Post by thread:oil company device

I live in Italy in an old apartment building (once a barn) built about 400 yrs ago. Nobody knows the exact route of the sewer pipe. We only know the location of the last drain well. Due to a court litigation, we need to ascertain the route of the sewer pipe. The only way known here is to begin digging from the drain well and follow the sewer pipe up to the main sewer pipe (the one owned by the city) buried somewhere under the street level. This would be very expensive, as it means breaking the floors of the shops located at ground level and stopping their activity for several days. I guess that someone must have built a simple device fitted with a gyroscope and an inclinometer that can be inserted in the drain well and follow the sewer pipe. The device will transmitting back infos by wire and a PC will be able to draw the route of the device, i.e. of the pipe. A jet of compressed air could be the chosen locomotion system. I heard that oil companies use this mousetrap, so someone out there must build and sell it. Any hint ? Thank you Duilio Foschi

Duilio, What you describe sounds practical but rather difficult to make. If a plan of the route would be enough (at least to start with) then another option may exist. Drain cleaning machines can usually push a long "rod" down a drain. If you placed a signal generator at the end of the "rod" which produced a short range RF signal you should be able to locate its position quite accurately with an above ground search coil. I believe that very low frequencies are better at ground penetration - essentially a high frequency audio oscillator driving a suitable coil. I imagine that GPS would be totally unsuitable for underground use. The device that you described is a full "inertial platform" - such devices are available pre-built from companies such as - i Systron Donner http://www.systron.com ii Crossbow (no URL sorry) iii Also possibly suitable equipment from - http://www.primenet.com/~watgyro/Ramenskoye/products/gvk-10.html http://www.fibersense.com/index.html http://www.microsensors.com/products.html Tokin ceramic gyros http://www.tokin.com/Tokin_America_Products/p46/p46.html Murata piezo gyros http://www.murata.com/develop/index.htm http://www.iijnet.or.jp/murata/index.html http://www.murata.co.jp/Ceramy/owa/CATALOG.showcatalog?sHinnmTmp=ENC-03J&sLang=2 http://www.nerorockets.org/haarlem/hegyro.htm Russell McMahon _____________________________ >From other worlds - http://www.easttimor.com http://www.sudan.com What can one man* do? Help the hungry at no cost to yourself! at http://www.thehungersite.com/ (* - or woman, child or internet enabled intelligent entity :-)) {Original Message removed}

What about the device used for determining where breaks are in underground telephone cables? I believe they induce a standing wave on the cable, and then use a search coil (or antenna) to determine where the feild is, and where it is not. I have seen these devices work through 2 feet of soil, to an accuracy of 4 inches. If there is a conductor (introduced, or pipewall, or standing water) that you can induce the wave into, then 'map' using a sensitive search device, you should be OK. Hope this helps, Des Bromilow

Duilio Foschi wrote: {Quote hidden}> I live in Italy in an old apartment building (once a barn) built about 400 > yrs ago. > > Nobody knows the exact route of the sewer pipe. We only know the location > of the last drain well. > > Due to a court litigation, we need to ascertain the route of the sewer pipe. > > The only way known here is to begin digging from the drain well and follow > the sewer pipe up to the main sewer pipe (the one owned by the city) buried > somewhere under the street level. > > This would be very expensive, as it means breaking the floors of the shops > located at ground level and stopping their activity for several days. > > I guess that someone must have built a simple device fitted with a > gyroscope and an inclinometer that can be inserted in the drain well and > follow the sewer pipe. > > The device will transmitting back infos by wire and a PC will be able to > draw the route of the device, i.e. of the pipe. > > A jet of compressed air could be the chosen locomotion system. > > I heard that oil companies use this mousetrap, so someone out there must > build and sell it. > > Any hint ? > > Thank you > > Duilio Foschi Here in the US they drill horizontally to install new pipe for cables. They can steer the drill while doing this. Somehow they must be tracking where the end of the drill is. I wonder if anyone on the PIC list knows how this is done. I have wanted to know this for quite some time and now seems like a good time to ask. :-) -- Rich