Caterpillar 786 haul truck.

slagpot · Mar 30, 2010

Another state of the art haul truck for its day.Very little information on it.

In October 1965, Caterpillar introduced a massive,240-ton capacity prototype bottom-dump coal hauler, Designated the 786. At the time, it was the largest type of hauler ever constructed by an manufacturer. The Cat 786 was in the same family of electric-drive-haulers as the 779 and 783. The same Cat D348, V-12 diesel engine was used in all of these trucks, but the 786 had two engines, one at each end, driving the leading axles through a Caterpillar-designed electric-drive system. The power ratings were 2,000 gross hp and 1,920 fhp. Only four Cat 786 coal haulers were built in this configuration. The pilot version had the engines mounted on top of the tractors, not in front. All five units worked at the southwestern Illinois Coal Corporation's Captain Mine (now owned by Arch Minerals) in southern Illinois. The 786 was 96 feet in length, and weighed in fully loaded at 670,000 pounds. After 1969, all work on the electric-drive hauler programs by Caterpillar ended. These incredible haulers were soon relegated to the Captain Mine's bone-yard, and scrapped by the mid-1980's.

Slagpot

stinkycat · Mar 30, 2010

Cat Haulers

Slagpot I had the honor of working on the Cat 779 truck in 68 & 69. It had some major problems in design Cat started making major changes to bed design and placement of fuel,hydraulic tanks, and control panel. But engine was the real problem the D348 was V12 with dual overhead cams we were replacing heads often because of carbon build up, because of the lack of space it was easier to drop the complete engine to replace the heads. The generator and traction motors were pretty much trouble free. The control system was fairly reliable, They were easy to operate 8 to 10 mph loaded on a 10% grade and about 30 mph on flat land. I'm still looking for pictures of the truck.

Aussie John · Apr 1, 2010

There is a fair bit of information and photos of these proto-type trucks published by Eric Orleman and others which cover the history of Caterpillar. I have these books and can post book titles over the next day or so. I also remember seeing a Cat film which showed the testing of the 783 truck back in the early '70's by dropping large rocks (probably 20 ton plus) into their bodies!

John

Aussie John · Apr 1, 2010

There is a fair bit of information and photos of these proto-type trucks published by Eric Orleman and others which cover the history of Caterpillar. I have these books and can post book titles over the next day or so. I also remember seeing a Cat film which showed the testing of the 783 truck back in the early '70's by dropping large rocks (probably 20 ton plus) into their bodies! Here is one photo I found on a diecast modlers forum after doing a Google image search.

John

AmerIndependent · Apr 1, 2010

Wow, that thing looks alien. Thanks for the pic John!

Aussie John · Apr 2, 2010

the book "The Caterpillar Century" by Eric Olemann has got a better photo of this twin power rig pluse a photo and some info on the 783 3 axle truck.
John

stinkycat · Apr 2, 2010

Cat 779 Electric Truck 1968 or 69

This is only picture I have left

activeorpassive · Apr 6, 2010

awesome pic.

Feodor · Apr 14, 2010

Hi, I am new to this forum.
I wonder if someone can help me out. I need parts for CAT 785 DUMPER.
Any idea where I can buy used parts?

Thanks

AmerIndependent · Apr 14, 2010

I may be able to help you with your parts needs. What is the serial # for your machine and what parts are you needing? If you have a list of parts you can email them to me and I'll get back to you with prices. My email is: trevor@americanindependentinc.com

Brian Bleigh · May 16, 2022

Aussie John said:
There is a fair bit of information and photos of these proto-type trucks published by Eric Orleman and others which cover the history of Caterpillar. I have these books and can post book titles over the next day or so. I also remember seeing a Cat film which showed the testing of the 783 truck back in the early '70's by dropping large rocks (probably 20 ton plus) into their bodies!

John

My dad was an engineer at Cat for 35 years. The Captain was one of his projects when I was a kid in the early and mid 60’s. Any info you might have on this truck would be appreciated. I think I might still have pictures of the truck he took.

digger doug · May 16, 2022

Brian Bleigh said:
My dad was an engineer at Cat for 35 years. The Captain was one of his projects when I was a kid in the early and mid 60’s. Any info you might have on this truck would be appreciated. I think I might still have pictures of the truck he took.

I would have liked to talk with him.
Do you think that CAT got the electric drive parts from Letourneau ?
IIRC they were in the same town.

Brian Bleigh · May 16, 2022

digger doug said:
I would have liked to talk with him.
Do you think that CAT got the electric drive parts from Letourneau ?
IIRC they were in the same town.

I’m not sure about the electric drive parts. I will reach out to a friend of his next month when he is back in town.I was born in 1961, and to the best of my recollection Letourneu was called WABCO then, a subsidiary of Westinghouse Air Brake Corp. Wabco was bought out by Komatsu in the early 1980’s. CAT was very upset when the sidewalks of their Administration Building in Peoria were replaced because the contractor who got the bid used Komatsu equipment to do the job. It didn’t take but maybe 1/2 a day before that was fixed.

