Highway construction NOT using scrapers

caver · Nov 8, 2008

I've noticed, on a four lane highway project on the way to my property, that they don't use scrapers anymore. Hills are dug out using a large track hoe and loaded into large, possibly articulated, dump trucks. I assume it is more economical this way instead of using scrapers to shave off the hills and fill in the valleys?
I remember as a kid watching scrapers and even turn-a-pulls, whenever
a bunch of dirt need to be moved short distances.

LBrown59 · Nov 8, 2008

caver said:
I remember as a kid watching scrapers and even turn-a-pulls .

When I was a kid I called them turn a pools.

JDPN · Nov 8, 2008

It all depends on the soil conditions and what a contractor has on site. Rocky soil or really muddy soil ie are not too scraper friendly

Renze · Nov 8, 2008

caver said:
I've noticed, on a four lane highway project on the way to my property, that they don't use scrapers anymore. Hills are dug out using a large track hoe and loaded into large, possibly articulated, dump trucks.

I allways wondered why Americans used scrapers instead of excavators and dumptrucks like we do in Europe... I'm curious about what some construction guys can say about this..

JasG · Nov 8, 2008

As someone said in an earlier post unless rocky or soft ground a scraper can be filled much faster, haul as much or more and spread its load easier than an ADT. A friend of mine was manager for a large earth moving firm and couldn't understand why someone would ADT's if condtions were such that pans could be used. They only used ADT's on job sites that scrapers would get stuck on or rocky or were small.
A few reasons I can think of are if you have ADTs and not scrapers you are going to use what you have. ADT's are a little more versitile than a pan so more contractor have them. Pans are getting harder to move, can't drive them on the roads any more due to weight restrictions. A Cat 631 I have been told the weight on the front axle is around 50000 lbs unloaded. Even with a lowboy you need special permits for over width and pilot truck in front and behind.
In our area, not as many jobs require large volumes of dirt moved so pans almost gone. Most of the jobs are repaving or remodeling a site. Taking a strip mall and demolish a site to put up new.
Pans in a lot of areas need a large dozer to load them, a 631 needs a D8 or D9 to fill it fast.

Scooby074 · Nov 8, 2008

In the right ground (soft without large rocks), scrapers can move large volumes of earth, cheaply and quickly. They also excel at grading and sculpting. Due to the difficulty of moving large scrapers around, they usually only go to very large jobs.

Around here, excavation is done with excavators and dump trucks due to the rocky and unpredictable ground conditions from site to site. Given that excavators are not tied into a specific ground type like scrapers, and are much easier to transport, companies choose to spend their money there. Scrapers are really rare here.

A local open pit mine has just bought 2 new Cat 657 scrapers to reclaim and smooth the previous works. They are huge with 44 Yard bowls and can move around 50 Tons at a time. For this job the scraper excels. The ground is rocky but the rocks are small and loose. Perfect conditions for a scraper.

Egon · Nov 8, 2008

Might it have something to do with the low bid and what the low bidder has available for equipment??

There may also be space limitations.

Contract specifications?

And a host of other factors???

john_bud · Nov 9, 2008

They just did a road project here and had a large ex loading dump trucks. Had about 12-15 trucks circling. But they had to dump the dirt about 5 miles away.

At work we had to dig out a hill side for an addition. Had 3 pans moving dirt 300 yards away. That went fast.

jb

Renze · Nov 9, 2008

Scooby074 said:
Around here, excavation is done with excavators and dump trucks due to the rocky and unpredictable ground conditions from site to site. Given that excavators are not tied into a specific ground type like scrapers, and are much easier to transport, companies choose to spend their money there. Scrapers are really rare here.

In Holland, the sea, as well as eroded material drifted in by rivers from the Alps, has formed our country... Speaking of differing ground conditions from jobsite to jobsite..

Plus, we have lots of soft or tough clay soils. I think that explains why i have never seen a real scraper here.

Nonetheless, tractor drawn ejector scrapers are widely used by agricultural contractors to shape and slope farmland towards the drainage ditches. But thats only landscaping, they are never used on construction sites. Wheel loaders are the weapon of choice to do the final digging and profiling of jobsites in Holland. With the bucket as well as with a laser plane.