D6 broken chain and rollers

[Ahmed9966]

Hello
i have D6T and D6R They work together in dredging project and after month the d6T chain got broken and the D6R lost most of he’s rollers
So what makes that happen .. note that the dozers work in sand-fills dredging project and any recommendations for in the dredging work ?



thanks ….

 

[Nige]

after month the d6T chain got broken and the D6R lost most of he’s rollers

Are you saying the track chains were brand-new one month earlier.?

Are the track chains in your photo genuine Cat or aftermarket.?
Same question regarding the track roller in the 2nd photo.?

What width of track shoe is fitted to these dozers.?

Do the operators use 3rd gear (either forward or reverse) on a regular basis.?

 

[.RC.]

Those rails look well worn, and have the rollers been flogged to death somewhere else and then a dodgy repair done. On top of that sand is nasty nasty stuff for abrasion.

 

[Ahmed9966]

It wasn't new but it was in a good condition

yes its genuine cat part number 234-9699

the track rollers for the d6R was new

910MM

no they don't

I'm just wondering is it because the nature of the job, 22 hours per day most of the work in salt water
also is there’s any suggestions or advices when buying the new undercarriage to fit our job ?

and does the tracks have life time ?

thanks for your help ♥️

 

[JPV]

From what I understand the Port of Portland who owns and operates the pipeline dredge Oregon on the Columbia River here gets less than 1000 hours out of an undercarriage on their D-8's, I think it is closer to 500. Pushing sand ain't a cheap hobby. Years ago I guess they tried rubber tire dozers and had lots of U-joint problems. I don't know if that is the only reason they quit using them or if it was because they were not as effective.

 

[Ahmed9966]

Are you saying the track chains were brand-new one month earlier.?
No but it was in a good condition
Are the track chains in your photo genuine Cat or aftermarket.?
Yes with part number 234-9699
Same question regarding the track roller in the 2nd photo.?
The rollers was new
What width of track shoe is fitted to these dozers.?
910MM
Also All the dozers we own LGP
Do the operators use 3rd gear (either forward or reverse) on a regular basis.?

 

[skyking1]

wow that's crazy low life on UC., JPV.

 

[nicky 68a]

I’m wondering if the wet,running sand you say you are working in may be responsible for causing the chain/rail to go even tighter and that’s caused the sprocket to go too tight on the bush and rip it clean out as in the pic?
Perhaps they need to be run super slack.
I’d also be thinking that they’ve been run in 3rd gear.
Dredge sand is a tough job to take on,and you need to up your game in track tension and operator education.
I think you may see final drives fail and possibly see trumpets break off unless you slow your operation down.
Things are going to break up further

 

[Cmark]

I had the job of looking after a fleet of dozers, Komatsu D65 thru 155 in running sand. Best I could manage for a set of U/C was 2000hrs with new segments and carrier rollers at the half-way mark.

All you can do is factor it into your hourly rate and if anyone comes along who thinks they can undercut your price, good luck to them.

 

[John C.]

I've been to a couple of dredging operations and what is described here is pretty normal. The first was when the Sand Point Naval base was shut down and then turned into a a dock for a research vessel. The pier area was dredged and the spoils dropped into a containment area for the water to drain out. The stuff was a soup when it dropped out of the drag bucket. An International TD25 and a D8H Cat were pushing the spoil to the far reaches of the containment and the soup was over the top of the tracks most of the time. I was told undercarriage life was measured in months back in those days.

 

[skyking1]

We only suction job dredge job I was on was a hazmat cleanup in the port of Tacoma. The stuff we pumped was the nasties. Later they capped it with sand from the Blair waterway and turned it into a parking lot. That was when the Blair was deepened up for big container ships and they took out the 11th Street bridge on the Blair. In short I never got to see the dozer operation.

 

[Nige]

I’m wondering if the wet,running sand you say you are working in may be responsible for causing the chain/rail to go even tighter and that’s caused the sprocket to go too tight on the bush and rip it clean out as in the pic?
Perhaps they need to be run super slack.
I’d also be thinking that they’ve been run in 3rd gear.

I wonder if dredge sand behaves something similar to snow and need trap holes in shoes to let it extrude out of the gap between the sprocket and the space in between the links.? The other alternative is run the tracks super slack as Nicky mentioned.

From the Undercarriage Management Guide - "Use center punched shoes in certain situations to help relieve extrudable materials such as wet sand, clay, or snow."

I also believe speed could be a factor. To the OP I suggest that you go and spend a couple of hours watching the operation from a location where the operators are not aware of your presence. That way they will operate "normally" by their standards without being influenced by the fact they know someone is watching them.

 

[skyking1]

<Richard Attenborough voice> And here we have the itinerant dozer operator in his element on the beach. Oh look, he's 'highballing it' in 3rd gear.
If you look closely you can see the sand squirting out of the rails as it passes over the sprockets. </Richard Attenborough voice>