I was taught the technique a while back by old timers, it works. You can't argue with the logic and principle of it, It's a tried and true technique. To make a long story short- Start closest to the pile and work up a blade full, jam it to the pile. Back up past your last starting point, far enough back as to achieve a full blade, jam it to the pile. Sometimes in ideal conditions you can cut up a full blade push it halfway to the pile, back up and grab another bladeful and then drift both blade loads to the pile. All of these passes are made in a straight line to the pile. I cut in first, get a bladeful, and then drift it in 2nd, The cut and drift technique, if you will. Once the cut is finished, clean up the windrows from the farthest point from the pile, funneling the sides into the center and pushing to pile. I personally push a bladeful in from one side, then one from the opposite side and then push them both to the pile. The sides of the cut and windrows trap the soil being pushed and contain it in front of the blade, no soil is lost to the sides of the blade. According to the Caterpillar Performance Handbook edition 36, section 1, page 42, slot dozing has a 1.20 correction factor when calculating dozer production, whereas a poor operator has a .60 correction factor. I just went over the jist of it, there are different conditions that will effect your outcome. I'm sure others will chime in with more detailed instructions, I'm just a dumb redneck so it's hard for me to put my thoughts and experience into writing. I just wanted to get the ball rolling and help other hands.
It is amazing the amount of dirt you can move this way if you keep your head in the game and try not to go for the easy dirt. Now if you have to rip hard dirt is it possible to push and rip at the same time?
I've ripped and pushed with dozers and graders, it probably isn't any more productive, just didn't have the snot. I've also "slot dozed" with a 12G. Poor girl was sweatin' when we got done, someone put gravel in the wrong spot and all we had was a 12G and a roller.
When building a dam and I had gotten my stripping and cutoff trench(or weep trench) done, I started at the back of the pond and in low gear. I pushed everything it would push plowing my way to the dam letting the extra fall off as I went to eventually build my 'slot'. Then I would backup in a higher gear, back down low forward and 'plow' again. Did that every push until time to clean up the loose stuff. When stripping topsoil off a place, I always started at the far point away from where I was going to pile it. Also kept a comfortable incline to push the biggest load of dirt I could push up it until the very last pushes
Bigshow, I agree completely with everything you describe as your method of slot dozing - exactly as you put it including the method of cleaning up. I also will sometimes push up a bladefull and then grab another and take it to the fill or pile. I am not sure if the two bladefull pushes, after calculating the extra time to do so, are more productive or not, but if the conditions are right it at least changes things up a bit. I believe it takes awhile to train oneself that pushing a bit less in second is indeed more productive than boiling material up all the way. Regarding ripping and dozing at the same time, it may pay off in the right material if you are not ripping full depth, but I am not convinced that it is more productive in general. This could also depend alot on dozer size ant type. It may work with a 9R and semi-U but not full U, etc. Often times if I know I will have to rip an entire area, I will cross rip, or rip at an angle before starting do doze.
Starting your cut at the "back" and pushing forward- I do that when stripping topsoil for two reasons, 1-Less contamination of your top and sub soils, 2-Once a blade full is achieved it drifts across the existing grass with less resistance, allowing for the cut and drift method to be used a with a bit less effort.
Thanks for the description I am new to bulldozer operation. So for slot dozing I am picturing the lost dirt from the edges of the blade making a little tunnel the whole way to the pile to push through. But what is the cut and drift method?
To my way of thinking it, the cut and drift method is describing the parts of the push. In the first part, you cut with the blade until it is full, then you ease up the pressure and drift, or as I call it, carry, the dirt to the end of the push. Some operators continue the cutting all the way to the end of the push making dirt boil over the whole way. That is a waste of time, power, fuel, and wear and tear on the machine. By easing up and just pushing the dirt already in front of the blade, you do more with less effort. This is where the slot comes into play, as if you have no slot, you loose your dirt around the edges and have to continue refilling the blade. When cutting your slot, start filling the blade close to the end of the push. The next time, back up just enough farther that you have time to completely fill the blade. This way, the slot is created by cutting a slot, not by piling up the windrow from the side of the blade. How far you back up each time depends on the size dozer and the type of material you are cutting. I was recently doing it with a D-8 in stockpiled gravel, and would cut about 3 to 4 feet deep and back up maybe 8 to 10 feet farther each pass. This filled the blade and left a slot as deep as the blade was high. The only time to start at the farthest point and work closer is when keeping material like topsoil separate from the other materials, or when pushing the final little bit of trimmings.
