Advice on rigging bridge for Les Mis

alberg99

Member
We are doing a production of Les Mis School Edition at our high school and I am handling the technical needs. We're all ready to go but I have a reservation about the bridge. We have a single purchase counter weigted fly system and for Javert suicide we are doing the traditional jump from ground level and bridge flies up. The bridge is also used between two set pieces for the Beggars scene where people both stand on it and walk below it. My question is, if it is properly counter weighted when suspended in the air in the fly space as it is most of the show, then when it rests on the ground, all of the weight will be on the line set and not on the bridge. How do people deal with this problem when they do this show. I've seen many do it and I can't imagine that they are actually loading and unloading weights from the line set during the show. Thanks for any advice in advance. I take rigging seriously and don't want to kill anyone.
 
Of course it's possible, but much more complicated.
You're talking about flying a 7ft tall load bearing structure.

the bridge itself is only 6 ft long. The weight isn't more than 100 lbs. The question is how can that work if at all.
 
I did Les Mis a few years back and I know the flymen didn't unload and re-load cradles mid-show. From memory, they weighted it correctly and then when it was in, got a rope lock (not the one fitted to the rail, but one of those ones which hooks the ropes together and stops them moving - I can't find a picture because I don't know what the proper name for them is!) and locked the lineset off with that. Our bridge weighed a good deal more than 100lbs, and although I wasn't directly involved with the rigging of it, I know that unless the head flyman and head mechanist had been completely happy with the safety aspect of it, we would not have done it that way.
 
There are two issues with flying the bridge. First, it is usually 3 dimensional. If it is flown on two linesets, the arbors must be married. Not something that is easy to do. Secondly, there is the weight thing.

Anything flying scenery has to deal with this. Usually, if a piece must be handled and must fly, all is needed is to either leave it slightly pipe heavy or to secure it with LP hinges/stagescrews/etc when it is in. You know when he is on it that it won't fly away which helps as well. Now, there is the possibility of a carpet arbor that releases just shy of the deck.

All of these things are doable. However, if you ever have a rigging question please get someone in there that can make sure whatever solution choose you perform safely.
 
the bridge we built "landed" on scenery. the weight of the bridge itself was counterbalanced on the married arbors. the added load of the actors was supported by the 18' bridge and scenic elements. we had 2 rolling platform "towers" about 80" high., and for the jump we landed the bridge on a pair of 24" stairs so Javart had only a short jump.
the towers had a key block that fit into matching blocks on the bottom of the bridge, once the bridge landed the three pieces could not separate unless the bridge was lifted.
The rigging was never out of balance. The crew did have to confirm that the bridge was properly supported before we could load the actors on. as long as everything was on spike it worked very well.
 
We are only using one line set on this. The bridge will be flown by 4 seperate pieces of airline cable on each corner. Again, my problem isn't with the initial counter weighting. The problem is that once the bridge is on the ground or on the set itself, it will no longer require the counter weights as there will be no load on that line anymore due to the bridge resting on the stage or set.
Theoretically, if a break were to let go while an actor was on the bridge, the bridge would want to fly up as the weights would want to go down. This of course would balance out the moment it wanted to take off due to the extra load of an actor on the bridge. *sigh*
I know it's done without just lifting the facade and with the bridge resting on the ground as it's in just about every clip I've seen of Javert's Suicide. Whether it's safe or not I suppose is my main question.
 
We are only using one line set on this. The bridge will be flown by 4 seperate pieces of airline cable on each corner. Again, my problem isn't with the initial counter weighting. The problem is that once the bridge is on the ground or on the set itself, it will no longer require the counter weights as there will be no load on that line anymore due to the bridge resting on the stage or set.
Theoretically, if a break were to let go while an actor was on the bridge, the bridge would want to fly up as the weights would want to go down. This of course would balance out the moment it wanted to take off due to the extra load of an actor on the bridge. *sigh*
I know it's done without just lifting the facade and with the bridge resting on the ground as it's in just about every clip I've seen of Javert's Suicide. Whether it's safe or not I suppose is my main question.

