While i search around the globe for info on lots of heavy equipment stuff it is funny to see how the same things are done in different ways. Downunder i could count on 1 hand the amount of cushion dozer blades i have seen and these have all been in photo,s only whilst in the scraper capital of the world,So.Cal you see lots of cushion blades and in France it is also very popular. The closest large population to Australia would have been the Kopuku site in NewZealand through the 70,s & 80,s on a swag of D9G/H machines. That said and with a healthy scraper work environment around here at the moment i am wondering if anybody can provide some details on there efficiency when used in a dedicated pushing operation and the pros and cons as you have seen them. I have a customer that has done it the same way for ever when it comes to pushloading scrapers but i figure surely all these other people around the world can not be wrong and am looking to find out the ins and outs of this system, and if you know of any cushion blades around to suit D10/D11 let me know aswell!, there is always a better mousetrap as they say.
Well Gavin, you don't need a push-cushion type blade to punch scrapers, but they sure help. Pushcats spend half their life in high speed reverse, which is very hard on front idlers and tracks. The less weight you have up front, the easier it is on the UC. It's also easier to turn with less weight and you can maneuver better without a wide blade sticking way out on each side. If you are running multiple Cats in the cut, it's just safer when they have more room to swing one way or the tother without worrying about a 14-16 foot blade sticking way out. It's easier to line up on scraper stingers when you can see better with the C-dozer, it's not so high as well, so visibility is pretty good. The biggest advantage is, of course, that you can run up on a scraper at a pretty good clip and pick it up on the fly without a real hard shock or slam that knocks teeth out and hardhats off, not to mention popping windshields and other "loose" objects off the machines. You also enjoy a big advantage in speed when you don't have to be real careful about punching a hole in a rear tire on the can. Owners get real brassed off about that you know. The narrower blade is a real blessing in that department. You do not have to back up past the scraper as far with the push-dozer as opposed to a regular blade. A quick touch of the brake whilst in reverse to line the dozer up with the stinger, a blip of the thottle (or not) when whipping the shifter to forward and off you go. We used to call this the "Wham Bam -- Thank You Mam" method of operation. The C-dozer frame is stronger and mounts to the inside of the roller frames. I've always found that roller frames seem to have less trouble with cracks and breakage when equipped with a C-dozer. What you do have to watch for is the bottom pins and bearings where the blade attaches to the push frame. They tend to wear rather quickly. Also the recoil springs and their mounting pins and retainers. They tend to come loose and can bust up pretty badly if left unrepaired. Make sure the C-dozer face is lined with a thick layer of steel plate too. It's gonna need it! For additional advantage, if one is running two pushcats behind one scraper, a push-cushion mounted to the rear of at least one tractor is very helpful. That way the 2nd Cat can run up quick and pile on with little thottle blip. If the 2nd Cat happens to have an S or U dozer, it's easier on both operators and machines that have that extra set of springs in back absorbing some of the shock. Believe me, a hundred thousand pound -- 400 horsepower Cat can slap you silly real quick without a push-cushion. But here's the thing. Push-cushions are for serious operations. If you got two or three scrapers roaming around you likely don't really need one. If you have two or three spreads of 631's or 651's with up to ten or twelve pans in each spread, you gotta have them. Speed in the cut, haul road and fill, are absolutely essential for these monsters and every second you can cut off their round trip is money in the bank. Years ago a 651 needed ten loads an hour to just break even. That's when they were selling for $150,000 each. If you wanted to make money with them you had to have a minimum of twelve loads an hour and a ten hour day. It's serious business moving a million yards a month, and push-cushion Cats were a big part of that. When you got the push to load a 651 scraper down to 8-12 seconds flat or less, you were probably in the ball park. I rarely see big scraper spreads anymore, but I've noticed even so, that push-cushion blades are a rare commodity these days. California still moves big dirt, so there are likely more there than the rest of the world put together. It was rare to see the C-dozers on anything smaller than a D9, but I have seen a very few on D8H's and K's. I've not ever seen one on a high sprocket 8. Most of those I recall seeing were back in the sixties and seventies when 621's and 631's were considered big units. I've run the D9's, 10's and 11's with push cushions, and a whole raft of Cats without them. I much prefer those with the cushion. I recall the days I've spent sitting in the cut with the production super and his foremen conniving different schemes to drop a second here or a second there with the scraper spreads. Those were the glory days. As I've written here before, working high production dozer/scraper operations are about as much fun as you can have with your clothes on. Oh, almost forgot. You may have to dig deep to find C-dozers. The used machinery rags and the internet are about as good a source as there is, but get a hold of your local Cat house rep and pester him about them too. Those guys are usually pretty knowledgeable about where is there some iron. Try Quinn and Peterson in California, Wagner in Colorado, Beckwith in Pennsylvania, and maybe Hoss and Zachry in Texas. Balderson (manufacturer) may be able to line you up with some too. Give Modern Machinery in Missoula, Montana a call, they used to have a bodacious used iron pit and Washington (owns Modern) used to have a bunch of the big C-dozers lying around. Kiewit may also have some for sale, and you can call Scott Tuel in Denver on the off chance he might know of some available. Good Luck.
