Fire Curtain Issue

[Malabaristo]

Our fire curtain has an unusual amount of resistance in the last couple feet of travel. After some investigation, I found that the issue is most likely caused by one of the lift lines rubbing against a steel beam just under the head block. The first photo shows the overall layout and the second a closer view of how the line is cutting into the beam. The head block is mounted to the top of that beam and another like it.



So, that's a problem... Without getting into a rule-challenging levels of detail, I'd like some 2nd or 3rd opinions on how to approach this. Some parameters:

• The arbor rides a lattice track and there's at least 4-5' of space for additional travel on that track.
• If I stop the curtain 18" off the floor, then that lift line is just barely clear of the beam.
• Conclusion: extending the lift lines by 2' is possible and would solve this problem.

Probably the obvious choice is to replace the lift lines, but there are some quirks relating to access that would make this more challenging than it ought to be. Today I had the alternate thought of adding a length of chain between the arbor and the end of each line. Aside from making future people go, "Huh?" ...are there any downsides to this approach I'm not thinking of?

Obviously this would need to be done by qualified riggers with appropriate materials regardless of approach.

To add some unnecessary detail: I have a strong suspicion this problem was caused when a certain company re-built the arbor due to a wear issue (...that they didn't really fix properly) 5-10 years ago. I'm guessing at the time they cut and re-terminated the lift lines without noticing the interference. Or, they saw it and didn't care--which would be entirely in character based on more recent work of theirs... The one positive aspect of the new problem is that it will offer an opportunity to add a more long-term fix to the wear issue as part of the process.

 

[BillConnerFASTC]

Have qualified riggers replace the lift lines.

 

[Van]

Maybe this was their idea for slowing the descent during the last 6-8 feet? <j/k> Augmenting the lift lines with chain, IMHO, is not a viable solution. If that cable has cut through that angle that deeply it must be replaced. Fire curtains are almost always a PITA so whoever does it should be used to it.

Have it inspected by a Qualified, Certified inspector and have the lines replaced ASAP.

 

[Malabaristo]

Augmenting the lift lines with chain, IMHO, is not a viable solution.

Just for the sake of argument/understanding, are you saying chain isn't viable because that lift line definitely needs to be replaced, or because it's a silly idea either way? If the latter, I'm interested in hearing your reasons.

Some of the point of posting here is to make sure I'm well equipped to make the right arguments. The district facilities staff is very likely to want to hire the same company that screwed it up in the first place... not sure I have the influence yet to win that fight, but I can at least be as prepared as possible going into it.

 

[Van]

Just for the sake of argument/understanding, are you saying chain isn't viable because that lift line definitely needs to be replaced, or because it's a silly idea either way? If the latter, I'm interested in hearing your reasons.

Some of the point of posting here is to make sure I'm well equipped to make the right arguments. The district facilities staff is very likely to want to hire the same company that screwed it up in the first place... not sure I have the influence yet to win that fight, but I can at least be as prepared as possible going into it.

I'm sure you could find a chain rated to hold the load. You could do the math to figure out the deflection necessary to move the line away from the angle but that lift line has got to be replaced, as does the one next to it which has also been rubbing that angle. Also it looks like the eye bolt the operating line is connected to is bent. An inspection is in order, again, IMHO.

 

[Malabaristo]

I'll have to double check, but I think the angle of the photo is a little misleading and the other line is not actually rubbing. Your point stands, though.

You are also correct that the bolt for the operating line is bent... and that shackle isn't moused, and there are a few other similarly sloppy issues. The scary thing is that I suspect the bolt may have been bent intentionally to keep the rope from rubbing where the arbor passes close to a beam.

 

[BillConnerFASTC]

I find chain and turnbuckles and such on top of arbors can cause problems. If a line or more go slack at all they may not straighten. Plus the bigger size of the chain and connection seems like it might contact the angle. You might better use wire rope with thimbles and swages. But replacing all the lines is the right answer.

 

[Footer]

Then send this picture to JR Clancy's scary rigging FB group...

 

[RonHebbard]

Then send this picture to JR Clancy's scary rigging FB group...

@eskramer C'mon, after 10 years of lurking, GO FOR IT! Take a chance. Post your FIRST post. PLEASE.
Toodleoo!
Ton Hebbard