No new threads today so here is a conversation piece to get it going: Been stripping some overburden at one of our pits. We've got 2 27g's working and for the last couple of days, I've run one and the other one has been running as well, but the operator changes because of other responsibilities, and well, that's not relevant right now. To get to the point: Been push pulling and been varying from front or back depending on who I'm running with. Had a guy that is pretty high on the food chain run with me for a few rounds today. Great guy, knows his stuff and has been around the block. Very successful in this industry at all levels. A field guys' guy (hope that makes sense) I value his opinion very much. This is the first time I'd ever run scrapers with him. I was running in the back and every time he pulled his can out, I was struggling to get the slack out of the bail, which caused me to miss tying on to his cut smoothly a couple times because I didn't want to get yanked. At first I thought it was me screwing up but after a couple rounds I slid my window open to listen to his rear motor and could tell that after he pulled out of the ground, he would throttle off the rear and wait for me to get the slack out and then would throttle up again. ??? This is how I prefer and was taught: As soon as both scrapers are hooked up, lead scraper is full throttle on both motors until he feels the bump from rear scraper shifting into 3rd when he pulls out of the ground. Lead guy then hits his tranny hold and away they go. The slack in the bail between the two is pulled out by the second guy and is his responsibility. He throttles off the rear a little when the first guy pulls up, gets the slack out, and continues the cut. When he parked his machine I pulled in there to tell him about the trouble I was having with the slack. He said that he was taught to do that, to let off the rear motor so the rear guy can do what's called a 'soft hook.' Rear guys lets off a little as well, turns slightly and lets the bail kind of slide down the hook until it's tight. And then as soon as you feel that you are pulling the second scraper, throttle back up again. This theory of both scrapers adjusting their speed for the slack doesn't fit quite right and that's why I thought I'd ask: Which way were you taught? discuss
The way I learned and prefer to do it. Load in second gear. When the first machine is done loading he picks up his bowl and does not let off ether throttle. Back machine lets off the throttle slightly and turns slightly in ether direction to allow the bail to slide onto the hook.
I have found that what Brian has said seems to work best, back machine throttles off and turn the nose to let the bail slide around the hook as this seems to take care of the slack and makes for a softer hook up, and plenty of grease on the bail and push plate makes things slide a lot smoother, Cheers RDG.
I agree with both of you, that's the way I like to do it. I slide the bail down the hook as well, I just prefer to be responsible for the slack. Always in 2nd gear, until the rear guy cans up when he's done and hits the tranny hold. I just want the lead guys speed to be constant that way I can adjust to him and not using both machines to do it.
Yup! Lead man should have the go pedals to the floor at all times!
I also like it a lot better when during the unhooking process the guy in front doesn't throttle off and wait to see me turn to show him my bail before he hammers down to head to the fill or pile. A lot of people do that. Lead guy feels you come out and throttles down to help you get the bail off. I'd much rather the rear guy hit his tranny hold when he comes out, shift into third and bump the stinger, 1st guy releases his and off you go. Both scrapers are coming out of 2nd gear within 2 seconds of each other(ideally about a second), but the rear one shifts first. That way the lead scraper never has to throttle either one of his motors up, he is full throttle all the way through it, even the unhooking process and gets up to speed quicker. Do this all day and you would gain several minutes at the end of the day, which means a few more loads. Of course what you're doing and the condition of haul roads and many other things play a factor in this. You definitely have to be comfortable with the guy running with you. I also know it's kind of splittin hairs but I'm production oriented. I guess another thing I notice and maybe there's been a thread on this already as I'm fairly new to the forum but I'm gonna talk about it anyway. A pet peeve of mine is to see a scraper hand go an extra 15-30 feet loading trying to get that load as high up on the trash rack as mechanically possible, meanwhile most of the stuff he's trying to load is falling out over the side. At some point ya gotta be satisfied with a good load and not spill 4 yards off the side trying to get that extra 1 yard in your can. That 4 yards that spilled is gonna get loaded anyway, whether or not you gave it a trial run through your can to get it "experienced" before the "for real" run of moving it from point A to point B. It doesn't need the practice and I know I'm not alone in thinking that way. I'm sure none of you do that because we're all the best scraper hands in the world, right? I'm talking about those OTHER scraper hands, the ones that work for the OTHER guys. LOL I hope you all know that was a joke and I certainly don't think I'm great. I've screwed up in a scraper more times than I care to disclose. Mostly because I can't. It's been so many I can't remember. One time I had a pushcat operator so pissed at me in my early twenties he wouldn't talk to me for several days. Just hand signals and violent arm movement from the cab of the dozer.
