Hey, Dozer Folks! As a non-dozer guy, i'm curious as to the max sideslope that a lot of these machines can grade. 1. What's the max sideslope generally accepted (perpendicular to the slope) for grading an embankment? Better to grade up or down the slope? 2. Same sideslope question but running longitudinally along the slope embankment? I see some guys on some wicked slopes from time to time and was just curious... thanks
Need more time to answer this one, be back later.
Well i don't have thousands of hours in the crawler but: - Some of our dozers can cope with 45 degrees before it stops the oilflow in the engine. Problem is u rearly manage to use that degree, friction is not good enough to help u back up. Spinning before u reach that degree. Sometimes u got to use a winch to help u go back up the slope. - You would prefer to go down the slope, cause then u got the weight of the crawler to help u push. Going uppwards means u use your power to go up the slope, not to push dirt. Then u go push downwards and backs up empty. - A sideway move is not recomended! u got nothing holding u back. And when u slide sideways, it comes to an end down the slope. Flipping it over is possible.... - When moving in a sideways slope i prefer to go at an angle so i have friction against slipping sideways/down the slope. And quickly can turn it 90 degrees to the slope and stop a possible slide. Winter,snow and slopes is a dangerous combination for a dozer. Sliding sideways happends in a split second. Planning is of the most importance when u are working in slopes at high degrees. It can go wrong very quickly.
I don't know the answer, but for what it's worth, operator comfort may be the limiting factor for working sideways on a slope. Leaning forward or back in the seat isn't too hard for too long, but trying to stay in a seat that's leaning too far to the side gets old in a hurry.
For working sideways, 2:1 is about max depending on soil type and conditions. As far as grading up or down, it doesn't really matter to me. It all depends on the site.
OK, Got some time now to elucidate on skinning a Cat on steep hillsides. Someone mentioned the fact that a Cat turns into a multi-bladed ice skate on frozen or icy slopes, hard rock, and wet clay or hardpan. Yeah they does, and it can assist in making a real mess in your pants when it happens. There is a limit to how well a Cat will operate sideways or straight on any slope, and every Cat has a different feel and ability with this. It's hard on rails, idlers, and rollers on high-sprocket tractors, and hard on segments as well on low-sprocket machines working sideways. Lots of extra wear and occasional breakage this way, and if you don't have to do it, it's best not to. If you do, try to keep some muck in front of the blade, and avoid backing across the slope. 30 degree slopes aren't too bad, anything more and it may be best to just go straight up and down, or at least at a fair angle. I've watched operators in many states run up and down slopes in excess of 60 degrees and I've done some of that myself, and like some other dummies, I've exceeded that up to 90 degrees and more, which is not the brightest thing I've ever done. In 1984 the dealer I was working for stole a nice rental contract from Clatterpillar. The Aspen Ski Corporation always rented three or four Cat D8H or K's every summer for ski run construction and maintenance. They usually waited for the snow and ice to melt off, then worked the crap out those machines and their operators from daylight to dark. When Wagner offered up three shiny new D8N's, those operators took one look and said, "no thanks!" "We're not operating those high-sprocket thingies on these slopes, no way!" So HW Moore rented out three new International TD25G's to the ski corporation and everybody but Clatterpillar was happy. Our D9 operators in Wyoming got tight cheeks when the Super decided they could pioneer a haulroad UP the right abutment (no way around to the top), push 651B's up empty, 500 feet or so, then have the 51's drive off over the edge of what had to be a 60 to 70 degree slope or better. All loose scorie. Needless to say they didn't need a pushcat on the way down, I doubt a pushcat could have kept up with them anyway, even free-wheeling. The scrapers boiled scorie out of the bowls and were moving so fast in about twenty feet that the engines were stalling cause the transmissions couldn't up-shift fast enough. But after a few runs they built up so much loose material at the bottom, the Cats had to follow them down and push them out of it. Some were buried all the way up to the top of the radiator caps and the 9's had to doze material away from the front of the tractors, and of course the Super called for mechanics to come over and clean the radiators out. We had some operators quit that day, good ones too. The D9's then would push more empty scrapers back up to the top, and eventually they got it knocked down to a reasonable point. I, of course, had to jump on one of the suddenly empty scrapers after the operator quit, just to settle a 100 dollar bet between the super and me whether I would do it or not. He didn't bet me any more after that day. What a ride!!..... I've had to retrieve many Cats that fell over forward right onto their tops because they drove off into a cut or a unseen trench. This most often occurred in Kentucky at the surface coal mines on the night shift, sometimes it happened on the hollowfill when it sloughed off as the dump-Cat was working too close to the edge. Our D10's, 9L's and 9H's, and one Fat-Allis HD31 all worked clearing extremely steep hollows for strip mining and they fell into all kinds of crap, like old hidden mine openings, caves, springs and seeps, you name it. Many times they could push down, but had to go all the way down -- clear to the bottom -- to turn around and drive uphill cause they couldn't back up and they couldn't turn on the slope to go back either. Sometimes they couldn't