Gavin, I forgot to mention that the old D10 (84W) C-dozers would bolt right up to D11's. Now that's a ways back. Don't know if they would fit current production models.
well bugger me SJ u sure tapped ur fingers to the bone on that reply, good work mate and thanks for the info, cushion blades are VERY rare in OZ. (scratches head)
After I saw your post Gavin, I started typing up a reply, saved it and meant to come back and finish it only to log on and see surfer-joe’s response that basically said everything that needed to be said. I agree with everything he wrote. And gotta admit with a bunch of 631’s and 651’s running around in Australia right now I’m surprised they’re not more common? They’re indispensable on a dedicated scraper spread. You oughta introduce them and slopeboards down under. With lots of scraper work I’m sure they’ll catch on with the big scraper contractors. For a few years Kiewit kept a handful of 651E’s and D11R’s with cushion blades for short-haul rock jobs. They spent a lot of time in the Decker and Buckskin mines, as well as highway work in the upper Rockies. I’ve see a few other D11 push-cats, but not many. Are there many D11 push-cats running around in Australia? Seems most contractors in the states will lean to double pushing with a pair of D9’s or D10’s before going to a D11. Kinda interesting, in well-blasted rock a D11R can have a 651E spilling over the sideboards in less than 13-14 seconds most of the time. A pair of 10’s is usually 3-4 seconds over that in the same material. I know of one D10N cushion blade that’s sitting idle at the moment. The contractor just sold their D10N so I’d be pretty confident that you could get it at a deal. PM me if you’d like more info. I know a couple other people who I could put you in contact with that will likely have, or be able to lead you to cushion blades for D10/D11 machines.
Thanks for the replies gents, a lot of the thinking with this setup down here is it will limit the tractor to what it can do too much and that is what we have to overcome. But if you push scrapers for 90% of your time well you know, what is it you are limiting??!!
Gavin One way to put it is this. If you have a large spread of scrapers, the pushcat should only be pushing. If it is doing anything else, there is a scraper sitting waiting on it to happen. If this is not the case, then it is not a large spread. Push cushions make the difference on large spreads. If you have a large spread of scrapers, there will be dozers that only push, while other dozers do the utility work that is always needed. It only makes sense to me to equip the push dozers with the tool that allows them to produce an extra 10 to 15% production. I have experience both ways, and on a small job, I want my dozer versatile, with a SU blade, but if all the dozer does is pushload, then the cusion is best. Remember, it is not a permanant change. If the job you are pushing scrapers on is done, it is simple to take off the cusion, and bolt the regular blade back on. Here in CA, the scraper spreads each have a fleet of pushers that stays with them. If the scrapers are not working, the pushers sit right next to them. The utility dozers go on and work elsewhere, but when it is busy, they are all going. I tend to look at the total cycle time of pushloading,and mainly the hourly load count, not just the push time. The cusion blade will not speed up the portion of time the dozer spends actually pushing does not change, but the transfer and pick up time drops, for all the reasons Joe mentioned above. When you time the total cycle, and go hourly, you can pick up about 10 to 15 loads per hour. I know a couple of used iron dealers that may be able to help you find a C blade if you like. Just let me know. Good day
pics, anyone??
D10 on left (sideways) and D11 on right (front on) Me and my D11 Cab view of D10 w/ push blade (you can see blade right above walkway) D11 D10 going by my 375
Cushion blades Vs Semi-U blades. Hi, Folks. I have never had the pleasure (?) of using a cushion blade for pushing scrapers so I don't know just how much difference they can make in the hands of a skilled operator. What I DO know is that a good hand with a semi-U blade will pick up a scraper on the run in 2nd gear with NO bump and little if any throttling down. If you want know how, you do the searching 'cos I've already posted about this before, describing the method even unto the point of posting 3 sketches with the description to show how it is done. And I KNOW it can be done 'cos I've done it my own self. What I will freely admit is that cushion blades and rear cushion push blocks would definitely come into their own when tandem pushing. My neck is in pretty good shape and I'd like it to stay that way if I ever get into a tandem pushing situation.
