Good idea or bad???

[vapor300]

Heres my idea.

Say you are using 631's and D10's to haul dirt, and you want to keep cost down so you dont want to use pushpull scrapers, what if you put a bail and a push block on the front of a 31, and a hook on the back of the D10, that way the 10 can be pushing a scraper and the 31 can come in behind and hook up so that when the 10 gets done pushing the front scraper, the back scraper can set in? I can see the flaws that eventually the 10 will have to backup even further, but in the right cut i think it would really speed up production?

FAIL or WIN???

 

[AustinM]

I don't think it's a good idea. I don't see the 10 being able to get out of the way fast enough to make it productive after pulling the second scraper through the cut. I guess the scraper could go around, but he would have to turn fairly sharp. And like you said, then the dozer would have to back up a longer distance.

Also, if a hook was placed on the back of the dozer the ripper would have to be removed for obvious reasons. That would mean if ripping were needed, another dozer would be required. I would like to have my options open with one dozer that can do several things than have two machines.

 

[vapor300]

sorry, i didnt mention in my scenarion that there would be around 12-16 31's running, and 3 10's one 10 with a ripper, one with a push block, and one with a push block and bail.

 

[Greg]

That also eliminates the possibility of having a push block on the back of the D10's so you can double barrell push if desired.

 

[vapor300]

??? No it dont, it be the same thing thats on back of a 37, a stinger and hook. Why couldnt you push it!

 

[Greg]

What I meant was machine with ripper on the back I wouldn't want to try to double barrell push.

 

[AustinM]

I think you mean you would have one 10 with a push block and hook(instead of bail). I don't think the increase in production (if any) would justify the cost of installing the hook on a dozer and the bails on the scrapers. The second scraper being pulled through having to turn to go around dozer would add at least 4 seconds to each load, doing this 50 to 75 times a day(because it wouldn't happen to each scraper each round) would mean 3 minutes at the end of the day (per scraper) being pulled by the dozer through the cut. Let's say hypothetically that equates to one less load per day per scraper, if 12 631's were running, that's 216 CY every day lost. (At 18 CY/load). I think 31's can haul more than that, just using a safe estimate. Add the increased risk for two machines needing to go in different directions at the unhooking point that are very close to each other. The likelihood of a yellow iron incident at this point is exponentially higher than normal.

That doesn't include the added time for the dozer to back up twice as far. If you've got 3 dozers pushing, and 3 scrapers are hitting the cut at near the same time and two of the them hook up immediately, then you've got to add the time for the dozer to back up and catch the 3rd one, which means that it has to single load for longer. (until the dozer gets back to him) Although the 4th scraper that comes in can hook up to the back to the dozer immediately. This may be a wash.....

I think at the end of the day, even in the best of circumstances, it will not increase production enough(actually I think you would lose some) to justify installing push block and a bails on several of your scrapers and a stinger and hook on the dozer. Couple that with the added risk of a downed machine because one your scraper hands tries to get fancy and clips the side of the pushcat on his way around, ripping the draft arm off or something like that and now you're in a pickle.

Personally I would keep them the way they are, tell 'em to haul ass and keep it consistent! Good luck and if you do decide to give it a go, come back to the thread and let me know how it worked!

 

[AustinM]

vapor300 I've given this some more thought and want to look at it a different angle, specifically from a cost vs. production standpoint and what would need to happen to get your money back from making these changes. All these numbers are estimates.

We'll use just installing the push block and hook on one scraper and compare it to one without.

I think it's going to take about 1 ten hour day for two mechanics to install these pieces on each machine,(dozer and scraper) possibly more. With a service truck and crane, etc. That's 20 MH/day for 2 days=40 MH. I don't know what your labor rates are, but I would say $30/hr would cover wages, burden, etc. That's $1200in labor. Add the service truck @$50/hr. Thats's $1000. So we've got $2200 in labor and rent.

I don't know how much the material is gonna cost, but I'll guess that the push block and bail is gonna cost about 5k and the stinger and hook will be 3k. So we've got $6100 to put this on one scraper and $4100 on the dozer. Initial investment of $10,200. Multiply accordingly if you wanted to install it on more than one scraper. Maybe you have these pieces in your yard, I don't know, but I'm gonna assume you have to buy everything.

Let's say you would like to pay for these improvements in one 5 month season.

If your average unit price for dirt is $1, you would have to move 10,200 more yards with the scraper with the push block and bail than the one without to break even. If you run these two scrapers 50 hrs a week for 5 months and average 150 loads a day, the scraper without the push block will move around 270,000 CY of material. (again, at 18 CY/load, use whatever CY/load you want to) This means the scraper with the push block and bail will have to move 280,200 CY to break even. Percentage wise, that's an increase of 3.5%. This percentage will get smaller as the volume goes up...... Keep in mind, this scenario is in a perfect world, with gobs and gobs of dirt to move and your scrapers work all day, 5 days a week for an entire 5 month season.

