Electrical Trenching

Electrical Trenching in Rocky soil - 265 feet

I've been working on trenching 265' for an electrical service run to be used for a gate and lights. I thought I'd post some pictures. This is a very time consuming job due to my soil - glacial till. It's heavy clay filled with boulders everywhere, which range in size from basketball size up to as big as a car. The trench has to be at least 30" deep to allow for bedding the service per code. I'm trenching with my B2920 and BH65 with a 16" bucket. The conditions make using a typical trencher impossible due to the large rocks. Quotes for excavation ranged from a few thousand all the way up to $12,500!!!!!

The project is taking a long time, but I am probably done with close to 200 feet now, though it took 7.5 hours of work today to go ~150' due to several large boulders that had to be dealt with.


The trench line, it's going in between a bunch of trees and some surface boulders have to be moved just to start work. Length will be over 265' when done. I used a string and utility flags to mark the path to attempt to keep it as straight as possible.


Partially done section. Soil and small rocks are on the right for easy backfill, larger rocks and boulders are on the left for use later in other projects.


The trench had to be routed around a big rock that was probably too large to move. The width is sufficient to get what I need under the edge of the rock and access is hard at this point so I left it VS trying to excavate it. It is at least 3' x 4 x 4, possibly much larger.


Tractor in one of the easy access sections.


A Problem. A rock that is directly across the trench and is close to 30" deep, 6' long and 30+" wide. The trench is right at it's center and initially it didn't move at all when pulled. Feather and wedges failed on this rock, partially due to it's thickness, but also due to the top breaking off and ruining the drill holes before splitting. Drilling was taking far to long (granite), so I decided to try to move it out of the way into a hole I dug next to it.


I was able to get the rock up on end and then with a lot of chain and effort use the tractor to tip it into the deeper hole. Now 2' stick above the surface, but it's out of the path of the trench.


Rock in it's final resting place. I broke a 4,000 lb come-along trying to get it here and ended up using the bucket to lift and pull to get it to tip into the deeper hole.


A view of more of the trench

Great job.
I did a similar trench, minus the big rock last year with my Kiotii and BH. Quite rewarding - when finished LOL. Put in an extra conduit just in case. I put 2 2 in hers in mine, never want to have to redig. If interested I posted in the Kioti forum, search for Trench should get it.

David Sent from my iPad using TractorByNet

sodamo said:

Great job.
I did a similar trench, minus the big rock last year with my Kiotii and BH. Quite rewarding - when finished LOL. Put in an extra conduit just in case. I put 2 2 in hers in mine, never want to have to redig. If interested I posted in the Kioti forum, search for Trench should get it.

David Sent from my iPad using TractorByNet

Click to expand...

Thanks i'll check it out! The plan is for a high voltage conduit, low voltage for controls and a spare. Definitely do not want to dig it up again.

Some pictures from today. I was hoping to get it finished today on the theory that when I got close to the driveway the material would be primarily fill material and easier to dig. However early indications are that it's not. I hit the rockiest section yet today and in 5 hours only moved maybe 20 - 30'. I stopped at a boulder that would not move, the others were right at the edge of my capacity to move.

I also had a close call when I started. There was a lot of rain this morning and the ground was soft. I went to back into position to resume digging, which is on a side hill. The tractor slid and the rear wheel spun, unfortunately the lower wheel dug in and the upper wheel was on a big rock. The net result was the tractor sliding to the side and on 3 wheels right on the edge of tipping. I was in this position for a while unable to move because of trees blocking the way. Ultimately i was able to get it stable enough to get off, put the BH uphill to add weight to that side and that gave enough traction to get out of there. I leveled the area with the FEL and BH prior to resuming work so it wouldn't happen again. The soft soil in the woods are definitely tough and I found myself sliding sideways and moving when using the BH or positioning.


Today's progress... not much


The section I dug today, notice the rocks on the side of the trench. To give some perspective the big boulder in the background is the size of a small car (I didn't move that one), the other ones are in general 2' cubes or bigger. All granite and all piled on top of each other.


Stopped after I hit this one, so far I can tell it is at least 3' x 3', depth is unknown, but when pried with the BH it does not wiggle. I'll have to dig around it and see what I can do.

If you are running conduit you might want to go bigger or add another run in case you decide to put in other things. ???

I had some trenching to do and I made a 6" bucket for my Hoe.
Having a Welding/Fabrication Shop really helps.
I just made a pattern of the 18" bucket side and then cut it out with my Plasma Cutter. Then some other fabrication for the rest of it.
The narrow bucket digs better because it doesn't require as much power to dig.
It really works great for things like stump removal.

Backhoes are fun, arn't they..... !!!!!!

Stimw said:

If you are running conduit you might want to go bigger or add another run in case you decide to put in other things. ???

I had some trenching to do and I made a 6" bucket for my Hoe.
Having a Welding/Fabrication Shop really helps.
I just made a pattern of the 18" bucket side and then cut it out with my Plasma Cutter. Then some other fabrication for the rest of it.
The narrow bucket digs better because it doesn't require as much power to dig.
It really works great for things like stump removal.

Click to expand...

For the conduit I'm running 3 runs, only 2 will be in use and we'll have extra pulls in them all for future things. No way I'm digging this twice.

Very cool bucket. I wish I had one like that. I thought of buying or renting a smaller one for the project, but our clay soil really sticks, so I even have to bang the 16" bucket at times to get it to empty out.

If only they made one of those rock breaking attachments for small backhoes, then I'd be in business.

Well I managed to get the latest boulder exposed today after work.

I'm now officially wishing I had a MUCH larger machine and hydraulic thumb! Anyone have any ideas on how to get this one out?

I normally would dig to the side of it and push it in, but this one is right between a paved driveway and a tree, so I have to drag it somewhat. I tried to build a ramp and pull it out, but couldn't even budge it (not enough traction). I can stand it on end with the BH and thumb, but cannot get it out of the hole. I've got a new diamond hole saw coming later this week so may try the feather and wedge method again, though it has yet to work on these rocks.... Progress is at a stand still until I can get past this one.

If it wasn't so rocky, you could just dig deeper and put in down deeper in the ground. I have done that with a big double stump heavily encrusted with wet sand. Dug a sloped trench down beside the stump so I could get the tractor lower, then dug down another nine feet and then slid the big stump down into the pit. Pretty scary, but was lots of fun.... You could also use my old standby stump solution... blow it out with a few pounds plastic explosive.. with the added benefit, that if you use enough.... the rock might not even be on your property when you are done...

Can you rent a jackhammer?