Trencher... buy, rent, or hire

[s219]

I have done a lot of work with trenchers for irrigation lines, water lines, and electrical. Cutting the trench can have difficulties, but is generally pretty easy. However, don't underestimate the amount of time/effort it will take to fill the trenches back in, and then to deal with settling, soil compaction, etc. I am not exaggerating when I say that I probably spend 4X the trenching time putting things back to normal. Some jobs are less complicated than others in this regard. Some require a lot of manual hand labor. SO have a good plan to fill the trenches back in!

 

[s219]

I've looked into 3pt PTO trenchers, and as much as I'd like to get one, I agree and think I'd not like it because of my need to clutch.

This is one of the reasons I was thinking about just going purpose built with a ride on trencher.

I don't think the 'Dingo' type would be enough for the amount I need to do. I will need to do at least a couple miles (over my entire farm) and I will need to have something big enough to drop in a 6" tile pipe. I don't think the Dingo sized machines would do what I need, at the depth and length I need, in a reasonable timeframe.

Does anyone know whether there is a 'typical' chain digging width? I know you can get different chains and they rely on differenty types and patterns of teeth, but on something the size of a Vermeer 4750, does anyone have an idea on the typical chain/cutting width?

Also, when laying pipe, cable, etc, is there a typical ratio of 'trench width:width of what is being buried'?

I normally get 4" or 6" trenchers when I rent. 4" is fine for electrical/water/irrigation but not for standard drain tile, need at least 6" for that. Obviously, try to use the narrowest possible -- less spoils to deal with and put back in the trench, less settling/compaction issues, etc... Also need to have good practices and trench neatly so that the spoils are windowed off to the side and don't fall back into the trench. When going deeper than 16", if spoils fall back into the trench you will have a devil of a time cleaning them back out. For example, I buried some wire recently, 4" wide trench 24" deep. In a couple spots, loose sand fell back in and the only way to clean it out was with my arm.

I don't know of any trench width requirements when burying single utilities. When using a common trench for multiple utilities, there will be, as well as depth and separation / layering requirements. Depending on the soil type and the utility being buried, you may need to worry about cleanly/carefully filling in the trench, for example, you wouldn't want to rake in a bunch of rocks, and so on.

 

[s219]

I should mention that the worst part about renting a trencher for me is that I tend to save up trenching projects to get the most benefit out of the rental, so for example when I recently trenched for electric/water to my barn, I also used the trencher to cut a couple french drains in some clay soil that is too tough to dig in. Well, it wasn't more than 3-4 weeks later that I realized I really needed to bury some drain tile in another location! So I'm either looking at waiting until the next time I have enough projects to justify another rental, or dig the trench by hand. I always tell people, no matter how old and well-off I am, I still seem to find myself hand-digging a trench in the mud periodically. I suspect that when I get old and die, they will find me with a shovel in my hand digging a trench or ditch or something.... Anyhow, if I owned a trencher, it would make things a lot more convenient and I could do stuff whenever it needed to get done.

 

[Gary Fowler]

I don't have a trencher but has seen them used on construction for years. The biggest problem with trenchers is the backfill. The trench is too narrow to use most compaction apparatus so they would just push the dirt back in with the front blade and grade it smooth. At the first rain, you had a quagmire that if you stepped into the trench, you would sink up to your knees. All you could do was continue to add fresh dirt as the settlement occurred which may take months.

When I put in water lines, I use my 8" backhoe bucket which gives me just enough room to step down into when needed to remove a rock of other item. The 8" width is also just wide enough for me to use the front tires on my B26 to walk in the backfill so it is firmly compacted. I generally push in enough dirt to fill the hole nearly level, the walk it in using several passes with the tractor, then add more dirt to the top, walk it in, repeat till it is level or a little high. Then use the FEL to backdrag the trench till the area is level. That way I little to no subsidence after rain.

The issue with trenchers is that you cant use the tires (too wide) and even if so, most operators don't take the time to do it right.

 

[D2Cat]

Interesting how folks have trouble backfilling. Probably the problems are caused by the dirt being dug when it's too wet. If you have to hog a line in on a project because it has to be done no matter what, then you will have problems getting the material back in the slot!

