Got into an argument with super on the job. He told me not to pry large rocks out of the ground because it will break the wishbone on the blade. I keep looking for a wishbone but haven't found it. Is prying rocks a bad practice or is that one of the things modern dozers can do? Personally I think he's full of $£!+. I've only been operating 25 years. D8T with 680 hrs COMMENTS ?
What kinda blade?
I guess it's a standard SU. Nothing special
There's a space between the curved face of the blade and the flat back plate of the blade, it's hidden in there. (shhh, don't let it know you know)
Wishbone? Never heard of it, unless he's talking about the tag link between the back of the blade and the hardnose.I've seen any number of the ball joints broken off those. Certain tractors have a hook at the back for prying out rocks, it's called a ripper... I wouldn't want to see an operator on one of my tractors prying out rocks using the end bits on the blade unless the ground was really soft with the occasional rock or if the size of the rocks was pretty small.
When he says "large rocks" that is a wide definition. To some, 6 inches is large, while to others, 6 feet may not yet qualify as large. I suspect if he is prying on it with the blade, it is too large to get the rippers over it to pry with. He may or may not have already ripped all around the rock. I have used the blade to pry out an untold number of large rocks over the years, and while I know I have stressed parts, I have not broken anything doing this. On the other hand, I have seen idiots fail at prying them out gently ans so they back up and get a running start. I have seen broken mainframes, trunions, push arms, moldboard edges, etc. from this practice. In some parts we can't blast, breakers are expensive, and the lesser of the costs is to use the dozer to push, pry, etc. to get the rock out.
Hey Jerr, would this rock class as too big...?
That one is good sized Nige. I once had one we pushed with a D-9L and a D-9H, both with 16' wide U blades. When the tractors were blade to blade, there was 3 feet of rock sticking out on either side. It was rounded, or really more oval, like a large egg. it was about as tall as the one in your picture, if it was rolled over to the tall side. I know it was as tall as the top of the stack on the 9L. We could not push it, but with coordinated effort, we could roll it over. Had to go about 1,000 feet with it. Took all afternoon. Too bad I don't have any pictures of it.
At that particular operation there were all sorts of complaints about the fact they were breaking things on D10's that nobody else was. They wouldn't believe us when we told them no-one else was having the issues they were (well you wouldn't would you?). After I took that photo things went very quiet, then they came in with an order for half a dozen D11's and all their problems went way............