I am preparing to take my CCO test and have a few questions that are puzzling me.
For starters;
This is a sample test question, and i am at a loss with the question.
Q. Eccentric main boom tip reeving causes:
a. increased sheave wear
b. increased wire rope wear
c. twisting of the boom
d. increased jib capacity
Q. What would qualify for the term;
"Duty cycle operation?
Thanks for any input i can get.
Bump.,
Thank you, please.
IANA crane operator, but the first question tickled me for some reason - I’ve probably heard the term in a nautical context. Since this might qualify as homework, all I’ll say is that search engines are your friends. Plug in ‘tip reeving’ without the quotes and you’ll get plenty of information.
“Eccentric reeving occurs when the hoist line is not centered over the boom tip and causes torque (twisting) in the boom.”
From here
Not to be a smart aleck here, but if you’re about to qualify for a license to operate cranes, should you be the one with all of the answers here? Is there some sort of well defined instructional program in crane operating, or is this something that comes off of the internet?
I’m not a crane person, but I am familiar with the term duty cycling. In a lot of critical applications, you will have two motors available to be used, so that if the first motor fails, the second one can be used. In order to keep both motors healthy and operating, you’re supposed to switch off duty between the two motors on a fairly regular basis. This keeps both motors at about the same operating age, and avoids the problem of having your backup motor unable to start because it has seized up because it has been idle too long.
Also, as an aside, according to the instructor for the OSHA safety class I took a couple of weeks ago, your timing is impeccable. OSHA is about to put in place some new rules that require the CCO certification you’re speaking of. In his opinion, there are a lot of people out there right now who are excellent crane operators who will be freaked out by the complicated test, and a lot of people who will ace the written exam, but don’t have the practical experience to operate the cranes all that well. He projects that those who can do both and get their certification in soon will be able to write their own ticket for a while until the supply of certified crane operators increases to meed the demand.
Thank you Blake & ywalker
I do not know where you are coming from. I asked 2 questions, one was a multi. choice right off a sample test question.
Thanks to those that posted.
I am through the practical testing and am preparing for the written.
I am overloaded with all the info necessary.
I have my own private crane and because of the new OSHA rules i am required to have a certificate.
Blake;
That is a very interesting site. Thank you very much.
Ywalker;
That same site answered the duty cycle Q as it relates to crane operation’s
Thanks again
Gbro
You’re welcome.
I figured you’d mastered 99% of the material but had a hard time coming up with that last 1%. Happens to me all the time.
I’m sorry, I wasn’t aware of the recent regulatory changes regarding crane operation from OSHA. I’m confident that you’re a perfectly capable crane operator but I had assumed that you were coming into the field for the first time to get a certification in a long-standing requirement for the field, and I found it a little odd that you were searching for such a highly technical answer on a general message board. Apparently the entire field is actually having to adjust to new OSHA regulation.
By the way, can anybody tell me how many people have actually been injured or killed in crane operating accidents over the past years that might be prompting OSHA to feel compelled to implement new testing and rules? Or is it just somethign they felt like doing?
I read in the materials i have been studying, that a crane tips, or fails(boom collapse), = 1 in every 10,000 hrs of operation.
I don’t know about other accidents but there was a death here in the Pacific Northwest last November. A High Rise crane on a building project completely toppled, fell into an Apartment/Condo building nearby and killed a resident of that building. The Operator was cleared of any wrongdoing, only after the Local media villified him due to his past indescrestions. Turned out the fault was in the shortcuts the engineers/builders made in creating the cranes foundation. When the wind picked up the crane foundation flexed too much and caused metal fatigue. The man that died was a Intellectual property lawyer for Microsoft.
On an episode of “Modern Marvels” engineering disasters, they told the story of a crane collapse during the construction of the Milwaukee Brewers baseball stadium, which occurred in 1999. There’s video footage of the collapse, and, IIRC, it was due to several factors, one of which was human error. 3 workers died in that collapse.
That incident is in the information you linked me to.
This is the page it is on.
http://www.cdc.gov/niosh/docs/2006-142/#case