drive up forwards and would have to go around on another route to start fresh at the top. You never headed over a slope without a blade full of dirt, brush or trees in front, well, you weren't suppose to anyway, but once in a while one of the boys would muck up and over he'd go! Then he'd lock up the brakes and skid down a hundred feet or so before he remembered that the blade was supposed to be DOWN, with DIRT in front of it! DUH!!.. Fairly often we had to rescue a Cat that got overloaded on the way down, maybe one too many big Oak trees you know, and they couldn't back up, so another Cat would have back down very carefully with a tow cable, hook on, and try to pull the other machine uphill a bit. More often they would simply go on around if they could, turn back uphill, and try to push away at a corner or something till the 1st Cat could move again. Once in a while (twice a week maybe), we'd have to rescue a Cat that lost a track on the way down. In the mine in West Virginia, and to an extent in Kentucky, we had to reclaim the highwalls. Some of these were 150 feet high and straight up. They had be sloped back in to the point natural dirt wouldn't fall off the incline. All the dirt had to be pushed up from the bottom cause the highwall was right up to the property line and we couldn't go outside it. Talk about a boring job, all day up and down, and when you started getting steep, your dozer didn't carry much dirt in front of it. Then you had to smooth things out and then "track" in the slope. Land clearing of General Lam's wall northwest of Danang was interesting. We were using International TD20B's. It was here that I fell into the bunker. Marine Engineer Surveyors had run a single row of stakes where they wanted the ground cleared of everything 600 meters wide. Didn't matter what it was, take it "down to the dirt" our company commander said. Marines are fairly ignorant of where a bulldozer will go, believing any that are operated by young and stupid Seabees "can do" anything-anywhere-anytime. What was it we said, "We the unwilling, led by the unqualified, can do anything, with nothing, forever!" And so we tried our best. The route led eastward for a few miles, thence south for 27 miles or so. It went up and down hills and valleys, off cliffs, across rice paddies and streams, thru jungle forests and cemeteries. The Marines had started this shindig using Eimco 106 dozers, but they were a high centered beast and even the Marines weren't so stupid as to run an open cab high-center-gravity Cat off a cliff. We, on the other hand, would take our trusty TD20's anywhere and we cheerily broke over all the spots the Marines shied away from. We never failed to be surprised at what we found on the way down some of the slopes. I often would break over with a blade full of brush, snakes, lizards, and some dirt, and in short order would find myself standing nearly straight up on the dashboard with the gauges under my feet and the top edge of the seat-back pressing against my shoulders. Then we would hit stumps, graves, boulders, ditches, all kinds of stuff on the way to the bottom. That's what happened to me one fine day early on. I took over the brow of a slope with a full head of steam and was headed down in the by then familiar near vertical position. All was fine and I was pushing a bunch of crap a D11 would have been proud of when, ooof! The TD20 nosed over straight up and down, standing exactly on it's dozer face, both tracks just a spinning in the empty air. If I hadn't already been well braced I'd have been pitched right off over the stack. As it was, I was well confused. My first thought was to raise up on the dozer blade, but I quickly realized that was a mistake as the tractor teetered back and forth, but mostly frontwards. So I tried pushing the blade down, and that was the trick, the tractor slowly moved back and then rushed down the couple of feet to solid ground. That allowed me to get one foot back on the de-accelerator and slow the engine down and stop the tracks from trying to push me over again. Ah! Lean back, way back, breathe stupid, breathe! OK, what now? I looked around to see if anyone was watching, and of course, my buddy Ski, the off-operator, was doubled up on the ground on top of the slope, trying hard to breathe himself -- between bursts of manic laughter! No cartoon character had anything on him. He was so red-faced I thought he'd bust. Well, no time for that, had to get out of a jam you see. So I pried the dozer blade up while reversing a bit. That let a bunch of muck fall under the blade and I was able after a try or two to run over it and keep on going down. I headed back up after turning around in the rice paddy and when I got to the top Ski had finally quit laughing and was leaning over the slope trying to see just what it was I fell into. We never found any, but some Bee's from another battalion found some old Japanese bunkers that still had some artifacts and military gear inside. What we had found, was part of an old French bunker system, one they had used for observation of the valley floor in front of us, which was, even in our time, still being used as an infiltration route by the folks now known as Viet-Cong. It wasn't real big nor as extensive as others we found later, but it was dug real well and real deep. I'd hit it dead center. It took an hour or so, but we worked around it and gradually got er filled in enough for our purposes. Naturally, Ski had to tell all the boys about my escapade as soon as we all got back to camp that evening. They laughed till midnight! Fortunately, I was only the butt for a couple of days. Once "Stony" Burke hit the dud 155mm artillery round or 8" naval shell and blew his left track off and wounded himself in the process, everyone forgot about my little deal. And in the days to come, exploits like mine became fairly common as the other fellas repeated my experience. So, slopes is fun! They can also kill you quick.
