Hello, I'm working with a junior mining company in Mexico. At our mine we have a local fellow working with his D9G at a flat rate per hour. I recently ran some numbers and found that we could rent a D8T from the local CAT guys for (all told) a bit less than what we are paying for the D9. So my question is: With all things being equal (Operator, type of work, etc.) would the much more modern D8T outperform the D9G from the sixties in terms of work done per hour. Despite the fact that it is in pretty good shape I imagine that the D9 must have lost some horsepower over the years, and it just doesn't seem to work as fast as the more modern dozers that I have seen in action. Anyway I know that there are a lot of variables to consider here and I'll answer any questions that you might have to the best of my ability. I'm just looking for a general ballpark up-or-down. Thanks.
The 8t would definetly out work that 9g but for priceing did you include fuel and wages?
Thanks for the response. Yeah, that 8T is a little cheaper on a monthly basis including fuel and wages. I used 13.5 gal/hr when I did my calculations for the cost of the 8T, which I've read would be at the top end as far as fuel consumption would go. How significant a difference might I expect to see?
What kind of work is ythe dozer doing? Depending on the application, the difference would change, but I would say the D-8T will outwork the D-9G in nearly all applications. They put the power to the ground much better than the older machines. The D-9G may not have lost any power due to its age, and on paper has more horsepower and weight, but the T will do more, and do it more reliably than a 40 year old D-9G. I can keep up with a D-9N with my D-8T in most applications.
I'm not actually an operator, but I'll do my best to describe the application: We have the D9G lowering a hill from the top down to get at iron ore veins. Its doing quite a bit of pushing and some ripping. I suppose the most taxing part of the job is ripping through some small iron ore veins, which it doesn't seem to have too much trouble with as the host rock is quite fractured and not very hard. Any deposits we encounter that give the D9 any trouble have enough economic value for us to bring in the hammer and excavator to recover the minerals. So anything overly difficult to rip, doesn't end up getting ripped. Hope that all makes sense. Thanks for the response.
I think the D-8T will be a good choice. In work like you describe, it will likely outperform the D-9G by 10 to 20%, and I would expect 12 to 13 gallon per hour fuel burn. If you have a good operator who pushes as hard as he can all day you may even hit 14, but not likely. IMO, The D-8T will rip as hard as a D-9G, due to the suspended undercarriage it puts its power to the ground better than the rigid track frame on the D-9G. The other thing is you wil get more out of your operator in all likelyhood with the comfort of the newer machine. A comfortable operator does not have to stop as often.
How many gallons an hour is the current D9G burning ..? You say the rock that the tractor has to rip is "fractured and not very hard". That doesn't sound like iron ore to me, even if it's only veins of it, unless it is close to the surface and heavily weathered. Will the rock get "less fractured and harder" the deeper you go..? If that is the case do you have any idea of the seismic velocity of the rock, or could you find out from your geologists..? Is the ripper on the D9G fully adjustable..? In other words does it have 2 cylinders for ripper lift and 2 to change the angle of the shank..? If the 9G has a simple non-adjustable ripper then a fully adjustable ripper on an 8T might rip even better than a 9G. Make sure that the 8T, if you actually rent it is equipped with a single-shank adjustable ripper, not a multi-shank. A multi-shank ripper would be no good for what you want to do, and don't let anyone convince you that removing 2 of the 3 shanks from a multi-shank ripper will turn it into a single-shank ripper. It won't ....... Agree with others that the more modern tractor would get better performance just by making the operator more comfortable.
Thanks for your time. The D9 is burning 10.5-11.5gal/hr. It has a Multi-shank non adjustable ripper, and they just remove shanks when they need to. As for the rock, any sizable veins of Iron Ore get removed by an excavator and a hydraulic hammer, so the dozer never has to rip through any actual mineral veins that are greater than foot in thickness. The host rock that surrounds the mineral (what the hill is primarily composed of) is not very dense, so I would imagine (though I do not know for sure) that it's seismic velocity is quite low. It is quite crumbly and, because the region has seen some significant seismic activity, the whole hill is shot through with fault lines - so it's all sort of fractured already (if that makes sense). What do ya think?
A D8T with a single-shank adjustable ripper versus a D9G with a non-adjustable multi-shank ripper, even with one or more shanks removed - no contest. D8T wins hands down .......
