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aostling
09-21-2013, 05:56 PM
Construction has begun on a 67-unit housing development in my neighborhood. I had a look at the two Caterpillar 627G scrapers on the job. I'd never walked around one of these before so was surprised to see that they have an engine in the front, another in the rear.

http://i168.photobucket.com/albums/u183/aostling/scraper_zpsb6622c30.jpg (http://s168.photobucket.com/user/aostling/media/scraper_zpsb6622c30.jpg.html)

There are two throttle pedals in the cab, one for each engine. That must take some getting used to.

http://i168.photobucket.com/albums/u183/aostling/cab_zps9fa1f802.jpg (http://s168.photobucket.com/user/aostling/media/cab_zps9fa1f802.jpg.html)

The 627G is a medium-sized scraper. How big to these things get?

WhatTheFlux!
09-21-2013, 07:26 PM
Good lord, what size lathe do you use that sucker on?!

(Oh not that sort of scraper! :D)

sasquatch
09-21-2013, 07:29 PM
Great pics!! Not sure how many yards the bucket is, but yup "Pull and Push".
When i was 8 or so used to ride my bike out of town to watch scrapers like that working at building the 4 lane hwy #401 in the early 50's.
Those scrapers were branded "Turnopole" (Spelling.)

becksmachine
09-21-2013, 08:10 PM
Those scrapers were branded "Turnopole" (Spelling.)

Tournapull, made by the R.G LeTourneau Co. ;)

Dave

sasquatch
09-21-2013, 08:50 PM
Thanks Becksmachine, it was exciting times for an 8 year old to watch these mighty machines bounce along.

kf2qd
09-21-2013, 08:52 PM
Two engine scrapers are fairly common.

RG Letourneau made one with 8 engines and 3 scraper pans and 6 axles. Was used near Longview Texas when building Interstate 20. It may also have been used during the construction of Lake of the Pines in East Texas. It was HUGE! Seems like it was something like 1200 Cu. Yards.

flylo
09-21-2013, 09:38 PM
I've seen the old single engine "pans" as we call them & when full they had to be pushed with a dozer, so this cures that problem.

Ohio Mike
09-21-2013, 10:32 PM
Tournapull, made by the R.G LeTourneau Co. ;)

Dave

As a side note R. G. LeTourneau was a truly amazing engineer. He had virtually no education (he didn't even finished high school) and learned welding, fabrication, and mechanics in the field. He was a prolific innovator and amassed hundreds of patents during his life.

aostling
09-21-2013, 10:47 PM
RG Letourneau made one with 8 engines and 3 scraper pans and 6 axles.

The only reference I have found to this is from http://www.ritchiewiki.com/wiki/index.php/Motor_Scraper#Monstrous_Machines. I wish we could see a photo.


With the development of the Electric Digger series in the 1950s, LeTourneau’s company manufactured the world’s largest motor scrapers.[4] The Goliath, or Model A4, was the biggest motor scraper built to date. This model contained an electric motor in every wheel. Following the Goliath was the development of the LT-360. This scraper, the biggest ever built, included three bowls for a capacity of 216 cubic yards (165 m3). It moved, with the power of eight 635 horsepower engines, on eight wheels that each measured more than 10 feet (3 m) in diameter. LeTourneau’s scrapers never sold in large numbers; they were mostly considered experimental.

R_Audano
09-21-2013, 11:26 PM
Thanks to leading me into some research and photo viewing.
Being a midwest farm boy I really never had the opportunity to see heavy industry until the web and all contributers made it available.
http://photostp.free.fr/phpbb/viewtopic.php?f=13&t=8607

It appears LeTourneau has made some interesting behemoth's.

Cuttings
09-22-2013, 11:08 AM
Spent most of my working life keeping these things running. You will notice a a push block and bale on the front and a post on the back. They usually run two of these machines together.
The machine at the back hooks his bale over the post then pushes while the front machine loads, then the rear one loads while the front one pulls. That way they have four engines to do the work.
The other alternative is to use single engine scrapers and push them with a Cat to get them loaded. They are actually not that bad to operate, one foot on each throttle and away you go.
It is a younger mans job because these things can be a petty rough ride.

