On Mon, 20 Mar 2006 22:23:36 -0500, Ned Simmons
wrote:

In article .com,
says...
Ned,

A standard section I-beam will have the same numerical value stress in
the tension and compression flange, when subjected to a given bending
moment.


On custom built beams one can make the compression flange thicker, also
add gusset reinforcings, to allow it to withstand higher buckling
forces. This type of design is generally too expensive for my
clientele because of the design time required.


Trust this muddies things not too badly!


Not at all, I appreciate the time you've taken.

I understand that the magnitude of the stress in a symmetrical beam is
equal in the tension and compression members. But since compression and
tension are treated differently in the sort of spans we're discussing,
I'm surprised to hear that fabricated beams are not more common in large
cranes - they're pretty common in bridge construction here in New
England.

Ned Simmons


Which reminds me...part of the load I brought home this past week was
5 LODESTAR electric hoists. All but one are 220 3ph, the orphan is 440
3 ph.

No idea if any work or what their issues are. I recently rebuilt a
Coffing J-4 1/4 ton unit for a friends shop. These are rated 1/2 ton

Most are missing the trolly..though a couple do have them. All have
chain buckets,

Anyone in California, interested?


Gunner



"A prudent man foresees the difficulties ahead and prepares for them;
the simpleton goes blindly on and suffers the consequences."
- Proverbs 22:3