Unbraced Length Cantilever Monorail w/ backspan

[drummingEng]

Please refer to the image. This monorail has a cable running across the top with pulleys. So, essentially a point load at the right of the image and at the end of the left side cantilever.

I am trying to decide what the unbraced length is of the cantilever at the left side. I am finding many conflicting answers that have me baffled as to which length to use. The section used as the monorail beam is (2) MC8x22.8 back to back spaced 2" apart with plates stitching them together every so often. There is a plate top and bottom for additional reinforcing.

 

[KootK]

Assuming that you've got effective lateral restraint for both flanges at the supports, I believe that the effective, unbraced length of the left cantilever = 2.5 x Lc = 23'. Hopefully it's carrying a light load.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[Ingenuity]

Bottom flange loading from the rollers?

From AISC's recent (May 2017) webinar on 'Design of Underhung Hoist and Crane Girders' by Lucas Pachal:

Also this AISC's 2005 'Modern Steel' article 'Cantilever Flexural Member Design' by Sam Eskildsen: Link

For a more theoretical approach, but surprisingly practical, there is Trahair's paper from 2008 'Lateral buckling of monorail beams': Link

 

[drummingEng]

Thanks "KootK " and "Ingenuity". That helped greatly!