Greetings to all: trenching question,

[fandango99]

I've been enjoying our almost new (300 hours) Kubota L4060HST to work our 10 acre parcel in Suisun Valley, CA just over the hill from Napa.
for the past year and a half. It's made a huge difference in what we can do with the land... wish I had done it way back... but here we go.

I registered to particularly get any/everyone's advice on a crazy scheme I'm thinking of. I need to place geothermal hose ~1" diameter
down about 6 feet deep into a trench. But I only need 1" trench width. No rocks/pipes in soil. Most trenchers only reach 4-5' and for
geothermal exchange 6' is just better depth for heat exchange. But typical trenchers claw up a foot-or-two wide trench which at this depth
brings in OSHA! OSHA requires reinforcing walls all along such a trench to prevent cave-ins burying workers/kids. But I just need to bury
a less than one inch hose. My narrow trench will probably need to be 600 feet long, placed into parallel rows, say 6 x 100'. Sooooo....

Is it possible to affix a long blade, honed like a 6-7 foot long axe blade, heavily weighted down, to the back of a **** powerful tractor or
caterpiller and slice through the soil to create my 6' deep, 1" wide trench, without any fear or worry about someone falling in? Any thoughts out there
or should I direct this question on to a specific forum that I need to get in touch with.

BTW, yes I'm in earthquake country and these hoses are proven survivors out here. I just want to tap the ground's constant temperature to cool
in summer and heat in winter.

Thanks,
Charles C

 

[robstaples]

Having watched my contractor install my underground grass sprinkling system with a vibrating trenching machine, I'd suggest a similar hydraulic driven attachment. It could be extended to 6'. The vibration minimizes the force required. In my case , they pulled the hose with the coil at the starting place, instead of feeding it down as the machine progressed.

 

[robstaples]

I just reviewed some tile plowers videos. The heavy weight works for sail boat ballast in à fluid. Pulling against the earth doesn't need bottom weight, just lifting force (displacing pipe dirt) and the ability to deliver it 6 ft down. Branco makes a 5 ft chain trencher. Dig a one foot wide trench and run a 5 ft bradco , then fill in??

 

[tractchores]

Look into a pneumatic mole or similar. You just dig down at each end and shoot it through. It works great if there are no big rocks.

 

[robstaples]

Also, WELCOME, to tbn!!

 

[Egon]

Check with local heavy equipment dealers to see what might be available.

[video]http://www.constructionequipment.com/static-plows-deliver-simple-speedy-installation[/video]

[video]http://www.tractorbynet.com/forums/owning-operating/157265-trenching-8-feet-deep-4.html[/video]

 

[Gary Fowler]

You don't have to worry about shoring a deep ditch as long as you aren't working in it. A simple barricade tape is sufficient for OSHA requirement on a construction site and even this is not required on your own property. Just make sure anyone walking around the worksite is aware of the trench. A 8-12" wide trench is to narrow for any adult to fall into and children shouldn't be allowed outside when the work is in progress.
A 6' deep trench is not going to be easily done with a trencher anyway as most don't have that long of a tail piece.

Likely your best bet is going to be a vibratory type of pipe laying machine (if you can find one)

 

[s219]

The vibratory machines scale up in size as you go deeper. I've seen how big they have to be to go 2' down, and imagine the ones that could go 6' down (if they even exist) would be the size of mining equipment. I know a guy who is a subcontractor for the utility companies here, and they use a small vibratory machine for telephone/internet lines, a giant one for power lines 18-24" down, and anything deeper they use a trencher or backhoe. One of their big machines has a vibratory plow on one end and a trencher on the other. It's about the size of a large compact utility tractor. That one only vibrates down to 24", but can trench down to 48".

 

[TBN Support]

Welcome to the forum!

:welcome:

I've moved your thread over to the attachments section, but it could easily fit in any of several categories.

You might want to check out the build it yourself , Kubota and customization sections as well.

 

[DJ54]

How about a directional boring machine, like they bury utilities with..?? I'm assuming they will be connected by some sort of manifold on each end, buried too. Maybe a V trench on each end to lay, and connect the manifold line, wide enough to specs for the area, to work in. Shouldn't take them long to bore 6 runs.

 

[gwdixon]

Even though the soil is nice in Suisun Valley, pulling something 6 feet deep with a 40HP tractor just isn't going to be an option. It appears you already know that. Something dragged through the soil will likely just fill in and it sounds like you will want an open ditch.

