# flying hardware



## Versha (Feb 2, 2012)

so i'm not sure if this is the right place for this question, if its not please move it to the right one. i'm working on flying a set of speakers at my church and i'm wondering if anyone knows of a good vendor (either online or in the seattle area) for grade 8 welded eye bolts. any help on this would be most appreciated.


----------



## derekleffew (Feb 2, 2012)

VER SALES, INC. - Machinery Eye Bolts
Sapsis Rigging Inc.: Shoulder Pattern Forged Steel Eye Bolts 3/8" x 2-1/2"
3/8? EYEBOLT, DROP-FORGED SHOULDER


----------



## MPowers (Feb 2, 2012)

You don't want welded, you want forged. You are correct though, in not wanting a bent eye but a closed eye. Also, don't look for grade 8, you won't find them. What you want is forged, domestic, Machinery Shoulder Eye Bolts. Probably the most common size for speakers is 10mm, so check the threads to see if they are metric or imperial. Check the speaker manual or on-line spec sheets to see if they list a minimum thread length. If not, measure the hole depth and get an eye bolt with a thread length 1/8" to 1/4" shorter as you don't want the Eye Bolt to bottom out in the hole. Lots of places to buy. In fact some, not all, hardware stores, especially in farm country, like Tractor Supply, carry the forged product. places to buy on line in addition to the above: 

McMaster-Carr
Fehr Bros. Industries, Inc.
Lifting Eyes | Fastenal
Eyebolts - Bolts - Grainger Industrial Supply
Shoulder Nut Eye Bolts Hot Dip Galvanized Drop Forged on Lexco Cable Manufacturers

BTW - Don't forget to use a lock washer, especially if you are hanging with GAC.

We get ours through Lexco as they are close and give us a good quantity discount.


----------



## emac (Feb 2, 2012)

As for sourcing the products locally, PNTA or Hollywood lights are the local theatrical supply houses. PNTA has a rigging section that might have forged eye bolts in stock. Else wise Tacoma screw is a great source for products such as this, I am not sure if they have retail outlets but PNTA I believe can order stuff from them for you.


----------



## Versha (Feb 2, 2012)

thanks MPowers, the first site you gave me had exactly what i was looking for.


----------



## Versha (Feb 28, 2012)

*flying hardware part 2*

I'm wondering if you guys know of any chain suppliers that are local to the seattle area? i'm looking for 5/8" grade 80 chain and would prefer to not have to order from an online supplier in order to avoid the shipping costs. this is for the same flying project i posted about in my last post inquiring about eye bolts (2 mackie speakers).


----------



## techieman33 (Feb 28, 2012)

*Re: flying hardware part 2*

What on earth are you hanging that you need that big of a chain?


----------



## JLNorthGA (Feb 28, 2012)

*Re: flying hardware part 2*

Grade 30 chain would work quite nicely for what you need. You are just hanging it. You don't need 5/8" chain - you aren't anchoring a ship or tying down a backhoe. Your speakers weigh what? Maybe 50-100 lbs? 1/4" Grade 30 chain has a weight capacity limit of 1250 lbs. Your big problem will be getting shackles to fit with your eye bolts and through your chain. Get the weight rated shackles.


----------



## museav (Feb 28, 2012)

*Re: flying hardware part 2*


JLNorthGA said:


> Grade 30 chain would work quite nicely for what you need. You are just hanging it. You don't need 5/8" chain - you aren't anchoring a ship or tying down a backhoe. Your speakers weigh what? Maybe 50-100 lbs? 1/4" Grade 30 chain has a weight capacity limit of 1250 lbs. Your big problem will be getting shackles to fit with your eye bolts and through your chain. Get the weight rated shackles.


We don't know what they are flying, it could be a 250lbs. WorxAudio X5-P or EAW KF850z, a 720lbs. Danley JH 90 or a multiple box array. 1/4" Grade 30 might be fine but rigging is not a good place to make assumptions.


----------



## MPowers (Feb 28, 2012)

*Re: flying hardware part 2*


Versha said:


> ........... i'm looking for 5/8" grade 80 chain .............. this is for the same flying project ......... (2 mackie speakers).



