Steep gradient coal haulage

[vanderghast]

I have a rather unique problem. Am building a 30km coal haul road in Indonesia. The only available land has a steep hill we have to cross.

I have 165 meter rise in height over 500 meters, ie a 33% gradient over 500 meters. To get this down to 10% gradient, we would have to cut and fill 1.5 bank cubic meters, and the height of the cut would be up to 80 meters.

We are looking for the most cost effective and fastest to implement method, I am thinking of increasing the gradient. We have considered tunnels (expensive and slow to implement), conveyor transfer (moderate expensive and moderate implementation speed).

We are using standard tronton, or 3 axle trucks bearing 30 tonne loads with a total loaded weight of about 45 MT. We use MAN or HINO trucks.

I am considering several options for the gradient, 12%, 16%, 20%. With our current trucks, at 20% gradient, I would have to half load the trucks and maybe do a rehandle at the top of the slope, fully loading the trucks at the top of the hill.

Are there any better solutions?

a) are there any trucks of a similar size, or could we custom make/modify to do a 20% gradient? Since it is only 500 meters, if there are trucks which can handle the gradient, I would buy a few to use as shuttle, so we would transfer to these trucks and transfer back.
b) I was also thinking of a powered tow up the slope. Could we use either a tow truck of some sort just to get the trucks up the 500 meters? Or how about a towline from the top of the slope powered by a crane?

 

[ben46a]

If this is a long term project, I think a conveyor will be your best bet. Over the long term the cost associated with trucks and fuel will be exorbitant compared to a belt system. If you really just need to get it going quick build the 20 percent road and use a couple push trucks until the belt is built. A tow line system will be complicated and eat up time with all the hooking and unhooking.

 

[ben46a]

Or get a fleet Pacific P12w3 trucks with coal bodies and water cooled brakes. But I'm not sure that they built them these days.

 

[vanderghast]

I looked up the P12w3, whoa! Those trucks are huge. But it looks like they don't make them anymore..

I found this http://www.youtube.com/all_comments?v=xp1f_EWJzRA
that shows a combination of a tow and push truck on a 30% gradient with 120 degree switchbacks.

Our situation will be much better than the guys in the video. I only have 500 meters to deal with, at 20% gradient, and fairly straight. But how do I figure out what kind of tow truck is feasible?

 

[ben46a]

Another option would be a western star 6900xd as seen here: http://www.youtube.com/watch?v=XH4HvJAdSuI&sns=em
This is a purpose built 50 ton (45 tonne) coal hauler for off highway use. Usually built with allison automatic gearboxes althought this one has an 18 speed manual. As far as a tow truck, I think a push truck would be more efficient, as you could have a cusioned bumper on the front to push against the tailgate of the truck hauling the load, and not have to hook or unhook chains or cables like you would need to do with a tow vehicle. Any high power truck with full axle locks and some weight over the drive axles could do the job. Even an old rubber tired dozer would do the trick quite nicely with a cusioned blade, but you may not get the speed you require. If you rather a tow vehicle, some sort of hydralically raised hitch that could be operated from the cab to hook the axle of the pulled truck would be speedy and you could put some weight from the toed vehicle onto the drives of the tow truck for traction, while maintaining a speedy hitch/unhitch of the 2 trucks.

 

[tireman]

Another option would be a western star 6900xd as seen here: http://www.youtube.com/watch?v=XH4HvJAdSuI&sns=em
This is a purpose built 50 ton (45 tonne) coal hauler for off highway use. Usually built with allison automatic gearboxes althought this one has an 18 speed manual. As far as a tow truck, I think a push truck would be more efficient, as you could have a cusioned bumper on the front to push against the tailgate of the truck hauling the load, and not have to hook or unhook chains or cables like you would need to do with a tow vehicle. Any high power truck with full axle locks and some weight over the drive axles could do the job. Even an old rubber tired dozer would do the trick quite nicely with a cusioned blade, but you may not get the speed you require. If you rather a tow vehicle, some sort of hydralically raised hitch that could be operated from the cab to hook the axle of the pulled truck would be speedy and you could put some weight from the toed vehicle onto the drives of the tow truck for traction, while maintaining a speedy hitch/unhitch of the 2 trucks.

That's no 18 speed, it's an 8LL. Definitely better to push than tow, but conveyer is most cost effective long term.