ACR I think, as you say yourself, you know little about running tractors. My advice to you, would be, keep your local man who knows what he is doing on his D9G or you will find out how much it can (shouldnt) cost to run a D8T. He should be the best judge of what tractor and ripper configuration will work for you. Im not a plumber, but if I hire one, I always pick the guy with a leather tool bag, and a work truck that is at least 10 years old. That way I know he knows what he is doing, and my problem will be solved at reasonable cost. Gear helps but it will never replace skill.
Hey, thanks for the advice. At the end of the day we will end up owning a great deal of equipment, so we will have to tackle that learning curve anyway. We can hire the appropriate people without much trouble. Furthermore the contract with the CAT dealer covers all scheduled maintenance and all repairs that may be required. So, a big portion of why I am investigating this is solely to evaluate which tractor boasts a lower cost per cubic meter of dirt moved. In any event, your point is well taken.
One thing to keep in mind on this front, is that the repairs will only cover what would normally be warranty. If it's damage, or caused by operator error, you'll likely pay quite handsomely to repair it. The dealer will probably insist on doing the work themselves, and charge you what they feel is reasonable, including lost rental time. Just something to think about.
A D8T may be faster and more manouvreable than a D9G but as for ripping in hard going I'd say the 9G would come out in front.
Remember ACR if it aint broke dont fix it.
For ripping, I would suggest the D9G. The superior weight alone makes it a better choice. All the high-sprocket D8's I have observed and operated, were light on the back end and did not rip hard rock worth a damn. The newer D8 is definitely a better and quieter ride, operator wise and it is somewhat quicker. If you can, I'd suggest that you request a demo D8T from your local Cat house, or maybe rent one for a month if you can and compare the two machines side by side. Good Luck!
Joe First I will say I have a lot of respect, and value your opinion highly, and have rarely if ever disagreed with you. That said, I have to say I disagree with you on this one. I have spent a lot of time on a D-9H, not a G, and I have more time on D-8R and D-8T. I have been looking for weight of a D-9G, outfitted with rippers, and have results ranging from 84,000# to 90,000#. All my Cat performance books are packed up, so I can't check there. My D-8T with SU blade and multi shank ripper is just a hair shy of 90,000#, so I am not seeing the weight advantage of the D-9G here. In addition to this, as per my comment above, the traction of the suspended undercarriage, especially in rough rocky ground, is much better due to keeping more track in contact with the ground, wrapping around obstacles instead of pivoting over them like the ridgid frame D-9H or G. This, in my opinion, overcomes the "lightness" as you say, in the rear of the high track machine. In my opinion, for what it is worth, I feel I could rip just as much with the D-8T as I ever could with the D-9H. The D-9H was years gone before the D-8T showed up, so I have no direct on the job comparison, just my memory and experience to draw from. I was just on a rock job last month with the D-8T, and the conditions were similar to what ACR described. I had no trouble ripping and dozing what was ripped. From my memory, the D-9H I used to have would not have done any better, and the D-8T gains a lot with the manouverability, not even counting the speed advantage. It rides better with the suspended U/C, so the rough ground is not as hard on the operator or the tractor as it is on an oval track machine. With my argument made, I completely agree that the best proof would be to keep the D-9G on hire, and rent the D-8T for a month and let them work at the same time in the same conditions. I doubt that a demo is likely, but a favorable rate for the first month may be possible. Also, if ACR is going to end up buying, credit towards the purchase for at least most of the rental is likely possible to be arranged for. As above, good luck, and please keep us posted as to how it works out.
I think what we need to bear in mind is that the current model that replaces the "old" D9G is in fact the D8 range if you are looking at BHP & drawbar pull. Don't lose sight of the fact that when the D10 became the D11 everything else from D9 upwards was upsized. The current D9T is almost 500 BHP compared to the 385 of the D9G. Like JDOFMEMI my experience goes back to D9G's 8H's, etc, and from there to the present day T series tractors. The amount of work the new tractors can do is amazing compared to 30 years ago when the D9G was in it's heyday. Regarding weights D9G - 385 BHP weight around 75-80,000 pounds equipped with a ripper, drawbar pull about 100,000 pounds maximum. D8T - 305 BHP and approximately 83,000 pounds equipped with a single-shank ripper, drawbar pull around 120,000 pounds maximum. Consider the added traction of the high drive and suspended undercarriage, as I posted before it's no contest. D8T wins hands down. I agree with other posters though, the best comparison would be to do a deal and rent the D8T for a month or two and run the 2 tractors side by side. Last but not least in order to be efficient the D8T has to be equipped with an adjustable single-shank ripper, not a multi shank.
