Letter To The Journal: Commentary On The Pipe Near Sourdough
A Section Of Alyeska Pipe Was Originally Intended As A Buried Crossing By Rod E. https://vilda.alaska.edu/digital/collection/cdmg2/id/6076...
https://www.countryjournal2020.com/2024/12/letter-to-journal-commentary-on-pipe.html
A Section Of Alyeska Pipe Was Originally IntendedAs A Buried Crossing By Rod E.
Also just use Google maps to go up near Sourdough. Follow the pipeline right of way to the bridge on river and then see the tight oxbow site on the river above the bridge a mile or two. There are also other historical photo on-line
Email To The Journal From Rod E... December 23rd, 2024
The background story is this:This site was originally intended as a buried crossing by Alyeska.. The geology & soils were suitable for that. But the burial depth for design flood was deep & difficult with no good time of year to do it either.
Upstream there was that tight Oxbow ~180 degree bend to the left looking downstream; not far upstream. It can still be seen now as a recent cut-off oxbow lake from when the river cut though the very narrow peninsula taking a short cut .
Engineering says shortening the river over a same length increases gradient therefore energy. Rivers react to such things over time This was a concern to designers and overseers and required even deeper burial. Alyeska decided the best solution would be the bridged crossing but that was pretty late in the project; and we were fresh out of standard predesigned & prefabricated steel girder bridges. A good idea came up:
Rejected out of round TAPS 48" OD pipe from so many years spent at the bottom of the storage yard stacks was used to support the two piers; one on each end; and an arched truss was designed to support the pipeline.
Good solution but a scramble to have it done in early 1977.
For a very long time (decades) the event of concern "cut-off" upstream never happened... but now I see it finally did. It does not appear to have changed the flow of the Gulkana River in the section below very much. The bridge is also Hell for stout; we did not have time to further debate the issue.
I think the Gulkana was the final river crossing to be constructed; and the oil fill "front" came through in Summer 1977.
About 48 years later... still looking good. - Rod
Also just use Google maps to go up near Sourdough. Follow the pipeline right of way to the bridge on river and then see the tight oxbow site on the river above the bridge a mile or two. There are also other historical photo on-line
The background story is this:
This site was originally intended as a buried crossing by Alyeska.. The geology & soils were suitable for that. But the burial depth for design flood was deep & difficult with no good time of year to do it either.
Upstream there was that tight Oxbow ~180 degree bend to the left looking downstream; not far upstream. It can still be seen now as a recent cut-off oxbow lake from when the river cut though the very narrow peninsula taking a short cut .
Engineering says shortening the river over a same length increases gradient therefore energy. Rivers react to such things over time This was a concern to designers and overseers and required even deeper burial. Alyeska decided the best solution would be the bridged crossing but that was pretty late in the project; and we were fresh out of standard predesigned & prefabricated steel girder bridges. A good idea came up:
Rejected out of round TAPS 48" OD pipe from so many years spent at the bottom of the storage yard stacks was used to support the two piers; one on each end; and an arched truss was designed to support the pipeline.
Good solution but a scramble to have it done in early 1977.
For a very long time (decades) the event of concern "cut-off" upstream never happened... but now I see it finally did. It does not appear to have changed the flow of the Gulkana River in the section below very much. The bridge is also Hell for stout; we did not have time to further debate the issue.
I think the Gulkana was the final river crossing to be constructed; and the oil fill "front" came through in Summer 1977.
About 48 years later... still looking good. - Rod
No time for much more. See this link for picture during construction
Also just use Google maps to go up near Sourdough. Follow the pipeline ROW to the bridge on river and then see the tight oxbow site on the river above the bridge a mile or two. There are also other historical photo on-line
