
on theproject, erected thePotains on
foundations in the river usingbarge-
The two Potain 485 tower
cranes, which had been on the
job for about two years, were
erected on foundations in the
river and stood at a height of 254
feet when the take-down began.
