Add a catwalk

tschnuckel

Member
About 6 years ago the local community theater built a new 400 seat and. They chose an architect who had never done a theater before. Originally there was to be a catwalk for the FOH. Somewhere along the line, it was cut. There is still a FOH rail. Accessed by 25 feet of scaffold. It gets set up and pushed through the raked seats then torn down for every show. That is about 8 per year. Stupid I know.

Now the board has contacted that same architect to fix the problem. Their suggestion is put the FOH on an ETC movable rigging. Not to mention charge another $12-18k for their time fixing the mistake. They say the roof will hold the extra weight and dynamic force created by the rigging.

I would think focusing 20 fixtures like that would be more annoying than the scaffolding. I'd like to just span the roof trusses with a platform. There isn't room to stand until your get to the FOH rail, but you could crawl out and back. Seems to me, if the roof can support the rigging it could support some boards and railing.

I know everyone will say contact an engineer, and we will. I'm asking if ther is another solution I might be missing besides scaffolding or a catwalk.

Just looking for thoughts and ideas.
 
It'll be cheaper to install a winched pipe(s) with moving fixtures that have shutters. Then a console to run it.
 
It is, as you predicted, an engineering problem, and a great many possible solutions.

Usually, a catwalk is less expensive than hoists, so I would always try for a low tech no maintenance solution like a catwalk and ladder. Consider annular maintenance required on hoist and it won't be easy without access. I can usually work with an architect and engineer to design a more economical catwalk but maybe one of the truss companies could do it all for less, since they have engineering. Lots of variables. Probably a ladder (or roof hatch?) Is as big of deal as the catwalk.

Options. If load is a problem, because catwalk is designed for load PSF even if you promise only one person, consider a track solution. Either a pair of rails and a creeper or cart that allows one person to move along behind the lighting pipe. A variant us the bosun's chair - a track (steel beam) and a seat hanging from trollies. Still, both of these require access from floor .

A classic solution uses two houses - one for lights and one bosun's chair. That solves access, just get in chair at floor and ride up.

I've not been able to make the movers work out budget wise. Consider a fixed site built catwalk might be $15,000 to 20,000. A hoist with feeder cable management installed maybe $25,000 to 30,000. Two hoist with bosun's chair probably $45,000-50,000. I know offhand what a pre engineers catwalk truss would cost. I point out the two hoists with bosun's chair is only $20,000-30,000 more than just hoist, and that doesn't buy many movers. And you're right, bounce focusing is awful.

Without knowing more, I suspect the creeper on rails is best bet and I don't know about access. Roof hatch in Iowa does not sound promising.

Let me know if I can help.
 
For 20 moving fixtures, even $2k a piece would be $40k. Plus you still need a lift or scaffolding for lamps, cleaning, etc.
 
For 20 moving fixtures, even $2k a piece would be $40k. Plus you still need a lift or scaffolding for lamps, cleaning, etc.
A mover that has the power and control of a source 4 for $2k? I figured an acceptable mover - iris or shutters, color changing, output like a S4 with a 575 - was at least $5k. Maybe that gets a S4LED and a Right Arm, but I'd miss the shutters.
 
Thanks for the pricing info. Bill, I never would have believed adding a catwalk could be cost effective.

Still, I'd rather have a winched pipe and a dozen or more MAC Vipers.
 
Thanks for the pricing info. Bill, I never would have believed adding a catwalk could be cost effective.

Still, I'd rather have a winched pipe and a dozen or more MAC Vipers.
It varies a lot but I figure between $125 and $250 per linear foot. If I've got 3 the fourth is usually less than $10,000 and usually in the 60' range. In this case, consider working directly with a steel fabricator who can provide the engineering economically.

(And it doesn't seem the MAC viper is in that $2K class.....)

I am looking forward to seeing the results ETCs current work on movers. Should we guess which show will be it's debut? Maybe a peak-a-boo at USITT 2017? I'm counting in it to be LED, at least an option for some beam shaping, quiet, and a new price point low for the features and lumens.
 
