Trans-Alaska Oil Pipeline

Traveling the Dalton Highway you see the pipeline. We stopped at one point to get up close to the pipeline. In building the pipeline, engineers faced a wide range of difficulties, mainly from the extreme cold and the difficult, isolated terrain. The construction of the pipeline was one of the first large-scale projects to deal with problems caused by permafrost, and special construction techniques had to be developed to cope with the frozen ground. The project attracted tens of thousands of workers to Alaska. Here are some facts on the pipeline:

- it starts in Prudhoe Bay and ends in Valdez (800 miles). Fairbanks is about halfway.
- it was built in 6 sections by 5 different companies costing way over the estimated cost - costing 8 billion dollars and took 2 years 3 months to build
- the pipe is 1/2 inch thick steel; 48 inches in diameter; has 3-3/4 inch fiberglass insulation
- the maximum grade of the pipeline is 55% and is at Thompson Pass (see our visit to Valdez)
- the highest elevation is 4739 feet at Antiqun Pass
- the zig-zag design in different locations helps the expansion and contraction of the pipeline
- "fins" on top of the posts of the support structure are filled with ammonia and there to keep the permafrost ground from melting - much like how refrigerator works
- 'pigs' go through the pipeline. One is to clean the pipes and the other is to record any erosion points and such. A helicopter flies over the pipeline and can pick up the signal from the pigs
- the first barrel traveled in 1977 and originally it took 1 month for the oil to travel from start to finish. It now takes 2 weeks
- the support structure has bumpers to allow for movement during earthquakes
- there are 11 pumping stations; 4 are in use now. They are used to relieve pressure and to maintain the temperatureLeggi altro