We had a job building a canal and the slopes were 1 1/2 to 1. Our D6H LGP worked those slopes non stop for a few months levelling them for concrete. Brian
follow up so it's not really a balance issue per se, with heavier rear end or front end dictating the action? Is center of mass located at pretty much center of machine on most of these bad boys? I can sure see the points being made, esp. letting gravity assist in doing the work on pushing material downhill...
Joe, I'm not trying to go "off-topic", but wondered if you'de ever looked at this sight. You might even be in one of the pics?!:beatsme http://www.538thlcc.org/work.html Their pic's are small, but interesting none the less. on edit: It came to my mind when operating dozers on slopes and then Vietnam were both mentioned.
My first year moving dirt we did a canal job with 1.5:1 slopes. I was on a 9L pushing 31's. I would often push them on the slopes. I would tag them on the bottom and then push them up onto it. We would get the cat and scraper sliding along it so that we were slightly angled on it. Was that ever a rush. The cabs of the scrapers would quite often go right up on their bumpstops as I was pushing them. They would grab the radio laughing "don't let go of me you little b*****d! keep pushing!" ...I was worried who was hanging onto me lol my high side track didn't have much weight on it. I learned a lot about working on slopes from those guys realy fast. I had to push hard enough to keep preasure between our push blocks but not hard enough to straighten us out. I miss those days sometimes. You would never see that anymore. Now like Alco said, a wide pad 6 does it. Or the grader. Everything is so safety wise nowadays, don't get to have that kind of fun anymore.
Nah Jeff. Those Army guys had more equipment in a single company than the Seabees had in the entire 31st Naval Construction Regiment. They also had a lot bigger iron than we did generally. We drooled over their scrapers and Cat D8 and D7 dozers. The only ones the Bees ever had were wore out by the time I got in-country, tho I did help load some of them out on a ship for Japan where a few were to be rebuilt. I know I never saw them again. I did run a Euc C6, and an International TD25 on my first tour, and I guess we still had one running D8, cause we used to have shoving contests while waiting for fill on bridge abutments around Danang. (the 25 out pushed the 8) We didn't get to see much of the Army Engineer stuff till my 3rd tour when the Army took over most operations in I-Corps. That and I was down south for about the last third of that tour and saw quite a bit around Long Binh and Vung Tau. My Seabee partner in crime and I tried every chance we got to cumshaw Army Engineer equipment in Vung Tau. We made off with a couple of jeeps and a deuce and a half, but couldn't quite manage a dozer or Cat grader. We would have been heroes if we got our hands on the grader and transported it over to the Rung Sat Special Zone. We almost had it, but some MP's busted our attempt and we had a hell of a time lying our way out of that deal. ForsytheBros, you will read a lot about dozer balance here. It's a actual point on the machine where horsepower, weight, and the machines center of gravity all come together. It's also a seat of the pants feeling one gets, and you can tell a good "sweet" rig from a bad one shortly after sticking your butt in the seat. Guys like Rollover Pete and Deas can tell you all about that.
