Haul trucks - Articulated vs Rigid

[lars]

So what are the advantages and disadvantages of using an articulated truck over a rigid truck (Cat 740 vs 769 for example)? Obviously you can take an articulated where a rigid can't go and you need more of a haul road for a rigid, but what about price, operating costs, maintenance, productivity, etc. Also, as the articulated trucks get bigger will they replace rigids or will rigids have their own niche?

 

[Lashlander]

I can't help you on price or operating costs. You answered your own question about the haul roads. I can't think of a reason other than terrain to run Artics over Hardtails. Artics will never replace them. It would cost to much to build an Artic that would haul 350 ton. Although I'd like to see one. :cool2

 

[CM1995]

I run 2 725 artics and like them very much. I know they are too small to compare to a rigid but they work very well for our application. I know from talking to other contractors that the 731? rigid will haul alot more but it takes much more haul road maintence - a little rain seems to mess them up traction wise. I think it really depends on your situation. Say sitework for a meduim size commercial or residential development (10-30 acres) an artic would be a better choice in my opinion because you can run it to haul brush, topsoil, mass excavation, gravel, RCP, storm structures, etc. (I have done all of this with our 725 and it makes a decent mobile gravel box.:thumbsup )

I don't have any experience with rigid trucks. It seems to me that they are better suited for a quarry and large mass excavation jobs. I don't know what a comparable size rigid is but a new 725 artic is $270K. (Just leased a new one with the snazzy new Cat logo :dizzy) Operating cost for an artic are relatively low. Suprisingly the fuel consumption is not that bad - 95 gal tank and you can run two days usually without a fill up. Obviously tires are your major expense but this is the same between the two units.

I think that both artics and rigids will have their place as long as we are moving earth. I think it boils down to a productivity issue that is directly related to the type of job you want it to do.

Later:drinkup

 

[Dozerboy]

X2 Imo

 

[biggixxerjim]

I run 2 725 artics and like them very much. I know they are too small to compare to a rigid but they work very well for our application. I know from talking to other contractors that the 731? rigid will haul alot more but it takes much more haul road maintence - a little rain seems to mess them up traction wise. I think it really depends on your situation. Say sitework for a meduim size commercial or residential development (10-30 acres) an artic would be a better choice in my opinion because you can run it to haul brush, topsoil, mass excavation, gravel, RCP, storm structures, etc. (I have done all of this with our 725 and it makes a decent mobile gravel box.:thumbsup )

I don't have any experience with rigid trucks. It seems to me that they are better suited for a quarry and large mass excavation jobs. I don't know what a comparable size rigid is but a new 725 artic is $270K. (Just leased a new one with the snazzy new Cat logo :dizzy) Operating cost for an artic are relatively low. Suprisingly the fuel consumption is not that bad - 95 gal tank and you can run two days usually without a fill up. Obviously tires are your major expense but this is the same between the two units.

I think that both artics and rigids will have their place as long as we are moving earth. I think it boils down to a productivity issue that is directly related to the type of job you want it to do.

Later:drinkup

He nailed it there

 

[Countryboy]

So would ya think this style truck would be the best of both worlds or a totally different animal? Whats the capacity of these things anyway? I've never seen one in real life but would suspect they would be used in the same environment as a rigid truck.

 

[JDOFMEMI]

Comparing the 769 to the 740 is like comparing a car and a pick up truck. They are made for entirely different things, even though they share some tasks.

Rigid Frame 769 is longer lasting, built to withstand heavy rock, travels faster if on a well maintained road, typically hauls a larger load even though both are rated at 40 tons, requires substantially less maintenance, which leads to a lower cost per ton in the proper application, which is longer haul distances, well maintained low rolling resistance roads, and grades typically less than 15%

Articulated 740 6X6 is built to function in a wide variety of site conditions, from sand to mud to extremely rough unimproved roads, though they are like anything else more productive when on a good road. They can haul loads up and dow grades of 30% or more, in nearly any weather. The trade off for this ability is a truck that requires more maintenance due to 3 drive axles, the addition of a drop box behind the transmission to distribute power to the added drivelines, a high maintenance center hitch assembly, and more complex suspension, a box that is not as rigidly built, and a great deal more tire wear due to scuffing while turning.

If I was working in a quarry or long term job in fixed conditions, I would have a rigid frame truck, but as a contractor, who never knows what the next job will look like, the articulated works better, but at a higher operating cost. That higher cost is made up by being able to work on jobs where the rigid frames will not go.


Just my 2 cents worth :my2c

 

[hdtruck]

Combined Articulated and Rigid features

Take a look at this: http://www.etf.ae/products/trucks

These vehicles can do both jobs.

 

[John C.]

I've worked on both and have little use for artics, particularly the three axle versions. They are always underpowered, there are always drive train problems, they just beat the hell out of operators, they are very hard on mechanics, people take them where only tracked machines should be, all their hydraulic systems leak and tires are a nightmare for damage.