Rule of thumb is if you grab a handfull of dirt and make a fist, open the fist and if the dirt doesn't fall out as dust, but you have a ball of dirt, it's too wet. Cut a trench in dry dirt and the spoils go right back in with no problems, and not required to go back and forth with a narrow tire to get it right.

I've buried a few thousand feet of water lines for automatic waterers for horses. The people who own the horses only want a trencher to dig to reduce the chances of a horse getting caught in a ditch that has settled. Never had one problem getting the backfill tightly in place.

I have a 6 way backfill blade and I find it interesting how people think they can fill a ditch with their tractor quicker!

 

[Dadnatron]

I don’t think rock will be an issue on 95% of what I will be working. But depth and contamination by falling dirt could be an issue. Having never done it, I can’t say, especially in this area.

I think most of the waterer lines around here are put in with a vibratory plow at about 30” deep. I can certainly see the benefit of doing it that way I suspect.

We have had more rain and water than I’ve ever seen before. Everything is soaked and running. So much so, that the spillway on my pond is being used rather than the 8” drain pipe, which currently is under water completely and running full bore. This from a single small spring which almost quits during the dry season. On my way home, the road is closed because one spot which is usually dry, is under 8’ (FEET) of water. I’ve never seen the water even get to the road at that spot, so I think it is because every water table is so high that no water can move anywhere.

But, I’m glad to see it, because I can now plan and design for it rather than be washed away because of being unprepared.

The drainage tile will cover about 95% of what is likely to happen, but I don’t think it would have made much of a difference today.

 

[Dadnatron]

The people who own the horses only want a trencher to dig to reduce the chances of a horse getting caught in a ditch that has settled. Never had one problem getting the backfill tightly in place.

D2Cat, what do you mean? Horse owners don稚 want excavator trenches? I am not sure what you are saying here. We have horses, and I want to make the best choices possible, to avoid expected/possible issues.

 

[D2Cat]

The conversation was about backfilling a trench and the difficulty. Therefore some used a backhoe to dig a wider ditch and after pushing dirt back in the hole, running over the ditch with tires that fit in the ditch to compact the soil.

The horse owners I buried lines for were very particular about the ditches dug on their property. I buried water lines 36" deep, and only dug when the soil was dry. I dug a 6" wide trench and backfilled that very day. The crumbs fall fit back in the ditch with a very slight hump, which I then drove over with the flotation tires on a 6,000# machine. Making it so no horse hoof would sink dangerously down and possibly cause an injury.

The bottom line everyone is saying is to get all the soil back in the same ditch no matter what implement is used to dig, and to make sure the soil is tight so it can not sink further.

When you dig dry dirt it goes back quite easily. With wet soil you have a challenge getting it back in the ditch (until it dries and the clods break down).

 

[s219]

Interesting how folks have trouble backfilling. Probably the problems are caused by the dirt being dug when it's too wet. If you have to hog a line in on a project because it has to be done no matter what, then you will have problems getting the material back in the slot!

Rule of thumb is if you grab a handfull of dirt and make a fist, open the fist and if the dirt doesn't fall out as dust, but you have a ball of dirt, it's too wet. Cut a trench in dry dirt and the spoils go right back in with no problems, and not required to go back and forth with a narrow tire to get it right.

Last trench I ran was through sandy soil -- nice enough sand that my daughter wanted to play in it. You'd think that would slip right back into the trench. But there was such a heavy/thick root mat on top that I still had problems getting the sand back in the trench. Had to push it past the roots and it was a fight.

 

[EddieWalker]

When you dig dry dirt it goes back quite easily. With wet soil you have a challenge getting it back in the ditch (until it dries and the clods break down).

Dry soil does not compact, so if you want the soil to remain in the ditch when it rains, you need to add water to the soil to achieve compaction. I spent my first summer after the Marines running a water truck, and figuring out how much water to add is crucial to passing inspection on a city job where they will be paving over it the day after you fill in the trench.

For all of us just digging trenches and filling them on our land, if the soil does not hold together when you make a ball out of it with your hand, you need to add water.

If not, that trench will become a river when it rains and wash out all your fill.