Yair . . . Some excellent explanations here. As folks will realise I have been banging on about this ever since I've been posting on HEF. There are thousands of 'dozer hands out there who don't understand the concept . . . and just as many "site managers" and "dirt bosses" who should be jumping on poor technique and practice. As was mentioned on another thread a good operator will modify technique to suit conditions but, generally speaking, the further the departure from the basic premise the more production suffers . . . to the extent where an indifferent operator will burn more fuel to produce significantly less. JDOFMEMI put it beautifully with this sentence . . . This (to me) is getting to the heart of the matter. The cut has to be in a fit condition to push. Unless the blade will bury in float (or slack rope on a cable machine) it needs to be ripped. Folks have set me straight about all sorts of horrible material around the world and I understand there are materials that just have to be peeled. I also realise there are beautiful bottomless topsoils, but, in my experience peat and sand are about the only materials in which a blade will bury without ripping. I have never noticed folks in the US speak of "floors"? A floor as I know it is the depth of a rip in any given excavation. Generally speaking, for general contracting I prefer just to use the two outer tines on a set of three tine hooks. It is easier to pull and get down to depth and of course better for ripping trees and stumps. Time spent ripping is seldom wasted and, with the two tine set-up I mostly rip two ways at right angles (cross-rip) straddling each pass. With a D8H this will give about three foot "floors" which as Jerry mentioned is taken out in one pass. That is to say . . . the tractor is backed about one length onto the cut and as it starts forward the blade is driven in until it bottoms out on the hard unripped dirt below. It may take a couple of pushes to get that first part of the slot established but that is the key to whole operation. You keep the slot clean and work the tractor on the hard interface between the ripped floor and the hard unripped soil below. This achieves maximum traction for the machine and minimum friction for the soil in front of the blade as it moves along the slot. And so it continues across the excavation pushing out the slots the full depth of the rip from front to back. I leave about a third of a blade width between slots as rills. This is the "cheap dirt" . . . often made into "expensive dirt" by an unknowing operator straddling them from the back and turning them into slots. As bigshow mentions they are worked from back to front and the slots must be maintained. I sort of set the tractor at an angle and push a section of the rill into the slot move it forward and then pick up a second blade full . . . sometimes in "ball bearing" gravel you can even take a third. I should mention that in a conventional steering clutch tractor the steering is mostly undertaken with the blade tilt. I have never run anything with diff or planetary steering and can imagine such systems would be very effective for this application. I don't go to much trouble cleaning up the floor and carry out the first pass of the next rip in the direction of the push. This knocks down the remaining rills with the main beam and makes for a smoother ride with the cross rip . . . I have seen it done the other way. (he grins) Cheers.
Curiosity question guys, are you using straight, semi u or full u blades on your machines?
Scrub, I'll elaborate a bit on the application I was talking about in the other thread, of pushing down for shovels. The main purpose is to lower the face height, so a shovel can safely dig it. Typical safe face height is around 60 feet, and you will mostly be bringing that down from about 120 feet to 180 feet in height before pushing. In this application, you work a 2:1 downhill slope, in hard material that needs to be thoroughly ripped. Part of the objective is to make sure the material going over the face is not too chunky, and that is, in part, one of the reasons I mentioned you have to cut the whole length of the push, and from the back. Another reason is the steepness of the cut. If you cut from the front end of the cut, and carve out a slot, the material will slab out on you, leaving a vertical face behind you that is extremely hard to get back over. This is why we can't use a true slot method, as you need to leave yourself an escape route, to make sure you don't have to try and get out of a slot that is too deep, and too steep to do so safely. The only other option is to go over the face. Which is fine when it's 80 feet or so, but when it's 150 feet, with no push down in front of you, it's not, in any way, pleasant. I'm on my phone, so I'm condensing this for ease of typing. Hope I didn't leave anything out.
I think the whole idea of slot pushing is to get all the dozer will push in front of the blade so it really doesn't matter that much which type blade you have.
Randy: I have machines with full U dozers, SU dozers, S blades, and PAT blades. Different machines for different jobs, but the method for slot dozing is the same no matter the size tractor or the type of blade on it. Alco That sounds like a similar experience to reclaiming waste dumps. You do not want to get too much of a slot going there, as good sized rocks will become exposed, leaving you to do the slip n slide while trying to back up a 2:1 slope. You need to leave room to maneuver around the shiny spots as you back up, or you may find yourself sideways in a hurry. If trapped in a slot, you will not get turned around, but if you can't get over the rock, because the first slide drags all of the crumbs down away from it leaving an insurmountable face, it may leave you with a long trip down the face and hopefully to a spot you can get back to the top. I learned this the hard way many years ago and had about a 4 to 5 mile tram to get back to the face I belonged on.