It's not so much you running the dozer you have to worry about. It's the guy on the scraper. An average spread (fleet) is what? Around 7ish scrapers? Each one does something a little different when pulling up or waiting to get pushed. With a large company like ours you are always getting new guys as well. Plus I have a saying. There is a reason why they are running a single engine. Cause they aren't good enough to run a twin yet (or in some cases, ever). The spring loaded blades help keep those "oops" moments from hurting alot (for both parties). Mind you if you try you can still get a pretty good slam out of them. Ahhh the good old days of having scraper wars between the cranky old pushcat operator and the "punk ass kids" on scrapers.
Vantage tes thanks for the pics that 11 looks like a relug would not even be able to be done those grousers are down so much and that blade sure is out there, we have a scraper guy from Decatur out next week and will be going to 2 jobs with D10T/631G & D11R/651E spreads, 16 51,s on this road job so should get some good pics.
Yeah I wonder what the bigshots in my company are thinking sometimes. I mean sure you would have to shut down the 11 for a day or two if you wanted to put new undercarriage, and it would cost alot. You would lose production for those two day. But good lord how much production do you lose when you have almost no traction?? But hey! I just show up, get paid to run it for the day and go home when it's over =)
Gents, what are your thoughts on the reduction in versatility of the machine once equipped with a cushion blade. This is the single biggest reason the operations guys would not fit one as they feel "what do we do with the tractor on a wet day" etc. Sure i understand it will not push volumes of material but it can be used for some general dozing i am sure. Whilst on site last week they had 1 11 ripping and one pushloading the 51E,s and all it did all day was push scoops, prime contender for a cushion blade i feel and when the scraper work slows up just walk the tractor back into the SU blade
Versatility reduction. Hi, Gavin84W. To my way of thinking, there is a substantial reduction in versatility with a cushion balde compared to a semi-U blade, even more so if the cushion blade dozer is bob-tailed or has a cushion push block on the back. The only time I have used a cushion blade, there was not a single scraper in sight. I was working for Abignano on (in) the Eastern Suburbs Railway Tunnel at Woolhara down to Edgecliff in 1973. It was on a D9G that had a Kelly ripper with two extra pockets welded on outside the main centre pocket and carried two picks to enable us to get right to the bottom of the tunnel walls. We were ripping and stockpiling shot rock on night shift for day shift to muck out. There was no way that the cushion blade was anywhere near as productive as a semi-U blade but there just was not the width for a semi-U blade to manoever in a tunnel only 16' 8" wide to get the rippers to the outside edges. Trade-off. IF - repeat, IF - you have enough scrapers running around ALL the time to be able to keep the cushion-blade machine(s) fully occupied push-loading, then I'd say they would be a worthwhile investment. How-wevver, if the dozers are going to be spending much time doing other things, I'd go for a semi-U blade and edumakate the operators in the fine art of picking up scrapers on the run, no bump. Trouble being, you also have to edumakate the scraper operators in how to set up for this sort of pick-up. I spent several hours on 3 consecutive days at the Best Show On Tracks running a late D9G with a semi-U blade and ripper pushing a Cat 660 scraper - I was just a tad out-classed - and brushing up on my pick-ups without the benefit of being able to edumakate the scraper operators 'cos they kept changing. Still, I had a LOT of fun, probably more than one body has a right to but I'm not complaining. It was a helluva show. Back to versatility - if your dozer(s) is/are going to be spending much time doing blade-work other than pushing scrapers or ripping, I'd count the production loss too great to settle for a cushion dozer 'cos the production loss IS substantial. A cushion blade will carry about half the material that a semi-U blade will carry, maybe even a little less, due to both the narrower blade width and the moldboard shape and height. How-wevver, if there are going to be times when you are flat out pushing scrapers and other times when you are engaged in production dozing, it could be well worth considering having 2 blades for the one tractor 'cos switching blades is not a big deal. With a cushion blade, you do not have the benefit of a tilt cylinder and dirt is constantly getting under the outer edges of your track shoes, increasing pin, bushing, roller and idler wear. You also can not stack material anything like as high when stockpiling without trampling on it, which somewhat defeats the purpose if you are stockpiling for loaders to load out. Just my 0.02.
Hey guys, learning alot from this thread. Dont mean to Hijack the thread but since it came up I'll ask. I've been told to avoid pushing dirt other than tidying up the cut with a push block because it wears out the springs faster taking the cushion out. I didn't really understand this to much just because when pushing dirt the top of the blade didn't seem to move much [ie- cushion] alot less than when pushing scrapers. Anyone else been told this or have info?
