Just some work pics

[DMiller]

Still have my Class A with ALL endorsements, going to drop Hazmat/Tank this next go round.

 

[terex herder]

You can keep tank with no extra BS. Its the hazmat that takes the BS. Wouldn't a truck crane be a class B? A is for trailers, no weight limit on B as I recall. School bus is a S endorsement, separate from passenger.

 

[DMiller]

And I will NOT EVER attain S Endorsement, EVER!!!!!

 

[skyking1]

You can keep tank with no extra BS. Its the hazmat that takes the BS. Wouldn't a truck crane be a class B? A is for trailers, no weight limit on B as I recall. School bus is a S endorsement, separate from passenger.

Yes, but I wonder what happens when you put the boom in a jeep?

 

[crane operator]

I actually had a discussion a while back with a guy. He claimed to need no CDL at all. Any truck crane in my state doesn't even have plates. They are considered "special mobile equipment", and as such- is not much different than roading a backhoe down the road.

But- a boom dolly does have plates, and is registered as a "trailer".

All my guys and I have class A CDL.

 

[skyking1]

I figured as much Flatbeds with counterweight, etc.

 

[crane operator]

Flatbeds with counterweight, etc.

Technically, cranes here in dolly are a permitted oversize load. All oversize permits missouri are supposed to be "irreducible". So you really aren't supposed to be traveling with weights on a dolly here- because you could reduce that load, but I know of some companies that do. I don't put any weights on my dolly, they go on a truck.

 

[skyking1]

that is what I was saying about your guys all having class A. Around here the rental guys are driving flatbed combos with counterweight, dunnage, etc and need the "A".

 

[crane operator]

One of the guys was swapping truck off the lowboy to rollback trailer. Thought he had pumps out, but didn't clutch it, and had truck running. Somehow he got the return line unhooked, dead heading the hydraulic return.

He said it went bang and dumped a lot of oil....

I think we have a damaged control valve also, it was leaking oil also, but I can't understand how it didn't blow a line off a fitting or a smaller connection. It just blew the butt right off that cylinder.

We got the cylinder removed from the neck friday afternoon. It looks to me like the end plate was never welded very well, with little penetration, but somehow its held together until now.

I'm debating cleaning it all up and trying to reweld the end back on myself, or sending it to the cylinder shop.
Cylinder shop is two three weeks out.

 

[John C.]

Was it a piston pump feeding that circuit? Generally and gear or vane pump will split before anything else.

 

[crane operator]

I think its a Gear pump. And it has a pressure relief in the pump, because I had to set it, but I don't think it could dump all the pressure with no return hose hooked up. I still can't believe it popped the end off the cylinder, and didn't split a line or fitting.

I'll get some better pictures of the end cap/ barrel end, it just looks like no penetration on the weld.

 

[Welder Dave]

Weld looks too small from what I can see. I think if put a slight bevel on the cylinder (for penetration) and a good 2 or 3 pass weld to get a 3/8"-1/2" fillet weld would be a permanent fix. A smaller root pass and 1 or 2 cap passes depending on what size rods you use. If you use Mig you could weave a 1 pass cap. With 2 or more passes would have to be a pretty bad weld to have a leak. I'd use 7018 stick if you have a choice.

 

[crane operator]

I'll mig it if I'm welding it myself. Its been too long since I stick welded anything. I may have to make a walmart trip to the reading glasses carousel before I start, my close up vision has really gone down in the last year.

I think I may make up some rollers to spin it on as I'm welding it. Tack it all up and go for it- what's the worst it can do- leak or bust back off.

 

[crane operator]

Had to get a new airport flag, I sucked one into the jib sheave at the hospital. It amazes me that I can have 220' of orange boom standing in the air, but I'm not legal because the pilots can't see me- unless I have a 36"x36" white and orange flag on the tip of the boom.

 

[skyking1]

In aviation it is all about responding to history. Go back far enough and you can find the accident that gave birth to that rule. There is typically some deaths involved.

 

[John C.]

You could check the bottom of the cylinder rod for marks that might indicate that the rod is bottoming out against the cylinder. It looks like some hammer marks on the rod stub.

 

[crane operator]

I think the rod can bottom out, but I don't think it usually does when its inline with the 3 other cylinders in the trailer. I suppose I could install a collar on the yoke end to stop the rod piston from hitting. But isn't that how most cylinders bottom out? and then the machine comes up against its "pressure relief"?

There's some marks on the rod, from someone beating it apart to reseal it sometime in its past. And one of the other cylinders in the neck isn't factory.

 

[skyking1]

That's another application for going old school. I've always shut off equipment to unhook hydraulic hoses on the hoe packs and breakers.
I see other guys leaving running and it just bugs me at some level. Spider sense, whatever.

 

[crane operator]

Looking at my own pictures, the rod has to be able to hit on the bottom. The bottom plate has a male of at least a 1/2", going up inside past the weld.

 

[John C.]

My impression then is of bad design being part of the issue. Is the cylinder single action or double action. My experience is that newer machines cylinders are designed to either not bottom out against the rod or to have snubbers that slow down the motion to lessen the affects of impact loading.

The reason I bring this up is because I don't see any obvious flaws in the welding. With what I see, the failure appears to be a sudden catastrophic release which shouldn't be possible from the pressure of the hydraulic system.