Working on side slopes or side-cutting batters Hi, ForsytheBros. Good question and, for mine at least, there is NO hard-and-fast answer. It depends to a great degree on the particular machine, the operator's skill and courage, the prevailing ground conditions and other available options for getting the job done. Many years ago, I was racing a D8H around in 2nd gear on 1.5 : 1 batters on a dam job and the works superintendent told me that those batters were too flat and that I would have to get back up there and cut them down some more. He sent the surveyors to check the batters and show me how much needed to be cut off. The batters were in two parts: the top 40 feet, above maximum storage level in the dam was 1 : 1 in 12" steps to hold topsoil and the 60 feet below maximum storage level was plain 1.5 : 1. This should have left the toe of the whole batter 130 feet out from the top. The surveyors arrived to check it about 1/2 an hour after the 'super' left, when I was about 5 feet from the bottom. They reported that the batter was going to finish up 135 feet out from the top. They also said that they didn't think I would be getting sent back up to cut any off the batter. I wasn't sent back up. And THAT was the first check that had been done on the entire batter. What threw that 'super' was the fact that I was running the D8H around on the batter in 2nd gear. He just wasn't used to people being that 'mad'. I have worked D8's and D9's side-cutting 1.5 : 1 batters pretty routinely and have run a D7F and a wide gauge Cat D5B on close to 1 : 1. In most of these situations, you HAVE to follow the batter down as the machine will not stay up on that slope without the flat at the bottom to stop it sliding. I have however, 'slid' various dozers along a batter, keeping the blade well up the batter and the rear well down the batter and using the steering clutches to maintain the angle and 'slide' the machine along the slope. In such situations, you are using the tracks as well as the blade to do your cutting. I don't recommend this practice as it is hard on running gear but it did get the job done - without killing either the machine or me. Incidentally, I have also used the above technique with the old Cat 12E graders when I could not reach the top of a batter with the blade fully side-shifted. Worked then too. I believe it pays to keep the nose of the dozer slightly uphill if you can as it is usually easier to back out of a near-tip situation than to drive out face-first. This is NOT a hard-and-fast rule, simply a generalisation and each case should be taken on its own merits. Another good idea is to keep the blade as low as possible at all times to keep the centre of gravity down. The ripper too, even lifting your ripper shanks up if possible when you are doing a lot of steep side-cutting to get your ripper beam lower without fouling the ground. Just a side note here. I will stop working the wide gauge Cat D5B dozer mentioned above quite a bit before it reaches its tip angle, simply because of the seat. The seat itself is set quite high and, even with my 240 pounds in the seat, the seat cushion is only about 2" below the top of the armrests, This not enough to hold my delicate butt in place in the seat on steeper slopes. This is the first, and so far the only, dozer on which I have worn a seat belt and that was purely so that I could stay in the seat while on steep side slopes. I do recommend wearing seat belts on machines fitted with ROPS. I am still a bit open minded about seat belts on non-ROPS equipped machines. As mentioned elsewhere in another thread on this forum, I once took an angle blade, bobtail D9G up an 8-foot vertical wall one night in an iron ore mine. I don't recommend this practice either but I managed it - without a lot of slipping and scratching - because it was the best way at the time. Whatever you do on slopes, do it slower and more carefully than you would on flatter ground. Most operators will press the 'chicken switch' before the machine reaches tipping angle and this is a good thing. Trying to prove that you are a brave man on a slope can get you slightly dead if you are not very careful. Hope this helps.
Wow great story Joe, I've been on lots of steep stuff, but nothin like that. Yeah its always that initial first time nosing over, after that its a cake walk. The mine story about pushing up hill, its alot of work for the machine to move itself let alone any kind of load going up hill. The times I've done it I keep thinking its like using an 80,000 or 150,000 pound machine to move a few wheel barrow loads at a time, yeah pretty unproductive. You'd be cool to meet in person, I'd love to hear the Jungle cruncher stories. So how many times up on one track? Thats always a fun deal.
I hate to be a skeptic, and I don't have a ton of seat time on dozers. I do have a bit of understanding slopes though and last I knew a 90 degree incline was vertical. Anything more that would put you upside down in some fashion. Even in an iron mine with magnetic tracks I'm not sure how you could pull that off. 90 percent slope I could accept, but not 90 degree
Read my earlier post Alan, it explains how that was done. I retrieved a D9H in Kentucky once that this happened to. It fell into a cut made by another dozer and, scared stiff, the operator shut the engine off and bailed out. The Cat was still standing on it's dozer face when I got there, but the production supervisor had already pushed some dirt up in front and was getting ready to nudge against a push-arm to get the straight up and down one's tracks back on solid ground. One of the Couch boys took a D8K over a rock fill at another mine and went down all the way to the bottom into a boulder patch. His blade dug in there against a big boulder and the D8 went straight up. It teetered there for a minute or so the operator said, then went right on over onto it's top. Luckily the thing had a good ROPS structure and the operator had his seat belt fastened. It took us two days to get back in there and pull it back over on it's tracks, then we had to pull it out of there. What a mess. I've heard of this happening in other places too from people, but it's rare.
