Have any owners/operators out there tried out the new Caterpillar D7E? Has Caterpillar even begun to field the new dozer? I have just recently learned about the new machine and have some doubts about it. Maybe because its such a radical change in their dozer line. But it does look good on paper, just want some ideas/opinions from someone who has actually used it or seen it in operation in person! I have the link from Caterpillar's website in case other people were in the dark about this new dozer or had any doubts about its existence. Any opinions or thoughts appreciated!!! :usa Heres the link- http://www.cat.com/D7E
Was interested to read efficiency data and compareing amount of m/3 moved etc. No mention I note on how far this Quantity was moved .I0 mtrs 100 Mtrs ??????? Not wanting to knock the machine,all the same,could well be a goodie. I also wonder how the price compares,with standard tractor ,Any mention of this ??? Regards
From what I gather the beast is still in the prototype stage and is having bugs worked out. It's been several months or a year since I heard anything new, that being said I haven't looked either.
http://www.pjstar.com/news/x931202664/Cat-launches-its-new-hybrid-product There's mention of a price in there.
Gang, Couple of things: D7E has been in field test for over 6 months with end-users Fuel Savings are about 20% on average over a D7R Series II It's about 25% more efficient in terms of material moved... it's actually closer to the D8T in terms of productivity than the D7R It's going to be pricey! Servicability is dramatically improved... The entire cab tilts up nearly 90 degrees so all major components are accessible... it also has far less moving parts because there is no transmission or torque convertor. The operator feedback in terms of power and response has been very positive. The biggest complaint is that it doesn't sound like it's working. The engine only runs at about 1700 RPM and doesn't ever really lug so that takes some getting used to.
I was in Peoria on Tuesday for Caterpillar's official introduction of the D7E. They were announcing that the unit will go into production in October, ramping up to full production by mid-2010. That's when production of the D7RII will cease. There are 18 pre-production (produced on the East Peoria TTT line) units in the field with customers getting real-life experience, and Cat arranged to have representatives of three companies in Peoria to talk about their experience. As you might expect, all were very positive. Some of the details were particularly interesting, and you can find some of them in this ConstructionEquipment.com machine analysis . We're in the process of posting some short audio clips of customers' comments about the machines. My summation of what those who are using the machine said goes like this: Maneuverable and controllable enough to work on sites previously restricted to the D6, but powerful enough to do most of what a D8 can do. Caterpillar has upgraded its estimation of the fuel-efficiency advantages. Back at Conexpo (March of 2008), they were saying 10 to 20 percent reduction in fuel consumption compared to the D7RII. Now they're saying 10 to 30 percent. And users are saying they see significantly more. As much as 50 percent less fuel consumption, particularly in lighter-duty work. Cat's saying they will set the MSRP at 20% above that of the D7RII. That puts the D7E at about $600,000, or within 12% of the D8T. Check out the D7E intro analysis for a comparison of the cost per hour of the 7RII and the 7E. With its fuel-efficiency advantages and lower undercarriage and PM costs, the D7E should cost about 7 percent more per hour to operate than the D7RII. In hourly production terms, it delivers about 10% more yards of dirt moved. But 10% more hours per year won't bring the 7E's hourly rate down to equal the 7RII's. Owners are going to have to think differently at least about their D7 work to take full advantage of the hybrid bulldozer's efficiencies. How many D7-sized-tractor users can expect to get enough additional work for a D7E by virtue of its productivity advantages to make it earn its keep? The D7E's hourly rate is easily 20% below that of the D8T. Users gathered in Peoria were all doing conventional dozer work with their machines -- pushing considerable distances doing reclamation in a lignite mine, gravel pit, and quarry. The loading supervisor from Dolet Hills Lignite, J.V. Ropollo, said he'd gone so far as to put the D7E in a job that is usually done by a D10. Ground got soft and the D10 was having trouble getting around. The D7E could handle the underfoot conditions better (the standard track puts as much track on the ground as a D7RII LGP). He said the 7E operator wasn’t happy about it (guess he had to work at it pretty hard), but he was very nearly keeping up the work pace he had done in better conditions with the D10! The D7E had also pulled loaded 785 haul trucks out of the mud that Dolet Hills' D7RII couldn't budge. Dolet Hills had 1,600 hours on the unit (they run two twelves). Its tracks are on pace to just out-last the tracks on their conventional dozers. Lots of sand down there, so they only expect about 2,200 hours to the first turn. Plote Construction's gravel-pit reclamation sounded like it was pretty tough, too. They parked a D8T, and the D7E was stripping and filling with all kinds of reclaimed asphalt and concrete. Plote said it was doing some really long pushing, although he didn't give any specific distances. Had pushed some scrapers, too. Crossfire, diversified heavy contractor in the Four Corners region with a lot of oil and gas business, sounded like they would be putting the 7E on some D6-sized projects. They'd done a lot of reclamation work in 500 hours, but were also sure it would perform on road and site development jobs. The diesel drives a generator that produces up to 480 volts. HD, armored cables with mil-spec connectors carry the voltage to a propulsion unit with two high-speed electric motors. The propulsion unit drives pretty conventional Cat diff-steer units and final gear reductions. The motor/diff-steer configuration does out-perform conventional transmission/diff-steer pairing in that the D7E electronic controllers are programmed to deliver lock-track turns. The stopped track will