Why scrapers ?

[Renze]

Yes i mean self propelled belly scrapers:

http://www.youtube.com/v/CCrSvl1f0I0&rel=1

In Europe, dozers are also less popular than in the USA, and they are partially replaced by payloaders.
I've read that, in the 60's, Case set up a european line of payloaders because the American ones did not statisfy in Europe: In america they were used to scoop, load and carry, where in Europe, the wheel loader partly replaces bulldozers and are also used to dig, which is much more demanding on the driveline.

Pull type level graders are quite common among agricultural contractors for levelling farmland.
The grader is used by some specialised road contractors but most general dirt contractors use a laser level blade on a wheel loader, because of the versatility.

 

[john_bud]

It may have to do with the economies of moving the dirt. Possibly job sites are larger over here? I know we used them to move 25,000 to 30,000 yards about 400 yards. I can only imagine how long that would have taken with payloaders digging and then dumping 400 yards away.

There was also a D8 on site to pull or push the 4wd scrapers when they got stuck. That was about every 2nd to 3rd trip.

 

[Renze]

I meant, payloaders are used for short trips - from the construction pit to the stockpile.
If the haul road is longer, trucks or tractor drawn dumptrailers are used.

 

[IMCA38]

If you can find a copy, there is an interesting book entitled Moving the Earth The Workbook of Excavation by Herbert L. Nichols, Jr. This book was written many years ago, but many of the concepts presented still apply today. It is about as thick as a good sized dictionary and makes for fascinating reading if you are into this type of thing. I lucked out and got a copy at the library used book sale a few years ago.

 

[JohnBarlow]

I have a copy of "Excavation & Grading Handbook" (revised) by Nick and John Capachi. It's a good read if you want to learn about earthworks, and goes through the trade-offs between different equipment (truck & loader, scrapers, etc) - even dual scrapers with dozers pushing and dual-engine scrapers with a dozer pushing.

Its all about time-efficient movment of soil over a relatively short distance.

 

[caver]

We use them at work (coal fired power plant)to move coal on and off the stock pile.

 

[jmfox]

I noticed an article in the wall street journal (12/10/07) about catepillar's travelling circus in China. It seems they are trying to promote "earthmovers called wheel tractor-scrapers." in China:

"During the demonstration at Baicheng, the scrapers dumped soil layer by layer to form the banks of the canals, while engineers took measurements of the canal walls. But they couldn't keep up with the machines' speed."

 

[ToadHill]

JMFOX: when I worked on road building in the summer durring college they were called Pans.