You really, Really, REALLY, DON'T WANT or need 5/8" G80 chain. That is rated at 18,100 pounds WLL. If you are hanging each speaker separately, by at least 2 points each, even if they are the 750 pound each mentioned in another post, you could drop down to 3/16" G30 chain rated at 800 # WLL. 

You will find even 1/4" G80 chain *extremely* difficult to work with. You can not cut it with a bolt cutter, 1/4" shackles only fit in an end link.

If you truly feel that you need a heavier chain (you don't) try either the SECOA STC chain or the JR Clancy Alpha Chain. Both are G63 alloy chain with a link size and thickness to accept 1/4" shackles in any link position, rated at 3250# WLL. The Alpha chain has one big plus, it is black if visibility is an issue.


----------



## MPowers (Feb 28, 2012)

*Re: flying hardware part 2*


museav said:


> We don't know what they are flying,..........



Actually, we do. The OP told us in this thread post #6.

> this is for the same flying project i posted about in my last post inquiring about eye bolts (2 mackie speakers).



For Mackie speakers, it is unlikely that they weigh more than 150# each, however, as you say

> rigging is not a good place to make assumptions.


 So the OP needs to use a chain rated for the actual load he will be rigging.

IMHO, if the OP intends to use the same chain in the future for other rigging with currently unknown loads, he should consider the SECOA or Clancy chains with a 5/16" shackle as that will handle a wide range of loads, is easy to rig and the hardware will fit a wide range of speaker fittings and rig points in venues. 

Hope this helps


----------



## Versha (Feb 28, 2012)

*Re: flying hardware part 2*

ok, so 5/8" is obviously too big. this is the first time i've sourced the chain needed and when i was researching chain grades at the beginning of this project i found controlbooth and according the post on this site about chain grades there were a bunch of sources that said that for overhead lifting grade 80 was the minimum required grade. the speakers are going to be hanging about 15' overhead so according to the NACM grade 80 was, again, the minimum recommended grade. i said 5/8" because i had originally misread the size of the shackle. yeah, grade 80 does seem to be overkill for this job but since there were at least 3 regulating bodies sited in the chain grade thread about this apart from the NACM that all agreed that grade 80 was needed I figured that that was what i needed in order to do this project safely. we are flying two mackie sr1521z speakers. these speakers do not have flyware on their own but we have found some steel fabricators that can make us appropriate flyware for the speakers w/o compromising the integrity of the speakers themselves for cheaper than buying new speakers (which is in the plans to buy in the future) we're hanging each speaker separately with 2 points hanging and a third point as a trim. plus the failsafe in case of catastrophic failure. the speakers themselves weigh about 50 pounds. so yes, a WLL of 18,000 pounds seems like way too much but again i'm going off of what the NACM, ANSI, ASTM, ASSE say about overhead hanging applications.


----------



## DuckJordan (Feb 28, 2012)

Over head lifting is a difficult term its mean actual lifting as in moving.

Sent from my ADR6300 using Tapatalk


----------



## Les (Feb 28, 2012)

MPowers said:


> ...First, over head rigging is NOT limited to G8 hardware, G5 is what is supplied by rigging manufacturers. *Second, but the major point, in the use described by the OP, it is not "Overhead Lifting". That designation is for chain that actually reeves over a cog wheel or winch drum.* See the white paper from the JR Clancy web site
> 
> http://www.jrclancy.com/Downloads/ChainforTheatricalUse1.pdf
> 
> ...



Emphasis is mine.

From this thread: 
http://www.controlbooth.com/forums/...ns/15843-difference-between-grades-chain.html


----------



## Versha (Feb 28, 2012)

so if i only need grade 30 chain then does anyone know of a chain supplier in the seattle area? i still would prefer to not buy this from an internet supplier so i can avoid the shipping cost on the chain being that chain is by nature rather heavy and would cost an arm and a leg to ship.


----------



## avkid (Feb 28, 2012)

Grainger stocks 20ft pieces of CM Grade 30 chain.