not freewheel, for example, if the tractor is on a slope when the operator puts the tractor into a turn that stops the inside track. The D7E drivetrain is also capable of counter-rotating the tracks. In a side-by-side demonstration, the D7E clearly outworked the D7RII. Now, the Cat operators could have rigged that any way they wanted to, and surely the things they did with the tractors played to the D7E's strengths. But I have no doubt that the new tractor will deliver 10 percent more work per hour. Cat puts that with the fuel-efficiency advantage and says the 7E produces 25 percent more earthmoving per gallon of fuel. One thing's for sure, they aren't exaggerating about the view from the operator's seat. I'm not a dozer operator (I did stay at Holiday Inn Express once . . . ) but I was in the cabs of a D6N, a D7RII, a D8T, and a D7E on Tuesday. There's no comparison. There just is not much to block your view. And it's quiet. Easily half the noise at high idle, as Cat claims. It's far smoother than the D7RII, and every bit as nimble as the D6N (I was doing laps with them in an indoor arena at Cat's Edwards, Ill., demo grounds). You gotta keep your eyes open because the 7E doesn't really lug down under load. If you have the electronic ground-speed control set too high (as this greenhorn did), the tracks start to slip with no audible warning. At max. 480 volts, mechanics don't need a certification to work on the drive train. There will certainly be some training required to keep these things up and running as they age. All of the accessories -- including the hydraulic pumps, water pump, air conditioning -- are run electrically. There are no belts off the front of the engine, no refrigerant hoses in the engine compartment, no alternator. Accessory power comes from an inverter over the right fender. More D7E technical details. Photo 1: "Look Ma! No belts!" Wide-open engine compartment is built to accommodate the aftertreatment that will take the C9.3 (pre-production only today) all the way to Tier 4i in 2011. Photo 2: Inverter powers all of the hybrid dozer's accessories -- including the hydraulic systems, water pump, air conditioning.
I am supposed to get to try one out in a week or 2. I am looking forward to it, and will post my thoughts after I try it out.
Larry -- that's an amazing account of the press event. Thanks for posting it here and in a different form to your blog. I really hope this dozer succeeds. I know far too many Cat people who have put their every effort into this machine, and while I don't expect perfection, it seems like it's off to a pretty decent start. Fingers crossed, but tentatively, well-done, Cat. This is definitely a high point in this rather dismal year.
plote is right up the road, and i have some buddys working there. i gotta check it out.
I missed out on it, too. I had no idea Plote got a D7E; I'm originally from the Glenview area!
It's certainly a departure from the norm for Cat. Without running one it's hard to make a concise opinion on wether it will be good or bad. I've run all kinds of dozer by all the main manufactures, with manual, torque converter, and hydrostatic transmissions. The D7E seems to have a drive very similar to a hydraulic hydrostatic drive which on the tractor I ran with that kind of drive I found did not work well for dozing operations. The machine in question was a Liebherr 732. I found it had the power but couldn't put it through the tracks to the ground. I only hope the D7E has a good power to weight ratio.
I heard that Liebherr has changed their dozers in the new 4 series. The hydrostatic has always had complaints about it being quiet. I would like to hear from someone who has used and compared these hydrostatics.
The D7E brochure is available on the Cat (US) website now... cat.com, Machines, Track-Type Tractors, Medium TTT, D7E.
Here is the link. Some good video and interviews along with the specs. http://www.cat.com/D7E I get to try one tomorrow, and will let you know what I think.
Well, Yesterday was it. I got to get a close look at the demo machine, as well as about 1/2 hr of seat time in the new D-7E. I have gotten the opportunity to run many new machines in my career, but this is the best dozer I have operated. I went in with some scepticism, and wanted to really find all the machines problems so I could tell the engineers about them, but I only had 2 small complaints. This new machine just amazed me with the performance. It is as fast as a D-4C Hystat machine, and even better control. It will operate as fast or as slow as you wish, and is very smooth forward to reverse. Even an animal of an operator will look good on this machine. The speed and directional modulates very smoothly, even with full speed directional changes. You have a foot controlled speed modulation pedal that will take you smooooothly from your set high speed down to a full stop. Breaking over an edge? You can inch forward as slow as you like to keep it under control. Turning is as fast or slow as you wish it to be, from a gentle turn to a locked track turn, to full counter rotation. You do have to go to neutral for counter rotation though. The visibility out of this thing almost makes you wonder if there is even a cab surrounding you. The only blind spot is a bit over your left shoulder. The cab pillar and AC ducts in the rear left of the cab block some of the view that way. This machine puts power to the ground better than any machine I have ever ran. You select the max speed you wish to travel, and it will gradually slow as you increase the load, but I was not able to stall it out. It slowed to about 1st gear speed under full load, and when your load reduces any, it runs back up to the max speed you have selected. You can even run max speed, 3rd, into a pile and it slows to pushing speed, then as the load gets spread out, speed increases. All this talk about speed, and yet it will go as slow as you need as well, if that is what is needed. sometimes in rock, even 1st gear is too fast in most tractors, but you can dial this one down to 1/10th of first gear, or anywhere in between to get the job done. I do not know if I described it well enough to understand, but I could not find a problem, try as I might. My firs impression is that Cat did their homework on this one, and it is a winner.
