so I was mistaken....

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I had said on Friday morning I was going out on a jobsite were I would possibly end up 600' underground in a (future) butane storage facility. I ended up over 400' in the air working on handrails on the main frame of the structure built over top of the shaft that leads underground.This is the ladder rungs I had to modify. they were built as walk thru ladders and this job site needed rungs all the way up. So I cut hole in the angle a ran a piece of 1" hot roll thru them. Simple enough. (except)I was pretty high up (tied off, of course) but none the less high up. My truck the white Dodge(FYI)company truck I should say.Also had to lower the cage about 3' Nothing to look at and it was dark when I finished. Quick fix to say the least. I thought it was pretty interesting, it was definately a different experience for me, being up that high. Hopefully next week we will be underground doing some welding. they will be taking equipment apart a lowering it sown the shaft and reassembling it.  More pics then I hope.
Reply:Thanks for the nice pics.How far away where your power source and torch set?
Reply:Thanks for remembering us with the pics!
Reply:Interesting ladder rungs.  Around here every time we have to do a plug weld and then a fillet on the inside or they are rejected.  You just do the outside plug welds only?
Reply:My welder and torch were both on the back of my truck. Believe it or not it did not affect the welding all that much.
Reply:That is all they had on the original fabrication of the entire unit so I fugured I could get by with the same. Besides I was working directly over the ladder opening and I wanted to get it done as quickly as possible. The safety director over the project approved everything befor I left. They actually did not expect me to cut the holes, they just wanted the round butted up against the angle and welded around it. So I guess I did them one better by cutting the holes.
Reply:Originally Posted by WVWelderThat is all they had on the original fabrication of the entire unit so I fugured I could get by with the same. Besides I was working directly over the ladder opening and I wanted to get it done as quickly as possible. The safety director over the project approved everything befor I left. They actually did not expect me to cut the holes, they just wanted the round butted up against the angle and welded around it. So I guess I did them one better by cutting the holes.
Reply:400'?? My eyes must be getting old cuz that looks more like 80' to me   Interesting how they spec. rungs like that. I've done it a number of ways. Makes me laugh when the engineer thinks a 150# person is going to bust all that weld with one foot on it
Reply:Dont matter how high it is..Your not getting me up there.. ...zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:looks like a fun job to me congrats.63' Lincoln SA200 2008 miller trailblazer 302fibre-metal pipelinermiller camo BWEand all the guns and ammo a growin boy needs
Reply:It felt like a thousand feet. Maybe I guessed wrong. It's more than 80' I'm sure.
Reply:Originally Posted by WVWelderIt felt like a thousand feet. Maybe I guessed wrong. It's more than 80' I'm sure.
Reply:Well, it was high up in the air, no doubt about that.  But I don't think it was 400' up in the air.  Do you have even -have- 400' to 500' of welding lead on your truck?Also, the materials and workmanship are 'oversized and overspeced' to address several items:- the ladder rungs are big diameter not so much for the need strength but to make the rung semi-comfortable to climb and stand on.  Having a skinny rung cutting into the bottom of your foot is not comfortable to climp or stand on, I think there might be codes or design guidelines for rung size/diameter somewhere (my rememberer isn't sure on that one);- the 'extra' material and weld is used so that 'oopses' like rust weakening things doesn't result in 'oops-arrrrgh-$#%@*-splat-sirens';- a general design and engineering rule for safety factors of structures for public or hard-use is to make it 5-10 times stronger than needed, again to cover 'oopses' in materials or workmanship and to avoid having to go to the effort and expense of intense engineering design and structural analysis, inspections, maintenence, and repair/replacement of parts.  It doesn't have to race or fly, so make it strong and avoid having to do constant NDT or visual inspections of everything;- drilling the holes in the uprights helps to hold and align the rungs during assembly and fabrication, so + on that.  Plug welding the ends of the rungs to the uprights is good, so + on that.  Not fillet welding the inside junction of the rungs to the uprights just made a trap-point for rust/corrosion, big-time (-) on that one in my book.  Just butting the rungs to the inside of the uprights and fillet-welding them in place would have most likely been plenty strong, but if you are going to drill the uprights and pass the rungs through you really need to plug weld the ends and also fillet-weld the inside junction of the rungs to the uprights to avoid rust/corrosion trap-points IMHO.