:laugh It does not matter how good you are. Every Scraper Operator makes a Cat Operators blood boil once in a while. I know I have peaced off my fair share.
I did have a little experience a fews yrs back where the scraper I was on was lacking a bit in the power dept compared to the one in front and on comming out of the cut I couldnt get enough speed up to get the bail off as the fromt scraper was always pulling me, bit spooky going down the haul road still hooked together till it finally came unhooked. In the right conditions push/pulling is a very efficient way of moving dirt. Cheers RDG.
I agree that the front guy shouldn't let off except to let the rear unhook after they are both loaded. With him slowing, it is hard to know how much to slow to get the bail tight, and you may end up nearly stopped to do it. If he decides to speed up again, then there is a jerking on the bail that is not needed. Let the rear guy take out the slack and it just seems to go easier.
Never seen or heard of anyone backing out of it to "soft hook". Brians right even the best scraper hands are no good POS at some point, but what can you expect from guys that are just gloried truck drivers?
Isn't that the truth!
Scraper hands are the back bone of a company...
Yair...AustinM. When it started to fall off the low side I was out of there. It was just a rule of thumb though and we were never as production oriented as you blokes.
Yeah, scraper hands sometimes get a bad rap just like truck drivers. It's funny how it doesn't matter how many drivers or scraper operators you have in an operation. If you've got 10 guys in a haul and just one of them is bad or screws up consistently, then they're all bad and grouped into "those damn scraper hands." It's not fair I tell you. I'm in management now and anytime that comes up in conversation with other bosses, (or anyone for that matter) I always stick up for 'em. Truck drivers and scraper hands. I mean if it's the same guy that just doesn't have it, okay. But don't group them all together. Because I think it's tough sometimes to be an operator in a LARGE haul building a fill that has to meet density and moisture. Not knowing what the fill is gonna look like when you get back because you don't know where everyone is gonna dump and have to survey the fill real quick while you're barrelling in there at a high rate of speed so you're not double dumping or (my personal favorite) thinking you need to run to the end of the ribbon only to find out it's already to the end and you've got a choice to dump on top of someone else's or turn around and dump it going the other way. One failed compaction test and a lot of dirt bosses would say "if I could get you guys to just pay attention to what we're trying to do." Second failed compaction test and it's "if you idiots could just get it together!" meanwhile he's spent the last hour putting stakes on the cut 4ft up from the toe of the slope for the dozer hand that doesn't need em right now because he established the 3:1 quite a while ago and was bringing it down just fine. I say that last part from experience. When you see a guy on the ground in the fill helping everybody out directing traffic, cuttin scrapers off to start new ribbons, there is a very good chance he's spent some time in the seat and has himself had that feeling of WWJD? when coming into a fill with that many scrapers running.
scraper hands rule!! i totally agree with the the lead scraper not letting off ever, and only shifting after the back guy gives the courtesy turn, if the back scraper is having difficulty unhooking the lead guy can lift his can higher in the air which lowers the hook, making unhooking easier, as long as you remember to lower your can after the unhook. austinm where in wyo are you at?
I agree with everyone. I always run the rear scraper when push-pulling and the lead always has the pedals to the floor and I let off some what and let it catch and then I drop the bowl. That's how I was taught. Its been about a year since I last ran scraper but if i remember right we just leave them in 2nd the whole time since the lead 27 has more power and slightly smaller tires than the rear 27. So my 27, the rear one, would only get into 3rd and over going down the haul road. Otherwise it was all 2nd.