Ohio Mike
09-22-2013, 11:10 AM
The only reference I have found to this is from http://www.ritchiewiki.com/wiki/index.php/Motor_Scraper#Monstrous_Machines. I wish we could see a photo.


With the development of the Electric Digger series in the 1950s, LeTourneau’s company manufactured the world’s largest motor scrapers.[4] The Goliath, or Model A4, was the biggest motor scraper built to date. This model contained an electric motor in every wheel. Following the Goliath was the development of the LT-360. This scraper, the biggest ever built, included three bowls for a capacity of 216 cubic yards (165 m3). It moved, with the power of eight 635 horsepower engines, on eight wheels that each measured more than 10 feet (3 m) in diameter. LeTourneau’s scrapers never sold in large numbers; they were mostly considered experimental.

The book LeTourneau Earthmovers has pictures. Google search 'LeTourneau Earthmovers LT-360'. One of the things LeTourneau pioneered was electric motor hubs on construction equipment.

I also recommend the Historical Construction Equipment Association, check it out. http://www.hcea.net/

Blackadder
09-22-2013, 11:49 AM
have a look at this as mentioned above

http://www.youtube.com/watch?v=ahH7B5-O8Vc

Stuart

camdigger
09-23-2013, 10:03 AM
627s are mid size scrapers. 657s are the largest I've seen. Smallest push Cat worth bothering is a D8 - about 300 HP . Largest to the D11. Subdivisions move huge volumes of dirt. I`ve watched 5 631`s ¸working with a D10 double strip 80 acres in a week. Moved about 8 - 10`each lift....

Cat, Letourneau, and terex seem to dominate the motor scraper market. There is a move toward pull scrapers behind beefed up Ag tractors - think tandem or triple scraper pans behind 500+ hp quad trac or wheeled 4wd tractor.


Youtube has many, many videos of motor scrapers doing their thing....

becksmachine
09-23-2013, 12:30 PM
I was looking for this video when I posted before. The two engines on one scraper would initially seem to be capable of anything a normal person would want to do. Apparently not. :p

Haven't done the math, how many hp on this cutting edge?

Can someone tell me why the rear scraper engine isn't used while loading? In the video it looks like the rear engine isn't doing anything.

Always wondered what it looks like when they encounter the fabled "immovable object"?

Dave

http://www.youtube.com/watch?v=9gAYeyUB7oA

Weston Bye
09-23-2013, 02:38 PM
For a mechanically-minded kid I had a blessed childhood. At age 15 I spent some time around single-engined V12 Euclids, riding, operating and pushing with an Allis-Chalmers HD12 dozer. It was glorius. I think the exhaust on those monsters added to my partial deafness.

Had the transmission go in one of the Eucs. (somebody else operating, I was not implicated) Dad and I removed it with the aid of a hydraulic excavator on the jobsite one evening, put it in the 1/2 ton pickup (overloaded) and drove it to Detroit for repair. A few days later we retrieved it and reinstalled it - again in the evening, after a day's work.

kf2qd
09-23-2013, 10:28 PM
For a mechanically-minded kid I had a blessed childhood. At age 15 I spent some time around single-engined V12 Euclids, riding, operating and pushing with an Allis-Chalmers HD12 dozer. It was glorius. I think the exhaust on those monsters added to my partial deafness.

Had the transmission go in one of the Eucs. (somebody else operating, I was not implicated) Dad and I removed it with the aid of a hydraulic excavator on the jobsite one evening, put it in the 1/2 ton pickup (overloaded) and drove it to Detroit for repair. A few days later we retrieved it and reinstalled it - again in the evening, after a day's work.

You lucky rat.....

Richard P Wilson
09-24-2013, 06:17 AM
I was looking for this video when I posted before. The two engines on one scraper would initially seem to be capable of anything a normal person would want to do. Apparently not. :p

Haven't done the math, how many hp on this cutting edge?

Can someone tell me why the rear scraper engine isn't used while loading? In the video it looks like the rear engine isn't doing anything.

Always wondered what it looks like when they encounter the fabled "immovable object"?

