Trenching a utility line.

[timberwolves]

Got a quick question, we are finally going to be bringing power up to our cabin. The line is going to be a private line owed & maintained by us. The lenghth of the run from the last utilty pole to the pad mounted transformer is 2260 feet. We are located in Delaware County NY also known as Delaware Shale County due to rocky terrain. The electrician will be installing 4/0 URD in 2" PVC 18" below ground. He is not going to be doing the trench a seperate excavating contractor will be digging. We are going to be paying him a day rate for him & his machines. He estimates 2.5 days digging and 1.5 days refilling the trench. About 1000' is open field the rest slopping downhill. I know its hard to estimate but how long does anyone think this trench should take him ? He will be using a small trenching bucket and a bigger machine if needed for big stuff. The trail through the woods is already blazed. Any ideas ? John

 

[Coyote machine]

Would someone with a 'ditchwitch' be able to do it for you possibly more efficiently? And you may have to have a power company rep on site, or at least involved to approve method and materials used etc., so look into ALL the pitfalls before you begin. Good luck, post pics of progress!

 

[whistlepig]

I had a 200' trench dug for power from a house to a pole barn by a backhoe operator. The backhoe was using a small trenching bucket. He dug the trench, put a layer of sand in the bottom of the trench, helped me lay the line in the trench on top of the sand, put another layer of sand over the line, and back filled the trench. He did this start to finish in eight hours with him taking an hour out of this for lunch.

 

[KYDan]

Sounds reasonable to me. I did my own which was 600 feet with a Case backhoe and it took me a day. I had to dig it 48" deep though due to local regulations.

 

[chim]

The time depends on the operator and the conditions. I once had a project with a lot of duct banks that consisted of anywhere between 2 and 8 schedule 40 PVC 4" and 5" conduits encased in concrete. We poured something like 1,300 yards just for that. There was also about 20,000'+ of concrete-encased 2" conduit for site lighting. I had two backhoes and operators on site for about 5 months. Many areas we worked in the jobsite had existing buried utilities. On our worst days we were lucky if an operator dug 50'. Most days each operator did several hundred. Three feet of fill on top of our work was specified, so everything had to be cut to that plus whatever our pipes took up. The most we had was two layers and there had to be 3" of concrete under and between the pipes, so that made it a bit over 4'.

We had one long run for site lighting where everyone involved investigated the area and guaranteed we were the first to dig there. The soil was in a valley where the topsoil was several feet deep and we turned the best operator loose. He started at 7:00 AM and by 1:00 or 1:30PM he had 1.200 feet of trench open and a HUGE grin.

 

[extrakt0r]

When I was trenching my utilities I could average about 125 feet and hour going 4' feet deep with a 24" bucket. So at 18" deep he should be able to cruise...

 

[whistlepig]

It does depend on the operator. Some backhoe operators are much better than others. The trench I had dug had several large watermelon sized rocks that had to be dug out. I knew this ground was very rocky and more than a trencher could handle.

 

[TYLERJOE]

I KNOW YOUR NOT ASKING FOR ELECTRICAL ADVICE BUT THOUGHT I WOULD HELP...IT IS 2260 FEET FROM THE POLE TO THE PADMOUNT TRANSFORMER THAT WILL FEED YOUR CABIN? SO IT WILL BE PRIMARY VOLTAGE/WIRE? JUST WANTED TO MAKE SURE-THAT IS WAY TOO FAR FOR SECONDARY VOLTAGE. 18" IS FAIRLY SHALLOW ESPECIALLY FOR PRIMARY BUT BEING IN PIPE WILL HELP...COVER BACK UP WITH GOOD DIRT IF POSSIBLE SO THE RAINS WON'T EXPOSE IT AFTER THE TREES HAVE GROWN BACK AND YOU CAN'T GET EQUIPMENT BACK IN THERE! I AGREE WITH COYOTE MACHINE...A DITCHER COULD BE A LOT FASTER-SO OBVIOUSLY CHEAPER.
I WORKED IN THE FIELD AS A LINEMAN FOR 6 YEARS BEFORE GETTING AN OFFICE JOB, HERE IN OKLAHOMA IT GETS ROCKY AND WE HAVE HAD TO LAY PVC INSIDE METAL PIPE FOR SAFETY BECAUSE WE COULD NOT GET THE DITCH DEEP ENOUGH-BUT A FAIRLY LARGE DITCHING MACHINE WILL MAKE A TRENCH WIDE ENOUGH FOR 2", THEY ARE USUALLY ALL WHEEL DRIVE AND HAVE A BLADE TO COVER BACK UP AND RENT FOR A LOT CHEAPER IF YOU WANT TO DO IT YOURSELF! ALSO THEY MAKE PTO ONES THAT GO ON THE BACK OF A TRACTOR-MAYBE HARD TO FIND TO RENT THOUGH-GOOD LUCK!

 

[Lineman North Florida]

Can't speak for the part of the country that you live in, but if you only have to put a single run of 2" pvc I couldn't imagine why anyone would want to dig in a 2000+ foot ditch rather than trench it unless it was because of rocks. With it only needing to be 18" deep you have to wonder if that is the usual or approxiamate depth of the rock in your area, as someone else already stated 18" is awfully shallow for primary, down here in my area it's 36" for secondarys and 48" for primary. Good luck.