----------



## MPowers (Feb 28, 2012)

Versha said:


> so if i only need grade 30 chain then does anyone know of a chain supplier in the seattle area? ...........




Believe it or not, 1/4" G30 proof coil chain is available almost every where, Home Depot, Lowes, ACE Hardware et. al. The tougher job is getting good rated shackles. In Seattle try:


Seattle Stage Lighting Company Information
Seattle Stage lighting
206-283-7464 
Email: [email protected]

PNTA
2414 SW Andover Street C100
Seattle, WA 98106
(800) 622-7850 Toll Free
(206) 622-7850 Seattle Area
(206) 267-1789 Fax
PNTA | Your Experts in Theater and Stage Equipment, Supplies, Rentals and Consulting

Crane Con Products CO
15303 1st Ave S, Burien, WA 98148
CCI Introduction

Rainier Industrial & SUPPLY
9026 E Marginal Way S
Tukwila, WA 

I have never dealt with any of these people , All I know is that they are in the Seattle Area. Hope this helps


----------



## Versha (Feb 28, 2012)

So will grade 30 be fine for the fail safe as well? i know that the force of a falling weight is exponentially greater that a static weight so i'm a bit concerned on this front. and yeah i was thinking of going with PNTA for the shackles, they seem to have a good price and they're rated.


----------



## Versha (Mar 1, 2012)

another question. what would be the best way to attach this rig to the ceiling? we aren't using truss or anything just four points straight onto the ceiling i have a few ideas but any feedback would be helpful


----------



## kiwitechgirl (Mar 1, 2012)

Sorry, but I think if you're having to ask this question you shouldn't be undertaking this project without some expert advice. Also, without knowing the construction of the ceiling there's no way we can advise. My thoughts would be that you need to get someone who knows what they're doing to come and look at the space and advise you - attaching to a ceiling is very different from finding the right bolts and chain. Do you know that the structure is strong enough to support the speakers you're planning to fly? Has a structural engineer OK'd it, or do you have building plans which indicate that it's OK?


----------



## Versha (Mar 2, 2012)

be that as it may, i've been commissioned for this project so i kinda have to do it. i have no doubts about the structure's ability to handle the weight of the speakers (there are engineers at the church). its not exactly a large church so calling in expert advice just isn't really in the budget. so again, any feedback on methods of doing this would be most helpful. i'll try to get pictures of the space for you, i just don't have any right now. its an A-frame ceiling with cross beams, one of which I was thinking about hanging the speakers from.


----------



## ScottT (Mar 2, 2012)

Versha said:


> be that as it may, i've been commissioned for this project so i kinda have to do it.



No, you don't have to do it. You say there isn't money expert advice but will there be money for expert lawyers when something goes wrong? You betcha.


----------



## DuckJordan (Mar 2, 2012)

Then turn it down you don't have the knowledge to do it right. Just as a contractor may not know how to build a barn he won't or at least shouldn't attempt to bs his way through it.

To expand upon my post, You brushed off some very important questions. Such as:
1. Have you had a structural Engineer in to see if where you want to hang them will hold the additional weight?

Without a minimum of someone who is willing to sign off on the project proffesionallly (Meaning they will take some liability when or if the points rip out) this project has hit a wall. Keep em on the ground. If you don't have the resources to do it correctly, then don't do it.

RIGGING IS NOT A PLACE TO SKIMP IN HARDWARE, EXPERTISE, OR FUNDING! If they really need to be hung they will get the budget to do it correctly, if not just don't do it. Another thing that comes up how are you going to get signal to the speakers when they are hung? are you going to run conduit to them? Are you going to use the correct type of cable for the job? What about processing to allow the room to be fully functional and not just be a giant echo hall that is worse with the speakers in the air?

Sent from my ADR6300 using Tapatalk


----------



## MPowers (Mar 2, 2012)

Versha said:


> another question. what would be the best way to attach this rig to the ceiling? we aren't using truss or anything just four points straight onto the ceiling i have a few ideas but any feedback would be helpful



OK!! End of the line. Now you are asking a question that we can not answer in good conscience. We do not know the structure or composition of your "ceiling" we don't know if there are beams or joists or.......! To give you good advice on this we need to be there or at very least have engineering drawings of the space, structure and load information. 

