From a search found the following from a science article from the University in Fairbanks, July 2008. It was just given the go ahead for another 30 years. BTW, it is now running at 50% capacity - but ANWR is only 55 miles to tap into it. Also, if Murkowski’s deal for a new pipeline was so great, how come the oil companies didn’t take it?
“Strung over and beneath the surface of Alaska from Prudhoe Bay to Valdez, the trans-Alaska pipeline, at 31 years old, is entering its second lifetime. The four-foot in diameter, half-inch-thick steel pipe had an original design lifespan of 30 years. The State of Alaska and the U.S. Department of the Interior recently gave the pipeline the green light for another 30 years of operation.
“It’s like a car,” said Johnson, who works for Alyeska Pipeline Service Company, while standing under the pipeline near Fairbanks during a recent permafrost conference lecture. “As long as you maintain it, it’ll continue to work.”
Correct. The older the car, the more maintenance needed.
As for the gas pipeline, the oil companies did take it, they approved Murkowski's plan. They negotiated the deal with Murkowski.