Reply:[QUOTE=MoonRise]Also, the materials and workmanship are 'oversized and overspeced' to address several items:- a general design and engineering rule for safety factors of structures for public or hard-use is to make it 5-10 times stronger than needed, again to cover QUOTE]Thats a bit of an exageration.   My understood saftey margin is 15-20%.  Not to split hairs, just dont want to give validation to these young idiot engineers that double the yield of project designs for no damn good reason.Lots of toys.
Reply:15-20% safety margin?  For public/hard-use structures?  Nope, no way.15-20% safety margin is for a design made and designed and analyzed and inspected all over.  Air-craft or race items may go down to 5-10% safety margins, but that's because weight is critical and knowing that extra care and steps will be taken in the design, materials, fabrication, inspection, and replacement of parts.  And all that extra design and inspection and care and replacement means that it all costs LOTS more in the beginning and in repair/replacement costs.Regarding ladders, OSHA and ANSI do have specs that may or will apply. Now you made me go do a quick search.  Fixed metal ladder requires minimum 1 inch diameter rungs where corrosion or rusting may occur, or painting is required (OSHA 1910.27 and ANSI 14.3).  Minimum metal rung diameter is 3/4 inch.  OSHA 1910.24 design specs for fixed industrial stairs require greater than 5x safety factor for normal anticipated load but not less than 1000 lb capacity.BTW, OSHA 1910.27(b)(6) requires welding to be done in accordance with AWSD1.0-1966 "Code for Welding in Building Construction".  Which looks like that spec is outdated and is now AWS D1.1/D1.1M:2006 (Rev 06) "Structrual Welding Code - Steel", all 503+ pages worth, unless cross-referencing to AWS D1.3 "Strutural Welding Code - Sheet Steel" also has to be used because steel less than 1/8 inch (3 mm) is used.Wire rope scaffold suspension require 6x intended design load strength (OSHA 1910.28).  And without digging through sub-paragraphs, I'll bet that that is going to be on TOP of the already 3x safety factor of the WLL (working load limit) rating or the wire rope versus its design strength.  The scaffold design strength requirements per OSHA 1910.28 are minimum 4x the design load.A compressed air hose/pipe typically has a 300% safety factor for the rated pressure versus the 'blowout' pressure.  A general purpose rope or chain has a typical safety margin of 300%, using it for overhead or man-rated lifting will require 5-10x safety margins.  If there is any vibration or cyclical loading, then the applicable material property determining allowable stresses will usually be the fatigue strength and not the yield strength.  Special conditions or design criteria may allow variation, but that will usually only be after a lot of engineering and analysis is done.YMMV.The young idiot engineer is the one who designs something using a 15% safety factor, in a high-stress cyclical-load or vibratory application, using the ultimate strength of the material, when there should have been the MUCH lower fatigue strength of the material as the critical strength factor, and when there are design codes and standards requiring much greater safety factors.  IMHO.
Reply:Originally Posted by zapsterDont matter how high it is..Your not getting me up there.. ...zap!
Reply:Just a little FYI my ladder rungs were 1" diameter. I also wanted to weld some "tread" on the rungs but the supervisor said no. All of the other rungs in the entire jobsite are made from 3/4" rebar. Not a good choice in my opnion. Rebar is very brittle and will snap. It does have built in tread but not worth the risk in my opinion.  Also I do absolutely agree with fillet weld on the inside but the company I was working for was more interesting i getting my job done and getting me out of there. We were charging $65/hour so they kind of rushed me a little. They did however have one of their guys prime and paint it all, so that should help. By the way I did not drill the holes I cut them with an O/A torch. Not that it matters but seen where you mentioned drilling the holes. So just to clear that up. Thanks for all the feed back I really appreciate it. I really enjoy communicating with people that are as passionate about their work as I am.
