Safety Factor With People Underneath
Safety Factor With People Underneath
(OP)
What design safety factor do you use for equipment holding a load where people will be working underneath?
Thank you,
A.M.
Thank you,
A.M.
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS Come Join Us!Are you an
Engineering professional? Join Eng-Tips Forums!
*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail. Posting GuidelinesJobs |
Safety Factor With People Underneath
|
RE: Safety Factor With People Underneath
If the "people below" were all of your family what Design Safety factor would you use????
Sometimes its possible to do all the right things and still get bad results
RE: Safety Factor With People Underneath
We had some spreader bars built, and the design factors were at least 8x.
= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube
RE: Safety Factor With People Underneath
I use SF=3 for general purpose spreader bars (From ASME BTH category B lifter, service class 0)
For manbaskets I use SF=5 (From CSA Z150)
So I usually use SF=5 for people underneath a load because the same risk is involved for a manbasket. But I have noticed others use 3,6,8, it is all over the place, so I was curious what other people use and why.
Does anyone know what safety factor automotive lift designers use? I tried looking it up but was not able to find it.
A.M.
RE: Safety Factor With People Underneath
RE: Safety Factor With People Underneath
And why is anyone working underneath it?
first rule of risk reduction is to eliminate the risk.
Failure of the static lifting equipment is only one potential cause of failure.
Consequence is very high (death), so acceptable risk of failure needs to be very low to achieve an overall risk level which may be acceptable if no other solution is feasible.
To put it another way, would you work under it??
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Safety Factor With People Underneath
For example if four chain falls were suspending an exhaust duct, the load was "shared" with four cables with turnbuckles once it was in location
RE: Safety Factor With People Underneath
Dik
RE: Safety Factor With People Underneath
We had other requirements for SF, some were for ultimate and other were for yield strength.
Littleinch, in my case my designs weren't necessarily that anyone was actually working underneath it at the time of use. The point was that these are above work areas, aka overhead, and therefore had a minimum factor of safety regardless if anyone else but the crane operator was in the room.
--Scott
www.aerornd.com
RE: Safety Factor With People Underneath
JME but its more common to work under suspended loads than to ban the practice, many plants have all manner of hanging conveyors, material handling cranes, etc overhead constantly. Many modular cranes on assembly lines are actually themselves suspended many feet from ceiling rafters. At a previous employer several of us got a regular giggle out of stopping tour groups at a particular spot on a main aisle and pointing out the line of 10+ ton engines inching along directly overhead, folks often became uncomfortable and stepped aside quickly. So long as due diligence is given to safety factors, maintenance/safety procedures, and loads/lifts are non-critical there's little need to worry.
RE: Safety Factor With People Underneath
LittleInch: by holding a load I mean for example an automotive hoist or a pair of stands holding up a larger vehicle where people need to be underneath to perform maintenance.
RE: Safety Factor With People Underneath
https://www.asme.org/products/codes-standards/pase...
RE: Safety Factor With People Underneath
RE: Safety Factor With People Underneath
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Safety Factor With People Underneath
RE: Safety Factor With People Underneath
RE: Safety Factor With People Underneath
RE: Safety Factor With People Underneath
MintJulep: that standard does not have design factors that I can see, only proof loads for testing (so at max, SF=2)
ANSI ALCTV for automotive lifts uses SF=3 to ultimate strength
RE: Safety Factor With People Underneath