637slayer I live in Sheridan and Scrub Puller, pardon my ignorance but what does Yair mean?
Been awhile since i ran 27's, but i ran one the other day and when unhooking when im running lead il let off the rear engine for 3 seconds then im back on it. I never wait for him to wiggle his nose, but we have been push pull partners for 5 years, so we pretty much know what the other one is thinking
IM the worst scraper hand on the planet i will admit. but he beatings i took in the seat always involved the lead running hammer down and the rear lifting off to hook then getting back on it.
How is that Dualie? Seems like thats the way I've always run back and worked great when the lead guy did that.
I never let off on ether throttle when I'm in the lead. I hesitate releasing the transmission hold for not much more than a second after my mahine is wanting to grab third. If my machine is ready to shift so is my partners. He should already have taken his tranny hold off and it only takes a second after he grabs third for his bail to lift off.
Front don't let up..I do like to turn out instead of bumping front man to let em know i'm unhooked
My theory is the rear scraper is like the push Cat and should be controlling things once hooked up, sure he has to follow into the cut the lead guy but that is where he takes over, the hook up and disconnect are all his to control and the lead scraper should be consistent with throttle position (100%) and cutting depth then his timing when to let go of the trans hold based on the rear scraper turning out to indicate disconnection. What are everyones thoughts on the bowl position of the rear scraper during the push loading portion? i see a lot of guys will have it a good foot + off the ground and beetween taking the slack out and lowering the bowl to begin his cut the pair can travel a long ways. My way of thinking would be to have it almost skimming the ground when in consistent material but another thing i have considered is the position of the push pad is possibly in a spot that should the ground be a little rugged and you do not have the pushpad in the meat of the front scrapers r send it may have a tendency to slide off as the nose of any scraper rears up when you have the bowl low? Sound feasible?
Gavin84w, I like to have the guy in the rear carry his bowl low so that he picks up where you left off. Ran with a guy a while back that carried it high and as soon as I picked up, I would turn around and watch him get the slack out and then he would turn around and bury his can. Would load like this for a while, working his can and I could feel that near the halfway point of loading his scraper, he would start to pick up and as we traveled a little ways, would bury it again to finish it off and then pull up. Was a little annoying because the momentum was changing and sometimes it was hard to tell if he was really pulling out all the way or not. I'd be thinking, "okay he's done" and get ready to shift out of second, then my machine would bog down again on a hard pull as he put 'er back in the ground. Not a crisis by any means, just a little frustrated. And as we unhooked and turned to go down the haul road, I could look back and see exactly where both scrapers loaded. If it's done smoothly you should not be able to tell who loaded where. So, my opinion in answer to your question, carry it low and barely skim the ground when pushing lead scraper.
That's a good way to drag someone to the fill and have them be very unhappy with you. No two machines are ever perfectly matched, especially when you are mix and matching series (G push pulling with E for example). That and the rear guy usually gets a larger load (front guys job is to make sure he gets a load quick to ensure the back guy still has enough cut left, plus the added weight aids in traction when he's pulling) so it takes much longer to pick up speed. The approved method is always wait for the nod of the rear guy turning out. That being said if you are always working with the same guy/machine you can have it timed pretty good, but you always get that one bad unhook if you start guessing. Back on topic: lead runs full throttle second gear from when he is tagged until rear unhooks after loading. Exception: slopes or you start spinning tires. Rear guy should ALWAYS have slight sideways pressure on that bale just in case. I like to steer right as I have a good view of the left side of the bale however if you're near and edge or on a slope you can steer in the direction you want to keep his rear end up. It's your job to keep the back end of the lead from falling off. http://www.youtube.com/watch?v=Rw6s1r4qp80
I agree with everything advatges said 100%, the back scraper is usually always loaded heavier then the lead guy, if hes not then you have bad scraper hands. I ran with the same guy for 5 years, and we got good enuff that i knew when to throw it in high gear and take off, but running with someone new id always wait for him to shake his nose
No two machines are that far mismatched, even if one is loaded and one is empty. If both machines are wide open, top speed in second gear they are both ready to shift. If your partner misses his cue, does not unhook in time and you drag him all the way to the fill he should mad at you. If you can't tell that you partner never unhooked, you are ether 100% green, not paying attention or need to make a career change because Scrapers are not for you.
