That is a good first guess -
Depending if the crane was A 36 or A 572 Gr 50 the 7018 should cover the job - - - BUT - -
make sure that you do several Rockwell or Brinnel hardness tests to show that the metal you are welding
is below R B 85 or BHN 170 which would translate to a ~ ~ 50 KSI yield
HOWEVER if the metal on the crane is greater than the above hardness limits - ALL BETS ARE OFF ! ! !
Hello stkwldr, it is likely that E7018 would be a good choice for this repair. HOWEVER, if at all possible you should get your hands on the set of drawings that the crane was built from, determine the code that was used to certify it, and also try to come up with the WPS that covers any modification or repair of this particular item. These documents will likely provide you with any specifics that you would need to determine the answer to your questions. In many cases, there could be requirements for you to posess a particular welding certification in order to weld on these. There might also be a particular procedure that is required to perform the welding, and finally, you will want to follow and utilize all of this information to safeguard yourself from any liabilities in the event that there is any sort of failure of this equipment after you have worked on it. Liability can be the name of the game with things associated with cranes, safeguard yourself to avoid any sort of issues that could haunt you for the rest of your life or cause you financial ruin. I may sound overly cautious here, yet if you happened to be the one that was deemed responsibly for any injury or otherwise as a result of your work it could cost you dearly. Best regards, Allan
Back in my days of erector engineer, I've had to deal with the repair of a double girder travelling crane. Due a mistake of the crane operator, who was a subordinate of the company I worked for, the crane got damaged. The equipment made part of the power plant we were erecting.
I inmediately gave a call to my company and they told me not to do anything and wait for further instructions, because they were going to require the crane manufacturer recommendations.
In fact, my boss told me over the phone, any attempt from our part to repair the crane without the manufacturer approval would put all of the responsibility on our shoulders. If anything happened to che crane after our repairing, it would have been our fault.
So, my boss said, we're going to require the crane manufacturer instructions and follow them strictly. A couple of days later I received a telex (no e-mails in those days!) containing the awaited instructions and the repairing job was carried out.
My advice: before doing any repair, get in touch with the crane manufacturer and ask for his reccomendations and follow them strictly, in order to save your responsibility.
Giovanni S. Crisi
Sao Paulo - Brazil
Giovanni hit the nail square on the head.
You need to know exactly what the material is before determining the best repair technique.
What is the capacity of the crane, what is the span, what are the materials used, where is the crack, what caused the crack, is false-work needed to shore up the girder to unload it before attempting to repair the girder, etc.
Liability, liability. Just one mistake can wipe out your career and financial well being, not to mention cost someone their life.
Best regards - Al
The job it self is not to do any repairs, it is 7 ft. too wide and needs to be shortened. This crane was bought in some kind of auction and the people who want me to work on it have already done some work to it themselves. I am going to go look at it Monday and see what kind of information they have on it. The actual building it is going in is 100' by 285' and it will travel the entire 285'.
Thanks for the information so far, any more comments are welcome.
Rick
Your question indicated you are welding on the girder when you asked if E7018 was the proper SMAW electrode to use. Dummy me, I assumed that you were going to be involved with a welded repair.
That being set aside for now, even cutting high strength steels can involve more than simply lighting up the torch and making the cut. Certain steels need to be preheated before cutting to prevent hardening and cracking in the HAZ adjacent to the kerf.
Once again, my recommendation is to know exactly what you are working with. It could be plain low carbon steel or it could be quenched and tempered steel. You need to know.
Good luck.
Best regards - Al
Rick, I don't know of any bridge cranes made of High strength material but I am sure there are some out there. We and contract crane people have done many repairs with 7018 on our numerous cranes in our shop about 14 from 10 Ton to 100 Ton.
All but the 100 Ton were bought used and we modified them to fit our building. Any addition of material was A36 or 1018.
http://www.medfordtools.com/evolution/evo230.htmlthis is just one of many brands but when cutting steel and heat may cause a problem this solves it.
i use cold cut rotary saws in the field to cut beams and hss(hollow structural sections) and the results are far and away better than the gas axe,
gas axe is the last resort now not the first line of attack.
darren
I did go out to the jobsite today. The overhead crane is a SHAW BOX 7.5 ton. I did find out on their website it is A36 steel an to only use 70XX welding rods. I did find prints on the website complete with weld symbols. The people who need this done do have someone to come in and certify the crane after the work is complete and hung.
thanks
rick
Cranes are equipment used to lift heavy weights, and if the weight drops after a repair (or modification, as in Rick's case) has been made, with damage to property or life, someone will be held responsible for that.
In Rick's case, his client will bring a specialist who'll supervise, inspect and finally accept his work. In this manner, he'll save his responsibility.
In the case of Ron, the company he's in contact with are cranes specialists and they repair cranes under their responsibility because they know what they're doing.
A word of warning: information found on companies websites and catalogs use to be just that: information, and no guarantee is given on data contained in them. To have guarantee, one must ask for written instructions.
Giovanni S. Crisi
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