Questions about moving dirt with a D8R

[DKinWA]

The project involves pushing 100,000 yards of material into three old gravel pits. The material to be moved is spoils from another construction project and is primarily sandy clay soil. The spoils were dumped right next to the pits and aren't much more than about 10' high. The longest push would be about 400 feet to the edge of the pit. I'm looking at renting a D8R to move the material and I've estimated it will take me two months to move it (based on a discussion with the local cat rental store).

I know there are a lot of variables, but I'm wondering if this sounds reasonable in a "real world" situation. Rental costs are $15,000/170 hour month plus delivery, fuel and maint. I'm figuring that costs for the month should be somewhere around $20,000 total. How does this figure sound? I'm also wondering how hard it is to learn to run a machine this size efficiently?. I've run smaller machines, but nothing this big.

[RonG]

The company I work for has a D8N and it is a fine dozer,well balanced with the ripper on the back and easy to run.You should not have a problem adapting to the larger size,the principles of dozing are pretty much the same.Just remember on a long push to build winrows and stay within those winrows to maintain a bladefull and increase your effiency and make that cat work!!
They say our 8n has an 110 gallon tank and it seems to take a lot of fuel at the end of the day although the bayonet gauge is missing so I can't say for sure.I am told at the end of 8 hours you need fuel and I also hear that the 8n has a smaller fuel tank than some of the other Highdrive 8's do but I don't know that for sure.
Maybe it's the A/C using the fuel. LOL
The soil you describe might be a hoot to push when it is wet but you will learn that as you go. Good Luck. Ron

[shaper]

Those D8R's are quite easy to operate. You seat is situated in the cab at an angle so you are looking straight at the left corner of the blade. Forward and reverse is is just a twist of the lever that is also used for steering.

The most efficient way to use that machine is to slot push, which means setting up one slot that you push everything through. By doing this you end up with two windrows that you will be pushing through. These windrows will help contain almost everything in front of the blade. It will take a few minutes of pushing to set up the windrows. This will work if you are pushing to one general area, not sure what you are up against though.

They are very thirsty machines plan on 90-100 gallons a day at the least. I would plan on at least $20,000. The dealer will also require proof of insurance for the value of the machine. You can add to the insurance you already have by contacting your agent.

[PAYTON]

get use to lookin at this

[digger242j]

An interesting thread....

The dollars and cents particulars and the question about the particular model of machine aside, how would you approach this job from a tactical standpoint?

The point about pushing between windrows to help keep the bladefull confined is one of the first things I was taught about using a dozer. Beyond that though, would you start pushing from the furthest point and try to make all long pushes, or would you start someplace closer to the pit and make shorter pushes? (I'm thinking in terms of spending less time backing up between pushes that way, at least to begin with.) And would you try to make a deep cut from the start, close to what your finish grade is going to be, or would you shave a few feet at a time off the whole area and work your way down to finish grade?

My dozer experience is limited to a few hours here and there stripping topsoil, or a little light (but not terribly precise), grading--certainly nothing approaching 100,000 yards. I'm interested in hearing how somebody with real experience would handle this job.

Not that it matters all that much, but I'm also curious why nobody took a machine and pushed the dirt into the pits as it was hauled in. It seems like that would've saved some work in the long run...

[DKinWA]

This project is kind of a weird deal with a real long story. I'm a habitat biologist for the state and also own a contracting business that I'm trying to get off the ground. Recently one of my coworkers lost the federal funding (going to Iraq) for a habitat restoration project he's been working on for several years. It's a really good floodplain restoration project that will not only improve salmon habitat, but will reduce or eliminate bank erosion occuring along several farm fields. Local landowners have been very supportive of the project, but the loss of matching funding pretty much sinks the project as planned.

The idea came up to use the remaining money to rent equipment if I was willing to run it and get as much work done as possible. Essentially the work involves moving the spoils that were originally placed there as part of the pit reclamation plan. The spoils were going to be spread out over the entire site and then planted with vegetation. Then along comes a large company that agrees to purchase the site for mitigation for a large project they were undertaking in the state.

