Differences between scrapers...

[Countryboy]

Having no expierence with scrapers, except seeing them work, I had a couple questions about some of the terms and phrases I've heard here on HEF.

1. What is a cushion hitch?

2. What is the difference between a cushion hitch and a non-cushion hitch?

3. Whats is the apron?

4. What would be the instances where a scraper would not need a push dozer?

5. Do dual engine scrapers need push dozers?

6. What are the benefits of having an elevating scraper compared to the other type? I don't know what the other type is called.

Pictures are helpful too.

 

[DPete]

A cushion hitch is a mechinism on the gooseneck (Hinge if you will ) That when raised uses a hydraulic ram and a nitrogen accumulator to absorb alot of the shock between the scraper and tractor during travel. Much easier on man and machine. A non cushion hitch is just ridgid( no shock absorber)
The apron is on open bowl scrapers, it is the front door that holds the material in when shut or allows the scraper to dump or load when open. Elevating scrapers don't need a dozer unless they are stuck or for ripping the cut. An elevating scraper can work alone, they can pick up loose berms left by a grader,they help process or mix moisture in the material as they load, they don't like rocks. Twin motor scrapers usually work in pairs or threes to help each other load, can be pushed also. Hope that helps. DP

 

[BrianHay]

Hi Countryboy Ill try and answer best I can for you and have a look through my pics to see if I have any closeups that show that stuff.

The front part of a scraper is refered to as the tractor and the back is the scraper. Where the two connect together is the hitch. Cushion hitch is one that has what looks like a big shock on it. Helps keeps the machine from bounceing. Hitch without a cushion is often called a stiff neck. In my opinion the cushion hitch was the best thing ever invented for scrapers. Its what allows them to go so fast. Stiff necks are realy slow cuz you can't get em moving fast without getting bounced out of the seat.

The appron is also often called the gate. That's the part above the cutting edges that opens and closes to let you load or dump.

Single engine scrapers need a push cat cuz they can't get enough power to the ground to get a full load by themselves. Although I have spent lots of time stripping without a cat with a 631 when the conditions were realy good. Topsoil is the easiest stuff to get a big load on with.

Dual engine, or twins as they are more commonly called (dunno why they called twins. They are not. The front motor is bigger because it powers all the hydraulics as well as front wheels) don't need a pushcat except for the rare occasion when the ground is really soft. And even in those conditions if two are working together pushpulling with good operators they will do good without a cat. If they can't do it working together its probably adt territory.

I have never run an elevating scraper myself. But have been told by guys that have that if the material is chunky it helps bust it up and also helps stack up a bigger load. Maybe someone who has time on one can better explain them to us. The other type is called an open bowl.

Did I explain it all ok? I will try finding a pic of the hitch and the apron.

 

[BrianHay]

lol took me a long time to type that book. I'm using my phone. Your post wasn't up when I started Pete

 

[DPete]

l

ol took me a long time to type that book. I'm using my phone. Your post wasn't up when I started Pete

Two heads always better than one :drinkup DP

 

[BrianHay]

Right on Pete cheers! And you brought up a good point I had forgoten. Even twins need a ripper cat if the ground is realy hard. Bigger loads faster and really saves the cutting edges.

 

[BrianHay]

I'm kinda surprised scrapers don't have theair own section in HEF? I don't know about the rest of the world but here in Canada everywhere East of the rockys up to Ontario (havnt been past there so dunno) scrapers are the big ticket were there is lots of dirt to move. With the exception of the big mines but they are there as well. And build lots of the roads into them.

 

[pushcat]

We pull our scrapers with 4-wheel drive tractors, haven't had very good luck with self-propelled scrapers. The only time we push is when it's too wet for the tractors to pull themselves. Usually have no problem getting heaped loads if the conditions are halfway decent. Tractors also ride a lot smoother. That's what works for us.

 

[BrianHay]

I have never worked with the pull type scrapers so I don't know much about them. They seem to be getting more popular though. Tractors are for sure way smother ride then a scraper. What was the bad luck you had with self propelled? What kind were you using?

 

[Countryboy]

lol took me a long time to type that book. I'm using my phone.

You typed all that with your phone? Are the numbers still on the buttons....

Thanks for the replies guys. :drinkup

More questions:

1. Whats the largest amount of twin scrapers that can be teamed together for loading?

2. Who else makes scrapers besides Cat? I've only seen Cat scrapers.

3. What is an average top speed of scrapers loaded and unloaded?

4. Why are all the wheels on a scraper mounted solid? I would think that if some travel was allowed on either end, traction would be gained.