I've seen large trenchers around here in orchard country that look like giant paddlewheels. They appear to be able to go down 6'. They are used to bury main water lines. However, they look to dig about a foot wide.

Google "large trencher" and look at the photos to see what is possible. Then go to a rental center and tell them what you want to do (or have done). A larger backhoe would do it also but it would take a while. North Vacaville has a couple of large equipment rental centers.

My advice is to go see Ron (owner) at Green Valley Tractor and ask what options are available. He has been in the area for many years. He lives and farms locally. Perhaps he has a connection.

Welcome to TBN. I'm just up the road from you in North Vacaville.

 

[Egon]

He's looking to plow the lines in. A one pass thing. At six feet it will probable be at the D-6 size for a non vibratory unit.

 

[CDN Farm Boy]

Lots of plows that big up here for installing field tile. But, most contractors don't want to look at a 6 acre job @ 30'-40' centers (6,000 ft) nevermind a 600 ft job.

Cost wise, digging it with a backhoe or excavator is likely the cheapest.

 

[jenkinsph]

I am in the middle of a similar project installing 2400ft of 4" pipe for geothermal heat and cooling. I am installing this 8' deep with the pipes on 24" centers. I recommend you use a backhoe to dig the line and lay the pipe in the trench and backfill. A good backhoe and operator can accomplish this job in one or two days most likely. You will need to make the ditch wide enough to make the connections at the end of the loops if you can't do that from the surface. Don't leave an open ditch for anyone to enter or fall into over night. Might want to consider a plastic safety fence or other safety measures.


I should add that a backhoe or mini excavator would both work for this job.

 

[texas42]

I suggest you think about an excavation rather than a trench. Hire a guy with a backhoe to dig a 6 foot deep excavation 15 feet x 100 feet. That way in the eyes of OSHA you have an excavation not a trench. You can safely go in the excavation lay out all your pipe, make all connections and pressure test then backfill.

 

[jenkinsph]

I suggest you think about an excavation rather than a trench. Hire a guy with a backhoe to dig a 6 foot deep excavation 15 feet x 100 feet. That way in the eyes of OSHA you have an excavation not a trench. You can safely go in the excavation lay out all your pipe, make all connections and pressure test then backfill.

When I started my geothermal project that is what I tried first. I used my box blade to dig down 4' deep in an area 55 ft x 110 ft. then dug down another 4' deep to install the pipe in the shallow trenches. For the second half of the project I am digging the full 8' depth and will not enter the trench, instead will use a piece of pipe to straighten the rolls of tubing. If that doesn't work I will excavate as before. I should know this week which works the best.

 

[Fallon]

A decent sized riding trencher will do it & they generally are 4-6" wide. My neighbor has a pole barn business & a riding trencher. I only needed 4', but he indicated he had a tail piece that could hit 6', barely if it was straight down.

Only being 4-6" wide means moving a LOT less material than a hoe of some sort. Unsurprisingly, a trencher is optimized for trenching, where a hoe is more versatile but slower & less efficient.

My 370' or so of trench was easily done in under a day & cost me $1,500. I may have been able to do it with a mini-ex in 2, probably 3 days ($300 a day rental + fuel). It would have looked a lot worse, moved a lot more dirt & tore up the yard a lot more. Not to mention have been a lit more work for me. Glad I paid the neighbor to do it, even though the mini-ex would have been fun for a bit.

 

[mike69440]

I think a ditch witch can only go 3-4 ft. +6' is going to be tough

 

[jimmysisson]

Trouble with a very narrow trench is you may not get good dirt contact to the pipe when you backfill. Isn't that what makes these systems work? A vibratory might be better in that regard.
Jim

 

[jenkinsph]

Trouble with a very narrow trench is you may not get good dirt contact to the pipe when you backfill. Isn't that what makes these systems work? A vibratory might be better in that regard.
Jim

That is a valid point I am concerned about. You do need to have good soil contact to get the thermal transfer. When I only had to dig 4' deep and 30 inches wide I ran my plate compactor over the pipe. My friend and I were discussing this yesterday. Excavating 4 ft. deep then digging 4 ft. with the backhoe may be the better route, just adds more work to the job.

For the OP with the smaller pipe and trench I wonder if using a power washer to help pack might do the trick? Weather permitting he could in a sense water pack the crack in a few lifts working to the surface.