"Capt. Mooron" wrote |
| Wrong, kanook.
| Have you never seen an engine crane?

Is the brace located at 25% of the arm's length? I believe
the hydraulic ram
is located at 50% or more of the arm length.

So you've never seen one. It is at 25% and less when the
boom is extended out. Here's a pic of one my little Canuck
friend.
http://www.jcwhitney.com/autoparts/P...lay/s-10101/p-
1498/c-10101


| A bascule type draw bridge?

It's only lifting the bridge [boom] .. and again not at
only 25% of the span


Only the bridge? You have any idea what a bridge weighss?
And the gear is at about 5%, I'd say.



| Any hydraulic crane with the boom out?

Not at less than 25% of the boom.... extend the boom and
the capacities
decrease exponentially.

Here's a pic of a Grove Crane, very popular in this area.
See where the hyd cylinders are connected to the boom? I'd
guess that's about 10%. What do you say?
http://www.marcelequipment.com/Misc/grovert58c.htm




| An excavator?

Double Hydraulic rams to the main boom at 50% distance or
better to the
elbow and a third along the top of the stick to control
breakout and curl.
Limits imposed are with bucket size and hydraulic
capacity.


Guess again office worker. Here's another pic for you.
Can you say 10%?

http://usediron.point2.com/Xhtml/Equ...ails/P2/Excava
tor-Long-Reach/CATERPILLAR/320C/153870/ByManufacturer.html


| need more?

Sure... the examples you provided so far hasn't done
anything to convince me
that the capacity of a lifting device secured to a
location less than 25% of
the span of the boom can lift as much as one located at
the end of the boom.

How about a diving board?

look at the pretty pictures again. Study them, measure them.
Take a few days, then get back to me.

Scotty