The counter rotation is because of the dif steer setup.I'm pretty sure.Don't you think? I hardly every counter rotate unless in a tight working area.Thanks for the report !:usa
you had me till you said you couldn't stall it.
So, does anybody have any ideas why CAT would put all this technology in a conventional track-type tractor? It seems to me that the high drive platform would be as well or better suited to this type of drive system.
I think its best explained by this quote from Dave Nicoll, commercial manager in Cat's tractor products department. "We carefully evaluated all of the kinds of work that a D7 does, and decided the low-drive undercarriage configuration is the best choice for the job," Nicoll explains. "You get the greatest value out of elevated-sprocket undercarriage when it is suspended, and only the D8 and larger sized elevated sprocket undercarriages are suspended. Certainly we will continue to use the elevated-sprocket undercarriage on the D8 and larger tractors." IMO this is only an admission that the hi-drive was a marketing ploy the last 20 years for machines without a suspended U/C, giving no real advantage to the tractor. I fully expect the D6N and D6T replacements coming down the road to be low drive as well. I speculate that the replacement for the 6N will be a hydrostatic and the 6T replacement will have its own version of E-drive.
or just leave them as they are and call them something else. I doubt seriously cat will spend any new development money on anything right now. buyers will look at spending a lot less for everything as well and this does not include new technology that costs much more with a promise that if you run it twenty years you might come out ahead a little. Everything works great until the work dries up.
IMO, the Cat M series scared me, what with replacing conventional, trusty controls with dodgy, unreliable Play Station 2 consoles, but the single raise/lower cylinder and electric drive (sounds dubious for an earthmover: sounds like something from Lexus), I'm seriously worried. I'm all for green stuff, like these power cells, but why not make power cell before you make something compatible with one if it doesn't even exist yet? And why not hybrids first?? I really think that Cat is jumping the gun. Or going on reverse with the G series 2 dozers for the developing markets (South Africa, India, China, the rest of Africa, etc, etc) when it hardly scrapes the International Emission standards???? Am I missing something? I really think that Cat has gone absolutely mad, if not bonkers!
Uh....Bellboy....just how much seat time do you have on a dozer of any type??? You seriously think you have a better idea of what will sell than marketing specialists at a company as large as Caterpillar?
Well I for one am glad Cat have gone old school on the new D6/D7G. Harks back to good old days of dozers. I'm also a fan of the old flat track dozers, don't get me wrong I like the high drives but give me a D6C or D6D any day. The problem these days is machine have too much technology stuffed into them that it is getting to the point where all you need is a guy to track them up and down and the machine will pretty much do the rest. Running a machine to grade by eye is rapidly becoming a dying art. I'm glad Cat is also trying to do it's bit to keep up with the 'Green' revolution too, as with anything in our in game it will appeal to certain people and others will completely detest it.
It's an extremely good point, and one that's been discussed here, too. Cars are gaining automatic parallel parking devices, planes are getting electronic sunshades instead of the usual sliding window covers, and the entire on-highway market is getting huge enhancements to improve emissions and fuel consumption. Beneath all of this, however, is one aspect that's often overlooked: talent. It's no lie that fewer kids are growing up on farms or around levers; sure, there are gearheads, but today's generation isn't always tinkering with nuts and bolts; today, it's about the computer. I will argue that companies that can recognize the value of designing operator stations that make sense to today's generation are going to prosper more easily ten years from now than those that continue to pander to the crowd that insists on mechanical linkages. (There is, of course, the question of what happens to companies that continue to produce crap machines of any sort but have "cutting-edge green technology" or other "operator pleasure facilities, but my hypothesis is based on equally good products.) This last parenthetical expression is worth additional note. The prevalence of GPS means that getting a site to grade no longer requires a seat-of-the-pants, experience-only expertise; the ability to sit in an easy chair while twitching thumbs means that the nerd from third period can run a dozen-ton machine. Continuing to produce machines that snap, crackle, and pop (and belch) may hold up for the next few years, but product quality and durability be damned, we may be witnessing the first complete overhaul of an industry previously associated with dust and grime. This isn't to say that Ph.Ds are going to be running equipment in the future; far from it. However, there is no doubt in my mind that what will set apart companies in the future is not productivity (even today, most machines are very close -- and are more dependent on the skill of the operator to eke out the last few drops of productivity) or on servicability; it's going to be how easily one machine can turn a non-experienced "nobody" into an operator who can get the thing going and stopped. I'm about as far from a Cat fanboy as a yellow-blooded guy can be, but again ignoring immediate product and company issues, if Cat's looking at the bigger picture, they're moving in the right direction. The immediate challenge is not to stumble on all this that they've predicted for the future and deliver on the new products yet to come. This execution is going to be far more vital than trying to nail down every technology that will turn Joe Compgeek into Bill Dirthogger. A note: this is in no way to say that current talent or old hands are useless now that new technology has superceded old. I can't grade worth a darn on any machine, and even with EH or pilot controls I still need to think my way through most ordinary operations. The ability to "see" a grade, to have instincts to the best way to move some dirt, is something I value inherently, and my awe in seeing those talents at work is what sparked my own interest in this industry. I'm a big opponent to change in general, but complete resistance to change is also what brings industry leaders to their feet. Sometimes, a little compliance is better than complete disregard.
