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wiredInUSA - October 2015
MAKING
THENEWS
New circuit flying high
INDEXThe Big Eddy-Knight 500kV line has
crossed the Columbia River in the final
stages of its construction near The Dalles,
Oregon.
The new line, which spans 28 miles,
will provide a route for power to cross
between Oregon and Washington,
bringing added capacity to an area
that has seen rapid growth in renewable
resources.
The Big Eddy-Knight project adds 42
circuit miles of high voltage wires and
128 new towers to the BPA system,
with each tower carrying two circuits.
The first circuit is the new BE-K line,
which connects the existing Big Eddy
substation just east of The Dalles with the
new Knight substation in Goldendale,
Washington.
The second circuit is a rebuilt portion of
the Harvalum-Big Eddy 230kV line. While
the second line will operate at 230kV,
the towers, conductor and hardware
are being constructed at 500kV for
additional capacity in the future.
To make the Columbia River Gorge
crossing the design team created three
towers that couldwithstandwindand ice
storms while supporting nearly 300,000lb
of bare wires. The crossing consists of
two dead-end towers in either state
and one 420-feet-tall suspension tower
on the Oregon side.
A helicopter was used to string the 18
conductors, first flying a rope through
a sheave on the suspension tower
and then connecting it to the tower
on the opposite side of the river; finally
positioning the conductor after a series
of rope and cable pulls.