So every day, the scraper you put this on must have 3.5% more production than the scraper without. If scraper A gets 150 loads, Scraper B must get 155, so on and so forth. Doesn't sound like much and seems very attainable, right? Possibly. Remember though, this 3.5% increase in production is just to get back to EVEN, not to give you a competitive advantage. You'd have to DOUBLE that to make it worth your time, in my opinion. The scraper with the push block and bail doesn't go down the haul road any faster than any other scraper in the spread. If you did this on one scraper out of 12, it would be critical to stay in alignment because what happens if that scraper shows up at an odd time and meets his dozer (one with hook) at the beginning of the cut? He's not (nor should he) wait for another scraper to come in ahead of him so he can get behind it.

This is probably more than you were looking for, and I apologize in advance if that's the case. This is just the way I would look at it if I were weighing it out. Good Luck!

 

[JDOFMEMI]

First off, I like to see this kind of out of the box thinking. Second off, I don't see the advantage of it. The initial cost is one, the layout of the cut is another. If you want to increase production by just as much or more then chain load. If your cut is long enough for the bail idea to have a chance, then chain loading will work well. If it is done right, and coordinated by someone who understands the concept, then the pushcat never has to back up. The scrapers simply change the direction they are loading in, and the pusher turns around at the end of the cut. The pushcat only has to turn away from the just loaded scraper and pick up the next one one lane over in the cut. Alternate right-left till the end of the cut, and the next scraper can see to go turn around and come back the other way.
A pushcat that almost never backs up can outload a conventional spread by a large margin, but it only works when the cut is long enough, and not to much grade from one end to the other. It needs to be weighed out the difference of more loads vs 1/2 of them loaded uphill, so they are slightly smaller loads. It works up to a point.

 

[Catskinner21]

Hey I understand that this post is older but I also have a ? Vapor this has to do with the 31"s and the 1O . Is it me are is the idea of only cutting one direction loosing production? The way I was taught to move dirt with scrapper if cut it large enough we cut both directions the only time the pushcart backs up is to back out of cut and pick up the next scrapper on the go . Not have the 31 stop 200 ft behind the 10 which makes him have to back up to pick him up. Vapor I know work for that same outfit but do not agree with there method. I may be wrong in this case but I can't see backing the 10 all the way back down the cut . Maybe someone can chime in with some more light on this subject.

 

[Scrub Puller]

Yair . . . slightly off topic but there's jobs and jobs. You blokes are talking organised balls out production which is very uncommon in places that I've been.

Messing around in tidal canals it was three or four green lizards or twenty sevens hooked together with an 8 or a 9 up their arse. Under those conditions it was very handy to have a hook on the back of the push cat . . . if you were at the wrong end it saved backing up throught the slop if a scraper got hung up.

I made up rough as guts hooks up out of broken and worn out ripper tines that slipped into the middle slot of the D8 rippers that was vacant any way.

On another subject. I've always thought that tandem pushing pretty much is BS but I saw outfit stripping overburden and they dropped the hooks out of the rippers and pushed on a block that pinned into the slots on the mainbeam. The few weeks I was there they didn't suffer no neverminds as far as I could see.

Cheers.

 

[durtmvr]

I have had parts scraper 637s pushblock installed on the front of my hot 31s. It is cool to have your good hand on those 31s and about all they do is hunt the edge cut (where you doublecut). Scraper 1 rolls into the edge and 31 with block goes in for the shove behind him. Pusher falls in behind #2, no need for a backup and relatch on your scraper doubling your edge. Have had some situations where the 31 with pushblock can latch up to another scraper and shove while the pushcat is farting around or fueling. However, if you have time like that cause the pushcat is farting around its time to find another catskinner. It proved handy a time or 2 when the pushcat went down and we still got some production.

I have also pushloaded scrapers in reverse stinger to stinger but the guy getting the shove had better be a hand and not try to go to China or his stinger will end up over the top of yours! I wouldn't try this in hilly terrain either or downhill. Fairly flat only. This is frowned upon by unions (wouldn't want a 31 operator taking the pushcats job now would we?) and those that don't know any better.

 

[Terexisking]

Go back to the 50's , this is how scrapers were assisted in loading. This didn't last long as they went to the rear push block.. Too many radiators damaged .

 

[Shimmy1]

Old thread but my take on it I used to move dirt with a converted Allis Chalmers 260 behind Cat 75C pushed by D7H. My experience was in hard ground you needed to pick up a little on the dozer blade for traction. That would be my concern with hook on back of pushcat. FWIW we once moved 3500 yds in one day. 16 hour day, good sticky clay must have been getting 22 yds or better per load on a 1000 ft haul. Was making a load every 6 minutes.