Carbon Arc Water Cooling Question for old timers

[Tj Hopland]

I remember seeing both recirculators and direct plumbed in systems and some where there were valves to do both so if a pump failed you had a backup option. Made sense since booths almost always had toilets that meant they had water and a drain. For a flow sensor what was fairly common was the discharge hose going into a funnel on top of the tank so you could visually see that there was flow. If it was direct you had a similar thing because the discharge was most likely into the sink.

Another flow sensor I saw a lot was they would go buy a 'sediment bowl' which was basically a inline fuel filter setup with a glass bowl commonly used on things like tractors and they would stick a fishing bobber inside the glass, you know the classic plastic red and white ones. The bobber would bounce around and spin when there was flow. I think there were also actual devices that had some sort of spinny wheel in them but I'm sure cost more than a tractor filter and bobber and the few I saw seemed to be jammed or fogged up so not really useful anymore.

I will have to look for sure but I think the pair of AA2's I still service still has some sort of flow sensor down in the base. Its never been hooked up to water or electrical in the 30 years they have been under my care. I would have to look at the manuals and see if that was a factory thing or something that was installed in their original home.

They actually had a pair of STRONG carbon-arc "Super-Trouper"
spotlights that were water cooled, which I'd never seen before, or since. So, you not only had DC
power cables running to the spots, but a couple of flexible hoses too, which hung down from two
water ports in the ceiling. They got their their cold water from the building's air conditioning system.

The carbon arc Super Trouper was the 1000w model based on the Strong Utility 1kw / Simplex High film lamphouse. Most of those ran off 120v and the power supply was in its base so self contained and burned 7mm pos and 6mm neg carbons so well below where you needed water cooling. Only fan in the whole unit was up in the optical section that sucked air past the diode stack and then blew it on the colored gel filters. The carbon Super Trouper was kinda the industry standard into the 1980's. It had a smaller brother the Trouper and then the incandescent little sister the Trouperette.

What you saw was called the Gladiator which was based on the Strong Futura film lamphouse which was the final carbon evolution of their 'big' lamps that started with the Mighty 90. Futura was the shell they used for the X60 xenon lamp. The Gladiator's I think ran in the 2000-3000 watt range and needed a separate power supply and had water cooling. The xenon Super Troupers used the Lume-X lamphoue and the Gladiator used the Super or Ultra 80.

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[Harold Hallikainen]

The flow sensor reminds me of rotameters as described at https://hallikainen.org/org/hi/brochures/060.pdf . There is a ball in a tapered glass tube (larger diameter at the top). Fluid entered the bottom of the tube and exited the top. The ball would float up with flow until enough fluid flowed around the ball instead of pushing it up. The flow rate was read directly on a scale on the glass tube.

[Ryan Gallagher]

I'm just barely old enough to have run some carbon spotlights in my career. Our big basketball stadium was very late in the game switching to xenon. Plus there was one musical production in college that with the help of the old-timer staff electricians, decided to deploy two carbon-arc spotlights from mothballed storage for atmospheric and period "visual effect". They constructed a suspended extension to the side-slot positions and put the spotlights and student operators (one of whom was myself) out there in full view of the audience.

I think our stadium was Gladiators as mentioned by TJ. The musical production was probably the smaller carbon trooper in the foreground of the side-by side photo.

Bonus points for that photo with an arc struck and an exhaust plume! We exhausted directly into the auditorium in that open booth situation... I guess that was part of the audience experience too.

[Stefan Scholz]

The theater's water bill must have been horrific, especially in desert areas where water is a scarce commodity.

I remember what I was told from a guy running 70 mm projectors with large carbon lamps. In the initial installation they used city water supply. Is is actually not that much of a flow, which was required to keep the rod holder cool enough, should not boil, though. With a fully sold out 70 mm show, the cost didn't matter at all back then.
When in summer people returned to their gardens and started watering the flower beds, the water pressure in the public supply dropped, large enough to trigger the water pressure safety switch, and thereby cancelling the lamp ballast supply power contactor. Resulting in an interrupted show. Bridging the safety switch was an option, but if the pressure dropped even lower, the silver holders melted, and caused an expensive repair.
So they ended up setting up an inflatable garden pool in a basement room, filled it with water, and installed an electric pump powerful enough to ensure the pressure switches to give contact.
The system worked fine until 70 mm screening was given up. 35 mm always ran from a second set of movie projectors since the opening of the house.

