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The lost art of slot dozing!
- Thread starter bigshow
- Start date
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.
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Scrub Puller
Senior Member
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.
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.
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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.
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.
rdr99
Member
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.
willd8r
Well-Known Member
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
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
Scrub Puller
Senior Member
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.
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.
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willd8r
Well-Known Member
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
Cheers
Scrub Puller
Senior Member
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.
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.
Scrub Puller
Senior Member
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.
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.
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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.
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.
Scrub Puller
Senior Member
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.
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.
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https://www.youtube.com/watch?v=YDv0RuImQRQ slot dozing explained by CAT at 44 minute mark