Advice for my first big job

[OldandWorn]

I need to trench 1800' for power to my retirement property. The trench has to be 3' deep and a minimum of 6" wide for 3" schedule 40 rigid PVC. My machine is a late 70's Deere 410 with a 12" bucket. I'm not an operator and have only dug a couple of small holes with this machine but got comfortable operating it pretty quickly.

I may end up renting a trencher but because of rocky soil, unlevel ground, and 3 small creek crossings I think there will be a need for the hoe.

Some concerns:

1) How to get through the creeks while water is flowing? The flow is small enough I could possibly dam them up and pump the water around my work area if necessary.

2) Picture these creeks as a 3' deep 10' wide swale with steep sides. I need to keep my pipe as straight as possible so the power company can pull the wire through. Do I gradually taper down to 6' deep entering and exiting the creek so the pipe will be 3' deep at the bottom of the creeks? I can use 22 degree elbows to help with the transition if necessary but I would like to keep all pipe joints out of the creek bottom. From what I understand this conduit doesn't bend much.

3) These creeks and about 800' of the run is on a neighbors undeveloped property (grass fields) and I'm concerned about making a mess and the trench settling over time. Any advice to minimize trench settling? Grass seed and straw over the trench? There is water availiable from a large creek but difficult to pump.

4) I'm really worried about digging in the hard rocky soil. Does anyone have experience with using a ripper on their hoe? I'm thinking I could rip the entire run and switch back to the 12" bucket. This could help the rental trencher also.

Any general trenching and back hoe advice greatly appreciated!

 

[JS580SL]

Ditch witch's are about as useless as **** on a bull in rocky material. I used one the other day, good size walk along machine. Everytime the chain would grab a rock the machine would stall if I wasnt quick enough raising the chain or stoping it. In clean material they work great. The plow end is the same, one good rock and the fight is on.

I'd look into a "hole hog." We use them to run gas services across roads sometimes. We have 2 on the truck a 2 and 4inch. Works very well in clean material but like the ditch witch one rock can bounce it off course. It works somewhat like a jack hammer. Set it level in the hole aimed in the direction you want it to go. Spin the end one way for forward other for reverse. Runs of a hose connected to an air compressor. A rental house may rent these and may be an option for crossing your streams with out disturbing them at a low cost.

I do alot of digging in rocky ground. Mostly trenching for gas main. Never use a ripper tooth. Would be nice to have a times but patience and experiance pays off. Get your trench started, once you at your depth, sink your bucket to the bottom every cycle, get a full bucket and rip out. Its faster than "taking of the top" and it helps free up material for the next bucket full.

Shoot me a pm if I can help answer any your questions, be glad to help.

 

[OldandWorn]

Thanks JS! I will look into the hole hog. My neighbors property is bottom land and relatively rock free. My property is a very different story.

 

[xcmark]

I am a elecrtical contractor that does this type of work all the time.. You want a very flat bottom first off and I would up size to 4" pvc. You will want a pull box about every 400' even if its strait threw and I would not do any angle pulls in and out of the box. The utility company I hope is running high voltage the 1800' then installing a transformer correct? as for the brook crossings I would really like more info , if its down hill from the brook to the turn up location your always going to have water running threw the pipe no mater what you do it cant be stopped. Electrical conduit is not water tight no mater what anyone says! You may want to consider encasing the conduit in concreat for the brook areas and 20' on each banking and four number 2 rebars (two above and two below) in the chairs. chairs want to be no more then 5' apart and you will want to buy base and intermediate pieces. The top pieces give you a good depth gauge on how thick the pour is and a place to set the bar in. When you get to the point your going to install put glue on both the bell end and the end of the pipe then push them togearther by hand and turn it slightly as it goes in to feel it set then stop turning. Also you can not glue damp or wet pipe it just doest seal or hold. To get a string threw it after two shop vacs on blow at first to push the glue fumes out of the pipe then swap it over to suck. Make a plastic bag that is just slighty smaller then the pipe with a bit of filler like a second plastic bag inside of the other. then tie it to a bucket of nylon string rated at 200~250 lbs . the two shop vacs sucking on the far end of the pipe will draw the water out and pull the bag with the string attached to the next manhole in 5 seconds. Some times if there is a lot of water we have to blow that out with a tow behind air compressor depeing on ig the water is trapped but a rise and valley. after the string is in then upgrade to 2500 lb mule tape or 1/4" rope . Mule tape is around $400 for a 3000' roll and the 1/4" rope is about $50 per 600' just depends on what the utilty company will accept. If my site guy gave me a trench really narrow and not strait I would make them fix it and sand in the bottom and top after , long runs really need the pipe to be layed flat and strait , slight curves dont count but nothing that requires factory bends would be acceptable to me . 560' to a factory bundle of 4" schedual 40 if they are 10' , I would special order 20' pipe (it only takes 3~4 weeks to get it) . Its much easier to install , less glueing and we can install 1500' of strait 4" in a day with 3 guys and some equipment to move the stuff.