I know you have said your speakers are only about 50 lbs, but if one falls, it can still be a major incident. We can give advice on Eye bolts, chain, turnbuckles, shackles etc, as those are all known elements. 

You are at the point where you need some professional advice.


----------



## techieman33 (Mar 3, 2012)

MPowers said:


> OK!! End of the line. Now you are asking a question that we can not answer in good conscience. We do not know the structure or composition of your "ceiling" we don't know if there are beams or joists or.......! To give you good advice on this we need to be there or at very least have engineering drawings of the space, structure and load information.
> 
> I know you have said your speakers are only about 50 lbs, but if one falls, it can still be a major incident. We can give advice on Eye bolts, chain, turnbuckles, shackles etc, as those are all known elements.
> 
> You are at the point where you need some professional advice.



Agreed, the expense of a rigger is nothing compared to the cost of losing a life.


----------



## museav (Mar 3, 2012)

Some of this might sound a bit harsh, but the general point needs to be reinforced.


Versha said:


> be that as it may, i've been commissioned for this project so i kinda have to do it.


As already noted, you don't "have" to do it. If this is a 'commission' for which you are being paid and you don't have the expertise yourself then you need to subcontract that expertise out of your fees and that should have been included in your bid or quote. If you didn't then it may turn out to be what would many would call an expensive learning experience and you would be far from the first to have that experience.


Versha said:


> i have no doubts about the structure's ability to handle the weight of the speakers (there are engineers at the church).


What is the basis for your assessment? What kind of Engineers and what studies or analyses were performed? What liability are they taking, in fact what liability are you taking and how are you protecting yourself and the church?

I've noted this example up before but it seems rather apropos here. I had a project where early in the design process I talked with the original Structural Engineer for the building and went over the general concepts for flying the speakers. They said it should not be any problem as all of the beams had been designed for the worst case loads and our loads were very small compared to the structural loads involved. So we proceeded on that basis and had them review the final design at which point they noted that we happened to have picked the two beams that actually had the worst case loads and that could take no additional load. We worked out a solution, albeit an expensive one, but the point is that what even a qualified Structural Engineer initially thought would be no problem turned out to indeed be a problem once it was examined in greater detail.

I also remember standing in a church with someone saying they were sure that the wood beams would handle the speakers. However, it turned out that they were only assuming that because one of the other beams had a big heavy cross hanging from it. No one had verified if that one beam had been designed specifically for the extra load or if all the beams carried the same structural loads. With exposed beam structures it is common to make all of the beams look the same even if they are not really the same or carry very different loads, but because what they saw looked identical to them they assumed that everything related to it was identical when that is very likely not true. 


Versha said:


> its not exactly a large church so calling in expert advice just isn't really in the budget.


Then neither is flying the speakers. This seems a simple point, just because someone wants something does not mean it is viable or that they are entitled to it, if someone can't afford something then they can't afford it and don't get it. You and/or the church need to either figure out how to get a qualified rigger and Structural Engineer involved or you should to pursue other options for mounting the speakers.


----------



## Versha (Mar 8, 2012)

well this project has officially become a necessity. by order of the fire marshal (the speakers are crowding the stage and thereby crowding an exit). I was considering (and by considering i mean intended on doing so) tabling this project until the budget came through but that's no longer an option. and there are literally all sorts of engineers in the church, from structural to computer engineers. but at this point, its beside the point since it has to be done. i'm still working on getting pics since i don't have a camera except on my phone and that's exceptionally crappy. and yeah, maseav, that did sound a bit harsh but considering the kind of experience i've seen you refer to in your posts i understand its reasoning. so, let me ask this: when getting an analysis done how much does it cost? and does anyone know of a company in the seattle area that does them?


----------



## MPowers (Mar 8, 2012)

If you have

> and there are literally all sorts of engineers in the church, from structural to computer engineers.


 in your church, you should be able to get one of them to do it pro bono or as a write off. Church members and their talents are a valuable asset, use them!