If you have to run artics you should be firing the engineer who put you in that spot. In this area of the country few people own them, but everyone rents them.

Artics have gotten better over the years. Now they will run about 3,000 hours before major problems start to happen regularly. When I first started working on them you were lucky to get two weeks on a new machine before a transmission shelled out, the brakes broke, the suspension went flat or you blew the drive lines out.

Straight frame trucks are just the opposite. Everything is build bigger, heavier and simpler. They can be a pain to have to fix but at least you can plan your maintenance and depend on your operating time.

 

[CM1995]

I've worked on both and have little use for artics, particularly the three axle versions. They are always underpowered, there are always drive train problems, they just beat the hell out of operators, they are very hard on mechanics, people take them where only tracked machines should be, all their hydraulic systems leak and tires are a nightmare for damage.

If you have to run artics you should be firing the engineer who put you in that spot. In this area of the country few people own them, but everyone rents them.

Artics have gotten better over the years. Now they will run about 3,000 hours before major problems start to happen regularly. When I first started working on them you were lucky to get two weeks on a new machine before a transmission shelled out, the brakes broke, the suspension went flat or you blew the drive lines out.

Straight frame trucks are just the opposite. Everything is build bigger, heavier and simpler. They can be a pain to have to fix but at least you can plan your maintenance and depend on your operating time.

Hey John -

I have 2 25T Cat 725's. The first one I bought used with 3000 hours on it. So far I have not experienced the breakdowns to the extent that you mentioned. The '01 used truck now has 5000hrs on it and the following has been done: 2 injectors, new main bearings - engine (it was already in the shop - preventive maintenance), 2 suspension blocks and a sway bar on the rear axle. The '06 725 has 1500hrs on it and the only thing we have had repaired is the handrail on the drivers side - broke the welds and fell off.

I haven't had to fire any engineers, at least for designing projects that require an artic - but that is another story. I haven't seen the problems that you have mentioned with hydraulic systems, drive lines, brakes or suspension - other than the '01 725 needing 2 new rubber blocks.

Sure rigid trucks are better for large projects with ideal site conditions. We do an array of project types and a rigid frame for me would be like using a 992 to spread topsoil. I can load my artics with a 30K lb hoe, track loader or rubber tire - if I need to. The versatility of the artic is the reason why I run them. I have hauled dirt, shot rock, gravel, storm piping and structures, brush, topsoil and small equipment in artics. The current project is running around 1500-2000CY per day of earth moved with the artics. I know this is not a major amount of earth moved on a daily basis but we are doing it with 2 25T artics and a 325. With the equipment we've got, I think it is respectable.

I do have a rather stringent maintenance program complete with fluid anaylisis, maintain the haul roads and train our drivers. The newbie doesn't just get the keys and a "here ya go". These trucks are expensive assets and need to be treated that way.

 

[Construct'O]

Hey John -

I have 2 25T Cat 725's. The first one I bought used with 3000 hours on it. So far I have not experienced the breakdowns to the extent that you mentioned. The '01 used truck now has 5000hrs on it and the following has been done: 2 injectors, new main bearings - engine (it was already in the shop - preventive maintenance), 2 suspension blocks and a sway bar on the rear axle. The '06 725 has 1500hrs on it and the only thing we have had repaired is the handrail on the drivers side - broke the welds and fell off.

I haven't had to fire any engineers, at least for designing projects that require an artic - but that is another story. I haven't seen the problems that you have mentioned with hydraulic systems, drive lines, brakes or suspension - other than the '01 725 needing 2 new rubber blocks.

Sure rigid trucks are better for large projects with ideal site conditions. We do an array of project types and a rigid frame for me would be like using a 992 to spread topsoil. I can load my artics with a 30K lb hoe, track loader or rubber tire - if I need to. The versatility of the artic is the reason why I run them. I have hauled dirt, shot rock, gravel, storm piping and structures, brush, topsoil and small equipment in artics. The current project is running around 1500-2000CY per day of earth moved with the artics. I know this is not a major amount of earth moved on a daily basis but we are doing it with 2 25T artics and a 325. With the equipment we've got, I think it is respectable.

I do have a rather stringent maintenance program complete with fluid anaylisis, maintain the haul roads and train our drivers. The newbie doesn't just get the keys and a "here ya go". These trucks are expensive assets and need to be treated that way.

So how many yards of dirt do you haul per load in the 725,would it be close to 25 yds heaped???

What are you using on your haulroads?

Sounds like the mp and operator training is paying off!!!!!:usa

 

[Tigerotor77W]

So how many yards of dirt do you haul per load in the 725,would it be close to 25 yds heaped???

Just as a reference, the last two digits in the Cat ADT range represent tons or tonnes (approximately), not yards. So the 725 isn't able to haul 25 yards [in general]; its payload is instead 25 tonnes or so.