Yair . . . Gotcha alco . Thanks for that, an excellent description of a specialised application. As you will understand my comments apply to bulk excavation in reasonable material often pushing uphill building pond banks and levees. On such applications correct technique can almost double production with the same tractor. Seems hard to imagine but I have seen it with calculated yardage. Randy88 . As others have said blade type doesn't make much difference, technique is the same although obviously the "U" type could provide some slight advantage when shallow cutting top-soil and the final clean up of rills. For me though the blade of choice was always an angle blade on a "C" frame with hydraulic tilt. For a while I ran a Seven with a string blade (front mounted PCU) and hydraulic hooks and tilt . . . one sweet rig that was, absolutely loved it. When working slots as described I believe the wider blade is an advantage . . . material falling off the side of the slot tends not to fall into the walking gear binding up the tracks. This is an interesting discussion and it would be good to have some more applications and opinions . . . there must be some folks pushing coal on stockpiles for instance, how do you blokes do it? Cheers.
Nice, we haven't had a good dozer thread in quite a while.
I am interested in what everyones opinions are on slot dozing production with a semi U vs. a full U. It is a no brainer when cleaning up and such, but I have often felt that a person can match a full U with a semi U by virtue of standing material higher in the slot in front of the dozer. Add to that less leverage and easier steering adjustment, and less surface area (horizontally - width wise) with witch to to create resistance, and I feel that production while in the slot is comparable. What say you?
Yair . . . Dunno Oxbow . When working floors as I mentioned I don't think it makes much difference. With a herd of tractors pushing up ring tanks the angle blades would often out produce the "teaspoons" as we called them. Under some (ideal) conditions the material doesn't roll and just shears off at the interface at the bottom of the rip. It is possible to have a "train" of ripper deep undisturbed sections getting pushed to the fill (complete with ripper marks) until the blade is lifted to start the spread . . . I never liked the full "U"'s on that application. As mentioned in a previous post in certain conditions a wide angle blade helps keep material out of the tracks . . . as you will know the machine loads up if a slab of clay falls into the sprocket. I would imagine it would be a factor in track wear, fuel use and production if it goes on month after month. I reckon a wide angle blade on a high-track would be the ultimate weapon to obviate the issue . . . do they fit the latest tractors with manual angle on a "C" frame, I can't say I've ever noticed? Cheers.
Yes Scrub, they do - at least up to D8s. Typically they are for special purposes I think. I saw a whole fleet of them owned by a pipeline company in South Dakota a couple of years ago, for backfiling I suppose?
I am pretty sure if the slot is right, you won't be able to tell the difference between a U and a SU blade. You are pushing the limit of what the tractor has the horsepower and traction to move, if the slot is done right. I have never had an angle dozer on a large machine, but they are popular with the pipeliners. I question the volume pushed by them, as the top of the blade seems much shorter than the SU I run. It does not seem to me like the width is enough greater to make up for it, and the material rolls forward sooner, not piling as high since the radius of the blade face is smaller. With material like Scrub mentions that does not roll, this may be less of a consideration. I do think the wider blade will create more friction with the ground as opposed to the narrower, taller U or SU blades. It may not be a lot, but like all the other little things, it adds up over time. There are applications where the angle dozer would be handy on a D-8 or even a D-9, and I would not mind having one to try some day. There was a contractor in these parts that built an angle dozer for a D-9L to use knocking down fill on large jobs where a grader could not keep up. I forget how wide, but I believe it was over 20', and it was built like the smaller Case dozers with hydraulic angle cylinders in the push arms, so the operator could reverse direction with ease on the move. As for keeping the material out of the tracks, I have no trouble most times with the SU blade on the D-8T. The blade is wide enough that with a good tall slot the loose material falls just to the edge of the shoes, but I am not running in it. Sometimes an odd rock slips by, but it usually does not get in the tracks, and it is easy enough to miss when backing up.
threads are more fun with pictures, here is one i found that has been posted here before but it's still neat. 13 D11's pushing side by side in slots
On the sand banks we use the D8's to slot doze all the time making sure to keep the front low enough to help the weight of the dozer push more with very little effort in bottom gear and not too steep so the dozer struggles to reverse.In 9 working hours the D8H's can use as little as 300 litres of fuel.Obviously on other applications they will sup another 100 litres for the same shift on soil or clay. On topsoil stripping with D8's we tend to start at the back first as starting at the front first means risking subsoil contamination especially if it's abit soft and you risk not being able to strip all the site.It's handy to leave as much grass sod on as you can untill the last minuit.