----------



## gafftaper (Mar 8, 2012)

Again, hiring a professional vs paying a multi-million dollar law suit.... let's think about that. 

Give my buddy Rick from TR professional a call. I'm sending you his personal contact info via P.M. He's an old road warrior audio guy. Used to be the pro-audio sales guy at Mills music, they closed that division and he started his own company about 4 or 5 years. He hung a big subwoofer for me a few years ago and is a great guy for these sorts of projects. My guess is as long as the access isn't too hard he would do it for $300-$500... and it's his responsibility if it comes crashing down. That's cheap insurance.


----------



## BillESC (Mar 8, 2012)

Rich or Steve at PNTA should be able to supply you with all of the materials and expertise required for this installation. Yes, it will cost a few more dollars than a DIYS but you'll be able to sleep at nights.

Or use Gafftaper's guy. You simply don't carry enough insurance to do it your self.


----------



## Versha (Mar 8, 2012)

MPowers said:


> If you have in your church, you should be able to get one of them to do it pro bono or as a write off. Church members and their talents are a valuable asset, use them!



that was my plan but i'm wondering if should be done through more official channels to curb the liability issues.


----------



## MNicolai (Mar 8, 2012)

If you've got some structurally savvy people, you'll be fine. Hanging a couple of Mackie loudspeakers isn't the kind of thing you need an engineer for.

You should have someone with some knowledge of carpentry, but a couple 50lbs speakers aren't the sort of thing that will collapse a roof, though they may fall if someone doesn't tighten a bolt down all the way.

There's no need to use a sword when a butter-knife will do. You just have to be able to recognize the difference between a stainless steel butter-knife and a flimsy piece of plastic cutlery.


----------



## Versha (Mar 8, 2012)

MNicolai said:


> If you've got some structurally savvy people, you'll be fine. Hanging a couple of Mackie loudspeakers isn't the kind of thing you need an engineer for.
> 
> You should have someone with some knowledge of carpentry, but a couple 50lbs speakers aren't the sort of thing that will collapse a roof, though they may fall if someone doesn't tighten a bolt down all the way.
> 
> There's no need to use a sword when a butter-knife will do. You just have to be able to recognize the difference between a stainless steel butter-knife and a flimsy piece of plastic cutlery.



well that's just annoying because the worship ministry director (who i'm obviously working very closely with) owns his own private contractor business.


----------



## MPowers (Mar 8, 2012)

Versha said:


> well that's just annoying because the worship ministry director (who i'm obviously working very closely with) owns his own private contractor business.



Problem solved! Just get HIM to sign off on whatever your beam attachment method is and you'll be fine. We've established that you can hang the speakers safely, the issue was with whether or not the roof would take the additional load, (High probability considering the very minimal load) and the method of attachment. The method of attachment was the break point and that is what you need to get approved.


----------



## gafftaper (Mar 9, 2012)

To me the insurance is the issue. We hung a big JBL sub in my black box and I called in Ric to do it. I was certainly capable of rigging the speaker. It was quite easy, I could have done it myself with the school's genie lift in a half hour. But here's the problem, I no longer work at that facility. I have no idea how that sub is being maintained or if the rigging is being abused or neglected. What happens if 5 years from now, long after I've left the facility, that speaker falls and kills someone? Who are they going to sue? Me. I wanted nothing to do with that kind of liability. I hung stuff all the time on a show by show basis. But there's no way I was taking the liability for a permanent install of something I'm not going to be around to care for. I wanted Ric's butt on the line, not mine.


----------



## museav (Mar 9, 2012)

MPowers said:


> Problem solved! Just get HIM to sign off on whatever your beam attachment method is and you'll be fine. We've established that you can hang the speakers safely, the issue was with whether or not the roof would take the additional load, (High probability considering the very minimal load) and the method of attachment. The method of attachment was the break point and that is what you need to get approved.


"Sign off", "approved", etc. imply their serving in a professional role and assuming professional liability. And if they are not working in a professional capacity, under contract, etc. then they may not be able to legally render such opinions, their Professional Liability insurer may not cover them and they may even potentially be putting their Professional License at risk. When you think about it, "volunteer" and "professional" are essentially mutually exclusive, one can be a volunteer or a professional but not both simultaneously. Thus a licensed professional may not be able to, or want to, act in a professional capacity without it being approached as their being contracted to provide professional services.