Acr, so the dozer is flattening the mountain as he goes and how far is he having to push spoils? The answer to your problem might be in efficiency rather than equipment
As of right now he doesn't need to push very far, maybe.... 15 meters. Of course that will change as we move lower. Thanks for the responses everyone. In the end we probably will get a direct comparison, and if we do I will be sure to report back. I'll keep checking the thread for any more advice that pops up and answer questions that might surface. Appreciate the time.
I've had both, sort of (D9G and D8R). I just don't see how a D8T can get more done than a D9G on a short push. Lots slower on a D9G, but more grunt doing it.
Sounds like maybe we will get a chance to hear firsthand which does better. Myself, I think the T will win out, but the operator will likely be the deciding factor. A good operator on the G will beat a poor one on the T, and vice versa.
I'm sure the operators will be willing to switch seats in the name of science. Might be a few months before I can give you guys a clear account, but I'll be sure to fill you in once we know for sure (in a new thread). In the meantime, anyone care to weigh in on a similar question? This time with a KOMATSU D155AX-6 w/ outfitted with a single shank adjustable ripper vs. the D9G detailed above? Thanks again! Edit: Side Question Should I pay any attention to this video? http://www.youtube.com/watch?v=Sg53I8KOVCk Can I infer from that video that the Komatsu would be relatively equal or better than the D8T discussed above. (I know it's an imperfect comparison because the one in the video is a D8R) Once again thanks for your time everyone.
Latest(ish) model 155 with single shank adjustable ripper should **** all over the D9G. 155 versus D8T. Flip a coin, a lot could depend on the operator. The 155 is slightly larger than current D8 size from memory, probably about half-way between D8 & D9. Can't watch the Youtube video @ work (IT Nazis strike again) but if that is a Komatsu video you can bet it will show their tractor in a better light than the competition
Looks like it was just uploaded by some guy comparing them, but who knows - might be covert advertising. =P
Close Nige, it's about half way between the 8 and 9 power wise, but about the same size as the 8 weight wise. My experience has shown that it would be a great performer until it got a few hours on it, and a dog after that.......and I do mean a FEW hours on it.
note, remember cutting edges and ripper teeth are wear itms, we have a couple d8ts pushing mostly rock and some dirt up here doing natural gas well pads, about 12 to 1500 hours per edge, all that will be on top of your rental,
Sounds like light work .......!! In iron ore I would expect ripper tips to last no more than 10 ripping hours (not machine hours). Cutting edges & end bits would probably go as much as 150 hours between turns/replacements.
I own and have ran both tractors. There is no way on earth a 8T will out rip a 9G but where the T will when is it will make more passes per hour than the G and burn almost 50% less fuel. But when a 8T stops ripping due to hard material the 9G may provel but if its that hard i would use powder. We use 9Gs, Hs, and Ns to push scrapers only and all of ours are outfitted with cushion blades and they will load a scraper in half the time and distance that a 8T will. I have worked them side by side many times.
ACR Any updates on how this worked out?
The heavier machine will always rip more and push more and would put my money on the 9G when the going gets tuff. At the end of the day u can never pull more than what the machine weighs, in the Cat performance hand book they list the coefficient of traction factors which put tracks on concrete at .45 and on dry clay loam at .90 and in quarry pit at .55 so one would assume that on dry clay loam a machine would pull 90% of its operating weight before spinning its tracks. Rubber tyres on the other hand pull .90 on concrete and .55 on clay loam and when it comes to ripping the operator plays a real big part in it also. D 8T might be quicker than a 9G but only until the going gets tuff.
Looking back at the late-70's version of the PHB from the time before high-drive tractors came into being the coefficient of traction was different. The maximum was 85% in ideal conditions. Elevated-sprocket tractors with suspended undercarriage put their power to the ground more efficiently. I'd say it would be a toss-up which came out ahead but in terms of operating costs my money would be on the 8T. As others have said the only way to definitively tell which is best would be put the two tractors side by side on the same ground, preferably with the same operator running both. Nobody has mentioned track shoe width yet, also the fact that the 9G has a non-adjustable mulit-shank ripper where the 8T has an adjustable single-shank which would be far better for prising rocks out. It's a shame the OP hasn't been back here for 3 years. It would have been nice to know how things turned out.