Dave

http://www.youtube.com/watch?v=9gAYeyUB7oA

The rear engine was certainly working during loading of the first scraper, you can see black smoke and the exhaust cap lifting. It was working on the second one as it approached (same reasons), but possibly not during loading. As each engine has a separate throttle control, this must have been operator choice, possibly why should I work when those 2 D9s are shoving? Maybe the operator was on a fuel bonus, and saving 1/2 gallon from time to time added up.

Richard

camdigger
09-24-2013, 01:24 PM
Haven't done the math, how many hp on this cutting edge?



Always wondered what it looks like when they encounter the fabled "immovable object"?

Dave



280 +490 hp on the 637, each D9G is about 400 hp, so all told, over 1500 HP. When they meet the immovable object something breaks....

aostling
10-14-2013, 09:46 PM
Subdivisions move huge volumes of dirt.

They are still at it, and it is fun to watch. Now they are using two-engine scrapers and a single-engine scraper, a road grader, a D8R Cat, and this water tanker which uses the same tractor as a scraper.


http://i168.photobucket.com/albums/u183/aostling/Cat621E_zps57bddfe4.jpg (http://s168.photobucket.com/user/aostling/media/Cat621E_zps57bddfe4.jpg.html)

The tanker makes tight turns, with the tractor at 90º to the trailer so that it is turning on the radius to the rear set of wheels. I see no drive wheel slippage so assume there must be a differential somewhere. Is the differential hidden inside the engine/gearbox housing?

There is something mesmerizing about watching these two-wheel tractors in operation. I wonder how they prevent them from falling over when they are detached from whatever they are trailing.

doctor demo
10-14-2013, 10:11 PM
The tanker makes tight turns, with the tractor at 90º to the trailer
I wonder how they prevent them from falling over when they are detached from whatever they are trailing.

As You see them is how they are thier entire life, there is no hooking and un-hooking like a semi truck.....well except for repairs.

Steve

1-800miner
10-14-2013, 10:45 PM
I was an operater on a fleet of 657'S. Nearly a hundred machines.
Sometimes they would gang up four or five together in the cut.
It would take two,sometimes three seconds to load up forty yards of dirt.
Every now and then some one would cut too deep or too slow on raising the cutting edge.
It would rip out the entire bottom of the can.

It should be a young mans sport but there are a lot of grey beards still in the seat.

Mr Aostling
They are SUPPOSED to stay together . Occasionally the goose neck breaks (the connector) and things go to hell real fast.
The front bumber falls to the ground right before your face slams the windshield and hopefully the cutting edge digs in deep enough that the can does not over run the tractor and you.

andywander
10-14-2013, 11:04 PM
How are the scrapers emptied?

lakeside53
10-14-2013, 11:34 PM
Those I've seen side dump - the bed rotates.

becksmachine
10-15-2013, 12:47 AM
How are the scrapers emptied?

There are various schemes to get the rear wall of the bowl to move forward and push the load back out of the loading slot.

As seen here; http://www.youtube.com/watch?v=-fDPS9iiVak

Dave

Richard P Wilson
10-15-2013, 02:57 AM
There were dozens of these things on the UK motorway sites I worked on in the 1960s and 1970s. One day, it was necessary to move 6 of them from one part of the site to another, but the direct route up the site was blocked (bridge falsework I think). The contractor didn't want to bring in low loaders for them, too expensive and anyway the official route was about 50 miles round for vehicles that size, though the direct route via a minor road was only 2 miles. The contractors sub agent thought he would chance taking them in convoy on the minor road, highly illegal because no way these things are road legal, not in the UK anyway. He set off in the Land Rover at the head of the convoy having set men at all the junctions to stop oncoming traffic and all went well until they came to a downhill slope with a sharp turn at the bottom. What he didn't know was that the brakes on the scrapers were shot, didn't need them on site because the operators just dropped the bowl when they wanted to stop. There was no way the scrapers would take the corner, bordered by a stone wall except dead slow, so the operators did the only thing they could, and dropped the bowls. It completely reprofiled the road, and not for the better either. That took some explaining to the county authority and the repair bill would have paid for the low loaders 10 times over.

