Unsure about physics of hoist boom

Hi,

I just joined, thanks to all for contributing to this unique resource. I started out in school as an engineer in the 70's, but then ended up in a software career and all my calculus and physics knowledge has just gone. I have tried to work the formulas some of you have suggested and I just don't have it in me. I hope you can give me some information about this project design I have been working on.

This is a hand brake winch powered hoist permanently attached to a rack on the top of a truck to lift two 100 lb 3' wide boats onto and off of the rack. It does not lift any humans and no humans are under the load.

My concerns are whether the 2" 304 SS sch 80 pipe mast is going to bend at what I have indicated as a possible fail point. Does the use of the brace and the surrounding 2.5" pipe concentrate the stress at that one point? Do you think it can handle it? The 2" pipe has .094 play in the 2.5" pipe and will be greased, but if the load deforms the pipe, it could bind I suppose.

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thanks very much for any ideas,
fred

See:

[U][B][URL="https://www.engineersedge.com/mechanics_machines/davits_design.htm"]Lifting Boom, Davits Applications and Design[/URL][/B][/U]

Kelly,

I saw that link in another post and tried to work through that page before I posted. I can't do it.