Fiber optics install gone BAD.
Fiber optics install gone BAD.
(OP)
Crews putting in a fiber optic line breached a gas main.

SF Gas fire
Several links on a page

SF Gas fire
Several links on a page
Keith Cress
kcress - http://www.flaminsystems.com
RE: Fiber optics install gone BAD.
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RE: Fiber optics install gone BAD.
RE: Fiber optics install gone BAD.
Keith Cress
kcress - http://www.flaminsystems.com
RE: Fiber optics install gone BAD.
RE: Fiber optics install gone BAD.
RE: Fiber optics install gone BAD.
"Not for gas lines."
When FO was installed (strung along telephone poles) in our neighborhood in 2014, they managed to avoid rupturing the large natural gas pipeline that runs through the area.
So I'd argue that good old fashioned wooden telephone poles have their advantages, especially for any nearby natural gas pipelines.
(Just kidding. I know what you meant.
RE: Fiber optics install gone BAD.
Brad Waybright
It's all okay as long as it's okay.
RE: Fiber optics install gone BAD.
https://www.ntsb.gov/investigations/AccidentReport...
That's just one example. Hitting subsurface utilities is a universal hazard.
RE: Fiber optics install gone BAD.
RE: Fiber optics install gone BAD.
RE: Fiber optics install gone BAD.
signs everywhere and so it's assumed when a USA call is made all the yokels show up to mark the lack of sewer lines and water pipes and maybe no one shows up to mark the 36" transmission line because, well, DUH, there are already signs. Problem is they don't actually say where the line is other than 'near by'. Then if someone digs by hand carefully and finds the line safely they know where it is and proceed to drill their hole. Unfortunately this doesn't work well if there are more transmission lines then one present.
Keith Cress
kcress - http://www.flaminsystems.com
RE: Fiber optics install gone BAD.
There would be other factors.
I understand that telephone poles go about 4 feet deep. Who buries pipelines that shallow? Our local NG lateral is (IIRC) about 8-feet deep.
RE: Fiber optics install gone BAD.
In the areas I have worked the most (central and southern California), it is very common to see water distribution and natural gas distribution pipelines designed for 3 ft minimum cover (water and gas transmission pipelines are typically deeper). Gravity pipelines, such as sanitary sewers and storm drains, also have this requirement, but in my experience it rarely governs (the need to be below the water and gas mains and the slopes required by hydraulics sends these pipelines deeper). I see this requirement in most of the cities and counties I have worked for, though one city I can think of requires 4 ft minimum cover. I have designed state and federal prison in California and both agencies required 3 ft minimum cover.
Fred
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"Is it the only lesson of history that mankind is unteachable?"
--Winston S. Churchill
RE: Fiber optics install gone BAD.
Maybe in some places, but not here - utility poles never go less than 8 feet here, since the top 5 feet is subject to frost heaving and therefore ignored for lateral stability.
RE: Fiber optics install gone BAD.
Old is a subjective term (30 years is a common failure time of UG electric, 75 to 100 years is likely the limits for water and sewer).
I would guess a 36" gas line would be made of steel, where the new and smaller lines are now made of plastic.
The location of this event I would doubt would have much frost heave, and might be shallow because of past earth quacks, or other ground movement/water table.
Then again a 36" gas line maybe a transmission line, and the transmission company might not have been given notice to locate. That's likely why they place so many marker posts.
RE: Fiber optics install gone BAD.
The line that was hit in the original post was a 4" distribution line.
The line that was hit by the auger rig boring a hole for the installation of the utility pole was a 36" transmission line with four feet of cover over it. This was the result of multiple breakdowns in communication as explained in detail in the NTSB report here:
https://www.ntsb.gov/investigations/AccidentReport...
I was on a job site once where a 4" distribution line was clipped by a 4" auger being driven by a horizontal directional drilling rig. This became evident when all of the mud in the annulus was blown back suddenly and sprayed all over the rig with no warning, followed by a continuous roar of natural gas. Fortunately (miraculously?) they got the machine turned off before the fuel-air ratio hit the sweet spot for ignition and it just made a lot of noise before the gas company showed up to kill the flow. I was long gone by that point.
There are pros and cons to installing utilities above or below ground. Utility locates are imperfect in either case.
RE: Fiber optics install gone BAD.
About 15 years ago I did the site civil design for an ethanol production plant. One thing the owner required of the design-build team (and which I thought was a great idea), was to perform a record survey of the new construction, including N, E, & Z for all underground piping, vaults, etc. before burial. They also surveyed building corners and FF, edges of pavement, etc. The prime contractor told me it added about $30k to a $40M project. The final product from the surveyor was a 3D Autocad drawing of everything underground and at ground. The process team did something similar for the above-ground piping.
Fred
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"Is it the only lesson of history that mankind is unteachable?"
--Winston S. Churchill