800-mile-long Trans Alaska Pipeline System (TAPS) is one of the largest pipeline
systems in the world. It stretches from Prudhoe Bay on Alaska's North Slope,
through rugged and beautiful terrain, to Valdez, the northernmost ice-free port
in North America. All of the oil is transported to refineries in the United
The concept of transporting oil
south from Alaska was discussed as early as the 1960s. In 1968, large crude oil
reserves were discovered at Prudhoe Bay by the Atlantic Richfield Company
(ARCO). ARCO joined with BP Oil and Humble Oil to form the Trans-Alaska Pipeline
Systems (TAPS). TAPS was proposed to ship crude oil to the southern Alaska
seaport of Valdez (an ice-free port), from where it would be shipped to
refineries by tanker.
Pipeline construction from
Prudhoe Bay required transiting a route where much of the right-of-way was on
federal and state lands. Legislation (the Trans-Alaska Pipeline Authorization
Act [P.L. 93-153]) was required to end what had become a stalemate over the
route. This right-of-way legislation enabled the pipeline to be constructed.
Environmental studies for the
pipeline were started and applications for permits submitted in 1968. Suits were
filed by environmental groups and others to block pipeline construction in 1970.
Several Native villages filed a lawsuit claiming the pipeline would cross their
land. The land ownership question was settled with Congressional passage of the
Alaska Native Land Claims Settlement Act and its signature into law by President
Richard Nixon in December 1971.
The 48-inch special cold-weather
steel was ordered from Japan in April 1969. The building permit for the pipeline
was issued in 1974.
The pipeline route
would cover 800 miles from Prudhoe Bay to the port of Valdez, the northernmost
ice-free port in the United States.
Actual construction began in
April 1974 and was completed in June 1977 at a cost of approximately $8 billion.
At the time, it was the largest privately funded construction project in
history. Approximately 2,000 contractors and subcontractors, as well as
approximately 70,000 workers, were employed to work on the project.
Paralleling the pipeline from
Livengood to Deadhorse, the Dalton Highway (locally known as the Haul Road) was
built as a supply route for use in construction, operation, and maintenance of
the northern portion of TAPS and the oil fields on the North Slope. This road is
now a State highway.
Alyeska Pipeline Service Company, named after the Aleut word Alyeska meaning
mainland, was established in 1970 and charged with designing, constructing,
operating, and maintaining the Trans Alaska Pipeline System, commonly called
Key events in the
history of the Trans-Alaska Pipeline System
discovered at Prudhoe Bay
August 14, 1970
Pipeline Service Company incorporated by the owner companies
of Interior issues final environmental impact statement for TAPS
November 16, 1973
Pipeline Authorization Act signed into law
January 23, 1974
Agreement and Grant of Right-of-Way
May 3, 1974
April 29, 1974
September 29, 1974
May 27, 1975
laid (Tonsina River)
October 11, 1975
May 31, 1977
June 20, 1977
flows from Pump Station 1
July 28, 1977
August 1, 1977
oil-laden tanker (ARCO Juneau) leaves Valdez Marine Terminal
July 1, 1979
reducing agent first used
daily throughput of 2.03 million bbl/day
March 24, 1989
July 10, 1989
Escort/Response Vessel System established
Pollution Act of 1990
Pipeline Office established
William Sound Regional Citizens Advisory Council contract signed with
enacted by Alaska Legislature amending oil pollution laws
hearings on TAPS operations
March 5, 1994
bbl reaches VMT
1996 - 1997
Stations 2, 6, 8, and 10 taken off-line and placed on standby due to
recovery system added at VMT
August 12, 1997
tanker leaves VMT
April 27, 2000
barrel reaches VMT
The Trans-Alaska Pipeline
System was designed and constructed to move oil from the North Slope of
Alaska to the northern most ice- free port- Valdez, Alaska.
Length: 800 miles.
Diameter: 48 inches.
Crosses three mountain ranges
and over 800 rivers and streams.
Cost to build: $8 billion in
1977, largest privately funded construction project at that time.
Construction began on March
27, 1975 and was completed on May 31, 1977.
First oil moved through the
pipeline on June 20, 1977.
billion barrels have moved through the Trans Alaska Pipeline System.
First tanker to carry crude
oil from Valdez: ARCO Juneau, August 1, 1977.
Tankers loaded at Valdez:
16,781 through March 2001.
Storage tanks in Valdez- 18
with total storage capacity of 9.1 million barrels total.
River tiered-arch bridge
consortium of companies that own TAPS today includes:
BP Pipelines (Alaska) Inc. 46.93% ConocoPhillips Transportation Alaska, Inc. 28.29%
ExxonMobil Pipeline Company, 20.34%
Unocal Pipeline Company, 1.36% Koch Alaska Pipeline Company, L.L.C., 3.08%
at the Valdez Operations Control Center monitor the performance of pipeline
Fuel required for all
operations (fuel oil equivalent) - 210,000 gal/day (also see fuel
requirements under Pump Stations, and Marine Terminal).
Design, maximum - 1,180
Operating, maximum -
Pump Station facilities in
original design - 12 pump stations with 4 pumps each.
Pump Stations operating, Nov.
1, 1998 - 7: PS 1, 3, 4, 5, 7, 9, 12. PS 5 is a relief station only.
PS 11 is a security site. PS 8 placed in standby June 30, 1996.