+1 for the suggestion of a track. We have a stand alone house pipe and had SApsis Rigging provide a focus track system. We had him build a cage that someone van stand in instead of a bosuns chair and it works well.

If you have a way to get up there ( fixed ladder on the wall, or a ladder that you can easily put in place ) it is a good, inexpensive solution.

Not as good as a catwalk, but less bulky visually and less expensive
 
I have avoided the design challenge of a person transferring to a bosun's chair but in my research, you can't transfer from a personnel lift in the air per OSHA, or even to a carwalk . You can board it and then fly it. A fixed landing is an option. Just pointing out this is a very tricky design issue.
 
I am looking forward to seeing the results ETCs current work on movers. Should we guess which show will be it's debut? Maybe a peak-a-boo at USITT 2017? I'm counting in it to be LED, at least an option for some beam shaping, quiet, and a new price point low for the features and lumens.

I'm just waiting for it to be an LED retrofit for the revolution.. :)
 
I have avoided the design challenge of a person transferring to a bosun's chair but in my research, you can't transfer from a personnel lift in the air per OSHA, or even to a carwalk . You can board it and then fly it. A fixed landing is an option. Just pointing out this is a very tricky design issue.

Bill

What I believe you could do would be to connect a self retracting lifeline to the bosuns chair. ( this is built into the device). Before you start up the ladder clip your harness into the lifeline. Not sure if this is legal in a lift, but with any kind of ladder it should be safe ( or are you seeing something I am missing ?)
 
Perhaps that is a solution. I just know that generally you can't transfer from say a genie to a catwalk - something I've had a desire to do - the "isolated" catwalk in middle of a big room. Maybe continuous PPE is the solution.
 
@BillConnerASTC it is permissible to transfer from a lift to lets say a catwalk, provided that your are protect 100% of the time from falling. So for instance lets take a "Floating" catwalk that has access via a AWP-30. For PFAS you would have a suitable harness, and a 6' shock absorbing lanyard.

So you start off by riding up in the lift. When you got to the access point of the catwalk you would then connect your lanyard to an appropriate PFAS anchorage (That can be a whole thread onto itself), then you could climb out of the lift and onto the catwalk. In theory you could design the access point of the catwalk to have a gate/chain so once you were on the catwalk you no longer needed the PFAS.

The important thing to remember is ANYTIME PFAS is used you must have a rescue plan, and be trained based on that rescue plan. Often implementing PFAS correctly is not as cost saving as people believe.

Regards,
Ethan
 
Actually when I looked into transferring from a lift it was to a TWG, not catwalk. I like them in some circumstances but, they are expensive;not solid so parts, lamps, tools, etc. go through; and make that magical theatre moment of an actor appearing out of blackness in a pin spot not so hot, as the eye is drawn to the light on the TWG.

And really expensive compared to catwalks.
 
And really expensive compared to catwalks.

So back to the track with a hanging basket idea. I used one at a local community theater. They use a ladder to get up on a platform. The platform is relatively large and has safety rails. You climb in the basket while you are on the platform then pull yourself out over the house. Would that meet safety code since you are transferring from a safe solid space into the basket and not directly from a ladder or bosun's chair?
 
So back to the track with a hanging basket idea. I used one at a local community theater. They use a ladder to get up on a platform. The platform is relatively large and has safety rails. You climb in the basket while you are on the platform then pull yourself out over the house. Would that meet safety code since you are transferring from a safe solid space into the basket and not directly from a ladder or bosun's chair?

I suspect it could if the person was protected from the fall hazard throughout.

We did seemingly learn from the Ringling Brothers report that it had better all be designed by an engineer.

I think the basket vs chair needs study, as to which one tilts more. I like the chair because it seems possible to achieve a better relationship, but basket can work. Any device with a double track would be more preferable, and not sway. My "creeper" on rails idea for instance.
 

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