|
After making the "one call" before you dig and lessening your liability, as well as having the line staked out, you still have to excavate this shallow trench, using the information provided by those who marked out the work area, and whose accuracy is still to be determined. If you damage the line, the cost to repair and the downtime of the service will be an issue, as well as liability for same. Best to use care. A one bottom plow, trenching machine and even a front end loader could be an easy way, depending on soil conditions, to dig 6"-8" deep trench, but using these methods you are not likely to see the utility line before you damage it if it is present or does interfer with your new line. Having quite a bit of experience at the controls, and having to excavate around utility lines in the past, I have found that having a laborer with a sharp eye, a willingness to use a shovel and an ability to pay attention is very helpful and absolutley necessary when locating something buried that you do not want to damage. Without that person's trained eyes, focused on the work, undistracted, you are at a big disadantage. If the existing line is dangerously close to the line you want to put in, ( after the locating service stakes it out ) reconsider your layout if you can and move it a safe distance, excavate, install the line, backfill it properly and with just a little cover over the pipe, lay some yellow caution over it, to warn someone else later on, in a deeper trench you can leave some more cover over the pipe to provide some margin of error for the next guy. If you must stay with the orginal layout, there is no question that you will have to locate the line if it is within the same elevation as this shallow trench, odds are it ought to be deeper or lower in elevation, but you never know and cannot assume anything no matter what.
Find a starting point to give you some indication of where it runs, see you can find where the line projects above ground, see if you can follow it to the work area, then excavate close to it but leave plenty of room for hand work. I prefer to over excavate nearby 1st and create a face to hand dig, it makes the hand work a little easier, the spoil falls into the trench as you collapse the trench wall, and look a little at a time, you can more easily locate what you are looking for by hand. Hard to explain, but it's what works for me, when I know I can get the bucket into the ground close by. Sometimes there is no substitute for hand work, right from the beginning, to locate something. It just takes time. I have seen numerous breaks when I did this work, and all of them were do to carelessness, lack of experience, and haste, everyone wants 30 second gratification, in this work that can also get you dead besides damaging utility lines.
If the line is exposed during the work and is in the trench wall, you are still not out of danger as if the fill undermines underneath, it has no support or if a trench wall collapses above it can also become damaged, so you must support said line and take photos of this to prove the work was done properly. At the depth you are working, this may not apply and hopefully what I write here is overkill, same principal but much smaller scale. At minimum, a hoe operated by someone who is experienced and accustomed to that particular machine, is probably the best choice of equipment. Once you have positively located the line, the laborer in the hole or on the ground must carefully guide the operator if the line is to be continuously exposed to get your trench excavated or is suspect to be close to the work but is not seen. No hurry here, one must take their time to avoid contact that could cause damage and support said line as the work proceeds. I have seen the results of broken phone lines, from minimal contact, stay away from fiber optics if they are present.
Whilst holding a 2" or 3" diameter phone line up with a rope, it was in the wall of our trench, soil conditions were fine sand, the bank around me fractured and before I could let go, the whole thing collapsed with me riding the firm crust on top into a very wide, but almost shear walled 17-20 foot deep trench, now instead of me supporting the phone line, I was hanging from it by the rope with one hand, and waving with the other so the operator could see me when he made the swing back after casting the spoil. 1000 feet of trench, along a state road, in sandy soil, for an 8" dia sewer line extension, phone cable in the work area, and a high water table, well points, dewatering, trench collapses, one of which buried a co-worker while I was operating, he disobeyed direct orders, went into the trench, lucky it was only 6 feet deep, up to his neck, I dug him out by hand, we were all real young then, stupid and green, including the owner only 3 years older, whose family was once part owner of a big heavy/highway outfit, went on his own after a squabble, he grew up around this work, but this job was something he may not have seen, everyone learned something on this jobsite, and 2 of us were involved with a collapse, yet we toughed it out, and of course the darned pipe settled and was rejected, he had to dig it up again, and raise it up to be accepted.
I can remember how long it took those phone guys to splice this thing together, they hardly touched the casing at this location and service was interrupted, where the trench collapse with me riding the sand wave into the pit, no damage. Well that's my phone line job story LOL ! There was a guy on this job who used a similar home made locating device, says it works for some people and he'd been using it for years, and in the same way as described,it did work too, except his was copper, like heavy stranded ground wire, it worked for locating the 12" high pressure water main, although it was funny how far the stream went into the air and over the house when the operator severed the service lateral for the home, clear over the house it went, had he even hit that 12" main, I'd have run for the hills.
|