 

[OldandWorn]

xcark, thanks for taking the time to provide such detailed information. Hopefully I can pick up hoe operation fairly quickly so I don't have to spend a lot of time fixing a wavy bottom. I'll probably achieve this at about 1,790 feet. Funny that you mentioned the 4", I called the engineer yesterday and got the ok for it because I am also concerned about this run. The last thing I want is to do this twice and pay the power company even more money for retrying a failed pull.

She came out to the property to engineer this run and placed the first pull junction 500' from the pole which will include 2 of the creeks and a turn that will require at least a 22 degree elbow. The next pull is 800' which includes the most difficult creek crossing, an even sharper turn, and a gnarly uphill that my hoe can't climb. I will probably have to dig this leg drifting down backwards. Because of the terrain this is the best she could do and it has to work or I'm screwed. The power company REALLY wants to avoid overhead lines and they have priced it so far out of reach that almost no one can afford it. The underground fee is making my stomach hurt and they already sent me a bill for it.

Yes, this run is for high voltage primary with 75' of secondary which they provide for free, bless their little hearts. She also said that I could backfill as I go which is nice because I'll be doing this on the weekends at my own pace. My neighbors land is a swamp right now and it will be mid or late summer before I can dig down there if this rain ever stops.

I'm curious about water in the conduit? it has to get in there from faulty joints, right? She did mention that many times she has seen the conduit full of water and suggested I might want to put a drain hole in the low spots. It is direct burial cable but they want it in conduit mostly for their convenience I think.

The brook crossings will be straight across, ie perpendicular, and the land is pretty flat other than the 3' deep creek swales that I mentioned in my original post. Two of the creeks dry up during the summer and one will always flow a little bit in drought conditions. What is up with the concrete and chairs? I need to Google that. Would it be visible? I think my neighbor would have a fit if I started pouring concrete even though this part of his land is un-buildable. I really like JS580SL's suggestion for the "hole hog". It sure would make life easy to be able to pound a hole under these creeks.

Thank for the info on the conduit length. I have been on the fence about which length to go with. I have a friend at an electrical supply house that can get me killer prices on everything but there is no way for me to transport 20' conduit 100 miles from where I would have to buy it but I can transport 10' on my trailer. There is a local building supply that will deliver 20' conduit and I need to get prices from them. The power engineer told me to use 1/4" rope and I was planning on using a long rod to feed it through each piece. She also gave me 2 1000' rolls of plastic caution tape to place in the trench.

FYI... I'm doing all of this right now to "lock in" power to my property. This run will be for my pole barn which is the only structure so far and it was here when I bought this place. In a year or so I will get to run another 300' of primary to a second transformer that will power my house along with another bill. What sucks is, the power company charges footage to your house and will run free cable to any out buildings. In my case, I have to pass the barn to get to the house so I loose out on the free cable run.

Thanks again for all of your valuable time and information!!

 

[mitch504]

you need to be real careful working on a slope a backhoe won't climb. Doing that without knowing what you are doing is an excellent way to wake up dead! I don't think I would do that without something big winching me down.

 

[OldandWorn]

you need to be real careful working on a slope a backhoe won't climb. Doing that without knowing what you are doing is an excellent way to wake up dead! I don't think I would do that without something big winching me down.

