Pyro tie-lines

[Ike]

Iím currently about to start putting some new cable in a ëmulti-purposeí venue and as the cable route is so difficult to get to Iím trying to put as much as possible in at the same time

 

One thing that I feel would be useful are pryo tie-lines running from the control room to the stage area. I am not trained in the set up and detonation of pyrotechnics (as I am only 17) and therefore will be taking advice from a suitably trained technician before commencing work however I would just like to know what cable and connectors I should use. For safety I obviously do not want the connectors to mate with any installed on other systems i.e. mains connectors, 3, 4 and 5pin XLRs, specon etc.

 

In terms of other safety measures the tie lines will run from the control room to the stage (direct line of sight), no intermediate break out points, switches or joints will be made and clear notices at each end of the lines detailing venue safety rules in respect to pryos as well as the fact no scenery, props or people must be between the operator and the pyro at time of arming and detonation will be posted. I also intend to site the break out box for the pryo lines to away from the others (speaker, mics etc) to reduce clutter around them.

 

Ike

[Rob]

The major problem here is distance - Ideally you wan't the person firing the pyro's to be the one closest to the device. They also need to have a clear line of site vision of the charge which may not always be possible from out front. Therefore, you probably want to be firing from on stage.

 

The standard pyro connector is a 3pin bulgin. As you said, definitely avoid anything already in use like 3 pin, 4 pin or 5 pin XLR.

[Ike]

Thanks Rob.

 

The venue is basically a square (ish) stage area and a raked seating area. The control room is relatively high up and gives probably the best view of the stage.

 

When pyrotechnics have been used before they have usually been fired from the control room and only once from the stage.

 

The choice of where to fire the pyros from will still remain with the operator, the only reason we are thinking of this is every production requiring pyros to be used barr one we have had to run the cables outside, up the side of the building and through a hole cut in the wall and along a corridor to the control room.

[Brian]

I am not trained in the set up and detonation of pyrotechnics

It's good that you are prepared to admit that.

Therefore, you probably want to be firing from on stage

Absolutely.

To quote the ABTT guide...

'The firing of a pyrotechnic device should be carried out as near to the device as is practical and safe to do so. The operator should have direct view of the device and its surrounding area.'

I personally would NEVER fire a pyro from the control box, there is just too much other stuff going on to distract you. Remember, you are just a button push away from seriously injuring someone.

 

I always place myself in a position where I have a clear view of the cast, the audience and the device.

 

I have on a number of occasions aborted a cue when an audience member has got too close on their way to the loo/wherever.

 

I would very much doubt that you could justify in your risk assessment firing a pyro from a remote location without taking extreme safety precautions.

[Ike]

Points taken, I will speak to the company the venue uses for setup/firing and ask for copies of previous risk assessments (I don't work in the venue all that often so haven't seen them).

[KaBoom]

Well said Brian,

 

I've been doing pyro for theatre and large scale stage for over four years and have NEVER fired pyro from any form of control booth.

 

I've always been either at the side of the stage or in a couple of instances, the orchestra pit.

 

You need to be aware that from the control booth out front although you have a great view of the stage, you cant see who or what is lurking behind scenery, or stage wings or flats etc. These are all places that pyro has the potential to be in the vicinity of.

 

I cant stress it enough, safety is always first when it comes to pyro, the show comes second. People are more important than any show.

 

As has already been mentioned distance here is also an issue. I know that a LeMaitre 6/24 controller will detonate 4 effects serialled onto a maximum of 100 feet of wire. Any longer than this and you run the risk of misfires. From what you've said about the cable route being tricky it sounds like it might need a fair bit of cabling to accomplish.

 

As for standards in connections, LeMaitre use little 3pin bulgin connectors on their 2channel and 6/24 type systems, although if you intend the cabling to be used for other systems they can use other types or most of the higher end programmable systems use spring terminals as all the effects are on wire tails instead of pods.

 

Hope thats of some help.

[Andrew C]

Given the above caveats about where you should control pyro from, I'll leave that and concentrate on the connectors issue. Le Maitra use Bulgin MAINS connectors. Mains connectors should only ever be used for mains, and it doesn't lock. Jem (are they still around?) use XLR4. Now I know that you get these on headsets, but that is not a likely mistake is it? "I'll just connect this pyro set to the beltpack" :D

 

So, personally, I'd go for the XLR4. Comes in black, mostly metal, is locking, you can make extension leads.

 

PS

ABTT CoP says that flash boxes should have 1m tails on them; all the systems I've seen (except a home made one, 10 years ago) have panel mount connectors. Any thoughts??

[KaBoom]

Although The 3pin Bulgin connectors are rated at 3amps @ 240volts, the voltage down the wires of a pyro system are nowhere near 240volts.

 

The triggering voltage on a 6/24 system is 12volts if my memory serves me right. This is the same with the little 2-channel ones and also many of the high-end programmable ones.

 

As for the flash pod issue... are we talking about flash pods where there are two terminals with a piece of fuse wire wrapped round it, with a pile of flash powder in between????