Take a 27F and a 27E series 1 and have the F empty and the E loaded and there is a very serious mismatch there!!! Nice vid vantages, but why are the 57's stopping to tag up?
I never said there was no mismatch. I said no two are that far mismatched . Your machine is ready to shift before your engine RMP's are maxed out. So even if one is maxed and the other is not quite there yet they are both still ready to shift. And the second the rear machine grabs third, no matter if it is the slower or faster machine, the bail will lift and you are good to go.
if both machines shift at the same time the bail will proably not have time to lift off!
Read my original post on it again. Hesitate for a second before turning off the tranny hold. Both machines do not shift at the same time.
You obviously haven't had to push pull with unit 247 at night in the pits. Fog so thick you're luck to see your bale, and that giant heap of a 657 was taking a good 17-19 seconds to unhook after he picked up. When your cut ends at the top of a 80% grade ramp down to the fill you better hope your partners off or it's going to be a wild ride around that corner! Like I said you can get away with it for a while, but sooner or later someone's gonna think the guys off when he isn't. Wait for the nod, then upshift.
Well in the roughly 20 years (most of the winters too) I have moved dirt I have operated my fair share of P.O.S machines and in some crazy places too. But I thought we were talking about machines that are running properly and in normal conditions. Obviously you adjust if a machine is not running properly or you are in extreme conditions.
Well said Brian. You don't do stuff like that when conditions don't allow it.
I agree with Brian, it's pretty easy to know when your partner has lifted, and any scraper operator who doesn't look back often at what's happening then they shouldn't be anywhere near heavy equipment. A decent operator will not pull his partner to the fill.
Guys, I hope that you'll accept my apology for bumping the topic a bit, but I'm still not entitled to start threads. My question is directly related to 'which way were you taught' though. When I look at the hundreds of scraper pictures on another web site, I see everyone loading with their aprons running with a lot of ground clearance. However, if you look at pictures on CAT scraper brochures, the aprons are generally pushing dirt. That is how I was taught also (about 45 years ago) and still do it today. But, I don't work for big spreads like most of you do. I'd sure like to see some discussion regarding apron position when loading. How were you taught?
Where I come from (a large outfit with 150+ scrapers) it's a cardinal sin to push dirt with your apron. I was always taught you have to open it up to let it in. But once dirt starts rolling out you need to lower the apron just on top of the pile to catch anything from falling out. If you did it right then your load will "boil" up real fast. Pushing the dirt with the apron is a good way to implode the apron, especially in hard or rocky material.
I do it the exact same way as sprknranger for the same reasons. Adding a little to that. When dirt starts falling over the top of my apron I start slowly lifting it to keep it from spilling over. Then I float the apron once I am loaded. More often than not I don't have to close my apron all the way, the dirt will pack in good enough to stay in with the apron partly open. That makes it like my apron is that much taller and allows me to stack my load that much higher.
Looks like my teachings are somewhat out of date...maybe never correct in the first place. Now I didn't intend to indicate that I pushed any significant amount of dirt...just dragging the loose stuff. If you look at CAT brochures, you'll see what I mean...wish I could figure out how to post pictures...but am totally computer illiterate. 150+ scrapers? Man, I can't even imagine something like that! Must be quite a sight to watch ya'all work.
Wow CAT D7 man, after 45 years still learning with an open mind. That is outstanding and I sure hope when I become that seasoned in life I still maintain a similar attitude. I would be willing to bet even if your way of doing it may be viewed as wrong to teach new operators, you have perfected it and it works well for you. Your apron is likely in very little danger if any as you know your machine, job and material well enough to keep it safe. And you probably stack it up as fast and tall as anyone.