As it turns out, this was the perfect opportunity to purchase the property and return the floodplain to it's original condition. This also takes care of some issues with bank erosion on adjacent land do to the construction of the gravel pits. When the gravel pits were in operation, dikes were constructed to keep the river from migrating into the pits during mining. The dikes are now forcing the river into the adjacent properties on the oposite side of the river. Now we just need to put the spoils into the pits and remove parts of the dike so the river can move back and forth like it did before. BTW, the pits are up to 25 feet deep and full of water.

We've looked into hiring local contractors to do the work, but we are so limited in what we have to spend we can't afford to hire it done. I keep flip-floppin' back and forth on whether or not to agree to do it since it's such a big project and all my experience has been with much smaller projects. I'm also torn because so much time and effort has been put into this by local landowners and our office that I'd hate to see them have to start over.

There's a lot more to this project, that I haven't mentioned because I know I can do it "no sweat". The part that makes me cringe is that 100,000 yards is a lot of material and $20,000+ a month is a lot of money. Normally I'm the take charge kind of guy and grab the bull by the horns, but this is a whoooooole bunch of dirt to move. Fortunately I've got a whole 3 days to decide if I'm willing to do it and figure out a way to share my regular work with my coworkers while I'm busy playin' :D

[Blademan]

If you are so sure that this job is easy , or it'll be " no sweat " , why get a D8 . I'd go at least a D9 . For a little more , you'd be done a whole lot quicker . Is this a contract job ? Hourly ? What happens if you work a week ,and get rained out for a days on end ? Or you get sick ? Injured ? Since you'll be working with clay/sand and water , do you have any backup if you get stuck ? Not trying to be negative , just something to think about . Remember , if you bid too low , and it takes a lot longer , you could end up just buying this job . Are you prepared to take this risk ?

Rob

[DKinWA]

Blademan,

Sorry about the confusion, I guess I wasn't really clear how this would work. I'm not bidding on the job as it would be a conflict of interest and is prohibited by law. This is an agency sponsored project and they're looking to me to do the work on agency time. All I'll get is my normal paycheck while I'm temporarily reasigned to my new duties (machine operator). Basically the limited money we do have would go to renting and maintaining equipment.

The "no sweat" part is constructing a small egress channel and moving some rock that was used to create the dikes. This part won't take me more than a couple of weeks on a 320 size excavator. I've got plenty of experience doing this kind of work so hence the "no sweat" attitude. The work will be done this summer during the dry season and historically rain isn't a big problem. A day or two here and there is the worst we typically expect around here. The part that is a little more concerning to me is moving the 100,000 yards of spoils.

The D8 choice was actually made with input from the local cat store. A D9 was considered, but there are some issues with availability and moving the machine to the site (roads, load limits, etc). We're going to have enough trouble as it is getting a D8 on site. As far as getting stuck, that's a distinct possibility. Same with getting sick or injured. All part of the decision process, and great examples of why I haven't committed to the temporary job change without some more discussion.

Thanks for the "real world" issues that don't always get considered until it's too late.

[PAYTON]

Originally posted by DKinWA
Blademan,

Sorry about the confusion, I guess I wasn't really clear how this would work. I'm not bidding on the job as it would be a conflict of interest and is prohibited by law. This is an agency sponsored project and they're looking to me to do the work on agency time. All I'll get is my normal paycheck while I'm temporarily reasigned to my new duties (machine operator). Basically the limited money we do have would go to renting and maintaining equipment.

The "no sweat" part is constructing a small egress channel and moving some rock that was used to create the dikes. This part won't take me more than a couple of weeks on a 320 size excavator. I've got plenty of experience doing this kind of work so hence the "no sweat" attitude. The work will be done this summer during the dry season and historically rain isn't a big problem. A day or two here and there is the worst we typically expect around here. The part that is a little more concerning to me is moving the 100,000 yards of spoils.

The D8 choice was actually made with input from the local cat store. A D9 was considered, but there are some issues with availability and moving the machine to the site (roads, load limits, etc). We're going to have enough trouble as it is getting a D8 on site. As far as getting stuck, that's a distinct possibility. Same with getting sick or injured. All part of the decision process, and great examples of why I haven't committed to the temporary job change without some more discussion.