Yes, it is steep and I need to be careful but perhaps I was exaggerating a bit. I was trying to describe this long difficult run to the poster without getting too wordy. Power and traction wise (no diff lock) the hoe can make the hill but it will lift the front wheels and drag the hoe bucket going foward. Going up in reverse has a much lower pucker factor. I do have an 18 ton track loader that I can cable onto. A large 4wd or tracked trencher may be the pick for this hill but it is also very rocky and I still need to sort this part out.

Thanks for your concern

 

[xcv8tr7]

When going up that steep hill, you could have the loader bucket full of dirt- front end will stay down then. I have had to do this when carrying large stumps and rocks with the rear bucket.

 

[OldandWorn]

When going up that steep hill, you could have the loader bucket full of dirt- front end will stay down then. I have had to do this when carrying large stumps and rocks with the rear bucket.

Thanks, and very true. If I do use the hoe I would want to be digging towards the uphill grade so weighting the front bucket would not be necessary in this case.

 

[DGODGR]

Digging the "steeps" will be easier from the top down. You can use a pile of dirt (pushing it with the loader) to help control your decent. The machine will also stay put while digging (machine will have a tendancy to pull itself down the hill if you try to dig from the bottom up). The downside is that you will be pulling your backfill down the hill as you dig. Be cognisent of this and place your spoils as far up hill as possible.
I would not use the "whole hog" (also known as a power mole) if it is rocky. If you do use one you will also have to use it to pull the pipe through the hole (you can't just push it through). I would also suggest "roping the pipe" instead of using the 22-1/4 degree bends. PVC will bend (3" easier than 4"). If you have warm sunny days you can employ a "solar bender". Take a joint of pipe and place on end in an elevated position (lean it on a tree, on a fence, or a rock, truck...most anything will do) with the middle unsupported. As the direct sunlight warms the conduit it will begin to sag in the middle. This will shape your bend. Simply rotate the conduit so that the bend is in the same direction as the curve in your trench. Since you are going "across country" I would assume that you have plenty of room to make the gradual bends. Sharper turns equal more friction during the pull. The 20' joints will bend MUCH easier than the 10 footers and the shorter joints probably won't have enough weight to "solar bend". I would tend to agree with the opinion that the 800' pull is too long. That being said the designer is an engineer and they (power company) do this all the time. I would assume that they will employ the use of a power tugger and LOTS of lube. We also don't know the cable size but, again, the engineer should have all of this data taken into account. The only real variable is your trench quality.
I also recommend that you go deep early, at your creek crossings, and not use 22-1/4 bends. Damming of the creek will be the ticket but I would bet that you still will have subterranian water intrusion. I suggest that you have the pipe ready and glued together before you dig the crossing (however much pipe you need to get across the creek and back into dry ground). IMO you should be able to keep the conduit dry if you use glue AND primer. The 20' joints are a must. Everything about this job will be twice as hard if you use 10' sticks. I also recommend a brush dobber instead of the crap foam ones that come in the can. They won't break off, like the foam ones, and they hold much more glue. They will apply the glue 3 to 4 times faster. More glue on the joint equals less effort to push it together. You can also save money by buying glue by the gallon instead of the quart. Be sure to hold pressure to the joint for few seconds after fitting it together.There will be hydraulic pressure in the joint (because there is glue between the two pieces of plastic) until it sets up enough to over come the force trying to push the joint apart. Always install the pipe from the bottom up on slopes. Otherwise gravity can pull them apart and you may not notice it until you can't make the pull.

 

[Tinkerer]

The best way to dig DOWN that steep slope is to have a trackloader positioned with its bucket against the front bucket of the 410 Deere. It is safe and you have complete control in regards to digging a trench just as easily as if you were on level terrain. We installed curb drains down 2/1 slopes on highway overpass approaches many times this way. We were using a 410 John Deere and a 955 Caterpiller trackloader. A small dozer with good brakes would even be better.
In regards to the creek crossings I would dam it up and rent whatever it takes to pump the water around and behind your excavating operation. Have another pump dewatering the trench if it needs to be. If you have to rent the discharge hoses you could save a few dollars by utilizing some of your conduit for discharge pipeing.

