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View Full Version : Cherry Pickr Tippng Angle & Potential Energy Req To Tip


glocki35
Oct1-09, 06:37 AM
Hi,

I have been tasked with working out load charts for various MEWPS (or cherry pickers) on board semi-submersible rigs, the iddea is to de-rate these in various sea states the same as an offshore crane, i have tried to simplify this as much as i can, however i am stuck when i try to work out the potential energy required to tip a cherry picker when the rig rolls and pitches (this is not a comprehensive engineering investigation, merely a simplification of what is required), i also would like to work out the inclination or angle required to make the cherry picker tip over.

Can anyone help with this?, i have attached a doc with sketches and figures to try and show you my way of thinking....

Thanks in advance

Glocki 35

mgb_phys
Oct1-09, 09:41 AM
It doesn't take any energy to tip - it gives off energy that's why it happens.
You just need the CoG (technicaly the centre of mass) to move outside the base (ie the wheels) all pitching and rolling of a ship does is to provide the tip

glocki35
Oct5-09, 10:55 AM
Hi MGB_phys,

just wanted to say thanks for the reply, much appreciated :)

nvn
Oct13-09, 01:34 PM
See thread 343039 (http://www.physicsforums.com/showthread.php?t=343039).