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MAJOR ATTRACTIONS:
Trans-Alaska Pipeline
The trans-Alaska pipeline carries oil 800 miles from Prudhoe
Bay on the Arctic Ocean to the pipeline terminus at Port Valdez.
Begun in March 1975 and completed in 1977, pipeline construction
employed some 30,000 workers at its peak and was the largest
and most expensive privately funded construction project ever
undertaken. The first tanker load of oil shipped out of Valdez
on Aug. 1, 1977. Today, the pipeline is owned and operated
by Alyeska Pipeline Service Company, a consortium of oil companies
that includes BP, Phillips, Exxon/Mobil, Unocal, Williams
and Amerada Hess.
The 48-inch-diameter pipeline winds through 3 major mountain
ranges, with its highest point (4,739 feet) at Atigun Pass
in the Brooks Range, 170 miles south of Prudhoe Bay. Along
the Richardson Highway, the pipeline crests the Alaska Range
at 3,420 foot at Isabel Pass, before descending into the Copper
River basin. It crosses the Chugach Mountains at Thompson
Pass and descends through the Keystone Canyon to Valdez, where
it is fed by gravity into tanks or directly into waiting oil
tankers at the marine terminal.
Built at a cost of $1.4 billion, the marine terminal complex
holds about 9.18 million barrels of crude oil in its tank
farms. Turnaround time for tankers, including berthing at
Valdez, offloading ballast, loading crude oil and deberthing,
averages 18 hours. Tankers are escorted by tugboats and other
vessels, with safeguards in place to avoid accidents. The
oil tanker Exxon Valdez ran aground on Bligh Reef (approximately
30 miles from Valdez) in March 1989, causing an 11-million-gallon
oil spill in Prince William Sound.
Because of varying soil conditions along its route, the pipeline
is both above and below ground. Where the warm oil would cause
icy soil to thaw and erode, the pipeline goes above ground.
Where the frozen ground is mostly well-drained gravel or solid
rock, and thawing is not a problem, the line is underground.
The zigzag pattern often seen in the above-ground sections
allows for pipe expansion or contraction due to temperature
changes or movement caused by other forces, such as earthquakes.
Travel time for crude oil from Prudhoe Bay Pump Station No.
1 to the Valdez terminal is 8.6 days, with more than 9 million
barrels of oil in the pipeline at any given time.
The line was designed with 12 pump stations (although Pump
Station 11 was never built). Pump Station No. 4, about 145
miles south of Prudhoe Bay, is a launching and receiving station
for devices known as pigs. These "dumb" and "smart"
monitors, matching the shape of the interior pipe wall, are
pushed through the pipeline by the oil, cleaning accumulated
deposits and enhancing pipeline flow as they travel (dumb
pigs), and measuring pipeline curvature and inspecting for
corrosion, changes in pipe diameter and other problems requiring
maintenance or repair (smart pigs).
Examples of “pigs” are found at the Delta Junction
Visitor Center, Milepost V 266, junction of the Richardson
and Alaska highways, and at the Trans-Alaska Pipeline Viewpoint,
located at Milepost F 8.4 on the Steese Highway just outside
Fairbanks. The Steese Highway viewpoint, which has an information
cabin, also allows visitors to walk up to the pipeline.
Opportunities abound for visitors to view and photograph the
pipeline as it winds its way from Prudhoe Bay to Valdez, but
visitor access to the pipeline is restricted to formal viewpoints
along the Richardson, Steese and Dalton highways. These viewpoints
are also be subject to closure due to security concerns.
The Richardson Highway also offers good views of the trans-Alaska
pipeline. There are formal viewpoints with interpretive signs
at Milepost V 64.7 (Pump Station 12), Milepost V 216 (Denali
Fault), Milepost V 243.5, and the Tanana River Pipeline Crossing
at Milepost V 275.4.
Although the Dalton Highway most closely parallels the pipeline,
the only formal public viewpoint is at the BLM Yukon River
Crossing Visitor Contact Station at Milepost J 56, 140 miles
from Fairbanks.
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