 

[EZ TRBO]

I myself haven't many hours on haul trucks in general, but for the type of work I do, quarry overburden removale and hauling sand at our sand pit, and somtimes using them to move fines with the crushing crew. The artics. work for us the best. At the sand pit, which is right on the Mississippi River, the haul road is for the most part decent, but no where near smooth enough for a rigid frame. After a good rain there are plenty of lil ditches and water holes that you can still get over and through with the artic's just fine. The quarry stripping is about as rough as you can get i think, as at most of our quarries there are no real defined roads in which you can travel on(as the top changes everytime you blast), and some of the smaller quarries require a truck to get into some tighter spots. Just for ref. we are running Volvo's, one A25C which we own, and renting a A35D. Both very nice trucks and the guys that have to be in them all day don't complain.
Trbo

 

[CM1995]

So how many yards of dirt do you haul per load in the 725,would it be close to 25 yds heaped???

What are you using on your haulroads?

Sounds like the mp and operator training is paying off!!!!!:usa

We estimate 15-16 CY per load, which is a little on the conservative side, but depends on material. Shot rock is less, good red sandy material is more.
We average about 50-60 loads a day, each truck.

We use whatever we have available, a motor grader would be awsome - don't have one. Usually it is either a D6N or D6R. Our haul roads change as the excavation does, like Turbo's quarry. We are taking a hill down and fillling valleys for a residential development consisting of 500 lots total. First phase is 148 townhomes and 54 garden homes. We have cuts up to 30' deep in some areas. All of the cut is going to fill in for phase 2 which is 164 50' wide lots.

 

[JimBruce42]

I have run both types, and I have to agree, they all have their place. Out in the field on a job (or stripping) where your haul route may change a few times in one day and conditions could as well, you definitely need an ADT. One of the greatest things about an ADT I think is the ability to go through or up almost anything. A rigid frame may be able to haul more and on good roads have an edge, but it is still a two wheel drive truck, once your wheels start spinning, hope you can back out of it otherwise:Banghead THe ADT's, you just have to lock up the diffs and that thing will grunt and pull its way through:notworthy

To go off topic a bit, CM1995 do you have any photos of the job your on? Sounds like a good sided job!

 

[alco]

A rigid frame may be able to haul more and on good roads have an edge, but it is still a two wheel drive truck, once your wheels start spinning, hope you can back out of it otherwise:Banghead

AHA! I take it you haven't had the displeasure f running Payhaulers then? Still a rigd frame, but 4 wheel drive...well, 8 if you count both tires of each set of duals.

Brian

 

[John C.]

CM1995,
I'm glad to hear you are having good luck with your trucks. Twenty five ton trucks are not used much here because a hiway truck is a lot cheaper. The 725 Cats are newer than I have had to work on and maybe they finally got something designed right. I have heard of plenty of bad experiences with some 730s and 740s.

From my past experience it seems more reasonable that your usage, training and maintenance program has more to do with the good availability than does the design of the units. Perhaps a better way to look at artics is they will do a job very well if operated within certain perameters.

My experience again tells me that they are primarily used to bail out projects in bad ground and adverse conditions using operators that are not necessarily trained. Again this all goes back to the engineer who designed the project in the first place.

Good Luck

 

[928G Boy]

one advantage to the rigid trucks is that they don't twist in the center when rolling down a cliff...

(pictures courtesy of my former employer who will remain anonymous)

NO I WASNT DRIVING THIS TRUCK LOL

 

[Construct'O]

Thanks

We estimate 15-16 CY per load, which is a little on the conservative side, but depends on material. Shot rock is less, good red sandy material is more.
We average about 50-60 loads a day, each truck.

We use whatever we have available, a motor grader would be awsome - don't have one. Usually it is either a D6N or D6R. Our haul roads change as the excavation does, like Turbo's quarry. We are taking a hill down and fillling valleys for a residential development consisting of 500 lots total. First phase is 148 townhomes and 54 garden homes. We have cuts up to 30' deep in some areas. All of the cut is going to fill in for phase 2 which is 164 50' wide lots.

Thanks for the info! I know you have a lot of investment already,but ever thought about 4-wheel drive tractor and drag scraper for the haulroads and fill? I'm sure the grader would be better, if it fit into the budget . Right!

One job i worked on they used a 824 Cat wheel dozer and pulled a 21' drag scraper with it.We were working on sandy loam soil and it worked great there for the haulroads and fill.It was an interstate job(I 29) in Mo.

The back slopes were cut to 1/4 to 1 slopes and benched out like 15 ft flat then down 10' and then down on 1/4 to 1 slope again.

Steped down until got to the bottom of the cuts.They had to run the blades with the blade out and tilted up to shape the backslopes.Some of the cuts were over a 100" and 90' fills.

It was an interesting job.Sorry about getting off subject.Just got to thinking about that job.:usa

 

[D5G]

CM1995, got any pics of your new 725? How do you like it so far?