Footer opened a can of worms there. Tie
line is not rated for
overhead lifting.
Some tie
line comes with the working load limit stamped on the spool. Some does not. There is definitely risk in working with tie
line. You need to have the knowledge to know if it's a good idea or not. Bill Sapsis and Jay Gelrum will tell you never use Tie
Line for
overhead lifting.
Some around here would say:
"Never use
tieline for
overhead lifting "
others would say
"YOU should never use tie
line for
overhead lifting, but I know what I'm doing"
Personally I have three rules the I follow regarding the use of tie
line. I will not use it for any
overhead lifting that does not meet all three standards:
1) I assume that if the tie
line fails, it is MY fault and I WILL take all responsibility for any disruption to the performance, injury, and/or damage. If I'm not willing to take those risks I use aircraft cable.
2) I only use tie
line in a stationary hung situation. I would never fly something in and out by use of tie
line. In some situations I am comfortable attaching something
very light weight to a moving
batten with tie
line (better be plenty of tie off points). But it's unacceptable to use a bunch of tie
line and pulleys to fly something in and out... get aircraft cable.
3) Most importantly, only use tie
line to hang something so light that I wouldn't mind to have it unexpectedly fall
on the head of one of my children* from the working height. If I have any hesitation that one of the people I value most in this world might get hurt by standing under the rig, I use aircraft cable.
How heavy is too heavy? The standard
safety factor for
overhead lifting is 10 to 1. If your tie
line is rated at 50lbs then I wouldn't hang more than 5 pounds per
point line on an evenly distributed load.
*We all cut corners and take risks at times in tech theater. I think with anything involving
overhead lifting the best test is to visualize the person/people you love in this world standing under it. If you believe that someone you would truly take a bullet for would be safe standing under your rigging. Then you have probably done a good rigging job. That said, there are far too many people out there who are well intentioned and don't have the knowledge or training to make that assessment. Nearly every Christmas we hear stories about well intentioned people killing friends by flying them to their death in church Christmas pageants. People who thought they knew what they were doing but didn't. But for me, a technician who has had rigging training, those are my standards. Take some rigging classes so you can have the knowledge to know what is safe and what isn't.
Also note, there are some fantastic synthetic rope materials used in sailing that are incredibly strong, have proper ratings, and are very low
profile to work with.