 

[OldandWorn]

The best way to dig DOWN that steep slope is to have a trackloader positioned with its bucket against the front bucket of the 410 Deere. It is safe and you have complete control in regards to digging a trench just as easily as if you were on level terrain. We installed curb drains down 2/1 slopes on highway overpass approaches many times this way. We were using a 410 John Deere and a 955 Caterpiller trackloader. A small dozer with good brakes would even be better.
In regards to the creek crossings I would dam it up and rent whatever it takes to pump the water around and behind your excavating operation. Have another pump dewatering the trench if it needs to be. If you have to rent the discharge hoses you could save a few dollars by utilizing some of your conduit for discharge pipeing.

Thanks!! I'll have to look around but I think I remember a 955 with good brakes floating around somewhere. I sure wish it had a single ripper centered in the rear. Or better yet, a bigass hydraulic trencher mounted on the front!

Got the pump covered. A neighbor just informed me he has a pump and lots of hose that he doesn't use anymore.

I REALLY REALLY REALLY appreciate all of the good advice I have received so far. This is not the best job for a rookie to be a-learnin-on and my stress level is lowering with each new post.

 

[OldandWorn]

Digging the "steeps" will be easier from the top down. You can use a pile of dirt (pushing it with the loader) to help control your decent. The machine will also stay put while digging (machine will have a tendancy to pull itself down the hill if you try to dig from the bottom up). The downside is that you will be pulling your backfill down the hill as you dig. Be cognisent of this and place your spoils as far up hill as possible.
That was my original plan, top to bottom with loader bucket pointing downhill. The dirt pile idea is sounding real good. I will try to keep the spoils high up.

I would not use the "whole hog" (also known as a power mole) if it is rocky.
There may not be any/many rocks in the bottom land where the creeks are. It could be an option. As soon as I start up the hill the difference is night and day as far as rocky terrain. It would be nice to get through my neighbors creeks without disturbing them.

If you do use one you will also have to use it to pull the pipe through the hole (you can't just push it through).
Pull the conduit through? Like hold the device in the air (with tension) and use it like a pneumatic slide hammer? How does one attatch it to the conduit?

I would also suggest "roping the pipe" instead of using the 22-1/4 degree bends. PVC will bend (3" easier than 4").
Do you suggest I go with 4". I can use either size.

If you have warm sunny days you can employ a "solar bender". Take a joint of pipe and place on end in an elevated position (lean it on a tree, on a fence, or a rock, truck...most anything will do) with the middle unsupported. As the direct sunlight warms the conduit it will begin to sag in the middle. This will shape your bend. Simply rotate the conduit so that the bend is in the same direction as the curve in your trench.
I like this idea! I have also heard of heated conduit benders. Maybe something else I could rent if needed?

Since you are going "across country" I would assume that you have plenty of room to make the gradual bends. Sharper turns equal more friction during the pull.
Well, yes and no. I need to follow a grass road as closely as possible. The 10' wide ROW runs along the side of this road. It's a real mess at the start of this run because I have the pole, a creek, and the need to get on the other side of the road as quickly as possible because of a buried barn that is not very deep in the ground. A solar bend or heater should do the trick though.

The 20' joints will bend MUCH easier than the 10 footers and the shorter joints probably won't have enough weight to "solar bend".
20' joints it is!

I would tend to agree with the opinion that the 800' pull is too long. That being said the designer is an engineer and they (power company) do this all the time. I would assume that they will employ the use of a power tugger and LOTS of lube. We also don't know the cable size but, again, the engineer should have all of this data taken into account. The only real variable is your trench quality.
She told me they have to keep the pulls under 1000'

I also recommend that you go deep early, at your creek crossings, and not use 22-1/4 bends.
Will do.

Damming of the creek will be the ticket but I would bet that you still will have subterranian water intrusion. I suggest that you have the pipe ready and glued together before you dig the crossing (however much pipe you need to get across the creek and back into dry ground).
One 20' section will easily span the creek depressions.