The d8's cut down about a meter or more in the slots before taking the windrows out from the back.Some times the D5 comes up later in the afternoon to clean up abit to leave a highwall on the edge for the night so the D8's dont have to fanny about hoovering up all the last bits. I generally go down once a month to check up so allways get a few pics if only to see them grading the haulroad as in this pic.
gusbratz, nice photo, but what was the project they were moving material for, open pit mine??
I will "slot doze" while stripping. I will strip perpendicular to my slots and make small pipes in line with my slots. Then get on top the piles and slot doze them down to the stock pile. But with the heavy clay we have out here its pretty easy to strip front to back in a slot. No one out here knows anything about slot dozing, but it isn't always the best out here. A lot of the time your trying to dry things out while working the dirt/mud, so slot dozing can cause you problems down the road.
Scrub , you are the best .
I don't know. here is the original thread HeavyEquipmentForums
Pictures are fun, but so are videos.. https://www.youtube.com/watch?v=iDFduzDAyhc This particular time, the 10 was pushing two blade fulls down to the end of his slot, where there was already another pile. There had been a grading change, so they had to build out the slope, hence the D8t sitting at the end of the pile. On an average day, the operator was moving 2500 yards a day in a 9 hour shift. This included the time required to clean up windrows.
I dont know if there is a big difference between a S/U and a U blade in a slot push but it does feel like you can push more if the machine has the dual tilt cylinders so that you can carry the dirt. On the current job I am on now it cost us around $3 a yard to move the material with hoe and trucks, when we can push the dirt it cost us just under a $1
Yair . . . vapour300 . How far are you pushing for a dollar . . . and what machine and hourly rate is that based on? Cheers.
That is a D10R pushing 50-100ft
Your hourly rate must be through the roof for it to cost $1.00 per yard pushing that short.
Yair . . . JDOFMEMI . Old feller I worked with way back reckoned it was twenty cent dirt at fifty feet, forty cents at a hundred and so on . . . when it was all averaged out over the whole job the old bugger was always pretty right. Cheers.
Dont know our hourly rate, was just told that all the dirt i pushed one day cost under a $1 a yard to move.
Hello HEF friends, As some of you know, I am not a fan of slot dozing unless your close to obstacles that need to remain in place. I like starting at the highest point first then the farthest point back. I will start closer to the fill area if there is a deep cut and work my way back. But I don't like hitting the same path 2 times in a row,I'll move over a blade and a half and take a new cut. After a few cuts I will start centering the windrows and cutting (boiling over the sides) all the way to the fill area. The operators that just slot doze and don't boil over some material are only moving 1 blade at a time and everything else stays put. When you boil material all the way to the fill area, you got your blade full and your boiling over material from where it was to 5 feet closer to the fill area as it is falling off your blade on every pass. You will have less trips back and forth with this method verses slot dozing. Less trips, less time, less fuel. $$$.
Yair . . . Dozerman400 . I think you should stop and read up on the subject . . . slot dozing moves at least two bladefulls at a time. If the dirt is boiling it means your digging and you should only dig for maybe a tractor length or so each push. It is obvious you have no understanding of the concept and, like a lot of "would be" operators are too set in your ways to consider some re-education. Cheers.
I thought about this thread the other day as I was working in slots...... Pushing snow off the driveway It seems to help even in the white stuff ...... The dog was happy with the job
I don't think you've ever truly slot dozed dozerman. Or perhaps you have, but just aren't sure how to explain it. It will become very clear once it has been done right that slot dozing will move way more dirt faster than any other way because it traps the dirt in front of your blade, material you DON'T see while you're pushing it but you know is there. Yeah, you may be moving some material 5' closer by boiling it over the side, but what you are missing is that the head of material is way longer in front of your blade when you are slot dozing. Material doesn't need to be boiling over the top of the blade and no material is boiling off the side. Guys that are good at it don't boil it over. They start cutting until they can see it at the top of the blade and leave it there until the end of the pass. If you ever got into a position where you could work side by side with an operator truly slot dozing, you will see it. You would have to move the machine in the same gears. Back up in 2nd, push in 1st or 2nd. The slot dozer will move more dirt.
