# Replacing or Repairing Gas Springs on Smoke Hatches



## Lambda (Sep 15, 2011)

Well, this is an issue that I've wanted to address for a while now. At the top of our fly tower, there are three smoke hatches that are original to the building and likely installed in 1965/66. They're quite large, much larger than any I've seen in my research. They were made by Bilco and installed with winches at deck level so they can be opened for testing, or ventilation and daylight. Until recently, we haven't had a crank to open them, but at the end of last school year I made one just to see if they worked. As I feared, when I loosened the cable, it just went slack and the hatch stayed shut. It opened when I pushed it from the genie, with a couple of pounds resistance, but did not spring open. Each hatch has three gas springs that look identical to automotive shocks (made by maremont/gabriel), which I assume have lost their springiness after 46 years. Needless to say, if there's a fire and the fusible links melt they will not open. Maremont/Gabriel seems to be defunct now, and it doesn't appear that Bilco makes this type of hatch anymore. 
So what do you suggest we do about this? 

The device in question:


The hatch itself:


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## Footer (Sep 15, 2011)

Get a mechanical contractor in there, they should be able to take care of it. Smoke hatches are not just a theatre thing, they are everywhere in general industry. Should not be a big job to fix from the roof. Get your maintenance/physical plant dept. on it, they should take care of this. The seals probably need to be replaced as well, might as well hit it all at the same time.


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## Lambda (Sep 15, 2011)

Footer said:


> Get a mechanical contractor in there, they should be able to take care of it. Smoke hatches are not just a theatre thing, they are everywhere in general industry. Should not be a big job to fix from the roof. Get your maintenance/physical plant dept. on it, they should take care of this. The seals probably need to be replaced as well, might as well hit it all at the same time.


 
I was hoping that it would be a simple order-and-install deal, but I figured I might get an answer like this. If maintenance gets on it at all, it will likely take them a long time. Most repairs inside the auditorium are responsibility of the tech crew (except houselights), and janitors never venture within the dark, mysterious, depths of the flyspace. But I'll talk to the head of maintenance about it. If they do decide to do it, do you think that the cost will come out of the theater budget? It is quite limited, and I'd hate to be known as "the guy who caused maintenance to squander the entire budget".
Believe it or not, the seals are still quite good. The only water we have a problem with is in the winter when the hatches get cold enough to condense water, and it drips.


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## Footer (Sep 15, 2011)

Lambda said:


> I was hoping that it would be a simple order-and-install deal, but I figured I might get an answer like this. If maintenance gets on it at all, it will likely take them a long time. Most repairs inside the auditorium are responsibility of the tech crew (except houselights), and janitors never venture within the dark, mysterious, depths of the flyspace. But I'll talk to the head of maintenance about it. If they do decide to do it, do you think that the cost will come out of the theater budget? It is quite limited, and I'd hate to be known as "the guy who caused maintenance to squander the entire budget".
> Believe it or not, the seals are still quite good. The only water we have a problem with is in the winter when the hatches get cold enough to condense water, and it drips.



Are you a student or a staff/faculty member? If your a student, don't worry about it. Tell the higher ups whats up... and thats it. You should be be responsible for building maintenance. Your job in a fire is to get out of the building. If your a staff member, same thing goes. Tell them but also don't worry about it too much. This should fall into building maintenance. Unless they are charging the theatre dept for painting, cleaning, or general repair. In my book, this is something to not lose sleep over. Alert the correct parties and forget about it. A follow up email after a month of not moving on it is not out of order but thats as far as I would go.


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## Lambda (Sep 15, 2011)

Footer said:


> Are you a student or a staff/faculty member? If your a student, don't worry about it. Tell the higher ups whats up... and thats it. You should be be responsible for building maintenance. Your job in a fire is to get out of the building. If your a staff member, same thing goes. Tell them but also don't worry about it too much. This should fall into building maintenance. Unless they are charging the theatre dept for painting, cleaning, or general repair. In my book, this is something to not lose sleep over. Alert the correct parties and forget about it. A follow up email after a month of not moving on it is not out of order but thats as far as I would go.


 
I am a student, a senior. At our school students do 100% of tech work (for the better or the worse). Thanks for the advice, it doesn't seem to make sense that they'd charge the theater department for general repair. I'll tell maintenance about it and let them handle it.
Just out of curiosity, is there anything in fire code against winching open the hatches during builds or something to let sunlight/fresh air in?


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## Footer (Sep 15, 2011)

Lambda said:


> Just out of curiosity, is there anything in fire code against winching open the hatches during builds or something to let sunlight/fresh air in?


 
I don't think it would hurt anything, though its not going to help anything either. Putting more strain on the system might not be the best plan. There is probably a very good reason why the winches that operate them do not have handles... they did not want them touched. Also, I would be concerned about birds...


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## avkid (Sep 15, 2011)

Footer said:


> Also, I would be concerned about birds...


Oh really?


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## Les (Sep 15, 2011)

I would have to go with Footer on this one. Opening the hatches during work calls might not do much more than strain the HVAC system. Now, if it's one of those days where they don't schedule the HVAC, different story.

The repair should come out of the school maintenance budget. If it doesn't, you're getting ripped off (it's like them charging for carpet or fire alarm repairs). Since this is considered a safety device, I'd also enjoy the security of knowing that I don't hold any liability in case those doors fail to operate after the repair.


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## Beeilly (Feb 16, 2012)

Lambda said:


> Well, this is an issue that I've wanted to address for a while now. At the top of our fly tower, there are three smoke hatches that are original to the building and likely installed in 1965/66. They're quite large, much larger than any I've seen in my research. They were made by Bilco and installed with winches at deck level so they can be opened for testing, or ventilation and daylight. Until recently, we haven't had a crank to open them, but at the end of last school year I made one just to see if they worked. As I feared, when I loosened the cable, it just went slack and the hatch stayed shut. It opened when I pushed it from the genie, with a couple of pounds resistance, but did not spring open. Each hatch has three gas springs that look identical to automotive shocks (made by maremont/gabriel), which I assume have lost their springiness after 46 years. Needless to say, if there's a fire and the fusible links melt they will not open. Maremont/Gabriel seems to be defunct now, and it doesn't appear that Bilco makes this type of hatch anymore.
> So what do you suggest we do about this?
> 
> The device in question:
> ...



The two shocks that you are showing in the pitcure are not what opens the door. The compression tubes in the corner is actually the culprit of the door not opening correctly, the shocks are there as a safety precaution (if the door just flung open, when it was new and someone was standing over the unit it would literally pick them up and knock them out. Any Monroe shock with the same dimentions will work as long as it is mounted rod side down. So if it does not function correctly have someone call Bilco, these things only carry a 25 year warranty. I was also wondering, there should be some labels on the unit somewhere now mind you I have worked with this company for 15 years and I have never seen a unit like this, even though this type of unit us not in production any more the parts as far as I can tell are still in use today, would not be nothing to get a hold of the compression springs (they are a real ***** to get in if you have never done this before). Even though I know this is not your responsibility you asked.

P.S. I would really like it if you would post more pictures of this. Looks to me like a custom job.


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