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Bars installation


knightdan65
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Just testing the waters here. What are your experiences (either as a client or consultant) with installing lighting bars that can be winched down from the ceiling for rigging at ground level, as opposed to fixed bars that require a tower or similar for access? The theatre in question has a stage area of 46 square metres and sits 70. Currently has 5 internally wired bars in the ceiling, that are a bugger to get to and safely rig. I’m interested in knowing about different systems available and approximate costs for consultation, design and installation. I could phone up a company for a quote but since I know I won’t have any funds available for at least two years, I don’t want to waste anyone’s time. But it would be good to know your thoughts in the meantime ?
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How are you going to get to the bars to focus?

 

I've got a set of installs in concert halls where no-one in the build team thought about access as "the bars all motor down - why would you need to work at height". Consequently focus calls are long, dull, and rarely of any real accuracy. Thankfully they largely live as fixed focus, so I don't have to refocus often. It's just workable for a concert hall, but would be entirely unworkable for a theatre.

 

Winch bars are worth it for the speed, ease, and lower risks of rigging at ground level, but unless your whole rig is movers it does not negate the need for appropriate access equipment for focussing.

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It is a perennial problem and I lost count of the schemes I saw twenty odd years ago, when I was more involved, where ceiling mounted IWBs were gaily specified at 5m with no consideration given to access at all - often by people who should know better. I suspect this is very often why kit that was put at the start has never ever been moved. But the last poster is right and I can't remember a time when I didn't have to get out the ladder even under the grid both to focus or because some built piece fouled flying in a bar I needed to get to. Years ago the problem was often solved at least on unobstructed flat floors by wheeling someone around on a scope or tower but often it was simply the platform ladder and a lot of effort. I can tell you trying to rig a Patt 243 off a platform ladder is not something I'd want to do too often, or even at all now at my age. Sadly, though, I think it falls under the heading of just one of things. Edited by Junior8
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Focussing at height is less of an issue for me, as I’m happy for both myself and my students (it’s a college theatre) to focus on a tower as no lifting or stretching is required, whereas manually hoisting up a 20kg Mac 600 on a rope, lifting it on to the bar (which is slightly too high for the tower) and then trying g to reach over the top to get a safety bond on....that doesn’t feel so good at 4 metres up on a single width tower! It becomes a four person operation and almost ten mins per moving head, with (in my mind) quite a lot of manageable but undesirable risk.
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That being the case, sounds like winch bars are ideal for you. Totally agree on reducing the manual handling risk, increasing the rigging speed, and reducing time spent working at height. Just cautioning that it doesn't remove all need for work at height and access equipment.

 

Don't forget to budget for periodic inspection and maintenance, as dictated by LOLER.

 

Manual winches will need less maintenance, but take longer and more effort to get them in and out. In a college theatre labour is cheap and the hard work can be useful way to tire out enthusiastic teenagers... You might be offered the manual winches with a nut on the front to take drive from a drill. I had these at a previous venue and to be honest it was just as much work as manual winching and introduced a load of extra risks (rotating machinery, backlash from a strong drill, students not engaging the drive properly and rounding off the nut).

Manual winches require a cable route to get the hauling lines to a winch station, elaborate divert systems can get FOH bars controlled from the stage house, but this costs money and adds to the effort needed to winch out. Electric winches can be a more subtle install, with the machinery hidden in a roofspace and a nice pendant panel on a long lead for the floor.

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Manual winching would be an agreeable solution keeping in mind a realistic budget. At the risk of sounding naive, how is the electrical cabling handled? Do the sockets to the dimmers remain fixed at height on a separate structure, or would the winch bars be internally wired with a load of slack cable coming out the end to allow them to reach ground level? Or something g completely different?

 

Also, if the bars are suspended from the loft blocks by cable, is there not the danger they’d swing a bit with movers pannining/tilting?

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Usually you'd have the sockets on the bars, with some form of cable management. You might have marcaddy reels (pricey and rather fancy), zig-zag track (a good compromise but needs looking after), or just simply haul the cables up once the bar is at height. All depends on budget/access/manual handling risk assessment.
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On the high end, we generally budget $25-30k per lineset (about UKP 18k) for nice ETC Prodigy Hoists and all the associated bits you need. Almost certainly overkill for this project, but that gives you the top end, at least. Can someone with experience of installing them in the UK speak to the accuracy of that pricing for the UK market?
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You have talked with AC-ET ?

 

LSI who did the install?

 

And Possibly Pete Smith Inspections ?

 

I had prices for ALL the options, Manual winches (or drill driven), Electric hoist, Motors, a split of manual and motor. Wheels, zigzags, you name it I got all the prices and options. The Number 20k-60k springs to mind, and it was going to be a whole summer job because of the need to extend all those cables. What ever the method was going to be. My ideal at the time was soca because then you could split or break a soca line and run to the floor. + soca is soca so kinda less than redoing the cables.

 

At the same time I looked at adding some more DMX to the bars, a splitter and maybe a bit more dimming so there was less of a pain with 48 channels of dimming and 50? something 60? sockets

 

My biggest issue at the time was that the actual running costs was high. The regular inspections was a sticking point of who was going to pay for it, not sure why!

 

Also have you been in the roof ? it wouldn't be too hard to add a bar or 2 if you wanted or make points that could be moved if you wanted.

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Also, if the bars are suspended from the loft blocks by cable, is there not the danger they'd swing a bit with movers pannining/tilting?

 

Yes they will move, and incidentally will blow in the drafts too. One venue I worked in fairly regularly had the wires dropping through holes in a suspended ceiling some 4 to 5 feet below the blocks which meant the ceiling tiles were getting badly damaged as the bar moved. While doing some other work in the ceiling (air ducts) we built some unistrut bracketry to provide rigid guide holes and having done that it was easy to bolt through the tiles to add some additional metalwork below the tiles which the bar was pulled up against to provide some stability.

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Where bars always fly to a fixed trim (relatively close to ceiling level), it is very minimal engineering (done by a competent engineer) to design a conical pin and reciever system to lock a bar in place and reduce/eliminate movement. If it is a suspended line set then obviously you have the RSC option.

 

If you are currently heaving movers up to a fixed grid, absolutely, motorised bars are a good option - you still need access though. I know a couple of venues that have gone down the "Well we can just bounce focus" route - or even better "All our lights are moving heads. No need to access them". "No ladders, no scaff, no access platforms". I don't believe a single one of them opened without a ladder or scaffold being purchased during the commissioning phase. Some things have to be done in situ.

 

Depending on the length of the bars, chain motors with ladder truss might be a cheaper option than a system requiring significant roof works to get diverters and headblocks etc in. It still has the same caveats that a SWR hoisting system will have (regular inspections etc) and probably more caveats when it comes to who is competent to operate it - because you can easily end up with motors out of sync and the load unballanced, but generally it can be installed in a tighter space with fewer cabling issues. If you are still going to be pulling out the scaff tower for focusing, you could potentially do away with a cable management system and just have a tail from the IWB going to a soccapex socket on the ceiling - it becomes an exercise in pulling out the ladder/scaff, unplugging the soccapex, then dropping the bar - and doing the reverse afterwards. A royal pain in the rear end - but cable management systems can tend towards the expensive - so would save significant coin.

 

I don't know the venue, nor do I know the general technical ability of the people in the space - however as others have said, even doing it cheaply is going to be expensive. Especially if your ceiling bars are not easily converted to dynamic load bearing points. I would strongly suggest engaging a professional to do a site reccy.

Edited by mac.calder
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