Uhm, reread my post again..... I was talking about untested technology, and new concepts that no one has seen before, let alone developed, and YES.... I recently spent time on an ANCIENT CATERPILLAR 814B wheel dozer .... just to answer your question Uhm, and the thread is titled "New Caterpillar D7E - Opinions?". Just stating my 2 cents.
Untested Technology? http://www.paxmanhistory.org.uk/de-mprop.htm Diesel-electric arrangements tend to be substantially more expensive than mechanical drives. There are the additional costs of generators or alternators, electric propulsion motors, and electrical control systems. The expense however can be outweighed by the several advantages of such systems which include: • Much improved control of propeller speed, for example when manoeuvring, as this does not have to be directly proportional to engine speed; • Engines can be kept running at their most efficient, and therefore most economic, speed even when a vessel is manoeuvring or cruising at low speed. This is a particularly important consideration when using medium and high speed diesels; • Much greater flexibility in deciding machinery layout as there is no need to place engines in line with propeller shafts; • Relative ease of engine installation - no lining up of shafts involved; • No requirement for gearboxes thus eliminating the noise and vibration associated with them. A major factor for anti-submarine warfare vessels; • Quieter running as engines can be isolated from the structure of a ship by the use of resilient mountings, thus minimising the transmission of noise and vibration to the hull. A consideration relevant to both warships and passenger vessels; • In modern multi-engine installations, engines can be cut-in or cut-out depending on the power output required at any point to achieve more economic running. Then if if you really want to get into this Technology: http://www.ossapowerlite.com/tech_library/fuel_efficiency/fuel_efficiency.htm And this example is more in line with this forum: Letourneau L-2350 Dated - March, 2001 http://findarticles.com/p/articles/mi_m0FZX/is_3_67/ai_72983699/ Where is there a working example of this monster? http://www.youtube.com/watch?v=JJBF7Hbggoo Found this link interesting: http://www.ask.com/bar?q=+LeTourneau+L-2350+wheel+loader.+&page=1&qsrc=2106&ab=3&u=http%3A%2F%2Fkaevandamine.wordpress.com%2F2008%2F11%2F23%2Fmaailma-suurim-kopplaadur-on-le-tourneau-l-2350%2F
Just can't see any un-tested technology in that machine Bellboy. The Diesel Electric has been around for a long time. And your opinions seem more about an M series grader than a D7E. Opinions are...well, everybody has got one, but I'll wait until I have some real seat time in one before passing judgement. I was sort of following this thread to see if anybody knew why Cat went with the 7 for the DE?. I would have thought an 8, being a more popular size would have been the best place to start.
Keep in mind the conditions. We only had the dirt at the dealers lot to play in, and it had already been well turned. BUT, this tractor puts its power to the ground better than any powershift or direct drive I have ever been on. I am saying this with over 20,000 hrs seat time on a wide variety of dozers. The electric motor has the ability of full rated torque from zero speed to max speed. The controls (brain) of the system adjusts speed to match the amount of load applied. I learned so many advantages in my 30 minutes or so in the seat, I can just imagine how productive I would become with a week in the seat. I would love to try it in heavy rock. You have the ability to select speed right down to 1/10th of first gear speed, and still have the ability to have full torque. This is the way of the future, with more and more electronics involved. The way I see it, you either embrace the change, or be made obsolete by the change. I am also thinking of component life as well. Take the engine. It does not throttle up and down all day, one of the most destructive things you can do to an engine. Engines running gen sets routinely last over 30,000 hrs. I am not saying this will, but I bet it outlasts any dozer engine by a long ways. Drive train? The shock loads have been reduced because of the smooth control of the electric drive. now the only shock loads are going to be those caused by rough or rocky ground conditions, and even those will be reduced. Other than locking the brake while running, I could not shock load the drivetrain, no matter how hard I tried. No more rookie operator mistakes wiping out a trans or diff. I guess the only component with an unknown life is the generator and electric motor. Even if they only match the life of a powershift trans, you will still be ahead of the game, and this is not new technology, just a new use for it. Check with the industries that use electric drives like this, and you will find a pretty long life. Only time will tell, but I see the makings of a long lasting machine here, and with Cat, you can be confident they will support it, unlike some of the other brands out there.
Squizzy About the D-7 being the first, I talked to some of the engineers, and it was several things. Sounds like the biggest being that this was a new machine from the ground up, not a re-engineering of an existing machine. There was also a rumor that the D-7, being a lower volume machine in sales, would not upset things so bad if it did not become well recieved. I suspect that the D-6 will be next, and redesigned similar to the D-7E, but on the D-8 and up, I was led to believe they will keep the same basic design they are now and just fit the new components. It will not happen overnight, but it is on the way.