Pushing dirt with cushion blades Hi, HoJay. Welcome to the forum. As mentioned in my post above, I have never used a cushion blade for pushing scrapers. How-wevver, a little use of one's powers of observation can often bring answers to all sorts of intriguing questions. For mine, I don't think that pushing dirt is going to wear the shock rubbers anything like as much as pushing scrapers. You will get some movement of these rubbers and the associated bolts, etc., even from dropping the blade on the ground or gently lowering it to the ground, without pushing anything. Personally, I see increased track wear as a bigger potential added expense from using a cushion blade to push dirt, as outlined in my post above. But what would I know? I'm just a mug operator. LOL.
Deas is right Gavin, push dozers are for strictly serious scraper pushing only. Yeah, you can do some straight dozer work with them, but it's like having a D4 on steroids you know. I knew a guy that bought a newly overhauled D9G at an auction in Michigan for 9 grand, had it trucked down to his place about 50 miles, did all kinds of improvements including digging a right nice fishing pond with it, then he sold it for 12 grand to some guy downstate. He did well, it took him about three months working part time to do what he wanted, and he came out ahead. But watching him push the muck in that swamp of his was fun and he used to get so frustrated. But he persevered and won the day. I've done some plain dozer work with a push dozer too, and while it's great fun to whack through the dirt, you just don't get a lot done in a hurry. However, it doesn't take long to swap out a dozer blade and arms with a push dozer setup, so that may be the best of both worlds though you do have some extra expense involved, and some capitol sitting for periods of time.
I have a cushion blade from a D9L that may work on a D10. But its in Texas. Not using it any more
I have used solid rubber tyres of a forklift hanging of a chain on the pushblock of TS 14s & 613s, a bit crude but made for alot smoother operation. Simple but effective.
Smoooooooooottthhhhhh. Hi, RDG. Welcome to the forum. Re the solid rubber tyres making for smooth pick-ups, if you learn how to do it properly, scraper and push-cat operators working together, you don't need any cushioning. Having said that, there is no doubt that a cushion push dozer is a big advantage in a scraper spread where all it has time to do is push scrapers. If more than one dozer is needed, at least one of them probably ought to be fitted with a semi-U blade and rippers for clean-up work and softening up as cushion blades don't move dirt well.
Pic's of 10N's with the C blade
D9L/D10N's w/ cushion dozers Mr 992G, Nice photos of the ACI push cats. I was told by some experienced operators,that the D9L w/ cushion dozer was the quickest due to having a shorter undercarriage. The little bit of extra length of the "N" undercarriage cuts down on turn ability. As for a D11N/R with cushion blade seems like a real long undercarriage. Heres a pair each in action Tandem Pushing Scarsella Bros Seattle Wa. Twin D10N w 520Hp each/631E Rommel Const Phoenix Az. Twin D9L w/ 460HP each/ 651E
Even the best operators on the best equipment make mistakes every now and then. That's why I told my scraper operators , "Always lean forward in the seat while you're waiting for the dozer to catch you. If you're laid back in the seat, it's gonna hurt."
im a firm believer in picking up the pushcat, cat scrapers and dozers match ground speed well in 2nd gear, lok it down pull in straight skim until i feel the connection then start digging, trying to do it exactly the same every time, which usually leads to overconfidence on both parties, then the 1 in 200 loads when i clip a rock right before he catches me, going full bore in 2nd gear the collision usually sounds like thunder, leaving me with a sick feeling in my stomache, these are the times i wish we were using the peterson{cushion blade}
Dug Overburden: “As for a D11N/R with cushion blade seems like a real long undercarriage.” A D11 does maneuver a bit like a battleship in a scraper cut, but it has its place. Like I mentioned earlier, utilizing 651’s on short haul rock jobs is a better place for a D11 than a D9 or D10. When loading rock in scrapers, it’s quite common for the scraper to bring the push-cat to a complete stop, and then adjust his can over/under the rock that caused the stop, and then continue moving. If you have a push-cat mate up with a scraper, and push-cat #2 about to mate up right when the scraper brings the whole works to a stop, the resulting “BANG” jars the hell out of the operators and often results in broken cutting edges or peels off frogs or router bits. In rock, it’s better to just run one large push-cat. DO: “the D9L w/ cushion dozer was the quickest due to having a shorter undercarriage.” In dirt, I agree that it’s hard to beat a pair of rebuilt, well-maintained D9L’s with good operators for double pushing. The shorter undercarriage does increase tractive effort which facilitates better ripping ability and greatly increases maneuverability in the cut. Thanks for posting that photo of two of RumCo’s push-cats. I don’t think those are 460hp machines though. Most, if not all of RumCo’s D9L’s have been rebuilt with C27’s under the hood. Hoss Equipment in TX started rebuilding D9L’s with D10 motors to cater to the scraper and mining markets that liked the D9L for its ability as a push-cat or rip-cat. Monks and Rummel quickly followed suit doing the same, and I’m sure other contractors have done so as well. In my opinion, twins are superior to singles when working in straight dirt. But when running singles in good dirt, a pair of over-rebuilt and well maintained D9L’s will just barely edge out a D10T push-cat with similar operating costs.