 

Havent seen them in ages.... and I dont think they are very risk assessment-friendly! if you know what I mean.

[Rob]

Given the above caveats about where you should control pyro from, I'll leave that and concentrate on the connectors issue. Le Maitra use Bulgin MAINS connectors. Mains connectors should only ever be used for mains, and it doesn't lock. Jem (are they still around?) use XLR4. Now I know that you get these on headsets, but that is not a likely mistake is it? "I'll just connect this pyro set to the beltpack" 

 

I'm afraid I'd disagree with that - XLR 4 is used for comms and scroller systems in theatre. The 3 pin Bulgin is not often used in theatre for anything but pyro. I've heard of such mistakes being made, particularly in schools - IIRC I read of this exact situation happening amongst these pages not long ago.

 

There is too much potential for someone to plug up the wrong 4 pin cable in the dark or out of a bunch of other cables and get it wrong. There is next to no chance of finding a 3 pin bulgin that is used for anything other than pyro - So why increase the risk?

[Andrew C]

Although The 3pin Bulgin connectors are rated at 3amps @ 240volts, the voltage down the wires of a pyro system are nowhere near 240volts.

You miss the point. The Bulgin is a mains connector, and should only be used as such. It is also inclined to fall out, probably the largest cause of mis-fires that I've seen.

 

I've heard of such mistakes being made, particularly in schools - IIRC I read of this exact situation happening amongst these pages not long ago.

 

In that incident the pyro cables were XLR3, no surprise there was an accident. Do any comms units have the 4 pole on the ring? Techpro use it for the headset which IMHO is VERY unlikely to be connected to anything else.

[Tom Baldwin]

I'm not aware of any talkback systems with 4 pin on the ring, but scrollers do use 4 pin XLR, and worse, place 24 V DC across one of the pyro circuits (according to the Pyropack pin-out).

 

I do agree that mains connectors should really only be used for mains, but Bulgin is the Le Maitre "standard", and Le Maitre is the most widespread theatrical pyro system. Anyway, either option still can't beat the local hire company (now defunct) who used 5A connectors for pyro!!!

 

But even if we assume that the control box is the best place from which to fire pyro in this venue, and resolve the connector issue to everyone's satisfaction - would you really trust a pyro tie-line, especially if you were coming into the venue for the first time? Tie lines can be dodgy; over time they get modified and bodged, sometimes not documented. Bringing up the wrong mic unexpectedly won't kill someone, and if my DMX ends up in the wrong place, I can live with it. Pyro's a bit different.

[Brian]

ABTT CoP says that flash boxes should have 1m tails on them;

The idea is that you can unplug the pod while reloading and then plug it in afterwards. If the pyro was to go off as you plugged it back in at least you'd be 1m away.

 

Le Maitre use Bulgin MAINS connectors

True, although in my many years on this earth I've only ever seen them used on Le Matire kit.

 

I'd go for the XLR4. Comes in black, mostly metal, is locking, you can make extension leads

Why not XLR6?

[Andrew C]

ABTT CoP says that flash boxes should have 1m tails on them;

The idea is that you can unplug the pod while reloading and then plug it in afterwards. If the pyro was to go off as you plugged it back in at least you'd be 1m away.

 

Granted. So why don't LM make their kit with tails?

 

Why not XLR6?

 

Why not? Inertia!

[KaBoom]

Wouldn't the pyro op have the key for the detonation system on his/her person whilst reloading or similar? Personally when it comes to pyro I trust no-one but myself and if I have the keys then I know I'm in pretty good shape.

 

Also, on the notion of xlr6 pin connections, I use exactly that for my pyrologic system (LeMaitre). the outputs on it are on fiddly RJ12 connectors which to be honest are a pain in the proverbial! I have little jumps from RJ12 to xlr6 and then I have my looms running off that.

 

To be honest about the tie-line thing, if I came into a venue that had pyro tie-lines around the stage area I would probably still use my own cables as I know they are checked and tested. Anything could be on the other end of a tie line.

[Brian]

Wouldn't the pyro op have the key for the detonation system on his/her person whilst reloading or similar

Absolutely, I guess they just thought it would be another line of safety.

 

if I have the keys then I know I'm in pretty good shape

To make sure I don't leave the key around, I have it on the end of a chain fixed to my belt.

 

So why don't LM make their kit with tails?

I suspect that the LM system has been around longer than the CoP. I don't think tails (or lack of) is a show-stopper, just a 'maybe it'd be nice if'. One advantage of tails is that it moves connectors away from the pyros which puts out some pretty corrosive muck. Which is another reason to use plastic connectors.

 

Why not XLR6?

My suggestion of XLR6 was to suggest a connector which is very unlikely to be found on stage and was both robust and locking.

 

fiddly RJ12 connectors which to be honest are a pain in the proverbial

We used a Pyropak firing system to do the air-burst on Lincoln's/ABTT's course the other day. It used RJ45s which might be OK for office use but I was a bit suprised to see them on a pyro system.