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Catenary calcs, software

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Catenary calcs, software

Posted by Paul Cook on Mar 11, 2011 9:14 pm

Catenary defines the shape of a line strung between two points. It is not the same math as a parabolic curve. I am looking for a program that will do catenary calculations to determine the change in sag of a line if the line is longer or shorter and takes into account the different elevations of the end points.

Can you help me find such a program??

Hope so.

Paul Cook, PLS
L. Paul Cook
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Re: Catenary calcs, software

Posted by RADU on Mar 11, 2011 10:33 pm

Hey Coooky non of the young bucks would have heard about such a thing as catenary...

Do you have the fomula or do you really also need that ?

Twinnie
RADU VALUE ADDING SURVEYOR
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Re: Catenary calcs, software

Posted by Kevin Samuel on Mar 11, 2011 11:30 pm

Catenary, never heard the term...

Hyperbolic cosine, yes too familiar back in the Calculus II (Integral Calculus) days.

I sent a message to a structural engineer friend that works on transmission lines all the time to see what software they are using.  I will let you know what he uses.

\cosh x = \tfrac12\left(e^{x} + e^{-x}\right)
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Steady on Kevin..

Posted by RADU on Mar 12, 2011 5:55 am

My Mate Cooky  being of stone age vinatge like my self will think  different of your coshx . Tis a club in our era.. and adding an x well you have an x rated club....


Sorry could not resist... I last coshx (ed) over 40 years ago!

Twinnie try this link   http://mathforum.org/library/drmath/view/53706.html


RADU


RADU VALUE ADDING SURVEYOR
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Re: Catenary ?

Posted by Paul in PA on Mar 12, 2011 10:46 am

Catenary:

http://mysite.du.edu/~jcalvert/math/catenary.htm

In the cantenery equation the weight is uniform along the length of the wire or chain. In a suspension bridge the weight is considered uniform along the bridge span and the length of the cable varies along the curve.

Factors to be considered include the temperature of the environment which gives a base temperature for the wire. However the current being transmitted also affects the temperature and the wire becomes longer with greater sag. The actual composition of the wire also affects the stretch.

I am not sure the power companies would give a surveyor sufficient information to calculate the results precisely, tread lightly.

Paul in PA
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Re: Catenary calcs, software

Posted by Kevin Samuel on Mar 12, 2011 11:13 am

PLS-CADD is the product they use.  Hope it helps.

http://www.powline.com/products/pls_cadd.html

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Re: Catenary calcs, software

Posted by Mike Falk on Mar 12, 2011 11:53 am

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Re: Catenary calcs, software

Posted by Paul Cook on Mar 12, 2011 2:04 pm

Thanks guys! I appreciate your help. I looked at the program you found Kevin and it may be what I need however, that is a very "all inclusive" (does much more than I need) program that requires 4-5 days of formal training and is very expensive, up to $9,000 for the full program.

So, I'm still looking for a simple program that can just do the math for cantenary calculations of "what if" i.e. what would the sag be if the line was longer by a foot? What is the length of the cantenary line with X sag and X diference in elevation with a given horizontal distance between the end points. etc., something like a simple curve calculating program or co-go program.... 

Any other suggestions??

Thanks!
L. Paul Cook
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Re: Catenary calcs, software

Posted by Mike Falk on Mar 12, 2011 3:07 pm

How about catenary calculations for your boat anchor using MS Excel?
http://www.johnsboatstuff.com/Articles/anchor.htm

or   Catenary for dummies at http://www.offshoremoorings.org/moorings/2005/catenaryb/CCCP_manual.pdf

Antenna wire catenary calculator at http://vk1od.net/calc/awcc/awcc.htm

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Re: Catenary calcs, software

Posted by Paul Cook on Mar 13, 2011 10:58 am

Thanks Mike, maybe..... I'll check them out.

Thanks again!

L. Paul Cook
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Re: Catenary calcs, software

Posted by mildeu on Mar 20, 2011 9:24 pm

Hi Mr. Cook,

If you are still looking for some help with the CATENARY PROBLEM I may be able to help.

I would help to know what type of computer, calculator you are using and most important, your application. At much less than $9000 ? was it.


You may respond to dennismiller.111@netzero.net 
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