Alaska Pipeline 101
It’s mid-February, cold outside and a long weekend looms (for some) courtesy of Presidents’ Day.
Nationwide we’re still masked-up and locked down due to COVID. But there’s more and more movement, which is a positive sign.
Let’s get away from it all, take a break and head off to… Alaska.
Alaska? In the middle of winter? Sure, why not.
While we’re up North, let’s visit the Alaska Pipeline and learn a few things. After all, it’s one of the engineering marvels of the nation, if not the world.
And a fascinating story of “then” that says much about “now.”
So off we go…
First, some basics. The Alaska Pipeline is a 48-inch diameter string of welded steel pipe, about 800 miles long. By comparison, the distance from Chicago to New York is 790 miles if you follow Interstate-80.
The pipeline was built between 1975–77, and is operated by the Alyeska Pipeline Service Co. It runs from Prudhoe Bay, at Alaska’s North Slope, south to Valdez on the Pacific Ocean. Here’s the map:
Route of Alaska Pipeline.1
The pipeline transports oil (not natural gas, just to be clear) and there are numerous pumping stations (PS) along the way.
Why is it there? Well, shortly after the great oil discovery at Prudhoe Bay in 1967, the challenge was how to exploit the good fortune. More specifically, how could oil companies move large volumes of oil south.
People actually looked at running oil tankers up north to the Beaufort Sea. But no… There were way too many problems with navigating in the then-frozen Arctic.
Another early proposal was to extend the single-track Alaska Railroad from its northern terminus in Fairbanks up to Prudhoe Bay and haul oil out by rail tanker car. Nope.
Even a cursory investigation made it clear that there was no way to build and operate a railroad that far in the frozen north. Among other issues, there was no way any railroad could ever cross the Appalachian-scale Brooks Range.
The answer was to build a pipeline through the Arctic wilderness. It had never been done before and likely will never be done again.
For example, due to the permafrost in many areas, about 420 miles of pipeline are elevated aboveground on 78,000 vertical support members, such as you see here:
Elevated pipeline on steel frames.2
Above and below ground, the pipeline uses over 124,000 heat-transfer elements along its course. These are, in essence, refrigeration units that keep the soil cold and stable in order to support the weight of the pipe and oil.
Filling the pipeline requires over 9 million barrels of oil, called “line fill.” Just this volume of line fill is over 40% of total U.S. oil consumption for a single day. In other words, it’s a lot of oil.
Since commencing operation in 1977, the pipeline has successfully transported over 18 billion barrels of oil to Valdez, including about 14 billion barrels pumped from Prudhoe Bay and 4 billion barrels from other fields in the North Slope region.
At the southern terminus in Valdez, oil is loaded aboard tanker ships. Over the past 44 years, over 22,000 tanker loads of oil have been dispatched from Valdez to ports south, mostly refineries along the West Coast of the U.S., such as Anacortes, Wash., and Richmond and Long Beach, Calif.
Valdez Oil Terminal. U.S. Dept. of Interior.3
At its peak of operations in 1987–88, the pipeline carried about 2.2 million barrels of oil per day. Back then, it was about one-sixth of U.S. daily oil use.
Anymore, due to depletion of the North Slope oil fields, the pipeline carries about 480,000 barrels of oil per day from Prudhoe Bay south to Valdez.4 It’s a mere 2.5% of U.S. daily consumption.
For much of its length, the pipeline passes through nearly unspoiled wilderness.
It crosses three major mountain ranges: the Brooks Range, the Alaska Range (home to the 21,000-foot-high Mount Denali/formerly McKinley) and the volcanic Chugach Range.
The pipeline crosses nearly 1,000 major rivers and streams, including the mighty and mile-wide Yukon River in central Alaska.
The pipeline begins and ends at sea level. Along the way, the highest point of the line is 4,739 feet at Atigun Pass, south of the North Slope and on the north face of the Brooks Range.
Courtesy Alyeska Pipeline, factbook.5
And the pipeline crosses earthquake zones, including the massive Denali Fault, which is comparable in size, depth, power and scope to the San Andreas Fault system of California fame.
Pipeline designers and builders came up with ingenious methods to protect the line from seismic damage. Here’s an image of one stretch that directly crosses the exposed Denali Fault.
Alaska Pipeline seismic protection features. U.S. Geological Survey.6
Bends in the pipe provide flexibility. And to protect against sideways shearing movement, this stretch of line rests on Teflon shoes that can skid along steel and concrete slider tracks in the event of ground movement.
The idea works. In fact, in 2002 the line withstood an earthquake of magnitude 7.9,and even moved in excess of 40 feet laterally on its skids. Or more accurately, the earth moved more than 40 feet laterally and the pipeline stayed where it was, per Newton’s law of inertia.
The point is there was no damage whatsoever to the pipeline or its structural integrity, which says something about that pipe, too…
The pipe is unique. It’s 48-inch internal-diameter, high-tensile steel, rated to 25,000 psi, stronger than the steel in the hull of a World War II-era fleet submarine. The metal is about half an inch thick. Indeed, the steel has stopped even armor-piercing bullets.
The cost for just the pipe was about $100 million in 1970 dollars, and this was back when the Bretton Woods dollar was still tied to gold at an exchange rate of $35 per ounce. Today, the equivalent cost for that steel would be north of $5 billion.
The pipe was delivered to Alaska in 40-foot sections, much of it staged at the site that became the Valdez terminal.
If you do some math, the entire 800-mile pipeline required about 110,000 pieces of 40-foot long, 48-inch diameter pipe.
Each 40-foot section had to be welded to another, of course. Some welding was accomplished in the shop, not out in the field. This permitted fabrication of 80-foot sections under roof. Then those went out to job sites.
