Locate Buried Cable
Locate Buried Cable
(OP)
On my rural property I am trying to map the underground location of an electric sub-main cable. This cable was laid before we purchased. There are no obvious obstructions and no other cables any where near but it apprently does not lie in a straight line between two outlets which I know come from it because I have dug two deep sighter holes to no avail. 
I welcome suggestions.

I welcome suggestions.





RE: Locate Buried Cable
The link below lists some of the models available over here. No doubt there are others in your own locaility.
http://www.surveyexpress.co.uk/cableframe.htm
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If we learn from our mistakes,
I'm getting a great education!
RE: Locate Buried Cable
RE: Locate Buried Cable
What I am about to relate was suggested to me when I was just a young engineering student, and while I was (very very) skeptical, I was also (very) desperate and (after havng dug up a lot of real estate to no avail) said 'what the heck'. I quickly became a believer. I later learned that the chief engineer at a renouned pump company (USA) had done some research on it, and that gave some credence to the technology behind it. It has worked for me, and on numerous occasions. Given your task, I would not hesitate to use it. I have used it on electrical lines, metal gas lines, plastic and copper water lines, and clay sewer pipes.
Take two long metal rods, coat hanger wires, welding rods, (I have seen it done with paper clips) and bend them so that you have a "L" shaped rod, one long side, one short side about 3:1, or 4:1 long to short. Hold the short leg in your hands right out in front of you, such that the two rods' long side are pointing forward. Slowly walk across the area that you thing the cables to be buried in. When you cross the cables, the rods will change direction so as to line up with the buried cables. The alignment will indicate the direction of the cables. That is to say if you are not crossing the cables at right angles, the rods will show the angle at which you are crossing the cables.
The theory (as I remember what I saw later) is that there is a magnetic field associated with the electrical cables which is an anomoly in the magnetic field of the earth around them, and the fields of the rods will tend to align with this anomoly. This is simplistically put, but that is the basics.
When I found out about this technique, I was about to begin my senior year of university, and I brought up the experience in a Senior level seminar class of some type. I was roundly laughed out of the class, but it was good natured, and all in good fun.
The technicians in the ME lab, being blue collar types, knew of the technique and believed in it, and made me a cart with two vertical tubes (pipe nipples) so that the "L" shaped rods could be carried with out human influence, and we used it it find buried lines in the vicinity of the engineering building, but the professors would not come down stairs from their ivory towers to look at our results. (We just surmised that they were afraid of finding out that it worked.)
To my professor's credit, when something was ultimately published on this by the aforementioned pump company engineer some 10-15 years later, he was a "stand up" enough guy to take the trouble to forward (we used mail back in those days) a copy of the article to me.
Good luck with your project.
rmw
RE: Locate Buried Cable
So, to give it the best chance, what are the hardware requirements for this?
Checklist:
Voltage 240V
Wires, 1 active 1 return 1 earth wire
PVC protective conduit conduit.
PVC insulated copper wire rated 20 amp continuous.
Existing current requirement 100 Watt
Current........ need to be on?
Optimum length of short leg
Optimum length of long leg
Optimum diameter of rod
Optimum metal
Best to hold rods in hands or indirectly with insulated [wood] bearing blocks?
What is the best time?
Weather conditions?
What else?
For all of the above WAG quite acceptable.
RE: Locate Buried Cable
Good luck.
RE: Locate Buried Cable
We had an employee (now retired) in the position of cable locator, and he would often use a single dowsing rod to predict where his fancy expensive locator would find the cables, and he was pretty close on a high percentage of cables. He could even find them when they weren't energized.
I assumed that he was somehow pulling our legs by simply 'guessing' based on what he saw previously on our system maps, until he twice dowsed the proper location of two cables that were mapped incorrectly, and 'located' via dowsing a cable that had been abandoned and wasn't even drawn on the map.
No one was able to replicate his results, and he himself had no idea how he did it!
RE: Locate Buried Cable
Don
RE: Locate Buried Cable
Being a basic magpie, I know that I still have that article that my college professor sent me, but I wouldn't have a clue where to begin to look for it among my engineering "stuff". I can't picture that I would have tossed that, based on the abuse I have taken over this topic over the years, and yes, even here. Anyone should feel free to pile on. I have big shoulders. Should I ever come across it, I will try to scan it, and post it to this thresd.
Second, the place I learned about this concept was at a summer youth camp, with hundreds of people in attendance, and the word spread fast, and soon everyone was doing it (males mostly-girls didn't seem to care), hence the comment I made about having seen it done even using paper clips.
Kids, campers and staff, were driving me nuts showing me places where they had gotten indications, most of which I already knew about since I worked in the camp maintenance section and was basically familiar with the layout of the camp's utilities.
