"Duncan Wood" <newsto@[EMAIL PROTECTED]
> wrote in message
news:op.t5plhrrwyuobwl@[EMAIL PROTECTED]
> On Tue, 29 Jan 2008 15:20:57 -0000, Rob <run2@[EMAIL PROTECTED]
> wrote:
>
>> I'm working with a friend at a new facility. The architects want to
>> install: "18' lighting pipes referred to as "pipe booms"...They are to
>> be attached to the floor using a threaded flange and tied of using a
>> heavy duty rope to a location above the stage"
>>
>> My concern and the concern of the lighting install company is:
>> "...that the pipe is too long and has too much load for the specified
>> flange attachment (5" floor flange). We recommend a larger floor base
>> which will offer better stability for a pipe of that length and
>> eliminate the chance of causing damage to the floor and also the
>> possibility of a more rigid attachment point for the top of the pipe
>> in addition to the rope tie off."
>>
>> The architects claim this is a 50 year old practice used in other
>> sites. I think it sounds suspect-- it would not be my choice. Any
>> comments?
>
>
> That's pretty standard practice for a bomm with conventionals on it in
the
> UK. If something stiffer is required the top of the pipe is scaff
braced,
> If that's not stiff enough you need truss anyway. Using a larger base is
a
> trip hazard. The tops normally attached with something fire rated
though,
> not heavy rope. If your floor can't take the point load then it's the
> wrong floor.
>
Yes those boom bases are a real pain from a tripping standpoint.
I haven't been seeing them much lately, but we used to use ladders
for side lighting a lot. They weren't real ladders of course, but they
looked like a short ladder with a clamp at the top. You hang them
off of the end of your electrics. You can't put ****n busters on them,
but they don't get in the way either.
I think he is worried about it tipping and ripping out the screws.
If is properly tied off to the grid it should not be able to tip.
The flange at the bottom is only keeping it from moving around.
Even with a 50lb base you can't go more that 10'-12' without
tying it off to the grid.
They make special fittings that screw onto the top of the pipe
and that should get steel rope tied off to the grid. Preferably
under a little tension.
Now this is just practically speaking, and does not take into
account any local regulations. So, take it all with a grain of salt.
David
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