Dozerman400, I think the point that many of us are trying to make is in regard to the last sentence in your post. Less trips does not necessarily mean less time, nor less fuel for that matter. I believe that one could even argue that undercarriage wear is less despite traveling more distance as the pressure on components is reduced. Slot dozing might be worth a try! :drinkup
I thought Dozermans post was a joke...:beatsme
Well, he certainly livened up the thread! I have worked side by side with guys with a very similar attitude to his, and despite being asked, told, and explained how I wanted it, they were set in their ways and would not listen. I was on a job with a 30 year experienced operator, both of us on D-10N's, and both tractors apparently equal to each other. We were sloping a waste pile about 120 ft tall from the angle of repose to a 2.5:1 slope. I slot dozed, in an advancing wedge shape, so the beginning of the cut was a short slot, and about 5 slots behind was the one that finally got to grade and stretched to the toe. Each slot was cut to about blade height on the low side, and each one got deeper into the cut until the final one was at grade. Each of these slots was running downhill at the ultimately desired 2.5:1 slope. The other operator refused to do it my way, and created his slope by making long passes from the top to the bottom each time, and cleaning up windrows as he went, even when there was 20 more feet of cut. He explained how much better of a job he was doing, because his "looked finished" all the time. My cut looked like a bombing range until the last pass when it all came together. I was the job foreman, as well as the D-10 operator, so I ended up only getting 6 to 7 hours per 10 hour shift in the machine. The thing was, when I started measuring the daily production, I was producing 30 to 40 percent MORE, even while working 7 hours to his 10. We were working separate areas of the same pile, and leapfrogging one another as a section was finished. The pile was nearly 2 miles long. When the other guy noticed I was placing a stake at the starting points for each of us, the next day I noticed his measurement was the same as mine. I suspected funny business going on, so the next day, I put the stakes out, then put another set over the hill out of sight to check. At the end of the day, his stake had been moved a couple hundred feet to make it look like he did more work. At that point, I decided I did not need him any longer and finished the job myself, as it was costing nearly double for the work he was doing. I have many times on jobs measured the piles in front of a blade per the directions in the Cat Performance Handbook in order to verify production of different machines. When I measured the pile I was moving in the slot, downhill at a 2.5:1 slope, I was amazed at the volume. I checked a few piles, and checked my calcs based on many times doing the same thing, and I found I was pushing close to 90 cubic yards per pass. I can't recall how many feet in front of the blade the pile stretched, but it was a really amazing pile for a D-10 to push. The material was perfect for this, wet crushed rock with enough binder to pile up and also afford great traction. I have never since pushed in such ideal conditions, but the production advantage is there regardless of the conditions, unless there is a compelling reason for another method like Alco pushing down a shovel face. In some material while placing compacted fill with nothing but a dozer, you need to roll the material to mix the moisture into it, so spreading out each pass is needed, and I am sure there are others, but to bulk push material, a good hand slot dozing the right way will outwork any other method.
Yair . . . Thanks for that JDOFMEMI . You may note that I too have spoken of a "train" of gravel moving ahead of the blade . . slot dozing is a tried and proven concept I have been teaching and promoting for over fifty years. Even in this enlightened day and age I still see operators like Dozerman costing themselves or their employers money by using incorrect wasteful techniques. Way back when I first started posting on HEF I got a bit of a serve by saying I thought that less than (I think I said) 5% of dozer drivers knew how to get the best out of a machine . . . judging by what I have seen in the past few years on job sites not a lot has changed. I believe this is inexcusable and is a reflection of poor management. These blokes are mostly competent, they just need some guidance and toolbox sessions to learn best practice methods. No one ever came onto my jobsites and did it "their way" it was the correct way (not my way) or the road. On those ring tank jobs I even went to the extent of a diagram on a blackboard showing a simple excavation. When asked how they would carry out the task most new operators weren't even in the ballpark . . . most in fact worked like Dozeman pushing rills through from the back. Cheers.
Hey Scrub, could you please define "ring tank". Thanks!
I used to try to help greener hands to produce more but it got very frustrating. Now I just do my thing and let others do theres, so long as its safe and not destroying equipment. At the end of the day some come around to a more efficient way of thinking while others think they know it all. Dozerman may be the best dozer hand ever, I don't know, nor do I care, it's how he does it and if he sees fit, well so be it.
This is some what of a poor depiction, and I had to stop to take the pictures... Bear in mind, this is only a JD 750c, with a 6-way, about 9 feet wide I think... how much dirt does anyone think that blade would be carrying, if out of the slot, on flat ground??? The area is not very finished looking at the bottom either, but that took very little time to accomplish... As I said... it's not the best example of slot dozing, but it is an example... OCR
I guess what dozerman is failing to realize is that if the machine is still able to cut and material is rolling off the side of your blade from the start of your cut till the end you are not actually pushing what that machine is capable of pushing.
Yup td, that's exactly how I do it, about every week or so... when making a new pad for my shop... OCR... lol
Yair . . . Oxbow . this is the first time I've tried this dunno if its going to work . . . this is a ring tank, I'll follow with text if it posts.
Yair . . . Another one for practise. Cheers.
Yair . . . Well I can post pictures from the net now, I'll do some words tonight. Cheers.
