How many degrees are in 1 percent

Everyone says to stay within one percent of level. Well the crane I'm operating has a boom indicator in degrees not percent. Is it 360 divided by 100 ? which would be 3.6 degrees

One more thing if on the low side the boom indicator says 65 degrees and on the high side it says 68 are you 1.5 degrees out of level ?

If you really need to ask these 2 questions you should just go find another trade where you cant kill people.

WELL EXCUSE ME. been operating since 84 still no cross bones on the cab. Guess the grace of God. Is the 3 degree chart manitowoc puts out a bunch of bull then?

You have been in the seat since 84 and you don't know how far out you can be on level? I guess that's the difference between setting trusses and making a heavy lift and tearing the boom out. My question to you is.... Does your employer know ? Go ask him and see what reaponse you get from them. Where do you get % from ? It's Degrees on any chart or stat I have ever seen and the fact you don't know how to read chart or know the basics of how the crane works ought to give you a clue you need futher training . If you got any to begin with. You need to kneel down and pray your luck holds with you if you are planing to stay in the seat. The rest of us don't need you killing somebody , It only makes us all look bad.

1926.550 (g)(3)(i)(D)
The crane shall be uniformly level within one PERCENT of level grade and located on firm footing. Cranes equipped with out rigger's shall have them all fully deployed following manufacturer's specifications, insofar as applicable, when hoisting employees.

Word for word off the osha site, (one percent of level grade), not one degree of level grade. my best guess is 1/2 inch in a 4 foot level is within one percent of grade, so hold on to your reins I can read load charts pretty good,

Do you have a CCO Cosme ?....I take it your runnin a crane with outriggers? if you are then you must have a bubble level in the cab , right ? If not then put a level on the turntable....EXPLAIN to us what you are working with ...otherwise read the operators manual.....

"Well the crane I'm operating has a boom indicator in degrees not percent" <----- well I hope its in degrees!!!!!!!!

CCO. since 03. Working near the water, In the past always leveled up as best as possible with levels mats and plywood. Now the job I have is very production based you walk up to the load pick it up and load it on the truck and go to the next one. No levels no mats no plywood. Just wanted to know how far out of level I could work without worrying to much. Hence the question ( how many degress in one percent of grade ) that way I could swing around and check my boom indicator. I looked up degrees and grades last nite and now I think .57 degrees equals 1 percent of grade not sure thou. No outrigger's on my crane. I have a blue book and need to knock the dust off of it. As far as manuals go I have read a ton of them and took a ton of test never have busted one , don't want to bust a crane either. As far as grades go I think 45 degrees equals 100 percent grade. I was looking for some help from fellow operators instesd I find some of them seem to be quite full of themselves Thanks for asking General have a good one

Are you running a crawler? or a cherry picker on rubber? You need too be on level ground with or without cribbing/mats...every pick...more than 1% out of level can put your crane out of the chart depending on your load and boom lenth..more than 1% can cause a slew of problems,..such as side loading..backward stability and increased load radius....Sounds like your doing duty cycle work? have you derated your cap by 20%? ... how deep is the water your working near? You should know these things , your CCO certified......I'm not trying to be a hard ass, There are alot of good operators out there that are not working, who in your situation would make damn sure that rig was witin 1% lavel no mater what it takes...get that Contractor to level it up for you...you do get paid by the hour right? just my 2 cents.......

I stand corrected. Tomorrow I start anew. level or no pick thanks.

Ok Cosme, You gave a stat that indicates the lifting of a man basket and you say you're doing prodution work . 2 different applications of a crane. You level the crane when using a man basket period.Not "it will be alright this time"to be out alittle. Prodution work has a manufacture's standard that may be different on each peice or type of crane and they use DEGREES. To determine degree , You use a tape measure and measure from the center of the car body to the outside edge of the track or on rubber the center of the car body to the center of the tire and divide by 90. This gives you one degree. Use the hook or a plumb bob centered on the deck to determine your degree out of level and refer to your manufacturers chart as to structural and load capibilities. If you refer to osha standards over the manufacturer, you will lose. Osha is using broad generalizations and the manufacturer is specific.This is the basics I refered to , given a chart, a tape, a level and the knowledge of how to use them an Operator knows the limits and capibilities of the crane and the proper utilization of the crane when confronted with different tasks.