Tom pretty much nailed the way it should be done. I have a feeling you are not really qualified to pull off this effect safely. I'm not even going to begin to discuss the idea of rigging a 3 dimensional set piece on one lineset. You will never get the thing to do what you want it to do with that rigging in place. Its going to flip and pendulum all over the place and could cause serious damage. If this is your intention, don't do it. Your going to hurt someone. Get someone in there who can help you do this correctly and safely.
 
If your bridge is in balance and you land the bridge on the stage and pull just 10-20 pounds more, the bridge will stay in place. Add non skid pads to the bottom of the bridge to increase the holding force. "All the weight" is NOT on the arbor side, just the few pounds you "pulled". The only way to put "all" the weight on the arbor side is to have a stage hand(s) that out weigh the bridge and to pull until the lift lines go slack. DON'T pull until the lift lines go slack!!!! You can pull up to 50 lbs over balance on a standard rope lock. In fact, very large stages with 60 foot long battens and grid heights of 60 feet of more can experience up to 100 pounds or more, out of balance in both directions, in the normal use of any line set, if they don't have compensating chains.

Bottom line, you should be fine as far as weight and balance are concerned. The only problem you might encounter is lateral movement as talent steps (jumps) on or off the unit. If this becomes an issue, use a cane bolt and a block. i.e. put the bridge where you want it. Determine which direction the unit wants to move during the action. Put a 4" long piece of 2x4 against the unit, drill a half inch hole and insert the cane bolt. The block will stop the lateral movement but allow the unit to fly at any moment.

Depending on the type of rope lock you have, the age and proper (or not) adjustment of the lock, you should be able to easily pull up to 50 lbs out of balance. Now, do not think that I advocate or advise to use line sets out of balance, I only want to point out that in the normal course of things, every counter weight line set is a little out of balance. The Clancy SureLock and the Tiffin Restrictor both "lock" when out of balance loads exceed 50 lbs. The RESTRICTOR is rated to hold 1200 lbs out of balance, the HAND LEVER is rated to hold 1000 lbs., the "CAST IRON" rope lock is rated for 150 lbs. So, as you can see, some degree out of balance is actually a "normal" condition in a counter weight line set.

Hope this helps.
 
We are only using one line set on this. The bridge will be flown by 4 seperate pieces of airline cable on each corner. Again, my problem isn't with the initial counter weighting. The problem is that once the bridge is on the ground or on the set itself, it will no longer require the counter weights as there will be no load on that line anymore due to the bridge resting on the stage or set.
Theoretically, if a break were to let go while an actor was on the bridge, the bridge would want to fly up as the weights would want to go down. This of course would balance out the moment it wanted to take off due to the extra load of an actor on the bridge. *sigh*
I know it's done without just lifting the facade and with the bridge resting on the ground as it's in just about every clip I've seen of Javert's Suicide. Whether it's safe or not I suppose is my main question.

The problem is that once the bridge is on the ground or on the set itself, it will no longer require the counter weights as there will be no load on that line
not true. the bridge does require the counterweight if you want to lift it on cue. The load remains on the lineset unless you remove it.

if a break were to let go while an actor was on the bridge, the bridge would want to fly up as the weights would want to go down
not true. The arbors and bridge should be "in balance" the weight of the actor will make the bridge go down. (the weights go up) but the bridge should be properly supported by the floor or scenery so nothing goes anywhere.

a properly balanced bridge lineset will stay where the flyman puts it as long as it remains "in balance"

If the bridge was unsupported and an actor stepped onto it. (not recommended) the bridge would want to go down (this would be bad)

setting the bridge on the floor or on scenery does not change the balance. adding a actor does change the balance but a properly supported bridge will transfer the weight of the actor directly to the floor, not the rigging.
as soon as the added actor load is removed the bridge is ready to fly.
 