undercarriage cost U/C wear cost is $10 to $20 an hour on the D8T as well
I recently sold my d8r series II it had 11000 hrs on it new tracks tall 28" shoes semi u blade loaded ripper valves but no ripper just draw bar its pulling a can now they gave me a deal I had to sell. Still have my low hour certified d8k cab w/air it had 26" shoes now 30" 583 sideboom pads it had a Kelly ripper took it off, moves quicker and got in the way pushing up steep hills the blade was rebuilt and is taller as its the later version semi u with a muck extension. I just put a bron 28 yd scraper on back of it soon it will be heading back to a nice 5 acre subdivision pond. short haul stuff. Always wanted a d9g or h but all the ones I came upon were worn out and needed more than I could afford so I passed My 41 is one bad vintage dog 1982 especially with 36" shoes to keep it afloat but there is no work for it to be found for it just sits slow maneuvering powerful slot dozer or strait forward grunt. No substitute for hp and weight I really love d8's and 9's this really big job I was on for a while where I was a sub to a big contracting company from W.V. showed up with 4 brand new 8t's and other sizes most all these operators that they hired were guys not from my area and not your top dogs I think 3 were really good the rest average they were stuck a lot 24" shoes soon changed to 28" helped a bunch. Compared to my 8k dead on pushing I was out working the average operators on those new 8t's just from more experience here what seams to be the norm with hi tracks go 2nd hi speed all the time hurry back up get another load start at the rear doze the whole distance no slots just go fast losing your load along your way looks like he really going. loose it in 2nd 1st gear will always push more back up in second if you can I do half throttle the big company boss loved my d8k I guess because its in nice condition it surprised those other operators. So a good/bad operator can make or break what seam to be a great deal My D8r well 2 of those really good operators from the big company worked for me after the big team went back home the comments I got about my d8r was they thought it was a bit snappier than the 8t's I never got to run the 8t's on that job so that their opinion The repair cost of some older cats can be cheaper some parts fall under the Cat Classic's parts deal and carry the same warranty at a much cheaper expense There is a nice Video of a Penn. mining company on you tube about their d9h still going strong thru the Cat Classic parts program.
Yair . . . Some interesting and in my opinion very true observations fiat41b . I was interested in your observations about slot dozing. When I can get to a decent internet connection I watch some of the large dozers pushing on You Tube and have yet to see a machine properly working slots. Cheers.
The operator of the the old D9G must be a good man to keep the old girl going and in profit. I've little doubt that the same operator would put the new D8T to work and leave the old D9 in the dust. But..... he isn't going to be driving the new D8T. With an idiot behind the levers on the 8T,it will struggle to do half the work of the old 9G. For my money,The old boy on the old 9 would be best deal.
In good ground conditions, I agree that the weight and horsepower of the D-9G would outwork the D-8T, but put it in rock, and like Nige pointed out, the game changes a bit with the suspended undercarriage. With the 9G, the track will ride up on a rock, and that point will be the only source of traction. With the 8T, the bogies will flex and get a lot more track in contact with the ground, and that makes a huge difference. The adjustable single shank over the fixed multi shank is another huge advantage for the D-8T. I stand by saying that the D-8T would outproduce the D-9G, in the rock described by the OP. However, as Nicky points out, the operator can make a bigger difference than the machine, so an average operator on the D-8T and a pro on the D-9G will swing things in favor of the D-9G. I spent years in rocky ground with D-8H and K, and D-9H. I now run D-8T's and the difference in what they will do, in the conditions I work in, is amazing, and I feel mostly due to the better grip in the suspended undercarriage, along with a better overall balance of the machine. In good dirt, the difference is not nearly as noticeable. Too bad the OP dissapeared on us.
I have just bought a D8R to sit in the yard with the others and do a few hundred hours a year. However,one of its jobs will be ripping Sandstone for one of my regular customers.I have previously ripped in this gaff with 155A,155A dash 2 and D9G Dozers all with 4 piston rippers.I will be interested to see the D8R perform. I assume it's lighter and has less power than the dash 2 155?
The dash 2 155
the D8R
I take it the decals were from the previous owner Nicky..? I don't see too much coal on that job site.
Nice bit of a dozer Nicky. Glad to see you with some modern gear to complement the others. I hope it works out good for you. In my opinion, the D-8R is probably the best D-8 of all. It is a modern powerhouse, well built with good components, and it is not so infested with electonics that it breaks down for no good reason like the newer ones do.
Yes Nige. Still topsoiling at the moment. 120C's went from 7k to 18k on that site and will be cut up this week. 777s from 10k to 30k.Many with new tyres. D8R's from 70k to 73k. D9R's from 68k to 90k. Cat 16H's 25k to 45k. Jerry.I hope it's good mate.....ha ha