First, a little background info. I manage the weld/machine shop for a medium sized constructon company, we do excavating, paving, and crane work.
I was approched by my employer recently, his question to me, "What do we need to do in order to repair latice boom sections in house?"
I didn't have an answer to that. We had been using a fab shop locally that advertised boom repair.
This fab shop has gone downhill in the quality of their work recently, to the extent that we find ourselves grinding slag pockets from their welds, and reworking what we already paid for.
All other welding is done in house, I have two excelent welders working for me who are most capable.
So, where do we start?
On occasion we have had to do minor repairs to cranes on our constructions sites. In those cases we contacted the crane manufacturer and they provided recommended welding procedures and we ordered any replacement tubes from them. I think you might start by contacting the manufacturer for each crane you have and obtaining a copy of their recommended welding procedures and replacement parts list for the booms in advance.
I entirely agree with Mr. Sims. Back in my days of erector engineer I've run into that situation twice and in both cases we contacted the manufacturer for instructions.
In first place, cranes booms use to be made of special steels whose composition no manufaturer will tell you.
In second place, if something goes wrong after you've done the welds without informing the manufacturer previously, he'll tell you that the fault is yours.
Giovanni S. Crisi
Sao Paulo - Brazil
It is interesting that this comes up about once a year. You might want to search the topic on the forum.
What MBSims has described is exactly what we do. The crane manufacturer is the best source of information. The important thing to remember is that the manufacturer certifies their booms, even though you own it, so any work done on them must be to their standards. There are times where load testing and factory rep inspection is required. If you ever wanted to sell the equipment, no sensible purchaser would touch it if the manufacturer doesn't stand behind it, and I won't even mention how OSHA would see things.
One word of caution, as MBSims said, buy the manufacturer's replacement lacing material. The boom is NOT made of ordinary material so don't make the mistake of thinking that all you have to do is match up the same size pipe or angle.
Chet Guilford
I agree with all. The crane manufacturer should make any repairs of this nature, because of the liability risk.
This was addressed at our facility a while back and I convinced our people not to touch the boom since they were not willing to "do it right". Please see http://www.aws.org/cgi-bin/mwf/topic_show.pl?id=4828#21922
OSHA has some very specific rules on repairs and modifications to cranes, see http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=10760
There are two provisions in 29 CFR 1926.550 that require crane users to follow procedures or gain approval of the crane manufacturer. Paragraph 1926.550(a)(1) requires that the employer comply with the manufacturer's specifications and limitations applicable to the operation of any and all cranes and derricks. OSHA has interpreted the language "specifications and limitations applicable to the operation" to apply to the way a crane is used and maintained.
Paragraph 1926.550(a)(16) addresses the requirement for manufacturers' approval before any modifications or additions can be made which would affect the safe operation of the crane. The section goes on to address what must be done when the capacity is changed. The intent of this paragraph is to assure any modification or addition that would change the capacity of the crane be reviewed by the manufacturer to make sure the change does not adversely affect other crane functions or components and cause an unsafe condition. By their very nature major repairs to crane components create the potential for adversely affecting capacity or safe operation, and for that reason such repairs should be reviewed and approved by the manufacturer to make sure that the crane's capacity and safe operation are not affected. Alternatively, this could be done by seeking the certification of a registered professional engineer that a repair has restored the crane component to its original configuration and strength so that the capacity and operation of the crane is unaffected by the repair. A crane user who has had major repairs carried out but has not taken appropriate steps to ensure that capacity or safe operation has not been adversely affected could be cited.
Rich
Thanks to all. I Now have sufficient info. Seems as if the paper trail is a bigger bother than we need.
By albcwi
Date 06-28-2005 19:38
Aws D14.1 covers the welding criteria once you find what the material is from the manufacturer.