A simple example is that when I renew my Professional Liability insurance the form I have to fill out and sign includes questions such as whether I provide services without a Contract, whether I provide any 'pro bono' work and so on. The answers to those questions can affect my insurance rates or even whether coverage is offered and we can be talking hundreds if not thousands of dollars a year. And that is is just addressing professional consulting services and not even getting into the licensed Engineering or Contracting services aspect.

There is also the aspect that if the church receives professional services of some value without paying for them then they may be seen as receiving a donation of the equivalent fair market value. The church could hire a member in a professional capacity and that person then voluntarily increase their tithing, that resolves some issues but does then represent income for the professional.

So you may find someone willing to volunteer a professional opinion but it can certainly not be assumed.

As far as a couple of 50lbs. speakers collapsing the building structure, maybe not, but what about a 400lbs. to 500lbs. dynamic load during installation or should the mounting fail? And what about a 50lbs. load falling? What about potential seismic considerations and requirements?


----------



## Versha (Mar 9, 2012)

museav said:


> As far as a couple of 50lbs. speakers collapsing the building structure, maybe not, but what about a 400lbs. to 500lbs. dynamic load during installation or should the mounting fail? And what about a 50lbs. load falling? What about potential seismic considerations and requirements?



This leads back to a question that has gone unanswered which is would the G30 chain be sufficient for the fail safe line? since the force exerted by a falling object is exponential to its weight i'm slightly concerned about this. according to an online calculator i found (so i'm not exactly sure about the reliability of this) the force exerted by a falling mass of 50lbs from a height of 15' is approximately 3200 pounds. however this would be falling all to way to the ground. falling to the end of the fail safe line as i would thread it would only be about 714 lbs. (falling only about a foot). now i've already confirmed the worship director's willingness to sign off on this so it would be in his best interest to make sure the highest probable fail points (the connections to the ceiling) are secure.

we are taking into consideration the possibility of an earthquake and the requirements of this. which, for me, is kinda amusing being a California native. a major earthquake in WA is the equivalent of a foot massage.


MPowers said:


> Problem solved! Just get HIM to sign off on whatever your beam attachment method is and you'll be fine. We've established that you can hang the speakers safely, the issue was with whether or not the roof would take the additional load, (High probability considering the very minimal load) and the method of attachment. The method of attachment was the break point and that is what you need to get approved.



the annoying bit isn't that the problem is solved. its that it wasn't a problem to begin with. the fact that his OK is sufficient just means that i was already doing what needed to be done and don't need to incur extra costs by going with an outside structural engineer which seemed to be the prevailing sentiment in the posts previous to this. thanks for making me feel like a blithering idiot though, really appreciate that.


----------



## MPowers (Mar 9, 2012)

The reason I mentioned using the resources you have, vs-a-vis the professional congregation members, is that we work with a number of churches in the area, ranging from one that has 8,000 + members and just built an $18 mil facility, to some with 500 members that have been built entirely by pro-bono in-kind architecture and engineering. They all have taken advantage to one degree or another of the professional abilities of their members. How they deal with the legal aspects of responsibility, liability, bid bonds, performance bonds, taxes and etc. I do not know, except that they do. For example, last year we installed a motorized clew winch in a church gym converted to a performance/worship space. Our installation involved adding structural steel to the roof to support point loads between the roof trusses. From those points we installed loft blocks, a head block and the winch, to hang a small 20' circular truss that supports lighting equipment two projectors and some sound gear, total of approximately 2300 lbs. plus the weight of the additional steel and rigging for another1500 lbs. Not a very large load or installation, but more than enough to hurt if it fell on someone. One of the congregation was a structural engineer and he did the official structural analysis and release for the project to approve both our structural design and the certification that the existing structure would support the additional loading. His firm and his signature was on all of the official project construction documents. We were told that his contribution saved about $8K from what it would have cost for us to supply the engineering study and various releases.