Yair . . . Oxbow and anyone who's interested. Ring tanks (I think) are an Australian aberration and it has always been a bit of a mystery to me as to how they pencil out. They must turn a profit though as many were built from the late sixties through to the nineties. With the price of diesel compared to that of grain and cotton I reckon it's unlikely we will see the likes of the ring-tank building boom again. They could be any size. The largest I worked on was basically pushing up a twenty five foot high wall around a two hundred acre paddock. I believe in later years it has been divided into bays to help counter wave erosion and give some extra options for managing the water. those early ones were built pretty much exclusively with dozers and we hired in a motely crew of machines from D6 size to Nines. The later ones used scrapers to get better compaction although I believe that during the construction of the tanks on Cubbie Station they had forty odd D8 and larger tractors on the site . . . some of the tanks there are over a thousand acres in extent. I should add that the point of them is to catch ephemeral seasonal cross country flows and, some times, to harvest from rivers when the flood reaches a predetermined height. They can be empty for years but the farmers still need to maintain them and the several thousand installed horsepower they have on the twenty to thirty six inch flood lifter pumps. If anyone is interested I can dig up some extra info and pictures and maybe start another thread. Cheers.
Please do
Thank you very much Scrub, I have heard you mention them many times but was unsure exactly what they were.
Thank you very much for the great information both the Senior Members and Members are giving on the procedure of "Slot Dozing". I have only used this method on a small scale to expand a parking-lot. It only added another 50 parking places, but it was the perfect time to try this method of "Slot Dozing" I had only read about. I found it to be a very effective and efficient way to move material. The Case 750 Dozer I was using was up for the challenge. I will certainly try this method again when I get the chance. Works Great!
Glad to be able to help, Where you at in N.Y.?
Rochester
Ah, you have turned over a new leaf. It seems you can teach an old dog new tricks! Thanks for the info on the ring tanks. I figured they were a pond of sorts, but did not realize how big they were.
ALL DO RESPECT TO EVERYONE! JDOFMEMI, I like the methods I use. I'm easy going and can run the machines (with out an attitude) any way the Bosses want me to. AustinM, I have gone side by side with operators slot dozing. I have always finished my 1/2 first then help them with their 1/2. Oxbow, I have tried slot dozing, I feel the machine is fighting harder by going deeper in the same paths verses staying on top of cuts centering windrows. bigshow, I enjoyed your post #43. Even snow plowing, I plow different than most. At O'hare Airport I started plowing a gate in terminal-3 the same time another operator started the gate next to me. He came to me said I was doing it all wrong. I said give me a chance to show you my way. He did, I got my gate done and 1/2 way done with my next gate before he finished his gate. After 2hrs I looked back and saw him trying it my way. vapor300, I do believe I get the max out of all the machines I run. Dozerboy, If I worked side by side with you, I am certain you would not be laughing at my techniques. ScrubPuller, I will ease up on this slot dozing thing. I was only trying to post what works for me and the people I've worked with. I normally get sent to the job site with the earliest deadline.
Dozerman, the reason the machine fights harder on the slot is because it's the only time traction is the limiter on what you can push (not cut), as you are pushing the max possible without it spilling past the side of the blade. Now when Cat and Komatsu recommend slotting for max production (as does just about every opencast mine, army engineers, Seabees etc.) how can they all be wrong? You need to get the blinkers off and ask just how good are these guys you've outperformed.
Yair . . . dozerman400 . No worries you go on costing yourself or your employer money. As I have mentioned I have re-educated many operators who work a lot like you. For those who won't listen and learn I sort of compare it to trying to teach pigs to tap dance. I just wont do it any more. It drives me crazy that they just don't get it and it pi$$es off the pigs. You have a good Christmas now. Cheers.
I feel there is some dissention here
Huh???... :lmao... ↑ OCR...
Slot dozing is the way to go in a great many applications, especially when moving ripped material any distance. Have found other methods work OK on short pushes, truck dumps, shallow cuts etc, more so when using a large dozer.
Yair . . . One thing that is never stressed in the various published slot dozing data is the ripping. If the blade can't be buried and loaded in a tractor length or so it must be ripped. Once ripped, the full depth of the rip is taken out in a single pass and the depth of the rip plus the rills on either side become the depth of the slot as the tractor works back across the cut. I don't know if I have mentioned that under some conditions with the tractor loaded and pushing hard you can some times slip into float and "give the pony her head". You will hear and feel the load come off and it must save a bit of fuel. Cheers.
