Fwd: RE: [TheForge] Lamp cord and heat generation

[dann]

Dave,

We  probably all see your project from different perspectives.

I imagine a blacksmith made iron chandelier that  would probably weigh well 
under 100 pounds, and most likely  under 50 pounds.    This  light  will be 
suspended using your new sisal rope with an electric cord "core"  ...  hung 
on an old barn carrier hay rope pulleys & track.  The subject home is a 
barn to house conversion?

For esthetic purposes,  the  sisal rope you make will probably be 
relatively thick and approaching an inch diameter  like an old hay 
rope.  Even a 3/4 inch home made  sisal rope  would  have a working 
strength exceeding 3,000  pounds and a breaking strength  exceeding  6,000 
pounds.

The chandelier  / light will probably  go  "up and down" only when he 
changes light bulbs.  Stress and fatigue should be a negligible issue for 
many years.  My old barn hay rope has been hanging/ holding the old  hay 
barn carrier  for at least 50 years.  We last used it when I was 8 or 10 
years old.

I should look this up in the David Himmelfarb  Cordage - Rope 
book.  However  according  claims made  in 1915 by the author to my  New 
Era rope booklet,  a home made  3/4 inch diameter sisal rope has a breaking 
strength of  6,500 pounds ( I believe working strength is considered 50% of 
the breaking strength).  A 3 strand one-inch rope has   a breaking strength 
of  12,600 pounds.

IF the staying power of my old barn rope is representative,  your newly 
made rope  should be strong enough to hold up a simple indoor 
chandelier  for generations.

The page link below has breaking strength data on  home made sisal binder 
twine ropes.

http://www.wctatel.net/web/equityrealty/NewEraPam7.html

Dann Johnson
Thompson, Iowa