Getting the machine on its' nose as a result of an accident is a world apart from operating it on a vertical plane, which is what your post implied.
You mis-understood what I wrote.
Joe, I think you're guilty of excercising "artistic license" but only for the sake of making interesting reading. Alan, please recognize that's what Joe was doing. There's no reason to have any misunderstanding get in the way of good storytelling. :notworthy Joe, I was told, long ago, by a guy who'd driven trucks in Vietnam, that once someone rolled a dozer down a steep embankment. The US (don't know which service it was), decided it was more trouble than it was worth to try and recover it. Supposedly, the locals went down and disassembled it, and brought it back up one piece at a time. Does that sound like it could be true, or was he BSing us?
Well, I mucked this up!!....
Hi Digger. No artistic license. Lots of facts and experiences and nothing but the straight skinny. The Vietnamese were (are) clever, patient, and persistent. They may not have had much experience with modern equipment, but they did have all the time in the world to sit back and observe, and I think most guys that knew or worked with them would say that. You know, they built roads and bridges all the way from North Vietnam to the southernmost tip of Cambodia and South Vietnam -- with shovels, hoes, rakes, and their biggest dump truck -- which for most of that effort was a soft pliable basket made of Rice straw that held about a quarter of your average wheelbarrow load of muck. They did thousands of miles of these roads like that. These little people also defused our bombs that weighed 250 or 500 pounds, often after digging them up out of soft, deep rice paddies, then managed somehow to pack them up to 25 miles more or less mostly by sheer human muscle power, bury or tie them off next to or in a road, reset the original or install a modified detonator with a trip wire or an electrical contactor of some kind, then wait on folded knees quite some time for some dummy to come along at which point they set the bomb off and then skedaddled. My battalion had a detachment north of the Hai Van Pass rebuilding a blown down rail road bridge. Maybe 15-20 Seabees, a small crawler crane, an air compressor and a generator, a truck or two and a Jeep or Weapons Carrier and a TD15B International dozer. The boys came back to camp one Saturday afternoon and announced that they had buried the 15 in a paddy so deep that all that could be seen was the rain cap on top of the exhaust stack. They had worked for several days that week trying to get it out with no success, it only dug itself in deeper. These guys stayed at the jobsite all week and only came in for one day to do laundry, pick up supplies and food, and drink the Seabee Club dry. Anyway, on the way out Saturday they happened to tell one of the local villages "boy-sans" that if they could dig the dozer out they could have it. Of course our fellas all had a good laugh about that. Imagine, poor ole Charlie getting a heavy and nearly out of sight bulldozer extracted from a bottomless and flooded rice paddy? It was too funny! Then imagine the chagrin and embarrassment Monday morning when they drove back to camp and noticed a big ole hole in the rice paddy where the dozer had been. You can then think how the boys felt when they saw that the villagers had cleared about a square mile of brush and trees from around their village and were still at it going for more with the TD15 when our chaps showed up. Stretch your imagination a bit more and try to feel how mad those villagers were when our crew took their TD15 away from them at gunpoint and took it back to camp to continue work on the bridge! I heard that it got pretty hostile for a while, till the detachment officer in charge figured out that the bridge crew was only using the dozer about half a day, than it sat. So he offered the chief of the village the dozer with our operator for that half of the day, and the villagers would pony up some beer and bananas. Well, there was more, but………. So everyone was happy, and I think this incedent shows that when the little people put their mind to it, there was just about nothing they couldn't do or figure out given some time to do so. I'd have to say that they may well have done what you'd heard. I'll write a piece about their mountain-side logging operations one of these days that was interesting to watch and also scary as all get out. It, again, shows the tenacity of those people.
Joe, I agree the Vietnamese are very intelligent people. I have worked with them many times and I am impressed with their intellect. Theres one that I consider a good friend. There was mention in this thread about backing up a 60 degree incline, well you would need some real special ground to do that. Any dirt I have been on the tracks just chew into it, and of course the down hill part of the tracks do the most digging in so it gets even steeper, reason is the weight cg shifts to apply more weight to the down hill end. I've never been 90 but I bet it was a good 75, that is not bad with nose down, but when standing on one track that is a bit unnerving, don't want to bend the tractor. I rolled a small one back in my beginning days. I though the excavator guy was gona hit me, grabbed reverse over a pile I went, throttle off, and foot on a canopy support and hung on.