Ok so you are from the Chicago area? That makes a little more sense to me now why you think that, biggest dozer they have around that area with a S/U blade is a D8. TJ Lambrecht knew how to move dirt but when it came to pushing they had no clue, they had never been around it or had seen it. Dozerman what you are doing may work good for you, and your boss may like it to, maybe he has never seen a bulk push. But we are not steering you wrong slots are the most effective way to push dirt. And i believe you that you have outpushed guys that have slot pushed while you take out your windrow, but lets be serious 1/20 guys that claim to be a dozer hand are actual dozer hands.
Anybody here slot doze in hard rock? I work in hard rock gold mine, pushing to either a 992 or 994 wheel loader. We have one section of the pit which has a fault, so any of the blast energy disapates, makes for very hard ripping and pushing.
I only slot doze in good material with no or not much ripping required,eg sand top soil.If it's hard ,rocky I tend work a 20 meter strip back to front style.You can't slot doze in anything that requires a far bit of ripping cause the blade is alot wider than the rippers.You can do a bit with the blade raised.With full u blades dual tilt you can shift alot.I would do a push then move over 2 or 3 meters do a push then take the windrow out,rocks have some where to go & you pick them next time.I been involved in time & motion studys on this sort work,45,000 hrs on dozers.I can't believe the operators who don;t and won't lay the blade back.I may be wrong but I have never had problem with alot of my work has been production bulk pushing. Cheers Will
Can't quite follow your reasoning. Many times have cross ripped in hard material, almost always only had a one tyne ripper ( dozers ranged from a D46u (trailing ripper) to D11s) so blade to ripper size is irrelevant. Working in rock, tried to rip/push whatever way was easiest and successful.
The slot method is the only way 2 move dirt no matter the material depending on material the length u take to fill will change cleaning the rill as u go defies the purpose the idea is to keep material in front of u by using the sides u make as u go something to remember a dozer can push more than it can cut and push remember to soft pedal to gain traction and give yourself enough room to get your next blade full in a long push u might even get 3 how ever u need to remember do not overload it is quicker and kinder to run in 2nd then loaded to the hilt in1st if the machine is rolled back on its haunches you got 2 much if done properly when your blade is full it will follow the ground u have already cut I can't say about out her machines but a cat blade no mater it old cable blade or u blade is designed to ride up once full cats are also designed to lad in the length of them selves and the rippers are designed to go to depth that the machine can cut in to the floor in that length oh nearly for got 4 anybody that doesn't know wat soft pedaling is it's riding the de accelerator so as 2 gain more traction or let the ground catch up u are using the torque of the engine and the machine weight to your advantage this will result in more dirt shifted for less fuel burn and less time spent if u don't believe me try it also if ur sought full step out your ground calculate ur cubes and time it do a couple hours 1 way then do a couple hours the out her way and then u will know
Yair . . . Dunno, it's got me beat. This is a pretty simple concept. Folks have come on here and explained slot dozing and then bloody hell and fark, we get this . . . willd8r. Mate, you do not try and rip the bloody slots except maybe to take out a guley that's giving you a hard time. You take out the entire floor of the area you are excavating . . . to slot doze material other than sand or top-soil/peat it has to be ripped and mostly cross ripped. The material needs to be conditioned so you can bury the blade the depth of the rip in a tractor length, that's the whole point of the slots, you take the material out in floors which in the case of an 8r I imagine will be a good meter a time, maybe more in good digging. you want to get the tractor down and pushing on the un-ripped material of the next floor down. You get better traction and the material can tend to flow easier. Cam85. It is obvious you know what you are on about. I have never mentioned "soft pedalling" as I thought it may be complicating things for some blokes on here who a having problems with grasping the basic principles of pushing slots. Good to see more Queenslanders on here and hope to read more of your posts . . . which brings me to formatting and punctuation. This forum is a great resource for folks to learn and it would be much easier to comprehend and understand the good information you posted if at least you broke your post up into shorter paragraphs and used some dots and commas. Not having a go at you or being a smart ass, that's just the way it is. (big grin) Cheers.
I c what your saying thanks 4 the tip and I totally 100 percent agree with nearly everything u say
Yep I just re read my own post it was hard to follow.Everybody just listen to scrub puller this bloke obviously knows what he is on about.
Yep I just re read my own post it was hard to follow.Everybody just listen to scrub puller this bloke obviously knows what he is on about.