I just closed a production of Les Mis Student Edition two days ago. Our bridge (30" wide x 13' long) was hung on two lines (aircraft cable at each corner going up two to each batten) and counter weighted to accommodate the bridge with no other weight. When the bridge is setting on top of the rolling set pieces for the "Paris" scene, the set pieces take the weight of the additional actors, and the bridge is only spanning the approximate 6 feet between the two towers. When the bridge flys all the way to the ground for Javert's suicide, it rests completely on the ground, so again, no other weight is required on the arbor to take the weight of the actor standing on it. No weights need to be removed from the arbor at any time, as a properly counter balanced set piece should be able to rest on the floor (or other set piece) and still be balanced.
 
Every time I have flown a large set piece, such as tall wall flats, archways, etc, the only time their weight is an issue is at the initial rigging and the strike.

A properly balanced lineset, no matter how heavy, will be able to be flown in and stopped at any position, including on the deck, without a worry of a run away. If it is in BALANCE it shouldn't move on its own.

I'm not sure how to best explain this over the internet but basically when the bridge is flown in, it will be able to rest on the deck while keeping tension in the lift lines, thus keeping the system in balance. You will feel this balance on the hand line. With all the weight there will be on the arbor it will not be possible for a single person to put slack in the lift lines thus transferring all the weight of the bridge onto the stage. If somehow one did put a little slack in the lift lines, the arbor will descend back just a tiny bit until the lift lines are again under tension, but it will also immediately come right back into balance, and thus the bridge will stay on the deck.

Honestly like most of the above posters I'm more concerned about your rigging and attachment methods.
 
While I agree with the others that are concerned about your plan of using one line, I am mostly concerned about your lack of understanding how a counter balanced fly system works, and doing a show like Les Mis!
 
I'm not really sure how you're going to do it with one lineset. With a lift point on each corner going to one lineset they won't be vertical and would be in the way on top of the bridge? Would they not? I feel like some basics have been missed here and you should really reexamine some things and how rigging works.


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Rigging a 3-D object from a single line set is easy. In the case of your bridge you will need a minimum of 4 points, 2 at each end, equal distant from the COG. That's equal distant upstage downstage for each pair, not necessarily equal stage left and right, though that would be best.
The problems are:
1. There will be a slightly greater tendency to sway/swing in the up and down stage direction.
2. The lift lines will converge as they approach the batten attachment which could get in the way for performers, depending on how high the pipe is rigged above the bridge and how close together the pick points on the bridge will be attached.
3. Because you intend to use only one line set to do the rigging, there will be high point loads on your batten. Place them as close as possible to a batten lift line. Make sure you do not exceed point load capability of your pipe batten.

This should cover the basics. Depending on the specifics of your design and structure, there may be additional check points.

all the above is based on your having done the necessary engineering to insure that:
1. The bridge is strong and stiff enough to endure the forces imposed during the rapid upward travel in the suicide scene.
2. The bridge is strong and stiff enough to endure the forces imposed as the actors cross over and perform their actions.
3. The attachment points on the bridge distribute the load throughout the structure, so the "lift" forces are evenly distributed.
4. The attachment points, the structure and the lift lines are designed to hold, momentarily (start of acceleration to constant or diminishing velocity.) a load equal to (estimated) 10 times the static loading.

Hope this helps.
 
Once you have digested all this information, Your biggest need will be: a block of time in the space to install and test this. it is best to get an early start on that. Never be in a hurry when doing this sort of thing. you need to check and double check all aspects of this project. that block of time should be devoted just to this rigging project, because once you start you cannot be distracted by other things until the bridge is hanging and balanced and all safety checks have been completed.
 
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Thanks for everyones help and advice. To us, rigging the 3D set piece wasn't the issue. We have blocks on the set that fit into grooves on the Bridge to stop any possible lateral movement. The physics now make sense to me. The batten can hold up to 1500 lbs. and the bridge is 115ish. After adding weights it balanced out as perfect as we can get it which feels pretty darn perfect. Doesn't move one way or the other. Tomorrow the set designer is helping me test it out but so far so good. It's hanging up there. Thanks again.
Al
 

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