problem locating PE gas main

[underground quester]

Was recently in a rural setting acreage lots 40 acres each. One road total 6 houses - 3 on either side of the road.

Road oriented north/south. Gas main ran north south 125 feet east of road.

Had a section of the gas main between 2nd and 3rd house on east side that would not locate, yet I would walk fifty feet forward and get a 700 signal. Then in a hundred feet or so would completely lose the signal again. Keep walking and would pick it up again. So I knew the signal was travelling along the line and not going to ground or whatever. So, WTF???

Finally hooked up to middle house west side of road, grounded out to inlet pipe of gas meter and cranked her up to high on high frequency. Could then locate parts of the main going south but not north.

Hooked up to the tracer wires at first, second and third houses East side and to the middle house west side.

Same problem, could not locate sections of the main between 2nd and 3rd houses east side of road.

This was essentially pasture land, not industrial or polluted land, or anything like that.

Anyone got any ideas why and what to do about it. (other than buy a pipehorn of course).

[sprayandpray]

Offhand, I would say that the line went considerably deeper or jumped over to a wire fence, or something else conductive. It would concern me that I lost a signal at one part but picked it up later and farther away from my transmitter although I have had that happenwith fiber.

[ifinditunderground]

I agree with S&P, it is a change in depth or direction, or interference from a fence, or paralleling utility causing that.

[TBONE]

The fence most likely threw you off the old depth vs signal all you can do is either line it up or try to spot it to ensure you are on it

[underground quester]

Hey, thanks so much guys.

It could well be the depth thing you are talking about. The soil conditions out there are number 1 black top with sand underneath. So, if they pushed the line rather than trench, they could have had problems with depth.

If that is true, then that would be a logical explanation for the signal coming and going so to speak, depending upon depth.

No other utilities parallel path of this gas main. Nearest utility is o/h power in east ditch of this road. Though, each house had overhead power to just before the house, then drops down a lateral & is underground to the meter.

I am out there about once every 10 days or so now, so will look at all the fences. There were a ton of them and some were 8 feet high. (They had "Wood Buffalo" in the pastures).

Just gave me a thought too, I will look to see if there are any metal fence posts.

ThanX again guys, I really appreciate the input.

[Goldenboy]

Depth does sound like it to me also. Maybe next time out there you could pull quite a few depth readings as you go.