Thank you Mr. Crandall
I have never heard the method that you described to level up a crane, I am going to print it out and put it to practice. I have always placed a two ft. level on the turn table and 1/4 inch equals two inches out so I put two inches of plywood under the low side and check again, then I'm on the money. At the moment I am on a production job and the yard does have it's low spots, so when we have to travel with a load I keep the load either in front or back and travel square to the slope and don't swing until I'm back on level ground. We do have an old 39T that still works pretty good. We keep a level in it and use it always when we set it up.My main reason behind starting this topic was to get some questions and answers going not to ruffle feathers. Thanks again

Hello Cosme. I too was curious as to how many degrees were in 1 percent since OSHA states that cranes are to be within 1 percent of level as you pointed out above, AND we as operators do not have an instrument to measure percentages, but we do have an angle indicator to measure degrees. And any GOOD operator knows that the level bubble in a crane can be very inaccurate unless he himself set it to be truly level. So other that using an actual level on the upper rotating superstructure as CCO points out to be the best place, some operators in the "REAL" world will use the angle indicator as an indication of the levelness of the crane by swinging around in a full circle and noting the difference of the angle indicator.

To answer your questions, 5.71 degrees equals 10%, but 45 degrees equals 100%. Therefore, the ratio of degrees to percentages get slightly lower as you move up the scale. So 1% would be equal to slightly higher than 0.571 degree.

Reference this link: en.wikipedia.org/wiki/Grade_(slope)

So as a general rule of thumb, if you leveled your crane to within 0.5 degree (0.6 degree maximum), you would be within OSHA's 1% of level requirement. This is only my educated guess and opinion for liability reasons.

As for your other question, if on the low side the boom angle indicator says 65 degrees and on the high side it says 68 degrees, than you are a full 3 degrees out of level, which is equal to about 1.7% out of level.

Another way to check level, which I find to be impractical, is that for every 100 feet of boom, 1 percent out of level will have the load line hanging 12 inches off center. 150 feet of boom equals 18 inches, etc.

I hope this helps. Have a good day.

Thank You Very Much Harry. Really do appreciate it.

Hi,i am from romania, and last month i worked on a 50 to grove. All the 3 bubles were showing diferent things...so first i leveled the crane by the eye, after that i started to swing around and to level the crane from the cab, until the degrees from the boom remained constant,after that i tuned the bubles

Hello Radu,

What you did was a good method. Another trick I would use, is to set the crane up so that the level bubbles read the same at all four quadrants of swing. This may take some outrigger adjusting till you get it right. But once the level bubbles stay the same during a full 360 degree swing, then the crane is level. At this point, you can reset the level bubbles to zero. Just make sure you don't change the boom angle during this process. I find (in my opinion), that the rotex of the upper is fairly balanced between the fully retracted boom and the counterweight at about 55 degrees with the boom fully retracted.

I hope this helps. Have a good day.

Cosme Perez in Houston, Texas said: One more thing if on the low side the boom indicator says 65 degrees and on the high side it says 68 are you 1.5 degrees out of level ?

yes. you take your change in boom angle on a full rotation and divide by 2. keep in mind flex in the upperworks is always going to cause some slight change as you swing depending on if your balanced heavy to the boom or the counterweight. You want to operate within 1 degree of level, so a change of 2 degrees on your boom angle is about the max acceptable.

really to do this levelling perfectly you want your boom angle at exactly the 'balanced' point, which unfortunately isn't in the manuals. i hear grove for example considers their RT upperworks perfectly balanced with the boom at zero degrees. however you almost never see an operator checking the level doing a 360 degree swing with the boom flat out. Myself I just remember to keep it low, usually at around 30 degrees for my check -- you want to be accurate but you also don't want to split hairs.

This is trigonometry. Tangent (Degrees) divided by 100 = percent.
Tan(1 degree) = 1.75 percent

Im surprised experienced crane operators question this? All these are clearly stated in title 29 cfr 1910, 1926 and ASME B30.5 if you are not familiar with those you shouldn't be running a crane.