We did make one observation, though, and it was that people who tended toward red hair, very fair skin, and/or freckles couldn't do it. I had some people almost in tears since most everyone else could do it, and they couldn't. Don't ask me to explain that, I am just giving imperical results.
Once, while walking through a parking lot at a major paper mill in the south of our country, I encountered a workman looking (unsuccessfully) for a water line buried under the asphalt. I went back to my car, dug out a pair of coat hanger wire rods that I used to carry with me back then (about 20 years ago-and I was still associated with the youth camp as an adult adviser) and got them out and went to searching, much to his astonishment and incredulity. I got an indication, and when you work with it enough, you learn how to do some triangulation and determine depth as well, so I said dig here and it will be "X" feet deep. I walked back to the car put the rods up, and went on into the mill to a meeting with the power sup't. Upon my return a couple of hours later, they were digging right where I had said, and had found the line at about the depth I had indicated. I asked him why he chose that location to dig, and he said he had no choice, since his instrument had produced no useful results, and he had to dig somewhere or get fired. He still had an incredulous look on his face.
As to your questions, I already gave the 3:1 to 4:1 leg length ratio, although all that is really needed for the short leg is just enough to get a grip on in your hands.
I have used 1/8" welding rods as well. So the range I have seen it done with ranges from paper clips to welding rods.
If I am going to seriously do this, I usually use a metal coat hanger wire, cutting away only the portion up at the top near the hook.
Since my Mamma taught me to get in out of the rain, I mostly have done this in fair weather, but wouldn't hesitate to try it in any season of the year.
It is not the current you are detecting, but the magnetic anomoly of the wire, conduit, and yes, even the trench in the overall magnetic field of the earth around them. I have detected both active and inactive electrical circuits.
I generally hold the rods in my hands, and only use wooden handles when a non believer is accusing me of using my hands somehow to infleunce the rods. (if it works for you, you will know when they move that you are having no influence on them. I just hold the rods out in front of me waist to chest high, elbows resting on my tummy. I give the rods a slight (very slight) downward tilt in order to keep them to the front. Get them too level, and your momemtum change will cause them to veer to the side. A little gravity assist by tilting them (only a couple of degrees off of horizontal) will keep the positioned. When they indicate, they will climb back up that slight inclination easily.
I hope you are not red headed. Good luck.
rmw
Oh, and PS to resqcapt19, I, too have found empty PVC lines with the method. And to everyone else, I have found this is an area where there is no grey. You either believe in it or you are a scoffer. No in-between.
RE: Locate Buried Cable
One more thing.
While there are no other cables I am certain there are any number of tree roots. Will these cause problems in regard to accuracy?
RE: Locate Buried Cable
Generally, however, the lines had been run in lanes (usually along roads or trails) where the trenching equipment used to bury the lines could operate, so we weren't that close to roots.
rmw
RE: Locate Buried Cable
Practice run No.1
Apparatus. 2 galvanized steel wire coathangers cut, straightened and bent at rt angles with leg ratios 4:1.
Degree of difficulty walking and keeping the rods ~ 5 deg below the horizontal and pointing forwards ? About the same as negotiating a long corridor with a too full mug of coffee but skill improves after about 30 mins.
After 30 minutes of praticing how to hold the rods steady I went to where I know exactly a cable exists and crossed over it very slowly at right angles to the buried cable.
The left hand rod swung to the right, the right hand cable swung to the left and after a few seconds they pointed 180 degrees in the opposite direction. I was very close over the cable but not dead over it.
Is this typical?
RE: Locate Buried Cable
AM radio gets pretty darn noisy when you drive under power lines. Maybe it gets loud when you walk above them too.
Take an AM radio out to your underground wire location and see if it picks up the interference. An external long wire antenna on the radio may help.
kch
RE: Locate Buried Cable
I didn't believe it. I accused him of guessing or trying to trick me but he swore that it worked. He said that they used it at his job (power construction for a major electrical supplier) to find buried pipes and cables.
I finally got him to put on a blindfold and let me watch as he walked across the property in a new location. I marked the spot where the L's spread and then dug a small test hole. Sure enough, the pipe was within 6 inches of my marker and about 2 feet deep.
I'm still skeptical about a lot of things but I have to lean toward belief in this case.
EFP
RE: Locate Buried Cable
So if there is too many things in the same area, its not good, but if you are reasonably sure only a few things are in the area..this gizmo does work.
You can imagine, the looks on the bystanders on a all "women" collge campus, while my client's electrical supervisor, who insisted on demonstarting this to me ,and I were walking around with these in hands..
I have not tried this for offical purposes.
RE: Locate Buried Cable
This method takes some practice to get the 'feel' for the turning of the rods. Sometimes they cross and sometimes they turn outward. It is random.
