7/27/2019 A closer look at the Olmsted dam project

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24

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60Paducah

OhioRiverOlmsted

Wickliffe

Mound City

Cairo

Metropolis

Smithland

Joppa

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145

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45

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60

Mississip

piRi

ver

MississippiRiver

Tenn

esseeR

iver

5 miles

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AREA

KENTUCKY

Louisville

Lock andDam 52

Lock andDam 53

OLMSTEDLOCKS AND

DAMPROJECT

BUILDING A NEW DAM

ON THE OHIO RIVER

BIGJOBONE

The Olmsted Dam on the western end of the Ohio River is beingbuilt as precast pieces on land that are then moved to the river for

completion in one of the largest construction projects under wayin the United States.

The Army Corps of Engineers plan is to build its first dam on amajor river without first building temporary coffer dams to createdry areas on the riverbed for construction workers. Instead, thecorps and its contractors are manufacturing 3,500-ton to 5,000-ton concrete shells on land, then lifting, moving and loweringthem in place, connecting them together like pieces of Lego toys.

Cradle

Shell

Shell

MAKING A SHELL, THE BUILDING BLOCKS OF THE PROJECTUsing concrete mixed at the site, reinforcement rods and supporting structures,workers build a series of concrete shells on land. Each will become a piece ofthe dam. The biggest shells are 125 feet by 102 feet and about 30 feet high.

TRAVEL SPEED: Loaded, the gantry crane travels at10 feet per minute.

LIFTING CAPACITY: 5,100 tons

Super gantry crane facts and figures

Catamaran barge facts and figures

COST: $9.5 million (for crane alone, does notinclude assembly, foundations or lifting equipment).

Catamaran barge

Super

gantrycrane

CATAMARAN BARGE

PLACING A SHELLBefore placing the shell, the bottom of the river is graded andcovered with stone, and foundation piles are driven into theriver bottom. Using the most precise global positioningequipment, the shells are lowered into the water in sequence,either on top of each other or next to each other, with amargin of error of less than one inch.

MOVING A SHELL

Supports

Supports

Supports

Frontview

Frontview

Once a shell is complete, a steellifting frame is attached. A specialcrane built just for the Olmstedproject rides on rails to move the shellto the top of a skidway, just abovethe Ohio River.

Concrete shell

Supergantrycrane

Lifting frame

Lifting frame

Cradle

Sideview

Skidway

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1

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2

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5

5

Ohio River Supports

LOCKS

DAM

DAMLOCKS

Catamaran

barge

Super

gantry

crane

Skid

way

Once each shell is inplace, its void isfilled with concrete,displacing water.

The shell is placed on a wedge-shaped steel cradlewith wheels and another piece of equipmentslowly lowers the shell down the riverbank, wherethe catamaran barge waits to pick it up.

Gates and wickets will be used to control the water levels. Heres how they work:

CONTROLLING THE FLOW

When the river is low When the river is high

Cradle

140 ft.

160 ft.100 ft.

Sixty four, 36diameter steelwheels areused to movethe cranes

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Aerial photo by Google Earth

STEVE REED/THE COURIER-JOURNALSOURCE: Army Corps of Engineeers

COST: $19 million (barge alone, does

not include assembly or lifting equipment.)

Shell lifters

Shell lifters

Shell lifters

Shell lifters

Shell lifters

Shell lifters

Shell lifters

ShellsSizecomparison

PROPULSION:Two 4,500-horsepowerpush boats

LIFTING CAPACITY: 4,500 tons

SPEED: Will not exceed 6 feetper second.

The wickets are lowered, allowing barges to navigateover the dam and avoid the locks.

Wickets are raised and gates closed, creating a pool forbarge transport and safe passage through the locks.

Gates Locks Locks

Navigable passareaWickets

Wickets

THE TRIP TO THE PLACEMENT SITEEquipment on the barge lifts the shell off the cradle andholds the shell in place, while towboats push the bargeout to the dam site.

6-foot tall man

6-foottall man

As more water isblocked by the

wickets of t

he damin this area of the

river, the water levelrises, allowingvessels to pass

throughthe locks.

As more water isblocked by the

wickets o

f the damin this area of the

river, the water levelrises, allowingvessels to pass

throughthe locks.

Navigabledamsection

Gateddam

section

Navigabledamsection

Gateddam

section

To see videos of the Olmsted Dam Project go to:courier-journal.com/olmsteddam

ONLINE