Thanks for the "real world" issues that don't always get considered until it's too late.



gettting stuck is a real chance
see the pic above.. 20 mins later i was burried up over the tracks
took to d8s one pushing me one pulling me with a winch.. and a 325 to get me out .. and u can see its mid summer in teh pic..

rember if u get stuck ur gonna need sumthing large enuff to get u out.. or a way of getting ur self out..winch etc.. ur local tow truck wont budge a d8!




as far as ho work goes.. how good are you on a ho.. and what kinda stock pile work are you looking at?
is it 10 foot high what.? another option would be track ho and couple tri axles and a smaller 5-6 pushing at teh dump.. yes would take another operator but could cut the work in half honestly if your good on a ho.. and can keep at least 2-5 tri's moving at all times.

or another solution dig for a day push for a day run ho and tris for a day dumping then run doxer pushing tri's piles for a day back and forth.. this would cut down on the need for a 2nd operator but would also add time to total project..

both methods mentioned above will require renting tri axle dump trucks.. unless you have access.. either point most tri companies will rent there trucks and drivers by the day.. pretty cheap if its a long term agreement


just hope that helps

payton

[Blademan]

Ahhhh , picture gets clearer . You also failed to mention having a 320 ( or near ) sized trackhoe available . This makes a big difference . But there are still many questions I have concerning this project . Is the hoe included in the price of the rentals , or does the agency own it ? What are your fuel estimates per month ? As mentioned in another post , pushing hard is a very thirsty endeavor . But these questions are really just the small stuff . Let me get to my bigger picture . Are you filling in these pits ?? Are the pit walls vertical , or are they sloped ? You mentioned that the highest part was 25 feet or something . Again , is this vertical , or are the edges sloped ? The reason I need to know this is this will be your biggest obstacle to overcome . For a first timer ( dozing ) pushing material over that edge is going to take a huge leap of faith , resulting in a very high pucker factor . If you are not 100% confident with your operating abilities at that point , it could get dangerous very quickly . Don't take this likely . BUT , if you have a hoe at your dispossal , you can spend extra time sloping off that edge , so that your pushes with the dozer will be easier . Also , you mentioned the pits are filled with water . Before you start dozing , figure out where you want this water to run , and push towards that point , always pushing to make it easy for the water to run out . Don't worry too much about the base , as long as you keep ' padding ' the bottom ( at least 3 - 4 foot lifts ) so it doesn't get to soft to travel on . Now if you can't slope off that edge with the hoe , and are going to try and push this material in first , make sure you have a look at all the edges first , just to make sure none of them have been undermined I once was pushed by a D8 when I was running a Cat621 scraper to the edge of a pit , we were removing overburden so they could mine out the gravel . At lunch time we stopped at a shack in the pit when we noticed the edge i was just on had been undermined slightly . Sixty foot drop !!!! Where was our safety coordinator then ???? It too was a very high pucker factor day !! Anyway , either way , you will have to push to the edge of the pit , and learn the D8s balance point very quickly . This will be your most difficult part , because you will have to push to it , but not over it , to get the material in the pit , or else you just build walls . I would try and push a little over , they try sloping down the edge . Then a little more , etc . until you've worked the slope into the pit . Work a little bit , then move over and do it again . Try and always be neat with every pass . Try to move the water out without leaving pools or small lakes in the pit . Be consistant across your pushing material in . so that minimal amounts of water are left in , so as to not have water coming up to the surface , making soft spots ( and potential stuck spots ) . Good luck in deciding , but be forewarned . Yes 100,000 yards is a lot of material , but safety should be your paramount concern . If you are not up to pushing over a edge comfortably till the machine reaches its teetering point , this whole job may be takin in vain . If you feel very sure about running on slopes , go for it and have fun . It would be , a D8r is a awesome toy .

Rob

ps , a silly little exercise . Visualizing is a huge part of operating . Try this when you have a little time . Make a small mockup of the pit , pile etc . If you can , make it big , bigger the better or more real . Then get a small stick or straightedge ( ruler ) and start pushing . I know this soulds childish , but you'd be amazed how much you can learn from it .