I usually walk over the search area, and let the rods cross, and keep going past the indication point and then let them uncross, and try to find the mid point of where that occurs.
Combining the momentum effects, all the while trying to maintain constant velocity in order to minimize them, with the movement of the rods from a straight ahead position and back will come with practice.
I will tell you now that I did find my buried plastic water line the first time I used this method, and my worker, a large teenage camp worder cut the water line on about the third or fourth stab with a sharp-shooter type shovel, so I had that kind of accuracy on the first try.
A man who was the son of a plumber had noticed us digging up half of the real estate in front of the boys bath house at the camp, and had made the rods, (borrowing my Kleins to do it) and did a brief search, but in what ultimately turned out to be the wrong area. I was still in the skeptical mode, not giving him much credence, so in disgust, he just set the rods on my truck, and walked off. Hours later, and much digging later, in desperation, I picked up the rods and said 'what the heck.' The rest is history.
I like your analogy to carrying two full cups of coffee down a long corridor.
Keep practicing, and it will come, and you will get good at it.
rmw
RE: Locate Buried Cable
Certainly worth a try and also worth a red star.
(or what did you said about red heads? - can I edit the stars? Hehehe
RE: Locate Buried Cable
RE: Locate Buried Cable
After you're done, adjust the rods to 'Dowsing Challenge' and you can score a quick US$110,000.
RE: Locate Buried Cable
Don
RE: Locate Buried Cable
Begin pasted message:
That was a great recounting of a great experience. If you want to add my story, here it is. And remember, this is from an English major, so credence may be a REAL problem.
In 1978 we were visiting my mother and father, who lived in Tampa, Florida. Dad was the handyman for the apartment complex and had a young man, named XXXX, working with him. Sometime during our visit they had to find a buried line. I was inside visiting with Mom, but took a break to see what Dad was doing. They had dug up, by hand, an area approximately 20' by 20' without finding the line. When I got the details, I just walked back inside and reappeared in a few minutes with my apparatus, made from two coat hangers. (Personal note: I learned this procedure at the same place and time as rmw.) You should have seen the look on my Dad's face! Here's this 61-year-old WWII vet, experienced mechanic, and guy who had basically "seen it all," whose English-major, youth-minster son, was now standing before him with two coat hangers bent into L-shapes, prepared to find that line. I took about three steps, the wires crossed, and I said "Dig here." Three shovel strikes later and the line appeared. The old man talked about that for years. bb
I knew you'd want to hear this story.
End of pasted message.
This is rmw again, and that is straight from a true believer. But always remember that in the signature block of a prominent member of this forum appear the words "the plural of anecdote is not data".
rmw
RE: Locate Buried Cable
http://www.randi.org/library/dowsing/
The ball is firmly in the court of those who believe in such nonsense to step up and claim the prize. You'll not only be proven right, but you'll also be rich to boot.
RE: Locate Buried Cable
The company had a guy who could not only find a buried pipe or cable but could tell one from the other. He would use the two bent wires and would twirl them before he started. He never failed to find a cable or pipe the first time in probably a dozen times while I was there over two months. Often the pipe or cable we were looking for would be 30' or more from where we thought it should be.
I can't say that dowsing works but I can say that guy saved a us bunch of hand digging. He was around 20 and said his dad was better at it than him.
Another thing I learned was that if you are running a Ditch Witch through a neighborhood at 9AM and get tangled up in the little drop cords the cable TV company uses you should run for your life. If you don't you will quickly be surrounded by mad women without makeup wearing house coats demanding that you hook it back up.
Barry1961
RE: Locate Buried Cable
Personally, this little execise is a pleasant and cheap diversion. I am very concious that the first time I crossed known buried cable the wires aligned with it without deliberate intervention. However, I am also very concious I was tired holding the rods out straight for 30 mins and it could well have been a sub-concious reaction to get it over with. To prove overall robustness of claims from either camp require repeatability and accuracy well beyond the scope of my insignificant project and require a scientific explanation because aside from repeatability there is need to know WHY as well as HOW and that would involve a considerable amount of R&D, I think well beyond the 1 million dollars JR offers. (see VE1BLL post dated 14 April 05 15:06)
rmw, any chance of finding that paper?
RE: Locate Buried Cable
Are you a "well witch?" I actually watched this done in 1984 by a co-worker that had hired a "well witch" to find water at his newly purchased home in the country. At least it was "country " then... After unsuccessfully drilling two wells at something like 1500 USD ea. He hired this person that came out and found the water veins and proved to my fresh outta college butt that "this hokus pokus BS" really worked! I was HUMBLED and shut my cake hole after that.
Hmmm. maybe this explains why my leg with the metal plate in it always takes a turn while I am cutting the lawn...BTW, I understand that this technique does not work for the majority of the populace in Ireland. If only I were more Irish, my lawn would be the envy of the neighborhood!!!!!