Nige · May 16, 2022

From the info I found the LeTourneau company was sold lock, stock, & barrel to Wabco in 1953.
Wabco in turn was sold to American Standard in 1968 but the trucks retained the Wabco "Haulpak" brand identity.
In 1984 the mining & earthmoving product range was bought by Dresser Industries and the machines were renamed "Dresser Haulpak". I had a brief involvement with trucks branded as such in 1988/89 in a coal mine in India.
Komatsu and Dresser were involved in a collaborative effort in earthmoving many years prior to the 1980's. This collaboration ended by Komatsu buying out Dresser's stake in the joint venture and soon after all the models in the electric-drive haul truck line were re-badged as Komatsu. Soon after the model numbers changed from the older 170, 190, 240, etc, which was the truck payload in US tons to the 630, 730, 830, 930, etc, in use today which is the Max GVW in 000's of pounds.

John C. · May 19, 2022

I was sent to a school for the Haulpak 30 and 50 ton trucks back around 1991. Komatsu had just taken over the Dresser line at that time and employees of that plant were on pins and needles as the Haulpak branded stuff was being phased over to the Komatsu paint and decal schemes. The factory was the original plant for Letourneau and they were still using the mobile cranes and original lifting and handling units that RG built back in the thirties and forties. The other other interesting item was that this plant was just across the river from the original Caterpillar factory in Peoria.
As I recall Dresser purchased that line from International Harvester around 1988 who had been in collaboration with Komatsu for years. The ownership histories though are so jumbled that I can't keep them straight. Dresser was an oil field supplier of things like drilling mud and supplies before getting involved with heavy iron.

Nige · May 19, 2022

John C. said:
Dresser was an oil field supplier of things like drilling mud and supplies before getting involved with heavy iron.

Didn’t a part of the Dresser (Wayne?) group make gas pump meters back then.?

digger doug · May 19, 2022

Nige said:
Didn’t a part of the Dresser (Wayne?) group make gas pump meters back then.?

This is the Dresser I always knew of:
https://dresserutility.com/about-us/

Seems they became a cash rich comglom, and started
buying "things".....like dozers, Off hiway trucks, etc.

And then....They got bought by G.E....and then got sold back off....Oiy!

"Dresser Coupling" has always been a term I have used allot to describe a compression pipe coupling.

John C. · May 19, 2022

I actually believe that the Dresser purchase of IH construction equipment was part of some kind of plan for Komatsu to obtain all the IH assets. Dresser only had IH for four or so years that I remember. I know all the IH people in that time period treated the deal as some kind of refinance program and thought things would just keep going along as normal. Eyes were getting opened when I went back to the Haulpak plant and all the new machines had Komatsu paint and decals with plenty of new engineering to boot.

Rmartin · Nov 12, 2023

slagpot said:
Another state of the art haul truck for its day.Very little information on it.

In October 1965, Caterpillar introduced a massive,240-ton capacity prototype bottom-dump coal hauler, Designated the 786. At the time, it was the largest type of hauler ever constructed by an manufacturer. The Cat 786 was in the same family of electric-drive-haulers as the 779 and 783. The same Cat D348, V-12 diesel engine was used in all of these trucks, but the 786 had two engines, one at each end, driving the leading axles through a Caterpillar-designed electric-drive system. The power ratings were 2,000 gross hp and 1,920 fhp. Only four Cat 786 coal haulers were built in this configuration. The pilot version had the engines mounted on top of the tractors, not in front. All five units worked at the southwestern Illinois Coal Corporation's Captain Mine (now owned by Arch Minerals) in southern Illinois. The 786 was 96 feet in length, and weighed in fully loaded at 670,000 pounds. After 1969, all work on the electric-drive hauler programs by Caterpillar ended. These incredible haulers were soon relegated to the Captain Mine's bone-yard, and scrapped by the mid-1980's.

Slagpot

In the mid 70’s a buddy of mine was a factory service tech for Kress haul trucks. I was a field service mechanic for a Michigan dealer out of Peoria. I was working on a dozer at River King and was waiting for parts. I knew my friend was at Captain mine for the week so I looked him up at his motel. We went out and he showed me those four trucks, all parked together.
Later, I saw a engineering friend who worked at Cat. I just happened to mention if he had ever heard of Cat building a bottom dump coal hauler.
He had a shocked look on his face and said yes he was a engineer on the project and how did I know about the truck. I told him I knew where all four were parked. He said when Cat gave up on the concept, they gave all the spare parts to the mine and said when they were gone it was the end.
I’m glad I stumbled on to this site.

Caterpillar 786 haul truck.

Well-Known Member

Well-Known Member

Well-Known Member

Well-Known Member

Attachments

Site Sponsor

Well-Known Member

Well-Known Member

Attachments

Well-Known Member

New Member

Site Sponsor

New Member

Senior Member

New Member

Senior Member

Senior Member

Senior Member

Senior Member

Senior Member

New Member