Yea 150 scrapers is a lot, but we never had that much on one job. If you go to ACI grading dot com, they have a picture of a job that we did at ladera ranch CA with about half of the fleet all lined up. Pretty impressive picture. But as far as pushing dirt with the apron, there will be some sluff that builds in front of the apron no matter how good you are, it's just inevitable, but if your plowing dirt then that's a no no. Sounds like your ways are just fine. And I too applaud a veteren operator as yourself being humble enough to have an open mind! Kudos to you sir!
Wow, that is incredible! Never saw such before in my life. Bet guys like you and Brian Hay get exposed to more situations in one operating season than many of us small-job old-timers see in a lifetime. Man, I bet that sounds sweet when all them big CAT engines fire up in the morning...and smell of diesel smoke...man-o-man. Anyhow, I do appreciate you younger fellows not ridiculing an old man's outdated techniques. Tis a real real pleasure conversing with you all. Larry
Geeez I can only dream of work being that good these days. Not one of those scrapers are runnin down here in CA, only about a 10th of those are runnin up in WY, the rest are just sitting or have been sold off. And believe me, I've ran with a lot of guys who claim they have 25 years experience, and 95% of them will never listen to a "youngen" like me. Even when I'm right. Now please don't think I am an expert. I am far from it, and I try to learn something new every time I sit in the seat. I've always said a good operator knows everything there is to know about moving dirt, a great operator never stops learning how to move dirt.
From an elevated view I switch on the elevator , get the bowl full, NOT overflowing, I shut the elevator off just before I raise the bowl, the jammed material over the cutting edge stops the elevator free running in reverse and ejecting 1/2 the load, something elevators are notorious for. useing this method I can leave the apron work to my dear wife in the kitchen. If I cannot find an elevating scraper so I can work by my cantcerous self, the apron open enough to let material in but not out is my system. Tell me, has any one seen or heard of a motor scraper with an auto returning ejector, it would save thousands of $ and a lot of embarring moments if the ejector returned automaticlly after a period time the operator could adjust to suit the job. great thread,
Most elevating scrapers I have operated namely E211/412 & 613B the ejector returns back, just push the lever to the return position and it will return the ejector and kick out when its there. The 2x 627Bs we have at the moment both do it but when its cold first thing in the morming for the first 5/6 loads they will kick out before its all the way back, just got to be awake to them and check the ejector before begining to load. Cheers RDG.
Showpony, do you run the elevator backwards when ejecting dry dirt? The only time you'll see me do it is if the load is sticky wet clay. Never quite understood why most guys run them backwards in dry soil, but then there seems to be way too much that I don't understand. My grandpa had this really cool plaque that read: "too late smart; too soon old" - translated from German.
CAT D7 man; Too late smart; too soon old" So True.... sounds like a great bloke your grandpa
Hi D7, Only if I need to, most often you need to run the elevator backwards if you have over loaded wet clay or heavy soil. its usually a good idea too quit in these conditions as the haul road and fill starts heaving and next thing you've got to put a blade on the job, this is never a good option if you are running one or two machines. Its expensive keeping an elevator turning in any direction. The less unnecessary running an elevator does the more you have to pay the tax man. I have to agree with Lee Too late smart, too soon old, how true. Im still trying to make a living out of contracting so at 54, I can safely assume I'm not too soon old.
We used to run ratchet's on the elevator sprokets, to stop the free wheeling in reverse worked ok if you had semi skilled operators on them but far too often we'd be out there pulling them off to reverse them to remove logs, fencing wire and everything else they tend to run over so we left them off I like your method, will have to keep that one in mind
Hi RDG the only reliable ejector return detents I have found in my limited travels, was on IH and larger Terex scrapers, all the others seem to jump out when cold and hang in when the oil gets hot, making the oil hotter, wasting power, fuel and hydraulic components. To avoid the latter we file back the detent claw in the ejector SCV to make them fully manual, we figure its easier to back up close the ejector and restart loading than replacing pumps, o'rings, hydraulic fluid and relief valves. A fully automated system that used an electro hyd valve controled by an ECU with an adjustable time switch & potentiometers would save a lot of grief many of us have put up with one way or the for too long.