Reply:Originally Posted by MoonRise15-20% safety margin?  For public/hard-use structures?  Nope, no way.15-20% safety margin is for a design made and designed and analyzed and inspected all over.  Air-craft or race items may go down to 5-10% safety margins, but that's because weight is critical and knowing that extra care and steps will be taken in the design, materials, fabrication, inspection, and replacement of parts.  And all that extra design and inspection and care and replacement means that it all costs LOTS more in the beginning and in repair/replacement costs.Regarding ladders, OSHA and ANSI do have specs that may or will apply. Now you made me go do a quick search.  Fixed metal ladder requires minimum 1 inch diameter rungs where corrosion or rusting may occur, or painting is required (OSHA 1910.27 and ANSI 14.3).  Minimum metal rung diameter is 3/4 inch.  OSHA 1910.24 design specs for fixed industrial stairs require greater than 5x safety factor for normal anticipated load but not less than 1000 lb capacity.BTW, OSHA 1910.27(b)(6) requires welding to be done in accordance with AWSD1.0-1966 "Code for Welding in Building Construction".  Which looks like that spec is outdated and is now AWS D1.1/D1.1M:2006 (Rev 06) "Structrual Welding Code - Steel", all 503+ pages worth, unless cross-referencing to AWS D1.3 "Strutural Welding Code - Sheet Steel" also has to be used because steel less than 1/8 inch (3 mm) is used.Wire rope scaffold suspension require 6x intended design load strength (OSHA 1910.28).  And without digging through sub-paragraphs, I'll bet that that is going to be on TOP of the already 3x safety factor of the WLL (working load limit) rating or the wire rope versus its design strength.  The scaffold design strength requirements per OSHA 1910.28 are minimum 4x the design load.A compressed air hose/pipe typically has a 300% safety factor for the rated pressure versus the 'blowout' pressure.  A general purpose rope or chain has a typical safety margin of 300%, using it for overhead or man-rated lifting will require 5-10x safety margins.  If there is any vibration or cyclical loading, then the applicable material property determining allowable stresses will usually be the fatigue strength and not the yield strength.  Special conditions or design criteria may allow variation, but that will usually only be after a lot of engineering and analysis is done.YMMV.The young idiot engineer is the one who designs something using a 15% safety factor, in a high-stress cyclical-load or vibratory application, using the ultimate strength of the material, when there should have been the MUCH lower fatigue strength of the material as the critical strength factor, and when there are design codes and standards requiring much greater safety factors.  IMHO.
Reply:Originally Posted by brandon75173I like you.  Someone that has info to back up claims.  So rare.  Point well taken, but nonetheless.  Not universally applicable, as you pointed out, either.   I speak to the general structural aspects of construction, other than that I am not qualified to remark.
Reply:General beam and column tables are figured on a yield of 120% of material allowable load........  I used to run an engineering dept. for a construction management company and figured calcs for spans and loads everyday.  By hand with beam tables and through stru calc.  NOW, I do not claim to know everything and would like to understand better what you are getting at exactly for reference sake, atleast.Lots of toys.
Reply:I hate having to give references, but what the heck . . .The American Institute of Steel Construction (AISC) specifies minimum safety factors of 1.67 for most properties of graded steel.  Fatigue is the big outlier with some specifications calling for safety factors as high as 40.  Safety of minimally engineered steel structures are even stronger than that due to incorporation of a number of other factors, such as the redundancy factor required to meet seismic requirements and the load factor used to account for basically the inability to predict true loading with certainty.The AISC also defers to local codes where local codes require enhanced safety factors.  My local code requires a minimum safety factor of 3 as in if the actual load is expected to be x, the test load of for example, a sample connection, would be 3x and if not tested, the engineering design criteria would be 3x, at a minimum.I'm assuming the tables you were using had the safety factors already baked in, or that the specifications providing allowable loads had those factors baked in.   If not, 1.2 would not even meet the minimums where I am for anything.  Where are you located?Last edited by phila.renewal; 06-18-2007 at 11:48 PM.Favorite right now is a Miller Syncro 200.Tons of tools and I blame at least one of them when things don't go right.