All jokes aside, I watched it work (for water) and I even tried it myself and the rods crossed. And NO, as far as I know, nobody got "dowsed" when the well was dug! (Bedtime!)
Scott
In a hundred years, it isn't going to matter anyway.
RE: Locate Buried Cable
I have already done a little looking for the paper, but so far without success. I have had a couple of employment changes and/or office moves since I would have gotten it, so it might be difficult. I can't picture having destroyed it based on the nature of the ribbing I have taken over time for putting any credence in it (all the while being a degreed licensed engineer). I'll keep looking.
As I remember it, once in the early '70's, when I was starting up a power plant shortly after I got out of the university, a start up engineer for Byron Jackson Pump Co there to fix a BFW pump problem and I were chatting and somehow the topic came up. He mentioned that some high level technical person for BJ, a chief engineer, or a chief research type person had done some work on it, and had some technical information on it. Nothing more came of that conversation other than the knowledge that there was at least one degreed technical person in the world besides myself that put some credence in it. He knew enough to know that the researchers work involved the interactions of magnetic fields, which I had long suspected was what was involved.
I seem to remember that when my former college professor sent the article, I think it was by the individual that the pump service person had mentioned to me. But it has been a long time ago. The paper was about the influence of the fields between the buried lines, and the rods.
The thing that has been enjoyable about it is that my supposed "education" and "training" would debunk such a thing, but in real life, it has worked for me repeatedly, and I would not hesitate to use it in a heartbeat if I neeeded to look for a buried line.
ScottI2R, I am not into finding water wells, water witching, dousing, etc. And, frankly, except for the fact that I hold a strong belief in something that others with my background are highly skeptical to downright incredulous about, and have been the recipient of some serious abuse over the topic, and don't want to treat folks that believe in their thing the same way, I am among the skeptics regarding "peach tree bifrucated branches."
So, if the rod method works for finding water wells, I will leave that for others to do. Buried lines is my thing. I guess I am not a candidate for the big bucks.
rnd2, I suggest trying the method on a variety of buried lines. Surely you have some other type lines, water, telephone, cable, gas, etc., that you know the general vicinity of to try it on. As you get the feel for it, you will know it is not your influence that is turning the rods.
If you need to, do what we did in the ME lab, and make a cart (we used a childs wagon) and attach a couple of vertical tubes (we used the type wooden handles like buckets used to have) to hold the rods, and then drag the wagon with the rods pointing rearward, so that the swing of the rods is counter to the direction of motion. Alternatively, walk backwards through the zone where you are testing. You really get a feel for it when the rods have to overcome inertia in order to turn.
I'll keep looking for the paper. I am getting more curious all the time.
rmw
RE: Locate Buried Cable
Without a huge amount of fuss the cable is located, and I am truly thankful for that.
Walked over the area and first the left hand wire moved. Rotated direction as carefully as possible until both wires moved. Retraced twice both ways and the wires moved pretty much when crossing the same place. Each time the LH wire swung to the right and the RH wire swung to the left.
Dug a deep hole according to the best interpretation I could make and missed everything.
Am I impressed? Certainly. Why would I not be, the cable is exposed. I now can confidently book the electrician and my original "engineering logic" estimates weren't even close compared to the wires. Am I convinced? No. Not on one success plus I have no idea why and I don't know how. Unfortunatley, I have seen promising concepts crash and burn under rigourous testing. Would I use it again not-for-profit? Absolutely.
One thing that occurs to me about JR's million dollar challenge is some smoke and mirrors may be in the yet-to-be-agreed terms of contract because, IF this thing is real, it is now cystal clear at least to me, that most anybody can do it.
Surely it would be a walk up start to win the mil for those truly skilled in the art but apparently no-one has.
Anyway, thanks to everyone who contributed to this thread and especially to rwm. May your wires always align accurately!
RE: Locate Buried Cable
This thread has been a trip back to the past. I haven't thought about some of those people, places or things in a long time.
rnd2, keep this phenominon in mind, and if you ever come across anything real concerning this, post back so we all can know why it works.
rmw
RE: Locate Buried Cable
I, for one, am glad it worked for ya. Does ANYONE know who started this concept or where or when it originated? Haven't had a chance to google it.....
Thanks,
Scott
In a hundred years, it isn't going to matter anyway.
RE: Locate Buried Cable
A star for having the guts to step forward on a Forum such as this and raise a fascinating topic.
RE: Locate Buried Cable
RE: Locate Buried Cable
"There are more things in heaven and earth, Horatio, than are dreamt of in your philosophy."
Hamlet, Act One Scene Five
RE: Locate Buried Cable
Sorry, couldn't resist.