Interesting posts JDOFMEMI good to hear a first hand review. What are the steering and trans controls like? Are they simular to the R series? When you mention speed selection how do you select it?
DPete Steering is by a tiller bar like any other diff steer machine, the only twist is a lack of twist. You no longer twist for directional control, it is a toggle very similar to a fingertip control type machine. Speed has several ways of control. One way is a proportional "dial" on the tiller that you roll with your thumb to speed up or slow down There is also a series of selections on a dial that work similar to the autoshift feature in some machines. You can dial in 1.5 F, 2.5 R which is a pretty good working range, and several other settings, I do not remember all of them, but the one I liked is the user programmable, where you set your selection of forward and reverse speed, then a second forward speed, that you "shift" up to after you fill the blade. With any of the pre selected speed ranges, the thumb wheel changes it when you desire, then at the next directional shift it goes back to the pre set setting. You can also select full manual, and just use the thumb wheel. The last way of controlling speed is with the foot operated speed modulator. It is a lot of choices, but once you set it for your style and conditions, it is very easy to use. The
Jerry, very informative posts from an experienced operator.:drinkup Thanks for the info. I thought the same when I saw the prototype at the last Conex show in LV. Not that the technology is so radical but Cat still had a plan "B" if the D7E was not well received. It wouldn't affect there more popular 6 or 8 line if the industry balked. I could see this technology adapted to many other pieces of iron in the future.
I wonder how it does on a steep downhill, if there is any hold back through the drive train. maybe it has dynamic braking like a freight train
Pete I forgot to mention that part. Because the speed is positively controlled, it maintains what you selected regardless of grade. We only had a small hill to climb, but you maintain positive control of the machine at all times. Also, if you go to neutral, it slows to a stop, then holds. No freewheeling downhill with this one.
Sounds real impressive to me, thanks for the info
I think the reason the D7 was picked was b/c of it awkwardness in most fleets. Too big to do a d6's job, to small to do a D8's. Especially the high track models, b/c it was the biggest non-suspended dozer.
Yeah, I think you're right. I don't think I've ever seen a modern D7 around here. All D6's and D8's.
looks like it would an efficent tractor to operate but i havent been around 1 myself either.who knows cat may be onto something.
It will be interesting to see how this all pan's out for Cat. But reviewing the posts in here from Jerry and Larry it seems that Cat may be onto something here. The diesel-electric drive is far from being new techology and I think will be used more extensively as they are able to produce smaller and high-torque producing drive motors. I would definitely consider purchasing, or at least leasing one, to see how it will benefit my operation.
My thoughts exactly Around here the D7 doesn't get much action. If they build a D8 capable machine in a smaller package then they are mony ahead. It also provides a huge BETA test for the technology, and some customer training. Then the rest will follow.
CEwriter, Did you say the hydraulics were powered from the electric system? The early pictures from Conexpo showed a hydraulic pump off the generator drive, did that change?
Hmm... that's a lot of Texas. Coupled with a large presence in Finning territory, I'd say Cat wants more D7s working the pipelines.
Saw some recent pics of one working for Eberhard in EU i think it was so they are spreading there wings wider than the US now.
I was telling one of my guys about it, and his first comment was "it sounds like the best platform ever for a pipelayer" I had not thought of it, but with the precise control, as well as the speed, and the ability to go smoothly from 0 to max speed, and slow back to a stop, and with the positive control on a hill, it would be a great pipelayer
I'm not sure I see the immediate potential of the D7E as a pipelayer. I don't know: a) if people would pay a premium for electric drive; b) if electric drive can offer any [substantial] fuel savings on a pipelayer. But down the road, assuming the D7E proves itself, perhaps. Just not in the interim.
I had been led to believe the D-7E would be comparably priced with the current D-7 model. Is that not the case? Though fuel savings is a factor, it is not the prime reason I like the machine the way I do. It is in the level of control, the speed, and ability to better control the machine in all conditions.
JDOFMEMI, you may have mentioned this already, but I'm curious if the engine speed remains steady or if it varies depending on machine load?
Steve The engine operates at a constant speed. There may be a slight fluctuation, but it is pretty consistent. You do have 3 or 4 different settings to choose from. All the demo's were done at max throttle setting, but when I got some extra time on it, I found you could dial down the engine speed, and still have a great deal of the speed, but with reduced power. For finish work, or other low power requirement jobs, you could run the engine in a reduced power mode, and probably save even more fuel.
No -- it'll be 20% higher. Larry mentioned it on page 1, but I forgot where else I read it (apart from the PJStar article I quoted, also on page 1). I've seen it in a few different places now.