[badranman]

DKinWA
Good luck with your project!
Just wondering if you could post some pics if you tackle this, would love to see them.

[PAYTON]

ok i gotta ask this .. once the dirt is pushed in what will the ground be used for?

thats gonna determine a lot of what needs to be done and what equipment its gonna take..

i didnt read far nuff into the water being in the hole! this could cause a hole nother problem..

what kind of drainage program does the area have.. what kind of sewer system.. what kind of irrigation system is there local!

all things that ya gonna have to look at real soon b4 decided to push water where ever!


payton

[digger242j]

pushing material over that edge is going to take a huge leap of faith , resulting in a very high pucker factor .

How about approaching the edge at somewhat of an angle? That way you get a better view of exactly how close you are, you still have some of that bladefull of dirt between you and the edge when you get close, and you also have one whole track still on solid ground when the front of the other track is just peeking over the edge.

As far as the "egress channel", am I right in thinking that is how the water that's now in the pits is intended to get back into the river? Is there sufficient difference in elevation that the pits will drain into the river on their own? If that's the case the scenario described in the next paragraph hopefully won't happen.

What I'm visualizing is that as the fill is pushed in, the water will be pushed out. Especially given that the fill is sandy clay, it seems to me that what will result is a great big mucky base to your area of finished fill. (Something about as competent as, say, mashed potatoes.) Is not the situation such that, you'll have to worry about the weight of the fill above exerting downward pressure on the muck below and causing some portion of the whole deal to move toward, or into, the river? (Which, if I understand the situation correctly, would be contrary to your intentions.) (I'm visualizing setting a concrete block on a pile of mashed potatoes.)

I'm not even going to ask how muddy the water entering the river from the pits will be. I'll assume that's been taken into account and found to be acceptable.

Are you beginning to regret having asked our opinion yet? :)

[DKinWA]

Believe me, I have NO regrets on asking for thoughts and opinions. I found out today that we now have some other options to make this project happen and fortunately or unfortunately, it doesn't include me in the mix.

Dang, you guys do ask a lot of questions though :D . I'll do what I can to answer them as best I can. Blademan brings up a lot of good questions and issues, that a lot of folks wouldn't think of. Fortunately for me, most of my family is or has retired from the construction field and I've spent quite a bit of time around construction sites. Two of my family members actually belong to the local operting engineers union and have a lot of experience operating larger equipment. I was actually planning to get one of them out there this weekend to look at the project, but that won't be necessary now. I probably should've told everyone this at first, but I tend to talk and write too much as it is and didn't want to get so wordy that no one would read my post. I have to write a lot at work and finding the happy medium between not enough and too much information is a fine line. Now to get to anwering questions.

The sides of the pits are virtually vertical walls (10-30 feet high roughly) with little if any slope. My plans were to knock the edges down with an excavator and do some sloping prior to doing any pushing. I was also planning to work the pile down nearest the pits first to keep the machine on a firm footing. The material that will be pushed into the pits is waaaay short of actually filling them. I don't remember what the estimate was to actually fill the pits, but it was well over a million yards. Based on some estimates I made, I could pretty much work the fill in around the edge of the pit and not have to run too far out onto the fill. Even still, getting stuck was possible and not something I really wanted to think about :D

As far as displacing the water, it isn't really an issue since summer levels are pretty low and there's lots of freeboard. The egress channel is to connect all three pits to the river so juvenile salmon could over winter in what's left of the pits. Essentially there would still be a lot of open water in them until mother nature decided to move the river back. Once the project is complete, there's going to be some nice fishing and duck hunting goin' on :cool:

As far as equipment costs go, I was planning on the D8 burning 100 gals a day (10 gal/hr with 10 hr day). Rental quote was $15,500 for a 170 hr month (for 2 months) and one maintence call at roughly $1,100. I figured I'd need the 320 excavator for about 6 weeks at roughly $4,800/month and if I remember correctly, fuel at 6 gals/hour. In other words, lots of $$$$$.

