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The Trans-Alaska Pipeline (TAP)

Quick Facts

  • Open for production in 1977
  • Length and width: 800 miles long and 4 feet wide
  • Purpose: to transport oil between Prudhoe Bay (adjacent to ANWR) and Valdez
  • Peak Load: 2 million barrels a day
  • Current Load: 1 million barrels a day (1/5 of the domestic oil production)
  • Cost to build: $8 billion in 1977 – the largest privately funded construction project
  • Number of spill: 2
  • Estimated usability: 25 - 30 years
  • Barrels delivered to date: 13 billion

The Trans-Alaska Pipeline (TAP)

In 1968 oil was discovered in Prudhoe Bay on Alaska's North Slope. The Alaska Pipeline was proposed as a way to get the oil 800 miles away to Valdez on the Prince William Sound where it could be transported by tanker ships. In 1977 the pipeline opened and has been pumping away ever since.

Constant Temperatures Must be Maintained

About one-fifth of U.S. domestic oil travels through the Alaska pipeline. It takes just under a week for the oil to make the trip. From the time the oil leaves the ground and during travel time, it important that the oil remains at a constant temperature.

The oil at Prudhoe is pumped from deep in the earth–10,000-20,000 feet down. That means it comes up hot! Actual temperatures can be between 145-180 degrees Fahrenheit. This is too hot for the trip south, so exchangers work like a car radiator to cool the oil to about 120 degrees.
Alaskan temperatures can vary between 100 degrees above zero and 80 degrees below zero. This could have a major effect on the temperature and flow of the oil. Fiberglass insulated pipes wrapped in a coat of aluminum sheet metal keep the oil at a constant temperature as it travels through the cold Alaskan tundra.

The pipeline is half above ground and half below ground. Can you guess why all the pipes can't be buried? If you said because the ground is too cold, you are right. Permafrost exists in sheets and wedges within the earth. This makes the ground tough to get through. In addition, the warmth of the oil could potentially warm the soil, thaw the ground, and cause the pipes to sag and maybe even leak. Some parts of the pipeline are below ground, but where there is permafrost, engineers opted to build the pipeline above ground supported by posts.

Threats to the Pipeline

Age of the pipeline is a huge concern. It was only intended to be around for 30 years, but many believe that if Prudhoe Bay keeps producing oil or if the adjacent Arctic National Wildlife Refuge (ANWR) is opened to drilling, the life of the pipeline could be extended indefinitely. To maintain the pipeline, by some estimates, will cost in the billions of dollars. Corrosion and shifting permafrost threaten the integrity of the vertical pilings, gaskets, valves, and wires that support it.

Sabotage is another big concern. In 1978 Vandals blew up a section of the pipeline, spilling 700,000 barrels of oil. Can you picture how much oil that is? An average square backyard pool holds 18,000 gallons of water. One oil barrel equals 42 gallons. That means that the equivalent of 1,633 swimming pools worth of oil was spilled at one time.

On October 4, 2001 (less than one month after the September 11 terrorist attack) Daniel Carson Lewis, 37, fired his hunting rifle at the pipeline causing it to leak 68,000 barrels onto the tundra. Clean up has cost $18 million so far. The incident was committed by a drunken man and not considered a terrorist act, yet it draws attention to how vulnerable the pipeline is.

The Future of Pipeline

Although the pipeline's use is down, if the United States Government ever adopts a plan to drill oil from the ANWR, the Alaska Pipeline could be in business for many decades to come.