PS 10 placed in standby July 1, 1996. PS 2 placed in standby July 1,
1997. PS 6 placed in standby August 8, 1997.
Approximately $8 billion for
construction of entire system, including Terminal and pump stations, at
conclusion of initial construction period in 1977. Does not include interest on
capital investment, or capital construction after 1977.
Pipe coating, river crossings
- 75,000 lbs. per 40-ft. section
Saddles, flood plains -
18,500 lbs. each
Animal, elevated, minimum
height - 10 ft.
Animal, elevated, number -
Animal, buried, number - 23
Animal, buried, refrigerated,
location - MP 645 and MP 649
Pipeline, types and number
Orthotropic box girder
Plate girder - 9
Suspension - 2
Tied arch - 1
Total - 13
Road, number -
North of Yukon - 21
South of Yukon - 23
refrigerated - Glenn Highway at Glennallen
Selection - Soil sampling and
other means were used to determine soil types along the route. Where thaw-stable
soils were found, the pipeline was buried in the conventional manner. In areas
of thaw-unstable soils, and where heat from the oil in the pipeline might cause
thawing and consequent loss of soil foundation stability, the pipeline was
insulated and elevated above ground by means of a unique support system.
Basic types and miles of each -
Above-ground - 420 mi.
Conventional below-ground -
Refrigerated below-ground -
Specially designed vertical supports were placed in drilled holes or driven
into the ground. In warm permafrost and other areas where heat might cause
undesirable thawing, the supports contain two each, 2-inch pipes called
"heat pipes," containing anhydrous ammonia, which vaporizes below
ground, rises and condenses above-ground, removing ground heat whenever the
ground temperature exceeds the temperature of the air. Heat is transferred
through the walls of the heat pipes to aluminum radiators atop the pipes.
Conventional below-ground -
The pipe is underlain with a layer of fine bedding material and covered with
prepared gravel padding and soil fill material, in a ditch from 8 ft. to 16
ft. deep in most locations, but up to 49 ft. deep at one location. Zinc
ribbons, which serve as sacrificial anodes to inhibit corrosion of the pipe,
are buried alongside the pipeline. The Atigun pipe replacement section, 8.5
miles in length, has four magnesium ribbon sacrificial anodes installed.
Electrical currents in the earth's surface, called "telluric
currents" and caused by the same phenomenon that generates the Northern
Lights, can be picked up by the pipeline and zinc anodes. The zinc anodes
act like grounding rods to safely return these currents back to the earth,
reducing the risk of damage to the pipeline.
non-refrigerated - In areas of thaw-unstable soils calling for
elevated pipeline construction, but where the pipeline had to be buried for
highway, animal crossings, or avoidance of rockslides and avalanches, the
line was insulated, to protect the permafrost from the heat of the pipeline,
refrigerated - In some areas the line was insulated and buried in a
refrigerated ditch. Refrigeration plants at each of these points circulate
chilled brine through loops of 6 inch diameter pipe to maintain the soil in
a stable frozen condition.
Pipeline buried in
the standard method lies on a layer of bedding material (well drained sandy
gravel without sharp rocks) covered with prepared gravel padding and soil fill
pipeline, thickness-3.2 in.
Under gravel workpad or road-2
in. to 4 in. (limited areas only)
River suspension bridge
Gabion & concrete mats
Used in Atigun Floodplain Pipe
Replacement Project for scour protection of the new pipe because less cover on
top of new pipe.
Topping units - 3 (PS 6, 8, and
10. PS 8 and 10 topping units placed in standby, summer 1996. PS6
topping unit placed in standby summer 1997.)
Pipeline Valves, types and number
Check - 81
Gate - 71
Block - 24
Ball - 1
Total - 177
Station 7 is about 1.3 miles southeast of the Tatalina River in a wooded area.
PS 7 is similar to PS 2 with two mainline pumps instead of three.
Thermal expansion - change in
pipe length due to change in crude oil temperature
Tie-in temperature - actual pipe
temperatures at the time when final welds were made which joined strings of pipe
into a continuous line
Hot position - pipe at maximum
oil temperature (145° F)
Cold position - pipe at minimum
(-60° F) (pre-startup)
Each 40 ft. length of pipe
expands .031 inches with each 10° F rise in temperature and contracts the same
distance with each 10°F drop in temperature.
Longitudinal expansion of typical
720 ft. straight above-ground segment from min. tie-in temperature to maximum
operating temperature - 9 inches.
Note: due to anchoring, the
pipeline does not expand lengthwise but shifts laterally on the above-ground
supports (See zig zag configuration , below)
Maximum above-ground lateral
Tie-in to hot position - 8 ft.
Tie-in to cold position - 4
Thermal stress - maximum, 25,000
psi - where below ground pipeline is fully restrained by the soil, the maximum
longitudinal stress due to change in temperature from pipe temperature at tie-in
to maximum oil temperature
Zig zag Configuration
Above-ground sections of the
pipeline are built in a zig zag configuration to allow for expansion or
contraction of the pipe because of temperature changes. The design also allows
for pipeline movement caused by an earthquake.
Refrigerated Burial of
VSMs (Vertical Support
Basic data -
Number - 78,000
Diameter - 18 in.
Types - 16, to accommodate
variety of soil and permafrost conditions.
Depth at which embedded - 15
ft. to 70 ft.
Distance between -
Anchor supports - 800 ft. to
Standard supports - 60 ft.
Heat pipes, number fitted with
- 61,000 (122,000 individual heat pipes, 2 per VSM, where fitted)