Certification of Existing Cranes 3

[dik]

I have half a dozen existing cranes that need certification; this is in Canada. The cranes are bridge cranes and a jib crane. I can easily analyse and design the cranes and supports for loads. They are lightly loaded cranes, all less than 2.5 Tons.

I am uncertain about load factors to be applied and if load testing is required. Regular steel design load factors are 1.25 for DL and 1.5 for LL for our steel code. I would suspect that these might be different for cranes. I know for mining stuff whether 'in mine' or 'in shaft' the load factors are significantly higher.

Can anyone provide me with what normal standard load factors cranes have to be designed for by whatever standard is required.

Thanks in advance...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better? Dik

 

[jayrod12]

Hi Dik,

Check out CSA B167.

That's the standard for overhead cranes include bridge, gantry, monorail, etc.

I've got another reference somewhere that I'll try to dig up for you.

Found the name of it, but can't find the pdf I used to possess. It's put out by CISC and is called Crane-supporting steel structures: design guide

 

[r13]

dik,

There are different type/class of cranes, and the requirement differs. In the US, I would check into CMAA's website, Link. Maybe Canada honor it too.

 

[jayrod12]

Found the second edition, couldn't track down the most recent 3rd.

 

[dik]

Yup, from my Project Notes:

"HOISTING EQUIPMENT
CMAA CRANE CLASS [A (INFREQUENT SERVICE | B (LIGHT SERVICE | C (MODERATE SERVICE |
D (HEAVY SERVICE | E (SEVERE SERVICE | F (CONTINUOUS SEVERE SERVICE])
HMI CRANE USE [H2 (INFREQUENT USE) | H3 (AVERAGE DUTY) | H4 (HEAVY DUTY)]"

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better? Dik

 

[JStephen]

In unrelated fields, one thing we occasionally run across- if a code describes how something is to be designed and built, there are aspects you can check after the fact, but others that you simply can't meet, after the fact. The main issue there is welding qualifications and certifications. You can inspect a weld to your heart's content, but can't certify that it was done per a particular welding standard or code. And to a lesser extent, material grades and certifications. To show that something is generally adequate, may not be too hard, but to show that it was built in conformance to a particular standard may be impossible. Ideally, you'd have the original item certified, and then any inspection after that would just amount to comparing it's condition to the original, not in re-designing the whole thing.

 

[dik]

Thanks JS... I had some of this identified... missed the welding...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better? Dik

 

[r13]

Here is a blog regarding OSHA testing requirement on overhead cranes. Link

 

[dhengr]

Dik:
I would really want to nail down the exact meaning of ‘certification’ for these cranes. It may not mean a full, new, structural and mechanical analysis of every part. But rather, a good thorough inspection for such things as wear, any cracking, deformations of various parts, damage, etc.; examination of cause of these issues and correction of same; and then a load test to 1.25 or 1.5 times the rated load. I don’t think it usually means bring things up to current stds. But, the newer stds., as well as those under which the cranes were built, should be good guides for your efforts. Have the cranes generally been performing well or have they had problems, which should be addressed?

 

[dik]

r13: from my project notes:

LOAD TESTING 1.25x SPECIFIED LOAD


Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?
-Dik

 

[r13]

Yeah, the recommendation is not to exceed 125% rated load, especially the rebuilt cranes, to avoid damage the crane. dhengr's mentioning of inspection is echoed by the service contractors, that suggest an inspection shall be performed prior/after (?) the load test.

 

[r13]

Another tech document for your collection use.

Link

 

[dik]

r13: Thanks...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?
-Dik

 

[r13]

You are welcome.

 

[KM_mech]

FYI, the 3rd Edition of CISC's Crane Supporting Steel Structures Design Guide is available for purchase at CISC website here:

https://www.cisc-icca.ca/product/crane-supporting-steel-structures-design-guide-third-edition/

Also note supplement here:

https://www.cisc-icca.ca/wp-content/uploads/2019/11/CraneSupportingSteelStructures_Supplement-1.pdf

 

[TLHS]

Make sure you check your provincial operational health and safety rules. They tend to explain the rating requirements and testing requirements.

 

[dik]

Thanks, folks... information much appreciated.


Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?
-Dik