Why does Caterpillar use high tracks?

[bteigrob]

I have a book on the history of Cat written by a guy who had help from Cat and even covers some experimental stuff that never went into production. It states that Cat went to the high drive to reduce final drive damage and to get the sprocket out of the dirt.

Rick

Rick, what is the title of the book?

 

[CDUB]

I've been really pleased with the stability of high track machines on slopes. The pivot points of the roller frames being further forward seems to help the machine cope with uneven terrain compared to my old oval track 7 that tipped and leaned on whatever the rear of the machine was running over.

 

[Nige]

That Liebherr looks like a knock-off copy of a D10T in my eyes. Anyone who quails at Cat spare parts prices shouldn't buy one a Liebherr IMO.

 

[dirthog]

Trouble is Clete track had a hi drive LONG time ago before Cat.

 

[digger doug]

I think the fore-and-aft balance of a high-track depends to a large extent what's hanging off the back of the chassis. Machines equipped with rippers seem far better balanced than those without. In fact some models even mandate the use of a rear counterweight if no ripper is installed.

I saw a advert for a Cat hidrive set up for logging, with the arch out back.
IIRC the frame was longer and the rear idler was further back, easy to build
various track lengths is what I saw.

 

[digger doug]

Also,
why have the rubber tracked skid loaders adopted the same scheme ?

 

[lumberjack]

Ground clearance on CTLs would suffer as well as putting the hoses in a more risky position.

 

[simonsrplant]

Anyone who quails at Cat spare parts prices shouldn't buy one a Liebherr IMO.

Nige, ain't that the truth!

 

[Foozzer]

I had heard Cat had pattened the High Track design, thats why no one has made one.... until recently when the patten ran out. Liebherr built a high track machine. View attachment 142745

I would love to put that liebherr through her paces,now that would be fun

 

[Nige]

And if right from the get-go it can't out-perform or at least equal a D10T it'll soon be consigned to the scrap heap of history ......... IMO

Liebherr couldn't have timed it worse. They spent lord knows how many years developing this new model and then released it right at the point the open pit mining industry has literally taken the biggest sh1t in recent history.......

 

[Foozzer]

I wondered if a high track has better leverage over the track its trying to move verses an oval track design ?

 

[simonsrplant]

And if right from the get-go it can't out-perform or at least equal a D10T it'll soon be consigned to the scrap heap of history ...

IMO, sadly, they are on two back feet. As you rightly pointed out, the downturn, and the after sales. Liebherr aftersales are much fewer spread than the global might of caterpillar. That fact makes sales.

 

[digger doug]

Ground clearance on CTLs would suffer as well as putting the hoses in a more risky position.

and yet mini excavators have not.....

 

[lumberjack]

Mini's final drives are a fair bit smaller eh?

 

[digger doug]

Mini's final drives are a fair bit smaller eh?

Which put's them even lower to the ground.....

 

[lumberjack]

Sprocket diameter dictates the height, the housing on my mini is comparatively smaller than the one on my CTL, relative tot the sprocket diameter.

Also the ctl's final drive is longer axially, which is what I was thinking. Their position probably helps with packaging the components of the machine as well.

 

[lantraxco]

Excavators have to have low drives in order for the house to turn above them. Mecalac makes a nice hybrid though.

One factor on the CTL's aside from ground clearance and ease of service is the tracks. With a longer track you get a bit more stretch to absorb sudden shocks and more length in the loop means longer tread life.

 

[movindirt]

Excavators have to have low drives in order for the house to turn above them. Mecalac makes a nice hybrid though.

One factor on the CTL's aside from ground clearance and ease of service is the tracks. With a longer track you get a bit more stretch to absorb sudden shocks and more length in the loop means longer tread life.

Besides that, who would want a flat track CTL? I wouldn't.

 

[John C.]

I have been a skeptic of the high drive for years but over the years I have seen plenty of things that color the arguments against it.

High drive life for the most part is about twice as long as oval tracks, both working in the same conditions. Then again the cost goes along with that. High drive is at least one and a half times as much money up front. I've seen high drives work slopes as well and any oval. The operators seem to be feeling the height and are more careful most of the time. The repair times are far less and actually I've seen fewer broken finals on high drives than what I've experienced over the years with the ovals. Not having to work with a hundred tons of pressure to free a sprocket was very high on my list a bunch of years back.

I have wondered about the number of teeth engaged with the track over the sprocket and increased wear. Basically a high drive engages three teeth at any one time. Doesn't seem to make the bushings wear out any faster though. The oval might hit five or more. I have never understood why there wouldn't be a top roller installed on all high drives. I've seen plenty of well worn front idler carriers where the rails basically cut through them.

All in all I think the design has proved itself over the years.

 

[CM1995]

and yet mini excavators have not.....

Mini ex's are an entirely different animal undercarriage wise compared to CTL's. Mini's basically rely on their undercarriage to transport the machine across the site. CTL's require the undercarriage to perform the work.