Thanks for everyone's thoughts and comments and sorry I didn't provide more information up front. I figured if I wrote the whole story, no one would read and offer their opinions. Anyway, once construction gets started, I'll make it a point to stop by and take some pictures to show progress. It's only a couple miles away from here and I drive by it several times a week. Whewwww! I'm all typed out ;)

[Blademan]

Originally posted by digger242j
How about approaching the edge at somewhat of an angle? That way you get a better view of exactly how close you are, you still have some of that bladefull of dirt between you and the edge when you get close, and you also have one whole track still on solid ground when the front of the other track is just peeking over the edge .

Yeah ,it could be done this way , but its not really efficent . You'd be lucky to get a quarter of your bladefull over the edge , and the rest is now just a new lip/wall . Also , two other things about pushing straight over . First , you can see the edge of the pit beside your blade and the edge of the blade out the front . When you see the blade pushing past or very near the edge beside you , you can plan on stopping the pushing and start reversing . Secondly ,as you get pushing over the edge and start going over your new edge , you can get really heavy push loads where it piles up over your blade .Just at the right moment , as soon as you notice it going into the pit and disappearing fronm the top of your blade ,you know you've gone far enough . Once you get the rythem down , you can start lifting the blade slightly giving it a nudge and leaving a tiny new lip . That though , takes a lot of trial and error and practice.


Rob

ps , another thing ( sorry for getting winded ) about angle pushing over a edge is that IF you ever start to slide down over that edge , your now in a wayyyyy worse position to try and get back up the hill . Tracks are great on their flat , frontal edge . On their side , they become toboggans and slide real easy , meaning no grip . Sets up a real dangerous situation . Ive ridden out a extreme nose diving over a edge dozing with the blade fully extended . As long as it's not wayyyy to steep , and depending on the material , she'll ride it out to the bottom . On it's side , she'd have a greater chance of just rolling over .

[DKinWA]

digger,

I tried to reply to your pm again today, but got a "mailbox full message again". Didn't want you to think I was ignoring ya :) We actually discussed your suggestion, but the risk to infrastructure was just too great if things went south on us.

[digger242j]

I tried to reply to your pm again today, but got a "mailbox full message again".

Ok, I rented a D8 and pushed a whole bunch of old messages over the hill, so I should be good to recieve new ones now. :D

As far as approaching at an angle, my thought was that it would be more likely to keep you from getting into the situation of sliding over the edge at all.

The thought of pushing right up to a *vertical* wall (a detail which DK has now shared with us) with a real heavy machine like that is pretty scary. :eek:

[Blademan]

Digger ,


Quote :


" The thought of pushing right up to a *vertical* wall (a detail which DK has now shared with us) with a real heavy machine like that is pretty scary. "

Oh yeah , actually a good operator makes it look so easy , but getting behind the contols is a very different thing . That's why working around pits can be so dangerous , and has a very high pucker factor ( dozing in general , really ) . On a job moving this amount of material , you'll be on the edge , teetering thousands of times to be really efficent . Each and ever one ( push ) though , you have to be fully aware that disaster is one tiny little slip up away , and this is why I really don't think this is a good place to learn how to run a peice of heavy equipment . At the very least , not without experienced supervision around . You can push at the edge sideways , and in some instances , it's ok , but it's not efficent . Trying to get material over a edge , either way , is going to put you on that edge . But , the amount you get over that edge , and the traction needed to get back up the hill is lost when attacking it sideways . And a lot of dozing is about maximum traction . I've actually seen a D10 on a slippery snowy ( frozen ) slope and the operator got a little too perpendicular to the downside and off she went like a taboggan . Except you're in a 40 plus ton peice of equpiment .Luckily ,he slid all the way to the bottom with out any troubles , but he was about 25 feet away from a very busy road .It could've been a huge error had it snagged on , say a rock ,and it rolled down that hill . Anyhow , hopes this helps .


Rob

[RonG]

Whenever there is any question about the stability of the soil or the capability of the machine I am running or my own competence as the case may be LOL I always leave a bladeful in front of me on the edge of the bank and the next bladeful on the next pass will push the first bladeful over the edge so you don't have to get near the edge if you don't want to.It makes for an easier day if you perceive it to be a problem. Ron