As a junior engineer, I wasn't supposed to drive these things, but we used to get the operators to let us try on Saturday afternoons when 'authority' had gone home. I never drove a 2 engined job, because I liked the big Cat dozers, and was quite good on a direct drive D8H in the end. I did try a single engined scraper, can't remember the make or model, all I can remember was that I'd long been puzzled why the operators all wore welders gloves on their left hands. The drivers position was alongside and to the right of the engine, and when I got on I also noticed the paint was blistered off the panel between the driver and the engine. As soon as I tried to put it in gear (manual gear change) I found out why they wore the gloves - the exhaust manifold was about 2" away from the panel on 1 side, and to get into first gear, my hand was touching the panel - instant defoliation of the hair on the back of my hand! The normal operator, who was watching, found this very funny for some reason.

Richard

lwalker
10-15-2013, 02:14 PM
I found out why they wore the gloves - the exhaust manifold was about 2" away from the panel on 1 side, and to get into first gear, my hand was touching the panel - instant defoliation of the hair on the back of my hand!
Richard

Classic case of engineers never trying to use the product they designed ;-)

Lyndon

aostling
10-15-2013, 06:43 PM
Classic case of engineers never trying to use the product they designed ;-)
Lyndon

Engineers don't route exhaust pipes. Where did you get the notion that they did?

J. Randall
10-15-2013, 10:44 PM
Engineers don't route exhaust pipes. Where did you get the notion that they did?

I always assumed engineers design the exhaust manifolds, which pretty much dictates where the pipe is going to be routed.
James

aostling
10-16-2013, 12:22 AM
I always assumed engineers design the exhaust manifolds, which pretty much dictates where the pipe is going to be routed.
James

An optimized intake or exhaust manifold is indeed a task for an engineer. The simplified theory is based on an assumption of one-dimensional flow in the header, with the cross-sectional area reduced appropriately after every bleed duct. The change in header area must be proportioned just right or the flow in the branching ducts will not be equal.

There is a classic paper on the theory of manifolds in the Transactions of the ASME, I think from the 1940s. The author derived an ordinary differential equation describing his model, but I noticed an error in the solution. I thought about corresponding about this but never got around to it.

Richard P Wilson
10-16-2013, 04:33 AM
[QUOTE=aostling;880124]An optimized intake or exhaust manifold is indeed a task for an engineer.

I don't care if the exhaust was optimised or not, it doesn't take a genius to work out that if the manifold is 2" from a steel bulkhead and the gear lever is 2" from the other side of the bulkhead, the operators hand is going to get burned. Engineers must have designed that scraper, including the engine installation, the exhaust and the gear lever. If they ever drove one, it probably wasn't after it had been worked hard for several hours, so that everything was nicely hot, or after the machine had a lot of hours on the clock, and the gear change had got really sloppy.

After a lifetime of trying to build other peoples designs out on site, I firmly believe that no architect should get an award for his building until he has lived or worked in it himself for at least a year.

Richard

aostling
10-16-2013, 03:01 PM
Engineers must have designed that scraper ...

Engineers certainly designed parts of it. Designers probably did the rest.

Evan
10-16-2013, 03:34 PM
I had a job when I was about 21 or so. It was to go up to Grand Cache at a coal mine to tear down about 50 trailers at a camp. When we got there on the bus the foreman had us all line up and asked us "Does anybody know how to run that backhoe?" I immediately raised my hand and he said "OK". I had never operated a back hoe with a scraper blade but I figured it wouldn't be too hard. It took me a couple of minutes to get it started and about 15 to figure out the controls. I knew that I wouldn't have to know much about running it because the job was to rip down all the walls on the trailers and scrape up all the crap into piles. The rest of the guys had the hard work of cleaning and loading anything worth while while I had the easiest job of all of them.

kc5ezc
10-16-2013, 08:38 PM
Way back in my youth I ran a RD75 Cat pulling a sheepsfoot roller. Job over; need to move equipment to new job; foreman's son and I drove DW21 Cat scrapers about 60 miles down the highway to the new job. Most fun I had had since ma got her teat caught in the wringer! (We were a lot cheaper that the regular operators, especially on Saturday)