In the end, over half of the welding on the pipeline was accomplished under field conditions, sometimes in winter temperatures as low as minus 70 degrees.
Most of the welding was via electric arc, which required immense levels of electric power to be generated in austere conditions.
Each complete pipe-join required seven separate, welding “circumferential passes” around the two opposing edges of the pipe sections. There was an initial weld and then a “hot weld.” Then there were four “filler welds,” topped off with a “finish weld.”
It was complex work and required a small army of highly skilled tradespeople, all union, by the way.
This translates into about 88 feet of weld being laid down for each joint of pipe, or about 9.7 million feet of welding just for the pipeline. That’s about 1,835 miles of weld over the entire length of the project. By comparison, it’s nearly the distance from Chicago to Reno, Nev. on Interstate-80.
Of course, each pipe weld had to be inspected numerous times, then X-rayed and pressure tested.
On the outside (and for much of its length above ground), the pipeline is fully insulated with about 4 inches of fiberglass. This is in turn wrapped with an aluminum skin, the grayish face of which is what one sees when looking at the pipeline today.
Pipeline opened for inspection. Courtesy Univ. of Alaska.7
The insulation is so effective that there’s almost no heat loss as oil moves through, at a temperature near 140 degrees Fahrenheit.
In fact, it’s normal for winter snow to accumulate on top of the pipeline and not melt until spring.
Of course, just building the pipeline was a logistical feat in itself. First, the constructors had to build a haul road to move people, materiel and equipment.
This road is 20 feet wide and made of gravel. It all sits atop permafrost along many areas of the line. Still, it can bear the weight of the heaviest equipment and loads.
The gravel was quarried from what civil engineers call ”rob pits” along the way. Typically, these are outcrops of bedrock suitable for crushing and roadbuilding. In fact, some of the twists and bends of the pipeline were controlled by where it was possible to build the construction road.
The haul road was laid down over rock and marsh, across rivers and mountains, atop muskeg and permafrost, in an engineering challenge that had truly never before been encountered by U.S. industry. The only thing comparable was the Alcan Highway of World War II, from the Lower 48 up through Canada to Alaska.
Some years back, I took a trip up the Haul Road, from Fairbanks to Deadhorse, a distance of about 420 miles.
It’s tough ground and not for the faint of heart. You share the road with big-rig trucks hauling loads of well over 100,000 pounds. And truckers always have the right of way.
We drove north for hours on end with nothing man-made but the haul road before us and the pipeline at our side. It was hypnotic in a way.
And yes, the pipeline is big when you stand next to it. But from the air it’s almost impossible to see unless you know exactly where to look.
With the exception of infrequent pump stations and an access port or relief valve here and there, one sees essentially nothing else man-made along the entire path of the pipeline.
The haul road is limited access, too. No scenic, rubberneck driving allowed. It’s an industrial road, built through a federally designated utility corridor. Although, again, it’s worth noting how incredibly beautiful the views are.
The haul road and pipeline required 515 federal and 832 state permits. Before beginning construction, about 330 archaeological sites were investigated or excavated. And that was in the ancient 1970s. Of course, things are immensely more complex now.
Along the route, constructors built 14 airstrips to facilitate ferrying personnel and cargo. Some airstrips accommodated large airplanes like the C-130.
Building the pipeline involved 29 construction camps, in which 60,000 personnel were (at varying times) housed during a grueling industrial effort that proceeded year-round, including working during the cold and dark of several pre-global warming Arctic winters.
Those who were there called it a “skinny city” located along a north-south axis across Alaska.
And as construction unfolded, everything about the effort turned into a big number.
The initial estimate to build a pipeline in the late-1960s was $800 million. Ha!
Ten years later, the total cost exceeded $8 billion for just the pipeline and another $3 billion for related infrastructure. And all of this is in 1970s-era dollars, before inflation of the past 45 years.
Today, think in terms of $100 billion — and more — to find an equivalent outlay.
The pipeline was expensive, to be sure. Yet the project still resonates.
Over 45 years, the Alaska Pipeline has supplied oil to run the nation; not to put too fine a point on things, but that Alaska oil fueled the West Coast of the U.S.
Meanwhile, pipeline planners and builders of the 1970s made many decisions that still control events today. Among other things, the pipeline and oil it transported basically funded the government of Alaska over many decades.
For many decades, just the existence of the pipeline impacted the price and availability of U.S. energy. It gave U.S. leaders strategic flexibility in dealing with diplomatic and military matters that involved oil security.
The pipeline also led to domestic political battles over future energy development in the northern reaches of Alaska, both east and west of Prudhoe Bay, where the rocks are definitely prospective.
It’s worth noting, too, that the natural gas of the North Slope is still there. It remains in the ground, never drilled out, available in the future. (Or when gas was produced in association with oil, it was always reinjected back into the reservoirs to maintain pressure.)
The Alaska Pipeline is a “system of systems” and has worked splendidly, continuously for many decades, with an operational reliability that routinely exceeds 99%.
The pipeline offers an example of what mid-century America could accomplish. The nation still ran a robust industrial economy and built great things. No coincidence, also, that the pipeline was built in the same era as when American astronauts were going to the moon.
Today, of course, the country has deindustrialized with more to come apparently. Green New Deal and all…
Plus, the economy is financialized. The culture is globalized.
Look back and then look forward. Could the country do this again? Anything like this?
Ponder it, and draw your own conclusions.
On that note, I rest my case.
That’s all for now… Thank you for subscribing and reading.
Managing Editor, Whiskey & Gunpowder
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7 Above Ground Insulated Pipe Opened for Weld Inspection, Alaska’s Digital Archive