Why scrapers ?

[Renze]

I have a question:

When i was a kid, i read about scrapers in kid's picture books. So i knew they existed, and CAT makes them. Recently i've been watching some videos on YouTube, and i saw them working in the wild.

However, i have never seen one, sitting or working, not in the Netherlands, nor in other countries i've been.
When i asked a friend who lives in Finland, he says he never saw a scraper in Finland either.

It seems that america is the only continent where scrapers are in common use.

Now i really wonder why ?
My friend in finland says its because scrapers are useless when the frost sets in early.
A reason i can think of myself, is that over here in Holland, most ground is too soft and slippery for scrapers to get traction.

However, Canada and the northern USA are at about the same distance from the north pole as Finland, and many areas in North America have the same soft and wet soils as we have in Holland.

Are scrapers used all over America, or only in some areas where the ground is dry and hard ?

And whats the benefit over loaders/excavators and dumptrucks/farm tractor with dump trailers ?

 

[AlanB]

Could you post a picture of what you are calling a scraper to insure we are speaking of the same item please?

 

[MrJimi]

I'm wondering the same thing, I think a scraper is a like a snow plow ?
In Ireland a highway is called a motorway ?
With a short searcch I found these
Fixed-blade ejector scrapers and carry-all scrapers from John Deere
Rowse Dirt Scraper, 7 yd, 5 yd, 3 yd,Rowse Hydraulic Rakes Company, Burwell, Nebraska.
Jim

 

[Egon]

Different conditions may use different equipment.

Mostly I use a scrapper to clean the frost of the windshield but I have seen the kind that move dirt, and there are many different kinds, working in -30 F weather hauling dirt. I've also seen them in sweltering summer heat doing the same thing in muskeg!

 

[EddieWalker]

Renze,

I think you are talking about belly scrapers? Giant tractors that scrape up the dirt from their bellies and haul them to another location, where they release the dirt, and do it again.

I never thought of why they don't have them in Europe, or at least they are not so common that you'd notice them. Here they are used for massive dirt moving projects. I was on a job in California where there must have been 50 of them running at the same time. We were taking out a hill and filling in the valley. It was millions of yards of dirt that was being moved and just keeping the roads drivable was a full time job. There was a line of big dozers that just pushed the scapers along while they were loading up, then they would back up and wait for the next scraper to push.

The big advantage to them is the amount of dirt you can move over a distance with minimal personel. They are becoming rarer today as the tractor pulled scaper is more fuel efficient and faster.

If you ever want a REALLY good book to read, R.G. LeTourneau wrote an auto biography about his life that is just fasinating. He had allot to do with developing and inventing most of what's in the modern day scraper. He also said he was the first one to attach cables to a dozer blade to make it go up and down. He worked and competed with Holt and Kaiser in California in the Early days. He has a University here that he started about 45 minutes from where I live. He kept ten percent of what he earned and the rest went to the church.

Here's a link that you might find interesting.

LeTourneau Technologies, Inc.

Eddie

 

[Jimbrown]

I believe you do not see the large scrapers in use in Europe do to a totally different approach to large projects in the USA and Europe. My experience is that in Europe companies tend to hire a few well paid employes and use just them to do a particular project. It does not mater that it might take months/years to complete. In the USA companies tend to hire and fire as many workers as neccessary to complete the work in the shortest period of time that they can. They use the large scraper to move large amounts of dirt as fast as possible. My experience is that in Europe particularly Germany large project such as shopping center and autobahn construction take considerable longer to be accomplished than they do in the USA. In the USA a company will hire a large number of workers and use considerable ammounts of machinery to do such a project and then lay off the workers and let the equipment set untill the next project.

 

[ultrarunner]

I think it is a question of scale...

I often see Scrapers used on large grading projects... tracts for several hundred to thousands of homes.

You would need large projects and a lot of them to justify the capital costs.

My experience in European construction is limited to Austria. I saw very little large equipment being used. The biggest dozer available was the Cat D6 LGP... and that is huge by Austrian standards.

A lot of the ground was just too soft and in some cases it is just not feasible to move oversize equipment on the narrow roads.

 

[jmfox]

Didn't we use to call them Pans?

jmf

 

[Egon]

Many of the machines would be difficult to transport from site to site in Europe due to size and weight exceeding the limits of local roads.

You will also find their transport trucks are smaller.

 

[ScottAR]

The big advantage to self propelled or motor scrapers is they don't stop to load or unload and they spread the load somewhat as they dump. They are the fastest way to move large amounts of earth over short distances. They excel at moving topsoil, clay and clay with sand mix.

The downside to scrapers; They are a single task machine and they are expensive to buy and maintain. They also do not like large rocks or mud.

Around my area, Most folks use large ag style tractors with one or two pans.
Most are around 400-500 hp and have 15-20yd pans. Tractors with pans are cheaper and almost as fast but need more room to turn around and such.

The last three years they've had a road widening/straightening project going just outside my town. The contractor is one of the largest earthmovers in the state and they ran all three types of equipment on this job. They used excavators and articulated dumps, Tractors with pans, and a few motor scrapers.

The tractor/pans were used where the borrow pits were fairly close to the fill areas. The excavators/trucks were used where the pit to fill area were farther away. The motor scrapers were used here for final cuts on the grading of the roadway and cleaning up windrows from the road graders.

 

[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.