Rigging Question (Tieing off a line set)

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Hi Guys,
extremely heavy loads (ie 700lbs +/-) and you do not want that pipe to move.

To soundguy 99:

First, 7000 pounds is not a normal counterweight lineset load and the basic hardware used in rigging is not designed for that load, so "really" qualified people are required.

Bill... it was 700#, not 7,000#. Not sure where you got the extra zero there.

Out of weight situations do happen especially when loading in Broadway style scenery. For an electric you should never be arbor heavy unless you are hanging fixtures longer then the low trim of the batten. This is one reason I like to see electrics low trim at 4' compared to the usual 3'. When I welded for a regional house I regularly built 1000# pieces that had to fly. These pieces where usually 25' or taller and were attached when laying on their back or face. You brought the pipe in, attached the load, snubbed the lineset, attach multiple bull lines, and got 10-15 of your closest friends to hang on the pipe while it was being loaded. After it was loaded everyone grabbed a bull line and let out the pipe while others walked the piece downstage or upstage. Repeat the same thing on the out. And got forbid you called the weight low and have to bring the thing back in halfway into the lift. General rule here is that the arbor is only loaded when the load is attached to the pipe and unloaded before the pipe is cleared. Even if the piece does take off (as long as the rigging on the piece does not fail) it will come into balance before it runs away. This type of operation should only be done by people who know what they are doing. However, it is standard issue stuff in any broadway style show.

 

[BillConnerFASTC]

7000lbs exceeds the capacity of ANY fly system I've seen by at least 2. Yes, there are ways to marry linesets (not about to get into that) but require extremely qualified riggers. However marrying 4+ linesets is stupid and dangerous. Get an engineer (PE variety) to determine ratings of beams, get some chain motors and truss and have a qualified and competent rigger rig them. They'll happily hold 7000lbs and are designed to be used that way.

It does depend on what you include in "fly system". I have more than a few projects with 5000 to 25000 pond loads on rigging, but granted only a few not fixed. I think of lighting bridges and acoustic shells. A few walls that are over 5000 on manual counterweight. Pretty remarkable how easily a person can move 5000 pounds without assistance.

 

[soundguy99]

Hi guys,
I appreciate the reply's.
Allot of of those practices and procedures you mentioned we do have in place, (ie loading the pipe before we add the counter weights ect), so we are not new to how to load and unload these pipes by any means.
My question was intended more to see if there was other practices that we weren`t doing that may help for those rare occasions where youre dealing with heavy loads.
Marrying 2 pipes together we generally don`t do that often but we do occasionally. We do also use hockey stocks or as some people talked about using pipe and put in between the hand line sets and twist the hand lines, but as i have been told before by a rigger when you do that any in balance in the line set gets transferred to the floor block, and in extremeness out of balance situations cause the floor block to fail. Of course it also stretches the rope.
I have also seen tying the arbor to the T rail, and I should look at getting some extra rope cut especially for that, so its on hand.
Also A large component to the arbor capacity is the actual physical siize of the arbor., as our bridge empty is at least 400lbs but iis also on a motor.
As you have point out, we also do have 4 acoustic shell roof pieces on abors with loads well over 600 - 700lbs, and is perfectly balanced.
So saying 700lbs is not a normal arbor load is a bit in accurate,
In Either case my question was more about other peoples practices of tying down an arbor for those rare occasions.
Although we have had professional riggers come through and shown us things and had training sessions with us, we are all still learning, and as I found each theater in different areas might have slightly different practices in how they do things, so its places like this forum to inquire and learn about how other places might do things slightly differently.
Definitely there is a few things you reminded me about here that I will have to look into.
Thanks for the advice,
soundguy_99

 

[BillConnerFASTC]

700 is not unusual, as most sets I specify are 1600 to 1800 pounds, and shelkscand electrics in the 2200-2500 pound range.

Just attach a 6' or so between at least every other rope lock and mnostr of the job is done and easy.