Bought this old D8H and am confused about which blade it is. U-blades (if this is one) are hard to identify. Is this blade a Full-U, Semi-U, U, or what??
That's a U dozer
Well D-Pete, "How are those types of blades for grading?" They have never been popular in Louisiana. I wonder why. Seems like something that could really save an U/C (reduced machine reverse time) by the 2X blade carrying capacity. What is the ratio of Full-U blades to straight blades on D8's where you reside? The only place around here that would use a Full-U would be a mine or a mill..... never seen one in the dirt. Why?
They are designed for bulking material, you can picture how close the end bits would be to the tires if pushing a scraper or any other machine that needs pushing. A semi U is more versitile for that reason. All depends on how you're going to use it. Out of the 3 D8's I have owned none have had a U blade. Best of luck.
I've read about the possibility of cutting a scraper tire with the U-blade, as per the Cat Performance Handbook, but I don't fully subscribe to it; I think that a full-U blade could be almost as good as a "CU" blade. Here's pics of both a D9G (94,000 lbs) with a "CU" blade for pushing scrapers and VERY limited cut maintenance ability and a pic of the D8H w/ large 4 bbl ripper rack and giant U-blade... allegedly for "load and carry" bulk pushing. I haven't yet weighed the D8H, but I would bet that it's almost 90,000 lbs, as equipped. That would make it a contender for push-cat duty... with the Full-U blade adding much needed weight! Here's what I come up with to share with you, for discussion anyway.
That last pic shows the depth of the Full-U blade for the D8H, and how it is less than 2 ft in depth. I think that it would be hard to hit a rear scraper tire with this blade, unless.................well ya know..... astronaut operator. You ever heard of anybody hitting a scraper tire with a U-blade?? I guess you could hit a scraper tire w/ "ANY" blade, given the right conditions, but hmmmmmmm.
Here's a couple of the old D8H w/o blade.
Try again.:beatsme
And here's what I'm planning on pushing; my old TS-18's. With the tape measure pictured, I'm measuring over 5 ft from the push-block face to the rear of the scraper tire. That would net over 3 ft of safety distance; I think that be pretty hard to encroach on, as a dozer operator. What are your experiences?
It isnt really the straight on pushing where you are gonna run into trouble. Its in tight areas, wierd angles, uneven cuts and the like. That 3 feet might seem like alot of clearance, but when your push cat is sitting at a 45 degree angle to the scraper, its alot closer!
Nice looking 46A Jason, I thnk you'll find the dozer cumbersome in the cut. Give it a try and if it causes trouble you can pick up a semi U, there should be plenty of them around.
Jason I have heard all the same stories, but I had a D-8K with a U dozer, and I loved it in the dirt. The worst problem I had was penetration in hard digging. Otherwise it was great. I pushed many scarpers with it as well, and as long as you pay attention, it is fine. I liked it for clean up too, as the wings kept the windrow from spilling out so soon, so you could clean up faster. It is harder to see the edge, but I go by feel anyway. It is also easier to roll material when mixing or drying. The wing helps, almost like a little bit of angle blade. I also had a D-9H with a U blade, and spent 2 summers pushing scrapers with it. It was a little closer, and you had to be even more careful, but I never had a problem. I ended up running it because the boss at the time said he would fire anyone who cut a tire, and everyone else refused to do it. I knew my skill, and did it without complaint. Not saying they don't have their drawbacks, but I never had a problem.
I see your point, but with the advantage of a super-wide U-blade w/ hyd-tilting ability, the cut should be able to be maintained easier....... much easier than the D9G with the "CU" blade.... that thing isn't worth a damn at dozing maintenance; no tilt, no effective blade width, rocking about on its lower hinge.... it's pure horror at maintaining a good cut area although I bought it purely to push pans; not to mention that it's a dream to mobilize with it's compact, narrow stance. But, I'd imagine, that if the scraper hands start messing up the cut, you can't fix it w/ the D9G and "CU" blade. On the other hand, the D8H, w/ it's monster blade could do almost as good a job as a push-cat as the D9G, and 5X better at maintaining the "cut area"....... This is what I'm imagining anyway, but field testing (next month) will quantify the argument of both. I'd imagine that the old D9G will load the scrapers faster, but keep a nasty-looking cut. The D8H will load the scrapers a bit slower, but keep a nicer-looking cut. I enjoy the discussion; keep it coming.