We experience the same in-kind of engineering in a majority of our church related projects.


----------



## MPowers (Mar 9, 2012)

Versha said:


> This leads back to a question that has gone unanswered which is would the G30 chain be sufficient for the fail safe line? ..............falling to the end of the fail safe line as i would thread it would only be about 714 lbs. (falling only about a foot). now i've already confirmed the worship director's willingness to sign off on this so it would be in his best interest to make sure the highest probable fail points (the connections to the ceiling) are secure........



Couple of things here. 

First, a properly installed "fail safe" line (not the same as a lighting safety with lots of slack to allow focus movement) allows no movement or only a slight degree of movement before absorbing the weight of the object, thus reducing shock load to as close to zero as possible. 

Second, If you are hanging the 52 pound speakers by the standard method of 2 independent chains (or cables) one each to the standard two top rigging points in most speakers and possibly a third chain to the center bottom back to adjust tilt, you have all the safety's you need built in to the system. Each individual chain or cable, even if only 3/16" or 1/8" respectively can handle 10 times the load by them-self, they are each other's safety. Multiple point rigging introduces redundancy in the design and that is just what a safety is, redundancy. Multiple point rigging is actually superior to single point rigging with a safety. In multi-point rigging, each suspension connection is under tension at all times. This means if any one of them should fail there is no shock load, only dynamic loading during the initial swing and pendulum action should one of the cables/chains fail. 

Unless you are hanging by a single point allowing the speakers to twist and spin on the connection, you do not need any additional "fail safe line", the system itself provides more than sufficient redundancy to cover any contingency.

And, to answer your original question, if you feel the need add an additional safety, either 3/16 G30 proof coil chain or 1/8" GAC (either one properly installed) would be more than sufficient to do the job. Properly installed in this instance means all connections, crimps, clips thimbles etc done correctly and all slack removed from the line.

Last and not least, If the worship director is not a licensed engineer, his signing off does not release you of all responsibility or liability. In fact, even if he is, you or us in the case example I gave in another post, are not entirely off the hook. Should anything happen, the lawyers will try to show that "just following orders" is not an excuse for poor practice, ignorance of good practice, etc.


----------



## museav (Mar 9, 2012)

MPowers said:


> One of the congregation was a structural engineer and he did the official structural analysis and release for the project to approve both our structural design and the certification that the existing structure would support the additional loading. His firm and his signature was on all of the official project construction documents. We were told that his contribution saved about $8K from what it would have cost for us to supply the engineering study and various releases.
> 
> We experience the same in-kind of engineering in a majority of our church related projects.


This is from NSPE, http://www.nspe.org/resources/pdfs/Licensure/Schinnerer_Advisory_on_Pro_Bono_Services.pdf.

I am not a lawyer, but based on related classes and seminars I have attended along with several other resources, pro-bono Engineering services for non-profits, including churches, is encouraged. However, there are apparently a few aspects that may want to be addressed:

It is still providing professional services, just for no fee. The parties are acting in a professional role and not as a 'volunteer'.
Services not clearly defined as being offered by the individual may put their employer or company at risk while services provided by an individual and not on behalf of an employer or company may not be covered under the employer's or company's liability coverage. Whether it is the individual or a company providing the services needs to be clear and understood by all. I have seen people lose their jobs for putting their employer at risk without their consent.
Professional Liability policies may address pro-bono work differently. It may be treated as any other work, may affect the premiums, may relate to limited coverage or may even be excluded.
It may still be advisable to have some form of Contract even if no fee is involved, if nothing else a Contract can help minimize confusion regarding what services were provided. And perhaps also a release of liability
If it is viewed as the church soliciting 'pro-bono' services specifically to avoid paying for the services or of the professional offering pro-bono services to potentially take work from a competitor, gain an advantage, etc. then that gets into a very grey area of professional ethics.
Understand that the language used can be critical. A professional may be hesitant to "approve", "accept", etc. but be more willing to "offer an opinion", identify "exceptions" and so on.