Right on Steve, I am sure I am not smarter than a fifth grader or Cat's army of design and marketing engineers but one thing I am sure of is that equipment gets better every day. More comfortable and easier to operate. Thank you Caterpillar. If Cat strikes out with the new D7E they will come up with something better. Worried about Caterpillar, nope, the only thing I worry about is which neighbor is stealing my chickens.
we love this machine it is one of the better dozers we have used
This is my first time posting on here but i just recently had the opportunity to operate one of the first D7Es and i was really impressed. With 5 different choices of engine speed settings, the fingertip speed adjuster and also the modulation valve it has the ability to move at a high rate of travel, and then also the ability to crawl at a extremely slow pace. As i read through out this form i saw a few questions that i may be able to answer. On the machine hydraulics there is still the normal hydraulic pumps mounted above the generator, but the control valves are mounted as close as possible to the machine implements i.e blade, ripper, winch, etc. which gives them a very fast response time to operator imput, and also the response time is adjustable to configure to operator and the ype of work they are doing. Cat has designed the machine so that Acccu grtad or trimble can easliy be installed at the factory or at the dealer, and is also one of the best machines designed and built for GPS. The cab does not pivot a full 90 degrees but only 60 upon the removal of some bolts and pins. On serviceablitity all of the grease points are on the left hand side of the machine. Additionally they also have increased some of the operating hours for fluids and filters. The generator and motor expected service life is 10,000 hours at the earliest. The machine itself weighs alomost 1000 more pounds then a D7R Seris II has 5 less horspower, but it uses less fuel and accomplishes more work almost into the range of the D8. According to a dealer advertisement the cost to savings begins to pay itself off by in a faster amount of time then you may expect due to fuel and time savings. With a price of 600,000 to 700,000 $ it does have a plenty hefty price tag. In my opinion as the D10 high track revolutionized s the TTT industry in 1977 this could be the next big thing. I have only limited operating time in any and all feilds of heavy equipment i feel that the responsiveness and ability of the D7E shall only bring more competiveness in the equipment for fear of being left behind and shall hopefully play a small part in the regenerizing of our economy. It is opinion so thats my two dollars.
Test Drive CAT D 7 E Test Drive.
-CEwriter I love the post and pictures! Thank you very much for the detailed and informative reply, I really appreciate it!
Have another couple of pictures.
What're your thoughts?
Well, unfortunately I have not personally seen or operated the D7E yet and at first I had a negative feeling towards the new dozer with my thoughts drifting back to the D7G... since those days I have been "spoiled" on the D7R's. But everyone who I have heard from or talked to has had nothing but good things to say about it. So all I can say to that is I cant wait to get a chance to try one out! It sounds like Caterpillar really did a great job with this dozer...but with Caterpillar I honestly wouldnt expect anything less!
I don't want to sound negative but the guys with all the Cat priase, have you operated any other new units lately? I know some Cat guys that would buy anything with a Cat sticker on it. Deere and Komatsu have hydrostatic units that have increased fuel savings as well as some of the other "new" innovations. I would like to see a side by side comparison by someone that doesn't have a picture of Cat under their name or come from the Great State of Obama.
Haha I hear what your saying them1677 I am partial to some pieces of caterpillar equipment especially thier dozer line, now when it comes to excavators... not so much. I mean we all have our favorites...some people have had good experiances some have had bad with a certain line. Who knows maybe some people have other things besides operation that they like about the machines. Plus the other good thing is that that both Cat and Deere are wholly owned american companies I believe. :usa
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D7E and ripping I realize that the D7 class is not intended for heavy ripping, but I still wonder if any of you has tried it in any sort of rock ripping. As the electric motors are capable of a very slow speed and still maintaining high torque I wonder if it can give the smoothness of a torque converter needed to avoid track slipping. I for sure did some rock ripping on the old D7E, in the late 60's not many other machines were available for rock work in my place. They were of course no match for the D8 class and many of them got prematurely worn down being exposed to that kind of work. The old 4 cylinder was incredibly torquey though.
Hjolli What I recall from operating it would lead me to believe it would be a strong ripper tractor. You can select any speed with the drive, and have full torque from stall right up to max speed. You can modulate speed without loosing torque. If you need less torque to control slip, you could dial down the engine speed as well which would reduce torque at a given speed, and do it with better control than a torque converter. The speed control allows for very precise creep control, and I believe it would work well to control track slip.
Can anyone explain how any of this is different from a hydrostatic machine??:beatsme
With a hydrostatic you lose a lot of energy as heat through the system and from other loses, pumps motors etc. Electric drive has come a long way in the past few years and is more efficient now. With a dozer your not going to have it I don't think, but with other platforms you can recover some of the energy during braking. Down the road if this pans out it will probably be used in more machines. Also would you have full torque at low speed with hydro?
I think one more thing that you can do and I think Cat is doing with the electric drive is load sensing. It will reduce speed to keep from stalling the tractor under heavy load, then as the load lightens pick up again.
I would contest that this electric drive system would loose close to the same amount of efficiency as a hydrostatic system. This is why Cat has made a big deal out of the motors being water cooled. Electrical components this large will put off a ton of heat...heat = power lost. I'm not saying that a hydrostatic system is any more efficient. All I'm saying is that there isn't night and day difference between the two. With this tractor I will say that it will gain some overall efficiency due to driving the HVAC and water pump electrically, but I'm guessing this would only be a few percent. With regard to full torque at low speed with a hydrostatic...the answer is yes because at low speed you're basically at a high pressure low flow situation...meaning high torque. Nothing new here either. Hydrostatic systems have been doing this since the beginning. I will say that with the addition of electronic controls, this has become light years better than back in the day with mechanical controls. I guess what I'm having problems putting my arms around is all of the marketing hype about this machine when (that other than a couple of minor efficiencies that I mentioned above) it is no different in features than a hydrostatic tractor. Low engine speed - check Constant engine speed - check Infinite speed control - check Dynamic braking - check Improved maneuverability - check Full power to both tracks in a turn - check All I'm saying is I don't think this machine is THAT revolutionary compared to what others (including Cat on smaller models) have been doing for years. No doubt it is a big improvement in fuel consumption, noise level & visibility over the D7RII and will more than likely be a pretty good tractor. I just think that it has been a little "over hyped" because of the greenies making the correlation with an electric drive anything saving the earth from evil carbon dioxide gas.