 

[Tigerotor77W]

dunno why they called twins. They are not. The front motor is bigger because it powers all the hydraulics as well as front wheels)

Probably "twin" in the sense of "two" -- akin to how two-engined jetliners are called "twinjets."

(Not "twin" in the sense of "alike.")

 

[JDOFMEMI]

CB

I'll try this in order:

1) I have seen as many as 5 twin engines hooked together to load, but it is usually not a good thing. I seen the results (secondhand) of 5 657B scrapers hooked up loading. The tail end hooked a hard spot, and with over 4000 HP pulling on it, the goosneck broke right in half 2 is generaly the rule, but sometimes we hook up 3 in soft sand where we are traction limited.

2) Cat is far and away the largest producers of modern scrapers. They have no current competition in the larger scrapers, but some others make paddle wheels. Dresser, Fiat, John Deere, and a few others recently were making small units, but none sell very well. Most people would rather have an old Cat than a new anything else.
30 to 40 years ago, it was a far different story, and Cat had to play catch up to get to the top of the heap. Euclid was the top scraper brand for many years in the 50's and 60's. TS-24 was the best around in its day, but does not compare to modern units. LeTourneau, which later became WABCO, and Euclid, which later became Terex, were the prime contenders. Cat surpassed them all, largly because of the dealer support. Currently, Terex is the only other choice for large scrapers, and they are mostly nearing the end of their service life. Here in SoCal, there are about 100 TS-24B and C scrapers running, but over 2000 Cat 631 and up.

3) Most scrapers have an average top speed of a little over 30 MPH, which is really moving for what they are.

4) The wheels are mounted solid for reliability and simplicity, which go hand in hand. Cat has one model, the 615 paddle wheel, with a front suspension axle, and the B and C model Terex TS-24's have a front suspension axle, with nitrogen struts similar to a rock truck. They ride pretty good when functioning properly, but create a lot of maintenance items to go wrong.

I would post some pics, but time is short for me, and I don't have it down to a quick process. Someday I will take the time to learn, but right now it takes a painfully long time to get them up.

Hope that helps. I'm sure surfer joe will chime in with more as well

 

[Countryboy]

Great stuff JD. :drinkup

I might've wanted to try one of these things out if not for the stories I've heard about them. So I'll stick to reading about them.

 

[BrianHay]

Lol numbers are getting a little faded

Most I have hooked together is 6. That was in sand. In hard ground 4 tops. And if its hard and rocky only two. I was second in line one time in a train of 5. The scraper in front suddenly hooked realy hard ground, bit off more then we could chew and stopped dead. The rest of the train never even flinched. Jack knifed me in a heartbeat and snapped my bail like it was just a spaghetti noodle lol before the train could stop. Scared the chit outa me. Thought I was gunna get crushed. I've heard lots of similar stories were scrapers have got ripped in two or the floor ripped out of them when one hooks a rock when to many are hooked together.

Cat and Terex are the most popular self propelled. John Deere makes them as well. Fiat allis used to make some. Don't think they do anymore but I'm not sure. Cat and terex are the only ones I've worked with. There are more but can't recall the names.

Top speed on hard ground is about 35mph. If the ground is hard they reach top gear empty or loaded no prob.

I agree about the wheels. I'm guessing its because its way to hard to design a suspension system that would last. But maybe someone will come up with a system sometime soon. They are doing some great things with haul truck.

 

[BrianHay]

Stupid phone I'm way behind again lol

great stuff jd

 

[BrianHay]

Here is a couple shots my wife took out the widow of her adt this winter.

 

[Countryboy]

Stupid phone I'm way behind again lol

Not behind, just working at a different pace.

More questions: :drinkup

1. Is the connection between the 2 engines on a twin scraper mechanical or electrical?

2. If someone were to develop a suspension system, would it better to have one end suspended or both?

3. Is there any articulation in the hitch besides the side to side, for turning?

Enough questions for tonight.

 

[BrianHay]

lol Right on

The connection is electrical. It has a little brain box that keeps the transmissions in sync. And the throttle is run by air.

I think suspension in the front would make a big difference. But wouldn't make a big difference in the back.

Yup. Moves like an atd (with dif type of connection of course). They have stops though that keep them for going all the way like a truck.

 

[Countryboy]

Your response time is improving Brian.

Excellent help. :thumbsup

 

[BrianHay]

Here is one articulated some but not much. They will go a lot further.