J.R. Clancy Announces the SureStop Head Block system as LDI 2012

[porkchop]

Via J.R. Clancy's facebook page:

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J.R. Clancy SureStop Head Block

The SureStop Head Block mechanically senses the head block speed, engaging a brake to stop its motion when the speed exceeds safe levels. In the event of a runaway lineset situation, SureStop halts the movement for both the arbor and the batten in either direction. This helps prevent the potentially dangerous impact of a runaway arbor on the locking rail, or an overloaded batten on the heads of actors and technicians. When the overload situation is cleared and the lineset’s direction is reversed, SureStop automatically releases the set, allowing normal operation to resume.

According to the attached video this product was the winner of LDI's 2012 Debuting Product Award for Staging & Rigging.

The video is not terribly informative, and I would like a few more details on it, but this system looks like it might be a very good safety feature to have installed in any facility, particularly in the educational/volunteer theatre world. Would something like this change anyone's mind on what system to install hoists or counterweight?

 

[cpf]

It would be most effective to install and never tell any of the operators - people can still get seriously injured or killed by line sets no matter how slowly they're moving, and you don't want operators thinking this system will magically compensate for their lack of care or experience.

 

[MNicolai]

Well, it's a show stopper. You certainly wouldn't want to rely on it to compensate because if SureStop triggers, it probably won't be at a convenient time.

By that, I mean, the arbor and the batten will probably be somewhere where it's a real pain in the butt to clear the overload, either by adding/subtracting weight from the batten or from the arbor, neither of which will be all the way out of all the way in, where they would be more easily adjustable.

I like the idea, and I don't think anyone who knows how difficult clearing the overload would be would ever want to play chicken with it.

Even though slow-moving battens can still hurt, it will at least be substantially harder for someone to get injured or killed.

 

[Footer]

Anyone have any more real info on this besides that crappy video that shows nothing? Press release, spec sheet, something? All the video shows is arbors traveling through truss...

 

[techieman33]

I see this being of more use in educational facilities where there is a greater chance of students not paying attention to what is going on. Also hopefully there is an easy way to disable it for linesets that have fast ins and outs during a show since it seemed to kick in while the lineset was moving pretty slowly.

 

[MPowers]

I see this being of more use in educational facilities where there is a greater chance of students not paying attention to what is going on. Also hopefully there is an easy way to disable it for linesets that have fast ins and outs during a show since it seemed to kick in while the lineset was moving pretty slowly.

You mean not paying attention like the IA crew at the Gallager in Iowa Falls when a run-a-way destroyed $1,000,000 worth of equipment for the Blue Man Group and closed down the facility for several days? Non professional facilities do not have an exclusive patent on accidents. Educational and ameteur spaces usually make mistakes due to lack of training and knowledge, pros usually make them when trying to trim costs by skipping proceedures or trying to meet a hard deadline with a lot of $$$ on the line, or the worst, "I'm a pro, I know what I'm doing, I don't need to mess with all those proceedures meant for beginers!"

When Clancy releases more info to dealers I'll post it. in the meantime, IIUC, it is unlikely to be a "Show stopper." It is not intended to be an out of ballance detector, like the Tiffin rope lock or similar, it is intended for those cases where a batten is loaded or unloaded at a far different rate than the weight arbor, thus causing the run-a-way condition. Again, IIUC, it triggers by over speed, not over ballance. This is highly unlikely to happen during a performance unless there is a carpet hoist or similar loading/unloading of the scenic element during a change.

 

[porkchop]

Funny, the Blue Man Group incident was the first thing I thought of too. Since reversing the direction of the lineset is supposed to release it the SureStop I'd imagine that after the system engaged if unloading weight wasn't a reasonable option you could use one of many methods to regain control of the lineset and then give it a tug and release it allowing you to move the arbor to somewhere where it could be safely unloaded. Because there is no real info that I could find (I did take a quick look at J.R. Clancy's website hoping for a spec sheet) we don't know just how far the lineset has to move in the other direction, but if a few people can't heave on a rope and release the arbor you've probably done something really stupid to begin with.

 

[Footer]

You mean not paying attention like the IA crew at the Gallager in Iowa Falls when a run-a-way destroyed $1,000,000 worth of equipment for the Blue Man Group and closed down the facility for several days?

I thought that was a student crew?

So, from the feel of it this is some type of centrifugal clutch in the headblock that locks up if it is spun to fast? On the list of things that I want to have to replace when it breaks, the head block is not it. I would rather see this technology go into a floor block or even on a loft block. Granted, anything to help stop a run away is a great thing.... and the damage caused by one runaway can be huge. Not saying that JR Clancy would make a bad product, but I would not want any extra moving parts in a part of the system that is the hardest to replace.

 

[Techfiend]

From what I understand and talking to one of the JR reps, the SureStop will be triggered if the lineset travels over a set speed, being 90, 180, or 360 Feet/Min. If the trigger was the cause of an overzealous stagehand, the operator just has to pause before the headblock releases. If the trigger is due to a true out of balance run away, the load must first be brought within safe operating limits before the headblock releases.
The speed settings are factory set, but was told that they can be changed in the field by a Clancy rep.

In response to Footer's post, the rep told us that the headblock could take a stop and still be operation, unlike an SRL or other arresting device that must be inspected before it can be re-used. And to the floorblock option, the rep spoke about how the grid was already designed to be exposed to such forces instead of bolting something to the floor.
As far as maintaing the headblock: I didn't look too hard at the model they had, nor was the question asked, but it looked like a normal headblock with the brake clutch riding shotgun. So it looked like if things did need to be replaced, it would just be a process of taking off the side plate that contains the clutch and tweaking/replacing. But this is all speculation, and also does not take into account the (possibly) already prime real estate where the headblocks are.

The way I look at it: to be inconvenienced by a run-away that is stuck in the middle of its travel VS. a hole in the stage floor/injury/death.

 

[MPowers]

I thought that was a student crew?.........

There are students on the crew,as over hire, but it is an IA house. Like many incidents, it was a combination of mistakes, first in established procedure, second in execution, third in communication breakdown. There is a fairly long thread on the incident. Rather than hi-jack this thread, if anyone wants to continue the conversation about that incident, go to that thread and make a new post.

 

[MPowers]

........ I would rather see this technology go into a floor block or even on a loft block. ....... I would not want any extra moving parts in a part of the system that is the hardest to replace.

As mentioned, head block beams are designed to handle large loading, not so much the "T" bar that supports the floor block. Loft blocks offer their own major problems. To make the system work all the loft blocks would have to have the brake, not just one, driving up the cost exponentially. In addition, all the blocks would have to stop at exactly the same time to prevent massive tangles, backlash or uneven successive shock-loads on the lift-line to batten connections and of course, the loft blocks themselves. Unless all the lift lines slowed to a stop at the same time and at the same rate, it is highly possible that a single lift line could take the entire load for an instant with obvious catastrophic results. Right now the mechanism is mechanical and for the precision needed for loft block brakes to work, it would require electronic control, feedback and cross talk communication between the blocks. Last but not least, the loft blocks don't have any positive connection to the lines. Line sets have been known to continue moving with a single frozen loft block, the GAC simply slides through the groove, granted with destructive abrasion, but still sliding. The combined friction of all the lines plus the purchase line allow the headblock to act like a traction drive to slow and stop the arbor. If the arbor stops, the lines all stop at exactly the same rate and time. A brake acting against the purchase line at the floor is only acting on the rope, even if you eliminate the tension block and anchor it hard to the floor, the brake is acting against the stretchiest thing in the system and again only one thing instead of all the things. So bottom line, ...... the head block is the most practical and logical location for this particular device.