 

[ben46a]

I know it has a blue button tireman, but I've been in the trucks. Struck me as odd too. They are indeed 18s.

 

[Hendrik]

That's no 18 speed, it's an 8LL. Definitely better to push than tow, but conveyer is most cost effective long term.

The problem with a conveyor system is that if it breaks down, production stops. Plus the coal has to be loaded onto conveyor and then from conveyor back onto truck.

 

[ben46a]

Well as long as you have a steady string of trucks, you save rehandling by using a 100 tonne or so hopper to load trucks,and having a feed hopper that truck can dump into. Make the load out hopper a drive thru design and there's no backing up. Coal isn't heavy so maintenance on conveyor would be low. I do understand your concerns though. Pound for pound, its hard to beat a belt in low impact, low abrasion materials.

 

[vanderghast]

Thanks a bunch for the suggestions! Shout out especially to ben46a.

I think I'm going to trim the hill to about 20% gradient and then use push trucks for the fast start. Then we will try to get access to more land to widen the corridor so that we can moderate the gradient a little more over time.

 

[blitz138]

You said it was fairly straight, cant put a switchback to cut down the grade?

 

[vanderghast]

Hmm, the switchback idea I had not thought about. I need to check on how much land we can get. Maybe possible.

 

[joispoi]

You said it was fairly straight, cant put a switchback to cut down the grade?

That was my first thought. Even if you add 1500 meters to the length of the road with switch backs, it's only over one section, you should be able to keep it under 10% (depending) and you can run full truck loads...no?

 

[ben46a]

Had another thought.... If you do go the pushtruck route, automatic transmissions (allison, not eaton autoshift) make life a lot easier on the pushtruck driver.

 

[Hendrik]

Well as long as you have a steady string of trucks, you save rehandling by using a 100 tonne or so hopper to load trucks,and having a feed hopper that truck can dump into. Make the load out hopper a drive thru design and there's no backing up. Coal isn't heavy so maintenance on conveyor would be low. I do understand your concerns though. Pound for pound, its hard to beat a belt in low impact, low abrasion materials.

Yes but the problem is that it will be going up a fairly steep gradient, which would put quite a bit of strain on the system.
Another thing to consider is the skill of the drivers, steep roads and inexperience is not a good mix. So a conveyor system might be a safer option.

 

[ben46a]

That's another good point, green drivers and a 20 percent grade, loaded or not could be quite hair raising, especially with slick coal dust on a wet day.

 

[blitz138]

How long is the total haul?

 

[JGS Parts]

Well also do you have a time frame when this needs to be done by and i am guess you have a budget? I guessing you want to be pulling the coal out ASAP , but i think safty should be the most stressed thing here I am with the others about green drivers and loaded trucks on that type of grad

 

[DoosanFan]

I have a rather unique problem. Am building a 30km coal haul road in Indonesia. The only available land has a steep hill we have to cross.

I have 165 meter rise in height over 500 meters, ie a 33% gradient over 500 meters. To get this down to 10% gradient, we would have to cut and fill 1.5 bank cubic meters, and the height of the cut would be up to 80 meters.

We are looking for the most cost effective and fastest to implement method, I am thinking of increasing the gradient. We have considered tunnels (expensive and slow to implement), conveyor transfer (moderate expensive and moderate implementation speed).

We are using standard tronton, or 3 axle trucks bearing 30 tonne loads with a total loaded weight of about 45 MT. We use MAN or HINO trucks.

I am considering several options for the gradient, 12%, 16%, 20%. With our current trucks, at 20% gradient, I would have to half load the trucks and maybe do a rehandle at the top of the slope, fully loading the trucks at the top of the hill.

Are there any better solutions?

a) are there any trucks of a similar size, or could we custom make/modify to do a 20% gradient? Since it is only 500 meters, if there are trucks which can handle the gradient, I would buy a few to use as shuttle, so we would transfer to these trucks and transfer back.
b) I was also thinking of a powered tow up the slope. Could we use either a tow truck of some sort just to get the trucks up the 500 meters? Or how about a towline from the top of the slope powered by a crane?

Considering its part of a 30km haul road, trucks would be less hassle than a belt and double handling on both sides of the hill. Put in some switch backs and get the gradient down to 10% and call in a MAN driver trainer to train up all of your drivers.

I assume they are side tipper trailers? You using TGA/S 40.480 or 33.480? 6x6 or 6x4?