Fire Door Closing

The rope was cut to release door manually?

There's gotta be some old codger here who would know.

We didn't have fire doors back on the farm. Not even at the church.

Probably a backup release mechanism....If sprinkler systems have been installed and/or water curtain, this may have changed code requirements...DASMA is the trade group association for doors, you might find useful info from their website...

http://www.dasma.com/

http://evanjacover.com/archives/category/engineering

I see where you got the picture. Our installation is similar, but the left-most cable goes up to near the ceiling, around another pulley, then to the right over the door opening where the rope section and fusible link are. All except the fusible link and rope is steel cable.

Sounds like the patent drawings above.

Yes this is an original design with all rope in the same configuration....The fusible link(160º), which is a modern upgrade used on fire doors and dampers today, releases on heat, the rope for flame...

===similar, but the left-most cable goes up to near the ceiling, around another pulley, then to the right over the door opening where the rope section and fusible link are.---

Could the extra pulley and rope have been added later to move the counter weight nearer to opening as a makeshift exit device? I can see this modification as it might not take as many people to get tthe door open enough to get through.

just a thought from the sidelines.

"Why was the rope used?" You don't really tell us about the setup. Is the weight suspended from the rope? Is the piece of rope a sort of splice in the cable? Does the rope look like it is intended by the manufacturer to be there?

"Can someone tell me where these specs can be found?" Manufacturer? This will probably be of little value; these gravity doors were often fabricated at some local steel shop to a project specific specification.

"The counterweight/closing mechanism on the fire door at my Church has broken." What, exactly, is broken? Is it a worthwhile effort to repair it?

"Why was the rope used?" You don't really tell us about the setup. Is the weight suspended from the rope? See my reply to #2. Is the piece of rope a sort of splice in the cable? No. Does the rope look like it is intended by the manufacturer to be there? Yes, but I don't know whether original or modified.

"The counterweight/closing mechanism on the fire door at my Church has broken." What, exactly, is broken? Is it a worthwhile effort to repair it? I haven't found who discovered the problem to find out what actually broke, but I suspect fatigue in the cable from running around the pulley. It probably has to be repaired to keep the fire inspector happy. Besides, I like to have old junque functional.

I haven't found who discovered the problem to find out what actually broke,

Well, okay. When you do there may be some helpful input from the forum, instead of our already assembled collection of guesses.

It probably has to be repaired to keep the fire inspector happy.

Prolly. Remember, it it does not latch it will not pass... See NFPA 101. No, a church is not exempt from building codes.

Belt and suspenders? Rope and FL.

Nice find.

Then it appear that the rope was the original safety link and a temperature senitive fusable was added at a later time.

The rope was the original "fusible link" that would burn to release the door. Sometime later the rope was partially cut off and replaced with the new fusible link, which was an advance in technology.

Possible, but I don't know that. If the fusible link was added, it may have been to take care of high temperatures without the flames to burn the rope.

Quite possible, but this was well before my time there. The link would have been added to take care of high temperatures without flames.

Those type doors were developed after the Chicago fire. The rope was the original fusible link. It was unreliable, let the fires burn too long in large areas until the temperature reach a level to cause combustion of the rope and failure of the rope after years of service had people replacing it with what ever was at hand the rope was never really spec out. A better fusible link was developed. In mandating it's use by the fire departments. On older door the rope was left. I guess they looked at the rope as back up if the fusible link did fail. Cheaper too then replacing the whole wire cable.

Thank you. This is the type of information I was hoping for. My son, who is a firefighter, never heard of the rope. Having it as a backup after better technology was developed makes sense.

The extra pully system may have been added along with the fuseable link. The link needed to be as high as possible to detect heat sooner.

This might be it.

http://www.freepatentsonline.com/1540647.pdf

Interesting! I think the old building where I used to work had some sort of latch, but I don't know it used whether a fusible link or something else.

The cable was too short and the rope jury rigged to make up the lenght.

Presumably the fusible link is what actually breaks in event of fire. You don't want the rope to break or burn through else the door won't shut.
Therefore use a thin wire cable (bowden cable).
The only spec is :- It must withstand the weight and still work in a fire.

I can't actually see the problem, unless gravity has stopped working in the region of the door.
Del

The fusible link and the rope are in series--either can break and disable the counterweight. The way it has been hooked up for years is that the door is always closed; the counterweight just makes it easier to open, but gravity will still close it. That means the cable is moving around one pulley with every opening, and eventually fails due to fatigue.

Does this failure mean that the theft and fire insurance is invalid until it is fixed?

Invalid fire insurance--I sure hope not. It was re-hooked up by some unknown person so that the door works, but it is illegal because the fusible link is beside the door, not over it. I have new cable, still have to find suitable rope, then re-do the hookup. That's why I asked here--to see if I can use some suitable sash cord, or whether I need to seek something made for fire doors. Looks like a suitable diameter sash cord (cotton) will be sufficient.

You know, this just occured to me.

Why not have the local fire inspector come over and have a look, and sign off on it when it's right?

Why risk being denied insurance money in the event of a fire?

Maybe it was all that was available to use at the time.

More than likely the rope was used as a fuseable-link.

Ideally the fire would burn the rope into removing the counterweight and thereby making the door more difficult if not impossible to open.

This is a simple way of keeping the fire from spreading to adjacent areas and to discourage/prevent personnel from opening a door and being immediately exposed to the affcets of a fire.

Have you tried N.F.P.A.?

Most appealing answer currently, where do you get your archer pics from?.

Del. He's trying to teach me the finer points of archery.

Archery hell. That's Debarchery, with a K.

Did you hear about the fella who built a wooden car? Wooden wheels. Wooden bodywork. Wooden engine, even.

And when he started it up it wooden go!