Great case study on cement truck weld failures

[Janger]

Why Welds Fail: It’s never just one thing – WELDING ANSWERS

Interesting article on welding failures of the axles on cement truck mixing drums. The follow up question I have is how do you repair 180 cement trucks located all over North America? I'm sure some members have seen this sort of problem in their career. Options I can think of:... Wait till they break and have a local shop fix them? Send a crew with equipment, crane trucks, welding trucks, to all the customers and fix them all on site? (Imagine a 3 person crew traveling for a year?) Send a replacement truck to the customer and bring the truck back to the factory for repair, then send the truck back and forward the replacement truck to the next customer?

Could an inspection, Xray?, acoustic?, clearly identify the units with the combination of factors which will cause a welding failure? Or do you just need to repair them all?

Anybody ?

 

[terry_g]

There is a large bearing at the front of the drum where the axle is, the rear of the drum probably rides on rollers.
When the axle failed the drum would drop onto the frame. Moving the truck with the failed axle would be a hazard.
The concrete in the drum would harden. I doubt if even a scrap metal recycler would want to deal with the drum.
Having the axle fail while driving could have catastrophic results.

 

[phaxtris]

The crack would most likely start at some undercut or stop/start location and take some time to propogate around the entire circumference of the axle, it could be caught before catastrophic failure with Regular inspection using die penetrant. Then it would be a matter of removing the drum, gouging the old weld out, preheat, and re-weld

Probabaly pay a local-ish guy, say if it were Alberta they may get a guy from Edmonton to cover all of the repairs withen 500km radius. I say they would probabaly have one guy for a big area because most likely they would need to get him/her qualified on whatever repair procedure they come up with

 

[Stuart Samuel]

Why Welds Fail: It’s never just one thing – WELDING ANSWERS

Interesting article on welding failures of the axles on cement truck mixing drums. The follow up question I have is how do you repair 180 cement trucks located all over North America? I'm sure some members have seen this sort of problem in their career. Options I can think of:... Wait till they break and have a local shop fix them? Send a crew with equipment, crane trucks, welding trucks, to all the customers and fix them all on site? (Imagine a 3 person crew traveling for a year?) Send a replacement truck to the customer and bring the truck back to the factory for repair, then send the truck back and forward the replacement truck to the next customer?

Could an inspection, Xray?, acoustic?, clearly identify the units with the combination of factors which will cause a welding failure? Or do you just need to repair them all?

Anybody ?

That was a really excellent read, thanks John!

It was nice to have my (educated) gut instinct confirmed.
While it hardly comes up in my curent job, I went through trade college for structural welding, and left with my all-position stick ticket. I just TIG these days, but to a degree, bad geometry is bad geometry. One look at that cross-section they showed was plenty, and should have been flagged In fabrication.