IMO you should be able to keep the conduit dry if you use glue AND primer. The 20' joints are a must. Everything about this job will be twice as hard if you use 10' sticks. I also recommend a brush dobber instead of the crap foam ones that come in the can. They won't break off, like the foam ones, and they hold much more glue. They will apply the glue 3 to 4 times faster. More glue on the joint equals less effort to push it together. You can also save money by buying glue by the gallon instead of the quart. Be sure to hold pressure to the joint for few seconds after fitting it together.There will be hydraulic pressure in the joint (because there is glue between the two pieces of plastic) until it sets up enough to over come the force trying to push the joint apart.
Will do. I'm an anal retentive obsessive compulsive machinist mechanical electrical engineer. My joints will be right or I won't be able to sleep at night

Always install the pipe from the bottom up on slopes. Otherwise gravity can pull them apart and you may not notice it until you can't make the pull.
I'm backfilling as I go because this is a weekend project. I need to dig down the hill. Will the backfill take care of this problem?

Thank you Thank you :notworthy

 

[bill onthehill]

Why are you worrying about backfilling if you have a trackloader? Dig down the hill and put the pipe together going up the hill. You are going to need a helper to put the pipe in and I would put it in as quickly as you can so the trench does not cave in. You should be able to dig 100ft. and then drop pipe. Have you done any digging out there yet? I would not even consider that long of a run without a few test digs. Will the power company be responsible for the primary once it is installed or does that fall on you? Mine wanted me to own the line if it was buried. I went overhead for that reason. It cost me $21 grand one time for a little over half a mile up the mountain but if it fails it is theirs to fix.

 

[OldandWorn]

Why are you worrying about backfilling if you have a trackloader? Dig down the hill and put the pipe together going up the hill. You are going to need a helper to put the pipe in and I would put it in as quickly as you can so the trench does not cave in. You should be able to dig 100ft. and then drop pipe. Have you done any digging out there yet? I would not even consider that long of a run without a few test digs. Will the power company be responsible for the primary once it is installed or does that fall on you? Mine wanted me to own the line if it was buried. I went overhead for that reason. It cost me $21 grand one time for a little over half a mile up the mountain but if it fails it is theirs to fix.

Having never done any trenching before maybe I'm missing the reason for a track loader. I don't want to just blindly push the dirt back into the trench. I want to get the better rock free soil close to the conduit and I would like to compact in layers with the bottom of the hoe bucket. I will most likely be using my farm tractor to do some of the pushing and leave the hoe positioned over the trench. I probably wouldn't last a day without being fired in the construction world but this is fun, not work to me, and I like to do things in a way to prevent future problems and work. Two other reasons are space and ground destruction. Up on my property, I would be tracking over a nicely finished gravel driveway. The steep hill is only wide enough to dig a trench and no equipment can come in from the sides. Down on my neighbor's property I don't want to tear up his road or field grass and I want to do the best I can to limit settling as there will be many 6' deep excavations.

I suppose I could trench the hill and install conduit from bottom to top, maybe I'm overthinking this. What I don't like about this is I would be learning how to use the hoe on a steep hill. I can't go onto my neighbors property until mid or late summer because of mushy ground so my run would have to start at a "to be continued trench" at the bottom of the hill. What makes more sense to me is to start at my transformer pad on top and get 500' of practice on level drama free ground and then stop at the bottom of the hill until things dry out so I can continue on to the next pull station on my neighbors property. But you're right, I could start at the bottom and continue to the transformer on my property. I would have to estimate how much conduit I could lay in a weekend so the trench wouldn't be open for a week or 2. If I do decide to lay down the hill I have some large steel spikes that they use for concrete curb forms. I could drive one into the ground at the end of the conduit to keep it from pulling apart until I get fill over it.

Are you thinking bedrock? I don't think that will be a problem anywhere on this run. I have dug 4 soil probe pits for the county septic folks and there are a lot of rocks in the ground but it was diggable. This route is my only option for grid power and I want to make it work. I'm a shop tinkerer type person and I don't want to worry about solar or generators when I want to fire up a welder or machine tools.

The power company will install the primary and secondary but retain ownenership/maintenance of the wire even after paying them a sick amount of money. As this is direct burial wire, the whole conduit thing is for easy maintenance and so they can pull it out and reuse it somewhere else if you ever discontinue service. Pretty smart actually.

Something else that kinda bummed me out and I never thought about it being a problem. I had the cable company come out to check my location for service and I also wanted to bury a phone line while the trench was open. Seems that the power poles going over the RR tracks are just high enough for power only so no utilities can be strung back to me. Luckily, I have good cell service and of course can get satellite for TV. Internet is very important to me but hopefully I can get it through the cell at a reasonable speed.