I'm really not familiar with how well this will work, but I'm going to disagree and perhaps make a fool of myself. First, I think the D7E will offer a lower operating cost than a comparable hydrostatic tractor (namely the 950J, given that everything else is torque converter at this point). This will be mostly driven by lower fuel consumption. Second, I disagree that the electric drive is similar to a hydrostatic. The D7E operates in a pretty tight RPM band. If you listen to it when not under load and when under load, you won't hear a significant drop. I realize this is hardly scientific, but if we're just comparing a seat-of-the-pants feel, there is a difference in how much variation there is between a hydrostatic transmission under load and an electric drive under load. I think -- and this is hearsay at this point -- that the electric drive is far more removed from the engine than is a hydrostatic transmission. When there is a load on a hydrostatic motor, the physical hydraulic pressure increases, which means the powerplant will have to work harder to supply the increased pressure. While the same will happen with electric drive, I think that because the engine is powering a generator -- and not a mechanical pump -- there is added isolation between the engine and the motor. Just as hydrostatic allows for some additional protection from huge torque spikes, e-drive does the same (at the proverbial "next level"). As a result, e-drive can operate within a much finer RPM range than can a hydrostatic machine. (My conjecture.) I'll give an example of how having an improved mechanical transmission is different from having a different transmission altogether. Cars can have, say, a conventional transmission with gears and the such, a CVT, or a hybrid propulsion system. I *realize* that Cat's D7E isn't a hybrid (in the sense that there is a battery pack and that energy is stored during some regeneration state) and that a CVT isn't a hydrostatic, but I'm just saying that having similar RPM characteristics isn't sufficient to have identical fuel economy. If I go from a Camry automatic transmission (roughly 21 city) to a Camry Hybrid (31 city), there's a pretty big jump. The Subaru Legacy (similar sized engine to the Camry I4, but with a CVT) improves only to 23 MPG city. (I realize that highway numbers are closer, but still different -- the Camry is 31; the Legacy, 31; the Camry hybrid, 34.) I'm just saying -- a CVT operates in a narrow RPM band; hybrids with CVTs do, too. However, it's the coupling of two different systems, one mechanical and one electrical, that right now offers the "best" results. (Note that this isn't a plug for hybrids -- I'd prefer if Americans just went to clean diesel -- but just a statement on different propulsion techniques.) The ultimate question I'd pose to you is about Deere's own line. Hydrostatics will probably endure into the future for some time, but what will Deere be doing with its wheel loaders (if not dozers)? Is Deere *always* going to have a mechanical, TC with LUC transmission? Or will you begin to look at hybrids or hydrostatics? Do your engineers consider one propulsion technology to be superior to the other in that regard? (On a parallel, Volvo could have pursued hydrostatic technology in the L220, akin to what Liebherr has done... but instead decided to go with Hybrid. Was that truly just a marketing perspective? That "hybrid" is somehow better than "optimized mechanical?" I don't know the answer to these, btw... )
I was offered the chance to run the D7E a few days ago and I would like to give my two cents.:my2c First off let me say I only ran it for 30 min so I can't answer every question out there, but what I can tell you is that it could have used a few more days in the design dept. I really liked the power train. There is not much I can say about it that hasn't already been said. I wanted to side load this machine to see how it compared to a diff steer machine and I found there was no comparison. When ever you wanted to turn a load or hard cut with a corner bit there was always track power to spare. The engine maintained a constant speed and never fluctuated. This machine could have used another 10,000 lbs for the amount of power it put on the ground. Now the dislikes. A single lift cylinder to lift the blade? When these machines get 10,000 plus hours and the wear points are sloppy my thoughts are controlling the blade may look like your playing on a teeter totter. :beatsme With twin cylinders some of that gets held to a minimum. I also think for those who clear big trees or need that max lift power it is going to be lost. Also does a dozer hand ever look over the hood for anything? Pushing scrapers or trees,maybe looking ahead to see changes in the ground so you can react, or even looking to see your laborer holding the grade rod. Now you have a cab post, air cleaner, exhaust pipe, and cylinder in direct line with you. The brace arm on the blade looks to be beefy in pictures but after a closer look it will bend very easily where it connects to the push arms. tilt cylinder looks small and cheap as well. Watch your head getting in or out you will hit your head on the mirror or backup monitor. Other than that the cab was typical, nothing to get real exited over. Although the visibility to the blade was second to none. Cat should take a few lessons from other manufactures on there electric over hydraulic controls. Smooth only if you were at full stroke. Making small corrections the blade would jump and down and was very hard to make fractional corrections. M series graders T series tractors and most all of cat loaders are the same way. One manufacture has there controls perfected but I won't mention names that always starts a new battle. My biggest complaint of all is the undercarriage. What were the reasons for going to a high drive system? Once again the finals are subject to impacts and high loads from rocks and stumps, and seals being cut buy foreign objects. Many of you talk about ripping rock ,I've never done so but that can't be good on a rearward final drive. I have owned 4 high drive machines and replaced 2 seals and rebuilt 1 final due to a bearing failure in 25,000+ hours. I have replaced countless final drives and seals on older flat track machines. I live in an area where we spade out the undercarriage every night in the winter and there is nothing that spades any easier that a high drive machine. 30 min, one person and your on your way home, that looks like a good hour to me. Overall it is going to be a good machine, but only time will tell. Remember before I get slammed for my thoughts these are my opinions about this machine. Opinions are like a$$holes. Everyone has one.
