Fiber Splice

[Shortbus]

Ok, here's a fun one.

I am attempting to find a fiber splice buried almost 10 years ago.

Problem - no marker ball or tracer wire, non-metallic sheath and am told the splice is in a fiberglass box.

Luckily, the fiber was buried in the same ditch as a copper cable, so I located the route. However, the splice is somewhere off to the side of a 2-track dirt road. OTDR measurements compared to copper TDR measurements and old job prints put me within +/- 300 feet. That all assumes that the fault is at the splice to begin with.

Plan A - (failed due to rocky soil and all kinds of metal garbage) use metal detector and probing rod. Hopefully detect case bolts or splice hardware. Then try to find case with probing rod.

Plan B - (in progress) use metal detector to detect case bolts or splice hardware. Dig every target until case is found. (Not fun. You wouldn't believe how much crap is along this road, gum wrappers, bottle caps, zipper pulls, bolts, nails etc.)

Plan C - use backhoe to dig along cable until case is found (last resort)

Plan D - use ground imaging equipment to locate splice (likely very expensive, no budget for it)

Plan E - dowsing rod?

Anyone have any better ideas?

[David]

Plan F- Go back in time and ask the stupid SOB why he didn't mark it, and then ask where it's buried. (not very likely to succeed and might be rather costly!)

[Splitpair]

OTDR measurements compared to copper TDR measurements and old job prints put me within +/- 300 feet. That all assumes that the fault is at the splice to begin with. Anyone have any better ideas?

What is the total length of the span?

Can you find any splices?

Is the loss common to all pairs or just one?

Fiber is “usually” reeled in set lengths if you can find a splice or two in known locations you might be able to use that measurement to predict where the missing splice is.

Also if you can find out what type of case was used for the splice, unless it is one of the old aluminum clamshells you are probably spinning your wheels using a metal detector.

Push come to shove go to the center of the loss per the TDR and using a sprinkler shovel and hand dig a lateral trench and locate the fiber, expose a few feet of it and see if there are any footage markers embossed into the jacket.

Walk off a hundred feet or so away from the fault expose the fiber again and see if the footage markers are way off, if so you have found the next reel and your splice is between the two trenches.

If it is truly in a fiberglass hand hole then you should be able to walk the line back while stoutly stabbing the ground every foot or so with your shovel and you will hear the hand hole if it is in line with the fiber run which it “should” be.

Wayne

[Shortbus]

Plan F- Go back in time and ask the stupid SOB why he didn't mark it, and then ask where it's buried. (not very likely to succeed and might be rather costly!)

Wish I could go back in time. However, talked to someone who was around when it was buried.

Apparently it was the first fiber buried around here and nobody thought about finding it later. Plus, the "fiberglass box" is a probably the hand hole type usually used for irrigation systems. And..... buried about 2 feet down (or more), swung off to the side of the cable run by about 3 feet.

On top of that, I'm told there is a second splice just like it along this section also. And... a generous slack coil buried with each splice. Which explains why footage doesn't really add up.

On the plus side, I am told it is the right general area. He just doesn't remember where the splices are.

What is the total length of the span?  A. close to 3000ft

Can you find any splices? A. One manhole with a splice, two more manholes with slack coils. No OTDR available though. End to end measurements were done by contractor.

Is the loss common to all pairs or just one? A. Distance to loss is close to same footage, +/- 10 feet for all defective strands.

Fiber is “usually” reeled in set lengths if you can find a splice or two in known locations you might be able to use that measurement to predict where the missing splice is. A. That might narrow the ballpark some. Not sure now after finding out there is also a second buried splice.

Also if you can find out what type of case was used for the splice, unless it is one of the old aluminum clamshells you are probably spinning your wheels using a metal detector. A. The guy was pretty sure it is a composite bolt together case. I would guess a coyote closure.

Push come to shove go to the center of the loss per the TDR and using a sprinkler shovel and hand dig a lateral trench and locate the fiber, expose a few feet of it and see if there are any footage markers embossed into the jacket.

Walk off a hundred feet or so away from the fault expose the fiber again and see if the footage markers are way off, if so you have found the next reel and your splice is between the two trenches. I really like that idea!

If it is truly in a fiberglass hand hole then you should be able to walk the line back while stoutly stabbing the ground every foot or so with your shovel and you will hear the hand hole if it is in line with the fiber run which it “should” be. I tried that last fall, then used a frost bar also. Everything that sounded close ended up being a large rock

Wayne

The detector I have is quite good. I easily picked up a lug nut buried about 2 feet and even found a very small wire nut at about 1 1/2 feet. Catch is, I have to crank up the sensitivity, which then picks up gum wrappers and other junk also.

[burner50]

I like the lateral trench idea...

Divide and conquer.

[Shortbus]

Even better, the fiber isn't direct bury. It's in plowcon. 

[Shortbus]

Found it 

Obtained some better quality OTDR tests with documentation. Then with that was able guesstimate and narrow it down to 60ft. Which put the fault in area of a supposedly straight run.

Thinking a crushed conduit was the issue, had a machine come out and dig down to the fiber. Couldn't find any damage. So, cut a small window on top of the conduit and ran a fish tape through it. It stopped dead 20ft away. Dug there and surprise, found an unknown third splice that was causing the problem.

[Bogey]

Well at least now there's a marker ball there, right?

[Splitpair]

Well at least now there's a marker ball there, right?

Yes sir there sure is one now and it's exact distance from the cable and the splice is duly noted in SB's "personal" log notes. ;-)

Wayne