Just wondering if anyone has come across a guide/chart stating what are the maximum angles hyd excavators 20t to 50t can work and travel on.
I'm trying to share my experience last time when I was being asked for the same question. 1.Generally speaking, most hy excavator can climb up to 35 deg or so. In catalogue of several machine brands, the maximum angle is stated,but this is I believe only for ideal condition where the drawbar pull is transmitted effectively to the ground surface. 2.There are such conditions where the machine can not climb as stated in catalogue. Machine weight, tire/crawler machine type and ground condition are the main factors when people need to consider maximum angle that can be climbed. 3.The optimum angle can be calculated before the slippage occurs, but I don't want to give the wrong figure since each machine has its own inherent capability and each manufacturer has its own reference + justification for this case. Any additional comments from others maybe?
Put yer bucket out front and start pulling and walking if that dont get you there trade your case in for a deere !!!
Gav, from about 10 tonne up to 400 tonne the travel gradeability is about 70% give or take, 60% at 400 tonne and above until you get to the big girl's around the 800 tonne mark and it's about 55%. Haven’t seen a chart, only the exact spec in the form of "Gradeability (%): 60%" etc Haven’t seen a spec for working gradeability, only a standard known as DIN 24087 which is the "Earth Moving Machinery; Determination of Stability of Hydraulic Excavators" I assume this is due liability if an accident should occur. When travelling up and down grades you should obviously be facing either up the grade (when travelling up grade) or down the grade (when travelling down grade) have the superstructure square to the carbody, travel motors at the rear, do not slew and if necessary use the bucket via the boom and stick to pull yourself up grade, or when travelling down grade use the bucket to float over the ground via the boom to counterbalance the machine. This is of course seen as much less of a risk and liability issue. Of course you already know this since you’ve climbed and ascended benches in a 55! At the end of the day specs are obviously OEM and machine specific, these are Komatsu’s but hopefully should give you a rough idea! weeee
chris I beg to differ, When going down a slope which is near the angle that the machine will slip it is safeist to put the travel motors down so the track slack stays on top, and to keep the bucket on the uphill, that way if you slide, you can just dig in and catch yourself. Keep your boom extended to keep your weight uphill. If you have the bucket in front of you and you slide, the bucket catches, and you slide around, probably flipping and rolling down the rest of the slope... Also with the boom extended down the slope you could transfer weight to the bucket heel rather than the tracks where you need it. And if your playing on slopes that steep, its always best to be tied off to a winch cat.
You both bring up good points but I like to see where I'm going,especially down a steep slope,I'll opt for the bucket pointed downhill, fully opened with teeth just inches above grade,and going very slow.I don't like being a hot dog in my older years anymore.
x2....except the part about "older years".
The biggest factor that no OEM chart accounts for is the body in the seat. If you have an operator in there then the chart will give you a good guide, the operators experience will tell you even more. If you have no operator, only a lever puller....................forget it :Banghead
When i ran a log/dirt Cat 988 loader in the bush i use to go down a few steep hills in low gear watching the gearbox temp. rise as i was trying to build up more air to use the brakes once they cooled a bit i kept the bucket out in front going down so i could ram it into the road if things went south.I think it was the second or third time going down i happened get in front of the log truck when we got to the bottom we stopped by this creek. He asked me why i went down forwards instead of backing down. He said the best way was to drag the bucket/forks slightly as i descended the hill so i could steer. I do that now with this excavator, i wasn't aware of the drive motors should be pointing down hill but as it turns out they are. Funny thing the woods foreman liked the surface of the road, pretty smooth after a few passes. Regards Charlie
Mate, you’re entitled to your own opinions but what I said is standard operating procedure and can be found in the operation and maintenance manual. At the end of day, right or wrong, if it's your machine, you can and will do whatever you want with it. If however it's not your machine then you have to respect the standard operating procedures. Going down grade with the travel motors to the front can be just as bad as operating a face shovel with the travel motors in the face. Not only do the idlers transmit cannon tension and guide the tracks but they play an important part in the shock absorption. Also, what you said about keeping the slack on top is the complete opposite of what you want for maximum traction. Nine times out of ten the surface is going to be somewhat rough and you want the tracks to follow the contour of the ground, if their tight then you’re going to have less surface area transmitted to the ground. We have to agree on something here, and if we agree to disagree then so be it!
Haha, that pic reminds me of me at Wambo, walked the 5500 up the bench many a time, very eery feeling sometimes till you get used to it.
i always go down idlers first, boom stuck out all the way, and teeth barely off the ground, i have heard that stuff about goin off backwards, but how the hell can you tell where you're going, and how are you supposed to work. If you start to slide, you can jam the teeth in the ground and stop, just dont get the bucket to close to the tracks, or if you try to catch yourself in a slide the weight and momentum of the machine will just keep folding the stick in and the your f#)@ed
I always go down idlers first too.
In my 330l If Im climbing a steep grade the idlers are to the rear and the bucket is to the front with the stick extended. Desending a hill the idlers are towards the front with the stick extended about 2/3rds, bucket very close to making contact with the ground, and will if need be. Many of the clearing jobs I do is on ground steeper than a man can walk with out having to hold on to something.
OSHA Excavator Instructions Here is an excellent link to OSHA safety on hills and much more: http://www.oshacampus.com/PDF/Excavator/Excavator_Instructors_Notes.pdf See page 24 for how to ascend/descend hill on excavator.