Scary stage

[Roderick]

This picture came in today:

http://sphotos-d.ak.fbcdn.net/hphotos-ak-ash4/1008353_10201413136229886_1359058098_o.jpg

 

Before we all get too excited, does anyone recognise the type of staging?

Or even who's stage it is?

It is rumoured to be a stage at the Citrus County Fairgrounds (Florida) at the middle of a row, the band refused to go on and cancelled the gig.

So the question is mostly pointed at our USA members.

[LXbydesign]

The fact that its all like thaT, suggests its how the system goes together. Bit like steeldeck stage deck butt to butt. It hardly an example of a stage set-up being dodgy cause there's a couple of missing legs.

[Andrew C]

All I can see is that there might be a leg missing at the front, and that maybe there should be more bracing on the legs using the round bars shown front centre.

[Shez]

A source with perhaps more eyes than here suggests it's Biljax staging with Telespar square tube legs.

[Andrew Edwards]

I would expect much more horizontal and diagonal bracing.

 

This pdf does show very little at shorter heights but further down on one of the higher structures has an amount that I would say looks 'enough'.

[musht]

Bambi on ice springs to mind.

[kitlane]

I wonder what the point loading on the feet is and what might happen if it rained heavily?

[paulears]

I rather like the design, where one edge hangs onto the next so it doesn't need side by side support on each corner. However I not the manual does state that cross bracing IS required on every third bay one height is above 30" - which this clearly is. Above 48" it needs double bracing. Not much bracing apparent in the picture is there?

[Giles Favell]

I'm not at all surprised the band ran away. Quite the most sensible thing to do.

 

I should do the same.

[kerry davies]

I opened this topic, saw the picture and her indoors was very upset. She thought I was having a heart attack or something since I don't usually go "Oh ######" and hold my head.

 

Those are 4 foot adjustable legs with very little structural strength and are very similar to a stage I banned 15 years ago. It doesn't even get anywhere near the manufacturers instructions and is possibly only suitable for podia and definitely not a performance stage.

 

Contentious Statement Coming Up;

If those who think it is "dodgy" because of a few missing legs wish my advice, it would be to never build a stage, never have anything to do with events using temporary stages and find a new career before you kill someone. This is a killer stage and anyone who cannot see that immediately has no business anywhere near temporary staging. Take heed of what Giles says, run away and do it fast, he is an expert.

 

News just in; Her indoors saw the picture and said; "Oh my God, that's not safe." She is a former nurse and drugs worker who knows nothing about staging.

[dbuckley]

This vertical only approach is similar to that used for computer room raised floors, where there are vertical things that the floor tiles go on, but because the tiles are within a room with fixed boundaries the walls provide the lateral stability. Some decades ago, an IBM mainframe service engineer related a yarn to me where a customer had taken a complete line of tiles out, and the floor (complete with mainframe) fell over.

 

Somewhat more recently, those of us in Christchurch watched and read the investigation into the CTV building, which collapsed in the earthquake. We learned how there are a number of approaches to designing buildings, and one approach (which the CTV building used) is very similar to this pictured stage. In this way of designing, the columns between floors in a multistory building are not required to handle lateral loads (requiring ductility), they handle only vertical loads, a/k/a gravity loads. The floors are kept from falling sideways by the presence of one or more shear walls and/or shear cores. You know the kind of building, large, open plan multi story office blocks, with one or more "cores" with the stairs, lift shafts and service shafts in them. Those tough concrete "cores" are a shear core, they have lateral stability, and the floors are attached to it such that lateral forces are transferred from the floors to the shear core, keeping all the floors in the same place relative to each other.

 

The CTV building had (short version) insufficient shear capability, and thus when the wobbles came, the columns became subject to lateral forces (by the moniker of inter-story drift) for which they were not designed (in addition to vertical forces exceeding their design load) and thus the columns failed, and the building pancaked.

 

This stage looks just like the computer models used to demonstrate the CTV building. I see nothing providing lateral stability. Sooner of later, this stage is coming down. The only question is when.

 

See, everyone in Canterbury is an expert on structural design now.

[kerry davies]

... and the artists said;

Sorry folks but...

I especially applaud the last paragraph and as one who has made that showstop call sympathise with them though I would far rather read that than

This.

[sleah]

... and the artists said;

Sorry folks but...

I especially applaud the last paragraph and as one who has made that showstop call sympathise with them though I would far rather read that than

This.

 

Excellent clear explanation of what happened in that first piece. Brave to name the promoter, yet good not to try and name those who actually did the work, as only they know if workers knew what they were doing etc etc.

 

On the flip side, looking at comments on the second story, it's so saddening that people feel it OK to make a flippant remark about 'saving us from their music' when an accident has resulted in death and injury to inocent workers simply doing their jobs. A bullet through the skull is surely the only humane way to deal with people like that? :(

[alistermorton]

This vertical only approach is similar to that used for computer room raised floors, where there are vertical things that the floor tiles go on, but because the tiles are within a room with fixed boundaries the walls provide the lateral stability.

 

It's something I've mused upon - not that long ago, a 12" gap under the floor was considered ample, and the tiles were relatively wide in comparison to the height of the risers, which had relatively wide spreader bases to stop them toppling. These days the height of the gaps are increasing, and I have worried for a while about frame room floors shearing under load.

 

It's not my responsibility to worry about these things, though, but it does cross my mind from time to time.

[GaryNattrass]

I know little about staging but that just looks well dodgy to me, I ask the question why did the manufacturers take the time to put all those holes in the uprights? They are obviously there to allow cross struts to be fitted as in the foreground, the other thing that leaps out at me is the dirt standing that they are sitting on, even a basic scaffolder would place a wooden larger pad underneath each leg of an bigger foot than these and good on the band for making safety their first priority.

 

We had Pat Benatar on The Tube in the 80's and all their crew from Clair Brothers were very professional as were the band.