Probably not good at explaining, should of keep out of this.One question is how do you cross rip when it is to steep an rocky like building a logging dump or drill pad on the side of a hill.Tthat's when you have start at back to lesson the grade.Some of my work the ground so bloody hard & rocky even on the 11 single pick you are constantly ripping.so sometimes it takes several pushes to get a blade full to carry to where ever it needs to go.When I carry I use windrows to hold the dirt in the blade.Some of the rock is the size of a d6. Cheers
Yair . . . Cam85 . Good one. I am pleased you took my comment in the spirit intended. As far as knowing what I am on about . . . some things never change and moving dirt is one of them. The dirt is just the same as it was forty years back when I was digging, the machinery is different but techniques and how we do it have been proven by time. As you can see by this discussion on pushing slots and another thread on cleaning out dams some of the old and tried methods seem to have dropped off on the wayside. As I mentioned this forum is a wonderful resource to discuss ways and means of doing things. I have a very narrow band of experience on 1950's to 1980's trucks, large dozers and scrapers and no knowledge at all of modern machines. I try only to comment on subjects I know a bit about. Cheers.
Yair . . . willd8r Valid points. You can't always work to the ideal but as I mentioned the more you deviate from a slot pushing system the more inefficient you get. There is no one system fits all. Both you and dozerman have raised the point at starting at the highest part of the cut. Obviously that's the way to go but once you get it sorted out it's time to start the slots. Some stuff as you mention will be impossible to slot but generally speaking if you have room to move and the cut is deeper than a rip the best way is to take it out in slots one floor at a time. There is no need to clean up much between floors just make the first rip on the next floor in the direction of the push and cross-rip the other way. If you read back through the thread there is a specific way of pushing out the rills, you try to maintain those slots right to the end. Cheers.
Bit hard to see.Tips on the corner tips make difference.I guess a modern version of the old ripper blades cheers
Is that an 8??? If so that is a big blade for an 8. I know what your talking about willd8r, have pushed some real rocky material and when you start breaking the rocks out that are as big as the blade you pretty much gotta do whatever you can to wrestle them down the hill. But when it gets real rocky i will do like scrub said, i will rip it going every direction i can and when i start the slot i will keep my cut very steep, makes it easier to rip if the dozer has a 3 shank ripping your slot with a single shank i dont think would help much but i dont know. And makes it easier to pry the rocks out.
Will I love the rippers on the corner. Can you show some more detail by chance? Looks pretty useful in tough going like pioneering roads in. Scrub and others Wills post reminds me of another place where I do not slot doze. I do a fair bit of work at times in tight river rock with rocks up to 4 foot, though most of the big ones are 3 to 4 foot. The rocks nest with each other and even when well ripped make it tough to sit on top of and push. The rock makes you loose traction to often, and it is hard to keep a floor. What I do then is to work into the edge, and keep the blade tilted down on the cut side. I try to undercut the floor by a bit, then leave the offside of the blade up a little to loose some fines in order to make a floor to keep traction. Leaving the fines drifted over the top of the rocks helps for both traction and ride quality. If it is a long push, I will get a slot going ahead of where I am cutting, then work a fan shape behind the slot leading into it. This way I can take two loads into the slot, then push it on. On short pushes, just work edge on back and forth. When doing this, I will adjust the size of the cut I take depending on the rock size. You need to be under the biggest ones or you can't get them out of the floor. The same thing works in rock that does not yield much in the way of fines when you rip it. By leaving a free edge, you can get different angles to work on tough rocks that are still anchored to the earth below. Many times in the river rock I will continually push with little to no ripping. The material is mostly loose except for the nested rocks, and edging into them leaves a place for them to fall out and come loose.
Yair . . . JDOFMEMI . Understand completely and your comments about working a fan shape at the top of a slot bought back memories of a job I had loading trucks with run of the ridge gravel over a "Chinaman" (as we used to call them) with a D4. I don't know if you blokes used Chinamen in the 'States but before the time of loaders most bush gravel pits had them. They were essentially a chute made from stout bush timber. The trucks (in those days mostly single drive five or six tonners, most with cable tippers) would drive under and the little dozer, under direction of the truck driver would push the gravel up the chute and into the back . . . very quick and effective but as the months passed it could become a long push for the dozers winning the gravel. I have seen slots where the tractors were pushing near a quarter mile and well remember one site where they had a 'big' Oliver (I think an OC12) bringing a virtual landslide down a slot from a yonder ridge above the loading site . . . how interesting it would have been if we had all had the foresight to use a camera on what was then the ordinary and mundane. Cheers.
https://www.youtube.com/watch?v=YDv0RuImQRQ slot dozing explained by CAT at 44 minute mark
Nice find Vapor, vantagetes has a video on YouTube where he does a nice job explaining slotdozing. As it is not my video I won't post it, someone else may have permission or he may share it himself.
Lol... bet you're a master at soft pedaling, as you're backing back up that... "real rocky, very steep" slot you're working... :cool2 OCR...
I will keep the start of my cut very steep, not the entire slot, Just need enough to get a blade full, after that you will level it out. Pretty easy to back up that.