Thanks D-Pete. The old 46A is my favorite dozer of all; and bought it right; new U/C, new engine, finals inspected, and tranny resealed...... all for under 30K! And Jerry, I think that I subscribe to your experience. I just don't see anything bad happening with the wide blade hitting the rear scraper tires; the dozer operator would really have to be a "ZERO" to create an incident. I understand Caterpillar's marketing strategy with push-blocks, and the "CU" blade; it makes sense to get the push-cat narrow, but let's face it, a D9G is not exactly what I'd describe as nimble, and the "CU" blade may be on the "lite-side" of usefulness. I replaced all of the round push-cushions in the blade and you still have to almost stop when making contact with the rear of a scraper. I was running the 9G, w/ new cushions, and made moving contact with a stopped TS-18, and believe me, he felt it. I was surprised; thought the cushion blade would be more effective than it was. Disappointed, I was.
Jerry, Doesn't it stand to reason that a U-blade equipped dozer would require less than HALF the reverse operation as a straight blade equipped dozer... in order to get the same amount of work done?... I mean if the blade has 2-3 times more capacity? (I'm thinking more like 2.5- 3 times LESS reverse operation, thence 2.5-3 times less U/C wear) Heck, I'm considering installing GPS onto the D8H, albeit passive GPS w/o full automatic blade control; With its wide blade, it'll carry almost 3X the amount of material as a straight blade. I don't know why the full-U blade is not more popular around here for big dirt projects:beatsme...... but I'll be the guinea pig. Old iron will never die!
Jason The U dozer doesn't push as much more as you are thinking, though how much really depends on the conditions. I have measured piles before on D-8's equipped with SU and U blades to get the answer you are after. The SU, in the average conditions I was in, and without slot dozing, would push about 11 yards loose, while the U blade would get 13 to 14 yards of loose material. That is still a lot, and when you can slot doze, and go downhill, it gets even better. You cut reverse travel by 30% or so, but there is a slight downside that the Idlers and front rollers wear slightly faster due to the weight of the U blade. It weighs about 4,000# more than the SU. I think you will like it. Not as much grunt behind a scraper as your D-9G, but as you said, much more versatile.
I guess my mind is tainted from reading the Cat Perf Handbook #'s. On page 1-36, it shows (3) blades, 8A @6.09 cubic yd, 8SU @11.4 cubic yd, and 8U @15.3 cubic yd. Though, these are the blades offered for new machines, it is the basis for my reasoning. But I believe you, Jerry, in the 30% capacity increase from an old SU to a Full-U blade. But there is more to my thinking. I often tire at watching even seasoned dozer hands only load 1/3 their blade widths, straight blades, and walk that little hat-full of dirt into position. They aren't carrying anything but a couple of cubic yds. They have to make many passes to get anything done. It just seems to me that the wings would allow exponential more production, and particularly "reverse time" We currently own about (7) or (8) D6M-size dozers with PAT blades.... because that's what industry has always used over here. But I don't think, after examination, that it's necessarily the smart way to work. I think that we could maintain the same fill area, with much less congestion, with the use of a single D8H- Full-U blade arrangement. A fill area supplied by dump-trucks or scrapers that used to require (3) P.A.T. D6M LGP's, could be handled with the swap to (1) D8H with a full-U blade and passive GPS. That's my belief anyway. And it's harder still, to put a production # to the time saved executing "clean-up" as you described.... that's even more time in "Nonproduction," fuel-waste, and U/C wear. Thoughts & observations??
Jason Sounds like we are thinking alike on this one. You are right on the fill maintenance. You could replace several of those small dozers with one D-8, and I love the U blade doing that work especially. The 8SU to 8U comparison out of the book is representative. They are a little more than for the D-8H, because the blade on the H is a little shorter than the K blades. The new ones match up well to a K, but a little bigger than the H. I like the little dozers, when used in the right place, like detailed finish work, but if there is enough room for it, give me a big tractor any day. Also, you will get more life out of a D-8 working easy than a little 6M working its tail off to keep up.