 

[sandcreek]

Definately use the 4". Make sure joints are clean and use primer and glue and stab joints and twist 1/4 turn and hold.

 

[volvobl]

id love to do that job for you here in uk we had 4" electric ducting or 6" personally i wouldnt use any smaller that 4" for that work now 3 years ago we used to use a ducting whitch you could bend it was not land drain but you could bend it by pulling on it and we could do slow bends on it so we could bend the pipe so it comes up straight with the pole brilliant stuff its now all solid pipes

i used to thread rope through as i went along like we used to tie a spanner on the rope and dropit through the pipes as we were fitting them other methods of this was to have a (cobra) like a rod but i dont think you would get one big enough to your pulling bays also try pull cable down hill makes life easyier

id have like a 6 ton excavator for this job better than backhoe and id do the creek crossings first to get them out the way bank the stuff up stop water and put a big pipe crossing the creek to carry the water flow over the creek good thing is then dig away nice flat bottom of trench easy to work in.

i then use the track of the excavator as a winch lift one side of the track of the ground where the cables are coming out of a pull box (joint bay) put the heavy duty rope around the track 2 or 3 times and get some 1 to push the track lever nice and steady not fast and just pull the tension on the rope a little so it tightens on the track and youve got a winch to pull cable but seriously have fun and stay safe

 

[AU.CASE]

I need to trench 1800' for power to my retirement property.

This is a great thread, top information herein, can we have some pics if you can?

The creeks and that hillock on your amazing long pipeline would be interesting!

I am using my backhoe on fencing on my property and putting in 'strainer posts' with Australian hardwood which I knock down with a dozer first. The old strainers are now mostly 80 years old and not giving us any paddock security on some fences so the two 'workers' take the back strain out of it. Make a giant hole, put the butt in sometimes and bucket ram really works!

It (the backhoe) has continued to really impress me with its stability in steep areas, although I did have a small front 'lift' coming up a bank the other day when the rear bucket wasn't stowed, so I'll watch that in the future.

 

[OldandWorn]

This is a great thread, top information herein, can we have some pics if you can?

The creeks and that hillock on your amazing long pipeline would be interesting!

I am using my backhoe on fencing on my property and putting in 'strainer posts' with Australian hardwood which I knock down with a dozer first. The old strainers are now mostly 80 years old and not giving us any paddock security on some fences so the two 'workers' take the back strain out of it. Make a giant hole, put the butt in sometimes and bucket ram really works!

It (the backhoe) has continued to really impress me with its stability in steep areas, although I did have a small front 'lift' coming up a bank the other day when the rear bucket wasn't stowed, so I'll watch that in the future.

Yep....I'm learning a lot thanks to the fine members here. :thumbsup I will be sure to take lots of pics. Digital cameras make it so easy. Take tons of pics and delete 90% of them with no worries about film and development costs.

That is a nice hoe you have there. I wish I had a 4n1 bucket like yours and that tree-pusher-over-thingy on the dozer. Much safer me thinks as it gives you some distance.

My old 410 Deere has a pretty heavy hoe on the back and it doesn't take much to make the front end light even with a full complement of front weights.

 

[OldandWorn]

Ok folks....last weekend I picked a random spot along the trenchline to do a test dig. I wanted to stay away from the transformer and junction pad locations until I'm sure I know what I'm doing. The hoe teeth sink about 3" into the soil and stop with a big clunk. Hmmm, do I have petrified earth or something? Surely I couldn't have hit a rock with my first stab.





After I moved the rock out of the way I found that the soil proved to be a more serious obstacle as it was heavy wet clay that wouldn't release from the bucket. After 5 minutes of shaking and abusing my poor hoe it finally fell out. I dug about 6' of trench with similar results, filled it back in and it was time to go home. Bill onthehill (thanks!) gave me a tip on another thread that I will try this weekend. I may also want to consider a rental trencher for speed and the hoe to move the rocks. The wheels and stabilizers of the hoe were also sinking pretty deep and making a big mess.

I thought I had unearthed a broken femur bone but actually it's just a strange looking root ball....I hope