Operating a dozer on slopes

ernemats · Mar 17, 2003

How steep a slope can a dozer work on safely? I have seen dozers operated on slopes you can hardly walk up. I realize there are a lot of variables to consider, types of machines, operator skills,etc. Any input would be appreciated.

Dozernut · Mar 17, 2003

There are too many variables to give you a set answer. A lot depends on the condition of the soil you are working on. Working on banks or dams, you have to be careful that the embankment does not shear off from the weight of your machine. Several experienced operators have been killed from banks shearing off. Never work a slope crossways, always work it head on. If your inner voice is saying don't do it, pay attention.
Some soils will pack well and some won't, especially sandy soils. This will impact the amount of slope your machine can safely handle. I know this doesn't answer your question, but every job is a different situation and there is no set limit on slopes.

Egon · Mar 18, 2003

If working a dozer on slopes It's best to watch someone with lots of seat time do the work. Proper ROPS and seat belt too. If the ground is frozen it could get real touchy. The condition of the growsers is also a factor.

I've seen a few go down a slope while the operators were making the initial road backslope cut on a side hill. The operator was very skilled and always ended up going blade first down hill. Another 9 with winch was required to get him back up as going down and around was not an option.

Egon

MarkV · Mar 18, 2003

Ernemats asks an interesting question that I have always wondered. Dozernut I am sure is right on with his explanation though I still wonder if there are some general guidelines. It is generally excepted that compact tractors are tested for a 20 degree side slope and 15 degrees is the reasonable working limits with the variables Dozernut mentions to be considered. If a CUT will work 15 degrees, in many conditions, will a dozer work 25?….30?…????

I am reminded of a story that kind of fits in with this subject. A couple of years a go we had a fire on the mountain where our weekend home is. The fire burned about 250 acres before forest service could get it under control and left for the day. During the night the fire jumped a fire line and started slowly heading down hill on our property. The forest service came back and used one of their dozers to cut new breaks and backfire the slope. All was well.

One of the firebreaks this guy cut was from an old logging road about 200 feet behind and above us to our parking area. The slope is at least a 45-degree angle with a great deal of rock. Where the hill meets our parking area it is a 12 – 15' vertical rock drop. The operator took a look at the drop, put his seat belt on for the first time that day and drove straight over with his plow down as a brake. With his blade flat on my parking area the rear half of his tracks come about 2' off the wall and I thought he was going over. The dozer settled back down against the wall sitting near vertical and he started crabbing his 6-way blade and walking the dozer down into the parking area. IT WAS AMAZING!!! This guy had been with the forest service for over 30 years so I guess he has done it all and has enormous amounts of experience. His only comment was "Guess I was all prayed up today."

Not that there is enough money in Fort Knox to get me to do something like that, I was impressed to see what could be done. This was a JD 450C dozer with a firebreak plow and 6-way blade.

MarkV

ScottAR · Mar 18, 2003

Most specs for dozers I've seen indicate **under ideal conditions** max working angle is 100% grade or 45 degrees. As Dozernut has already pointed out, ideal conditions rarely exist in the real world. Soil type, compaction, and ground debris can alter the safe working angle. Experience is the only way to gauge the safety of slopes and even that isn't absolute.

MarkV · Mar 18, 2003

Thanks ScottAR, do you know if that is a running cross slope or perpendicular to the slope?

MarkV

ScottAR · Mar 18, 2003

45 degrees along the slope. Up and down is a steeper angle though I forget what it is.

Taylortractornut · Mar 18, 2003

When i was 5 or 6 dad worked along time as a foreman operator for Wright Brothers Construction and they had a big job cleaning rocks and trees off a slope. The slope was too steep to stop on once yo broke over the edge it was a commitment. They let one dozer at a time go down it and when it go to the bottom it drove around to the otherside off the hill to go up an access rod. One real young operator went down it and raised his blade in the air like youd take out a tree on the ground instead of using dad and others advice of keeping the blade down and use gravity and the machine to push the root ball out. when he contacted it the tree fell over and the root ball got under the skid pan. dad said th dozer made about 13 rolls on its side. It messed the guy up pretty bad he had his belt on but he still took a beating. They rolled it over with a 245 and put a mnew muffler and changed the oil in it and put it back on the hill in the same day.
Dads tken i D8 hightrack on slopes id be afraid to take a little machine on. Ive gotten better at running on a side slope after working directly with him. Before my time when the Tenn TOm water way was built through here they had a few fellas that dressed slopes with D4D and such with swamp kits they had 36 inch wide pads and a straight blade with tilt. THe blade was 10 feet wide and abot 12 to 18 inces high. Ive seen pictures of them hangin on a slope id be afraid to look down lol.

jtn · Mar 18, 2003

I have taken a dozer up and down a 35° slope, and up a 40° slope. I know it does not sound like much but let me tell you it felt like it was vertical.

The most impressive side sloping I ever whitnessed was a guy working a D8R with an A blade. The A blade was the only thing holding the machine on the slope. The uphill tracks were barely touching the ground. I watched him work the slope in 1 direction and then turn around on the slope and work back the other direction. It was more slope than I ever want to work across.

JT