Question SurferJoe, I have never double pushed. I have seen it done, the machines had the C-blades and rear cushions. I wonder how do you double push without cushions on the back?
If you jump over to the Quads thread in the dozer folder you can see a real treat of 3 D10T pushing 57E,s and the tractors are all equipped with rippers and have had a push block installed but it is not cushioned so only the C blade to absorb the shock there.
Thanks Dug, I have also been told that the original D10 is a quicker push cat than D11's. The D348 engine in the 10 revs up quicker than the 3508 in the 11. The operators that I talked with said the 11 had too much lag time when going from reverse to forward due to getting the engine back up to high idle, thus made trying to pick up a scraper a little bit more time consuming. Would like to here from someone if they run a new 11T how it's power is with the new engine? I got to get my 35mm pic's transfered. Have some of Washington's D10 and D11 push cats in Vegas from 96. Worked well with 51's and 57's
Tripple Pushing with (3) D10T's Looking at the photo and knowing how spreads run, I would say this is not full time tripple pushing. It is not necassary, they probably just once in while get 3 tractors hooked up when it works out. The 3rd tractor could not be connected for more than 3 seconds, as the other two are only pushing for less than 10 seconds hktom I borrowed your photo for this thread. Dug
i was wondering the same thing, seems like an ideal setup for a scraper, downhill taterdirt, seems like a 57 could load that stuff fast on his own? i had another question too, i always thought that the block on the backside of the rippers was for pushing only when the rippers are in the ground, because if your pushing while they are up seems like your pushing against the cylinders?
The cylinders in that set up will be taking a bit of load but the key is to set the ripper to the right height to minimise it. You can see on the first 2 tractors how much lower the ripper is positioned than the third tractor. You pretty much need it in the same position as ripping wherebuy the ripper table is parallel to the ground and the ripper box just cranked back a little from vertical. That way there is pretty much a straight line of force being transferred through the box to the table to the chassis. You can see they run the shanks in the bottom hole but even in that dirt dragging them a little while push loading would not matter.
thanx for the explanation, learn something all the time.
10T pushers
Kiewit had some 651E's stripping a quarry near here a few years ago, using a D11R and a D10N together push loading. It didn't take much more than a scraper length to put a cube in the bowl. What I thought was dumb was, when the 651's would get down to the waste area, they would spend several minutes banging the pan on the ground trying to get that cube back out. Often they would get hung up on their own load, they had a D9L working the fill, which had to come over and push them off. Sure, it got the cut out in a hurry, but negated any time advantage I could see to using that much pushing power. Gain on one end, then lose it on the other. Kiewit's method seemed to be, get in front of the cat, dig as deep as possible, and get out. Which might work in California soil....but not so well in Nebraska! alan627b
Hey guy's I know this an OLD thread, but I found it an thought it was interesting. I was alway's under the impression that the cushion blade was made the way it is, was to keep the force of double pushing on the frame of the dozer's instead of on the track frame. Isn't that why the blade mount's directly to the frame instead of to the track frame like on all other blade's? I was told it take's the force of two dozer's off the pivot shaft, which isn't designed for two dozer's worth of power, any truth to this?
Yeah . . . Okay you call them things "cushion blades"? What were the things Hamblin had at Fairbairn, we used to call those nines "pigs". From memory they were mounted on the mainframe and were a bit like the push-pad on a 627 . . . what are they called? I havn't seen one for yonks. Cheers.
The pushin-cushions were designed mainly to allow the push-cats to fit into the cut behind the scraper. With outside roller frame mounts, the push-arms would stick out too far, besides which having one or more push-cats (4-800+ HP) behind the first one tended to be very hard on final drive bearings, seals, and gears on the older Cats. High sprocket tractors do not have that problem, but still need the side clearance in the cut. By the way, Old D10 84W push frames also fit D11's. So far as I remember, there is just about nothing more fun to do than operate a good push-cat in a double or triple push configuration with a herd of 651's out in front in good material! Some would say as much fun as you can have with your clothes on!