Externet Posted December 24, 2011 Posted December 24, 2011 (edited) Hi. In need to lift 700Kg to the place an item will be installed, I have been looking for a winch. A couple of salespersons said the winches they sell are rated for 2000Kg; which fits safety margins but are not meant for lifting vertically, just pulling horizontally with such force. I do not get it. What am I missing, what am I not considering as why the winch force cannot be used for lifting ? [The industry uses hoists for the same task, but chain length limitations do not fit my task (35 metres height). That is why am after a (wire rope) winch] Edited: added a random picture borrowed from the net as example of task: ----> http://escocomm.com/wp-content/uploads/2011/11/Lucas_Oil_Speaker_Cluster-246x300.png Edited December 24, 2011 by Externet
Xittenn Posted December 24, 2011 Posted December 24, 2011 Most likely their figure just doesn't meet the dynamic requirements of a swinging load, and they are giving you fair warning. Just to be slightly clearer. If you suspend a 2000kg load, at rest the downward force is 19600N, and this would be the force of tension on the wire. If a force accelerates the mass during lift, you will have to vector sum the forces to get a value that is greater than the maximum rating. Also think, at some point it will be required that a force will be applied that is greater than 19600N to accelerate the mass into upward motion.
ewmon Posted December 24, 2011 Posted December 24, 2011 I get the impression that the sellers (and makers) of the winches don't want to be responsible for anything falling (damage to the object or what/who it falls on), so they say it's approved only for horizontal pulling (trucks out of mudholes, downed trees through the forest, etc).
Pantaz Posted December 24, 2011 Posted December 24, 2011 Rather than relying on salespeople, I would look at the winch manufacturer's published specifications. You might also contact their technical/engineering departments. Also, if you will be using this in a commercial setting (i.e., on a job site) then OSHA (in the U.S.) regulations might be a problem. Finally, if this involves overhead lifting, there are even more considerations. I just visited the Warn Winch site and found this: ... "Lifting, on the other hand, requires lifting dead weight into the air vertically. Therefore, a lifting/pulling product like PullzAll has some unique design features, such as a load limiter, and it does not utilize a freespool clutch." ... And, they have a selection of industrial wire-rope hoists that should meet your requirements: http://www.warn.com/industrial/winches/industrial_hoists_all.shtml
Xittenn Posted December 24, 2011 Posted December 24, 2011 IPT Publishing and Training Ltd. releases prints that include proper rigging procedures and standards, if there are any questions with regards to the equipment used and proper functionality. These are thorough publications that serve as reference manuals for trade professionals.
InigoMontoya Posted December 25, 2011 Posted December 25, 2011 (edited) A horizontal winch doesn't need a brake. Turn it off and it isn't required to hold the load. A vertically rated system, on the other hand, IS rated to hold the load after it has stopped movement (ie, will have a brake of some sort). Alternatively, some ratchet-based horizontal systems don't have a reverse so once you get the load up, you have no safe way to lower it back down (if you're stupid enough to use it vertically). Edited December 25, 2011 by InigoMontoya
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