A step backwards? Without having ever tried or seen this machine in real life, I would agree with you Dirt Dogg on the subject of the low drives, and what also struck me when I first saw a picture of this machine was the "old fashioned" bracing on the blade. The D8 and up have the diagonal bracing bar, an ingenious and simple solution, and the D7H and D7R has this as well. I would also think that one of the main advantages of the high drives is to keep final drives away from abuse. It would be interesting to hear from users of the conventional drive machines (Komatsu and others) what their experience is with the low final drives, e.g. in ripping work.
I saw one of these monsters about a month ago but didn't get to run it. As a mechanic there were some things I liked and some I hated. I liked the jack over cab and the serviceability of the machine. I'm kind of ambivalent about the electric drive attachments. Water pumps and air conditioning take a certain amount of horsepower to run them and don't care how that power is supplied. Belts are far cheaper and easier to fix. Wires get chaffed and shorted. I don't like my machine to light up literally when things go bad. What I really didn't like was the fact that high voltage could be contained in the system with the engine shut off. There is an electronic function that is supposed to ground the system out when the engine is shut down. I don't like the idea of getting zapped when an indicator fails or the software gets a bug. The drive system is really a red herring. I know from personal experience that low drives rip better. In smaller machines the extra cost of the high drive undercarriage doesn't break even with the oval tracks. Cat apparently has conceded this as all their small machines now are oval track. On the large machines Cat has increased the service life of their high drives and the component access really makes a difference in reduced down time and life cycle costs. The high drive works great on big machines and I would recommend it. I know when I did run machines I never looked over the nose to see where I was going. I really liked the idea of being able to see under the corners of the blade. I wouldn't think I would have to run the machine for a hour or so before I got the feeling of exactly where the blade cutting edges were. Time will tell how good of machine this turns out to be. I think this is a pretty good first production effort.
Hello all, first post here. Lots of information and guessing in this thread. To confirm with what I know: The D7 was chosen as the test mule for the electric drive platform because it is a low volume machine. It was changed to oval track for engineering reasons. As far as I know the plan is to expand the electric drive to other dozers if the 7E is well received. Also, the first customer machine has been delivered so you can all get your hands on one now. I have never operated one so I will not speculate about it however guys I have talked to say it is a great machine.
I'd sure like to take one for a test drive. They look pretty interesting. Quite a change for Cat.
My opinion Just wanted to share some pros and cons from my experience so far: My first impression after only one day of use was that I didn't like the dozer, but I figured I should give it a fair chance and wait until I was more comfortable with the controls. I have had the dozer for three months now and here's is my evaluation. Pros: The line of sight in this machine are probably the best I have experienced. The hydraulic speed of the implements are adjustable and the blade is very fast. The engine is cleanly designed and has no belts. Cons: The straight track design along with no decelerator make for an incredibly rough operating experience. I was sore after every day I ran this dozer. I would say it is comparable to a 155 komatsu it terms of ride. The toolbar and ripper controls need to be addressed, the round toolbar is so massive that you can't see what your ripping until you are 30 feet past it. The ripper controls are a little bit award as far as where they are located, if you have long arms you almost have to turn sideways to use them. As far as fuel economy....I understand that the machine is design to keep a constant rpm when in operation and in theory that should probably help fuel economy, but in reality I have actually used more fuel in a day than with the older D7r. I personally feel that having no decelerator may be the contributing factor. In summary I'm really hoping I can find a lower hour d7r to replace this with. I hope caterpillar reconsiders this design before changing any other models. Newer isn't always better and don't even get me started on the J.U.N.K. Series H model scrapers.
Deere is developing two types of hybrid drive systems for loaders, one for large and the other for smaller machines (see 944K & 644K Diesel/Electric Hybrid Loaders ). I thought they were being discussed here at HEF, but can't put my finger on where. L
Dirt dogg? Why dont you like the quickness of the controls and the pressur it takes to control them, i love the T series dozers and M series graders just because of how sensitive the controls are
D7E bin there done that we have one at work i ran it for a week had a blast
Usually with electronic controls the operator can adjust the sensitivity of the control response from the Monitor System.
Not on the D6 you can on the 8's and on up the 7E idk. And i dont think you can on the M's either