----------



## MPowers (Mar 9, 2012)

Brad,

Excellent post. It states more clearly than the way I stated it in the last paragraph of my post, the various pitfalls and potential issues involved with pro-bono or "in kind" type of work. There are lots of gray areas in this kind of work and no "Signing Off" by any party absolves anyone else from negligence or poor workmanship. Thanks for a well parsed post.


----------



## Versha (Mar 12, 2012)

MPowers said:


> Last and not least, If the worship director is not a licensed engineer, his signing off does not release you of all responsibility or liability. In fact, even if he is, you or us in the case example I gave in another post, are not entirely off the hook. Should anything happen, the lawyers will try to show that "just following orders" is not an excuse for poor practice, ignorance of good practice, etc.



I never considered that having a structural engineer or having the the worship director sign off on the project would alleviate my or the church's responsibility or liability in case of a catastrophic failure. it does help to keep the bases covered and assure safety which is my goal in this


----------



## Versha (Mar 14, 2012)

ok so here's an update, kind of. we've decided to simply buy new speakers with integrated fly points. 2 Mackie HD1221 speakers to be exact. now in the owner's manual the size of the forged eye bolt needed is M10 x 1.5 x 37 mm, now finding that specific size has been a bit of a problem so i'm wondering if you guys know of an alternative size or know where i can find said size. as always help is appreciated.


----------



## MPowers (Mar 14, 2012)

McMaster Carr

McMaster-Carr




M10×1.5	230	507	25	17	3107T43	$4.14
Type 304 Stainless Steel
M10×1.5	170	370	25	17	3100T12	7.92
Type 316 Stainless Steel
M10×1.5	170	370	25	17	3130T12	9.73


----------



## museav (Mar 14, 2012)

Versha said:


> ok so here's an update, kind of. we've decided to simply buy new speakers with integrated fly points. 2 Mackie HD1221 speakers to be exact. now in the owner's manual the size of the forged eye bolt needed is M10 x 1.5 x 37 mm, now finding that specific size has been a bit of a problem so i'm wondering if you guys know of an alternative size or know where i can find said size. as always help is appreciated.


Mackie - Accessories available from:

Mackie PA A2 Eyebolt Kit for HD Series Speakers | Full Compass
Mackie PA-A2 Eyebolt Kit for Mackie HD Loudspeakers PA-A2 B&H
Mackie PA-A2 | Performance Audio
Mackie PA-A2 Eyebolt Kit for HD Series Loudspeakers
and many others...

Maybe not the cheapest option at $47.99 for a kit with four eyebolts but they seem readily available and you know they're what is recommended for the speakers. Be sure to read all the rigging related information in the HD1221 manual.


----------



## Versha (Mar 15, 2012)

yeah i found those about 5 min after posting about this, they are a bit pricey especially since we're only gonna use 3 per speaker.


----------



## gafftaper (Mar 15, 2012)

Versha said:


> we are taking into consideration the possibility of an earthquake and the requirements of this. which, for me, is kinda amusing being a California native. a major earthquake in WA is the equivalent of a foot massage.


The 1994 Northridge quake was a 6.7, the 1989 San Francisco Quake was a 7.1, The "Great Quake" of 1906 (estimated largest quake in San Andreas history) is estimated at a 7.9.

Now, look up "Cascadia Subduction Zone". Short version: 9.0+ quakes about every 300-600 years (plus it can generate massive Tsunamis, similar to the one in Indonesia in 2004). Our primary fault has been pretty quiet since it's last major quake in 1700 and that's a very good thing. 2012-1700=312 years  

Then there's the "Seattle Fault" which runs East-West from Hood Canal to the Samamish Plateau. It can create 7.0+ quakes and generate small tsunami's inside Puget Sound which would wipe out everything near the waterline with a 16-20 foot high wave in less than 2 minutes from the start of the quake. 

So I wouldn't use the words "foot massage" to describe earthquakes in Washington, I would use the words "time bomb".


----------



## SHARYNF (Mar 15, 2012)

In my experience all the sign off etc only works to have the insurance companies who have insured the person/company signing consider paying the claim . If things go horribly wrong, everyone gets sued. 

Sharyn


----------