Since you live in La! mud might be your biggest problem for a U dozer.It's made to carry more dirt,but when working in the mud you will find out it'll be more then you can handle(traction) comes to mind. The dryier the material the better it will work and you will like it. 13 to 15 yard of mud is tuff to move in soft conditions.The U will fill up quickly and hard to get rid of quickly. Anyway for me and here the semi blade is the blade of my choice.Goo luck:usa
Those are valid observations and I have to remind myself that you have a good point, Constructo. But I doubt that I'll be working in the mud very much. La. is stereotyped as being the mud capital of the United States, and it is, south of I-10. But anyway north of I-10, the ground can be pretty good. All of the land clearing for farming was done with D-7's, D-8's, and to a lesser amount D-9's. So, big dozers can be utilized. And anything that can be dumped out of a bottom-dump should be able to be manipulated by a Full-U-blade.... wouldn't you think? And how can I expect the blade to work in silts & sands? And Jerry, I agree with you. In our field conditions, a little D6M LGP (PAT 13 ft wide straight blade) has to take at least (3) stabs at a big conventional-truck-load pile of dirt; that would be reversing the machine (3) times, where the D8H should be able to just walk it out in 1 stab, reverse only (1) time, and leave very little windrows. Not to mention the chance of a serious accident caused by the congestion of the (3) little D6M's... working their butts off; especially in reverse! (I'm just thinking) I really think that I could replace (3) D6M LGP's with a single D8H. Is that wishful thinking our logical?
Jason, just took another look at your dozer pic. Looks like the bottom eye pieces where the push arm pins to the face are worn pretty bad, would be easy to weld on a piece sitting as is before you put it together. Just a thought.
Must be where the bracing pins up, my bad. Is that a Cat dozer or Balderson?
A u-blade on a CAT D10 is rated at 23 yards on a flat without slot dozing. It's deffinately a hogging blade but with duel tilt to turn the corner bits up a little, it can smooth grade nicely. You would want to be set up with more jobs requiring a lot of dirt moved to make the ware and tear of the heavier on the front idlers and rollers worth while. Happy dozing.
Jason M , so if you had to scrape some mud off the road why use a flat shovel when you could use a scoop shovel and get more done ? Better yet use a snow shovel , twice as wide so should get done in half the time right . Point is everything has its advantages in particular applications . We run d-9s with 9U , 9C , and 9SU blades and I can't imagine using a 9U blade to push scrapers any more than using a 9C blade to production doze spoil piles ,besides the occasional very short term exception . 9SU can out work 9U bye the end of the day as soon as the push starts to get less flat and there is some shaping being done or more turning involved (can't hardly do anything but doze straight with full blade on 9U). Also 9U is a little harder on trans./torque and burns more fuel . My suggestion would be go work it with what you have and with all the old d-8's parted out you could pick up a SU blade for cheap . Then you can just switch blades as needed to get the best production possible in any application . Good Luck !
I really wouldn't know if the blade is a Cat or a Balderson. There's no info on the blade, no tag, no #'s welded that I can see. But the padeyes are indeed worn; was planning on welding 'em up w/ my MIG. I'm certainly going to do some testing.... and see for myself, the advantages and disadvantages of the big U-blade; just too wet right now to do it. I'm just getting excited about testing and wanted opinions before I test. Maybe pick up a few things. Anyway, I've learned something. Really would not have expected the front idlers and forward bottom rollers to take a much more significant wearing than the rear.... but it certainly makes sense. Like I was taught at an U/C class. It takes (3) elements for wear to occur: A certain coeff of friction, speed, and pressure. Remove any of the three variables and wear cannot occur. Add any more to one of the variables and wear increases. Interesting. So, slow down, keep the drive loads down, and stay out of the more granular, rocky materials. That big, heavy U-blade, by virtue of its weight, will certainly create more of the "pressure variable" particularly toward the front of the dozer :usa
Old thread. Well Jason M what was the results Pj
Yair . . . old thread but interesting. I've said it before on here . . . bulk pushing means slots and once you're working a slot the style of blade becomes of less significance. We had straight angle tilt bades with mesh hungry boards on nine g's and they would push more than floppy old semi-u's every day. We were taking out four foot floors and the wider angle blade slots were more productive because there was less material falling into the walking gear. Cheers.
i personally think a U blade on an 8 is a little more then it can handle, I've never seen a newer 8 even setup with a U blade
With the stinger on the ts-18s as far out as it is you probably wont have much trouble cutting tires. I would much rather have the U-blade than the push blade unless all you did was push scrapers. Like DPete said though, the semi u would be my preference for all around use. Less leverage on the tractor when pioneering, production dozing in a slot is 6's, cutting hard material is better with the semi u, but cleanup is a bit faster with the full u. Depending on your area the full u may require a pilot car for transporting where as you may not need one for the semi u. You have the full u though so if it were me that is what I would use. I just realized how old this thread is, guess I soulnd a bit thick between the ears, eh? Sorry folks.
Use D7 with "S" blade here pushing Cat 80's behind D8K. Got to be careful with this one or blade can get into tires. Don't have a "CU" blade here but I can see where that would be the best for pushing.
yeah Jason, did you blow some smoke??