The Backhoe, The Internet's Natural Enemy

Juha-Matti Laurio writes "Experts say last week's Sprint outage is a reminder that with all the attention paid to computer viruses and the latest Windows security holes, the most vulnerable threads in America's critical infrastructures lie literally beneath our feet. A study issued last month by the Common Ground Alliance, or CGA -- an industry group comprised of utilities and construction companies -- calculated that there were more than 675,000 excavation accidents in 2004 in which underground cables or pipelines were damaged." I estimate that one third of those accidents occured within the 5 block radius surrounding my office.

Re:Nothing is for certain...

[Ryan Amos]

They are. You're supposed to call the telco before digging more than a foot underground. Very few people actually do, and in some states it is against the law to dig without calling. But in the end it's got to be up to the contractors to make the phone call before they dig, and very few do because of tight schedules. 99/100 times this is not really a problem, but when it is a problem, it's a big one.

Re:Nothing is for certain...

[gEvil (beta)]

And if you'd read TFA, you'd see that the contracter did call. They were given the go-ahead to dig.

I work in the pipeline construction industry

[iibbmm]

In California we are required to notify USA DigAlert before all excavation. DigAlert then notifies all agencies with pipe in the area. Most of the time, they come out and mark, the other times, nobody does.

When nobody comes out an marks, and their line gets hit, it's on them. If it's marked and we hit it, it's on us. Accidents happen. Digging around mismarked and unmarked utilities in a big hole in the ground isn't easy.

Personally I'm more worried about my guys hitting a pressurized gas line than someones precious telco wire. Wire gets fixed in a matter of hours.

Re:Nothing New

[Vellmont]

Ok. It wasn't from a backhoe (but from a software bug) but on January 15, 1990 114 AT&T switching nodes went down and cut off service to at least 60,000 customers. http://www.cs.berkeley.edu/~nikitab/courses/cs294- 8/hw1.html [berkeley.edu]

Re:Nothing is for certain...

[krlynch]

In many states there's only one number to call, not several. Anywhere you live in MA (and a bunch of other NE states), you call "Dig Safe" at 1 888 DIG SAFE, tell them the date and location of the dig, and they make sure all the appropriate companies are contacted.

Re:Nothing is for certain...

[chroma]

Here in Georgia, USA, at least, you can make one phone call and have all underground gas, cable, phone, sewer, and electric lines located for you. For free. People come from the various services and stick little flags in the ground over the lines.

I had to do this when I dug up part of my front yard to put in a flower bed.

Re:Cost??

[a55clown]

Hardly. My 3M certification for fiber took less than a week to achieve, and splicing was only a fraction of that time.

The only difference is the cost of the equipment needed. Fusion splicing is actually very easy.

Re:it's called backhoe fade in telecom

[Ironsides]

you need protection from backhoe fade, you have to do the interagency engineering for separate feeds on separate systems from separate directions. will at least triple your cost to bring it up.

I believe it is called a Sonnet Net. Two completely independant paths that are at no time closer than 25 feet from each other, including the locations where they exit the building. Various telcos offer this.

Re:Cost??

[iamlucky13]

$50,000 for a fusion splicer that can be used in the bottom of a muddy trench (at my last job, I think our benchtop models cost $20K) or $20 for a pair of crimpers? I'd wager repairing fiber is a lot more expensive. Heck, copper hardly even matters if it's clean or not. Either way, you're getting a couple of on-call guys each spending a couple hours getting gear together, driving to the site, doing the fixing, and testing and documenting the repair. Add that to the theoretical cost of down-time that accountants like to talk about, and half a million or so accidents can add up pretty quickly in value.

Cable information isn't always right

[kmahan]

Usually you tell the marking service how deep you're going to be digging. For most jobs they'll mark everything since the stuff isn't buried too deep.

For a lot of the "middle of nowhere" fiber feeds they bury them at least 6' (2M) deep. An electrical contractor friend of mine was doing a job "just north of middle of nowhere." He'd had the major fiber carrier in the area come out and mark where the bundle was buried. And they assured him it was 6' down -- which worked since he was only digging down about 4'. He tore the cable apart with the backhoe at 3'. The original contractor that had laid the fiber cable hadn't buried it to spec. The marked path of the cable was right on though.

Re:Nothing New

[AKAImBatman]

Slashdot auto-screws that second link. Here it is in plain text:

http://web.archive.org/web/*/http://www.att.com/pr ess/0498/980414.bsa.html [archive.org]

Re:Human error...

[el_gordo101]

My father-in-law is a dispatcher for Keyspan, the company responsible for that blunder. Apparently, some of the older gas lines are not clearly marked as to whether they are high pressure or low pressure lines (which is what caused this balls-up). The tech hooked a high-pressure feed line up to a low-pressure residential feed line. This caused gas leaks in many homes along this line as the high-pressure gas popped open any weak fittings or connections inside the house. MAJOR screw-up.

To drive home the point

[Khyber]

I installed a fence across the "true" (city surveyor marked) back end of my property line. I called phone/cable/power companies, and had them mark where my lines were.

They were all off by two feet, in the same direction.

We were told they were 6' down, we snapped cable at 1 1/2', good-bye phone at 2'. After that first snag, we dug VERY carefully with hand tools, only to find power not a foot away and a foot further down. Either the ground is shifting in Tennessee, or we've had some REALLY stoned public workers/contract workers.

Re:Cable information isn't always right

[SmurfButcher Bob]

You're on drugs. NO utility gives depth info, and I'm not aware of any major one-call center that TAKES depth info from the caller. I know for a fact that we don't.

Depth is useless; in Arizona, for example, snow-plows are required to "call before they plow". Why? Soil erosion.

Here in my state, depth is likewise useless; not as much from erosion as it is from grading. Infrastructure goes in first; landscape happens last. It is QUITE common for a 48" deep line to be 24" from the surface after several years.

And that isn't accounting for things that were discovered when trying to bury the lines in the first place; intersections with other plant means you change height at that location. Hitting Bedrock... means you change height.

> had the major fiber carrier in the area... assured him it was 6' down

Not likely. The moron sent to locate the cable may have mentioned the depth in passing, but I work with these "major carriers" and their locators every day, and there is no way in hell they'd say "you're fine to use your backhoe directly on top of my wire up to 5 feet 11 inches deep". Most "Major Carriers", on a long-haul line, will physically PUT A BODY on-site during the dig to enforce the protection of their cables by hand digging over it. If it's an issue, or a very high-value asset, they'll even go so far as to hand-expose it, themselves. They do not, ever, say "sure! Just dig right on top of it".

Ever.

What I'd suggest is that you ask your contractor friend to define what he means by "assure". And as you do this, remember that he's getting sued for being at fault... he won't do anything to deflect responsibility, at all... he certainly won't exaggerate what was said, for certain.

Not always legal...

[mkosmo]

My father is a former big whig for a nearby city, and he tells me that often times the maintanance crews would find fiber lines where they shouldnt be, often illegally located in and along and through santitary and storm water lines. He told the crews to treat them as big tree roots if they were not on the plans... Telecom companies would get soooo pissed, but couldnt do anything, since the conduits they laid in those cases were illegal to begin with and were causing infrastructure issues for the city.