[Ryan Gallagher]

Did the big KW carbon arc search lights have to do similar for liquid cooling their rod holders etc? Those stayed carbon for much longer then our industry.

[Tj Hopland]

There may have been some searchlights that had some sort of liquid cooling but the most common big 60" American ones made by GE and Sperry were just air cooled. There is an exhaust blower on top of the 'drum' but its just a good breeze, not any kind of super suction.

The pic on the work bench is what they call the positive burner assembly. Its got the feed mechanism, electrical contacts, and the flame shield. I don't seem to have any real good pics of the feed mechanism, will have to go take some. Basically there are little wheels with teeth that bite into the carbon and feed it forward but the catch is its also rotating so its not as easy of a mechanism as you would hope.

The pic in the unit is after a run where I ran it down to a nub which is why the positive is burnt at an angle and all the soot. WHen the carbon gets too short the feed mechanism looses its grip and it stops rotating as well as feeding forward. You can let it run for a few more minutes if you want to without causing damage but if you don't shut it down it will pretty much self destruct. As long as there is carbon on one end it doesn't really care if the other end is a carbon or part of the machine, it will burn.

The way the military limited the chances of destruction is they made the negative carbon run out first. When the neg runs out the light goes out which the operator(s) would hopefully notice. If you let keep running eventually the positive will catch up with whats left of the neg and kinda make a mess but its not as bad as when the POS runs out, that leaves you with a molten pile of metal stuck to your mirror if it was angled up at all.

The reason I was able to burn the positive out is I likely swapped in another negative or was using non military carbons where they more matched the burn ratio. Advertising and shooting down aircraft have different time and budget goals. Carbons have always been expensive and now even more so and hard to find so unless its a big show where they are paying for fewer interruptions I will swap em out and burn em down to nubs.

And yes in the first photo the Super and Trouper were burning real carbons, I just picked that shot because it had both models in it.

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[Jim Cassedy]

(edited)The carbon arc Super Trouper was the 1000w model based
on the Strong Utility 1kw / Simplex High film lamphouse. Most of those
ran off 120v and the power supply was in its base so self contained and burned
7mm pos and 6mmneg carbons . . (edit) What you saw was called the Gladiator
which was based on the Strong Futura film lamphouse

My aging memory is playing tricks on me, and you you're right, because now that I think
about it, every 'Super Trouper' I can recall seeing did run off off a standard electrical outlet
and had the power supply built into the base. Your suggestion that what I saw was a
"Gladiator" makes a lot more sense. The venue I mentioned in my post was a huge 16,000
seat sports/entertainment arena where rock-concerts, and basketball and hockey games
were (and still are) regularly held, so they were going to need some heavy-duty spotlights
up there to cover the long throw and arena floor area. The spotlight booth(s) were waaaaay
up above the highest level of seats, and it was hot up there!

>Here's a pair of standard Super Troupers that were no longer being used that I found in
storage at the AMC Kubiki here in San Francisco over a decade ago. I actually could have
had one (or both) but I had no place to put them, and I knew nobody who could use them.
I have been told that these, and awolebuncha other 'unused' equpment were eventually dumped.
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[Tj Hopland]

I'm not a real expert on the usage of follow spots (I just fixed em) but I was told that xenon came later to the follow spots and just like in film the directors didn't like the difference in colors so often specified carbon for their shows / tour. If the venue didn't have carbon they would put together a second kit of color filters with slightly different colors to compensate for the light difference. I guess the way it worked was the show would travel with a set of color gels / filters for each light required for the show. If it needed 2 lights there would be travel cases with how ever many colors were needed for each light and they would be numbered that tied to the cue sheet so the operator knew which color to use at which point in the show.

Unless you were one of the few Vegas or Broadway venue doing multiple shows a day every day many venues didn't put the hours on per year to justify the lower operating costs of xenon vs having to buy the new hardware plus if the touring shows preferred carbon anyway many of them just stuck with carbon well into the 80's. And if you were a large arena that maybe only did circus and icecapades you were running maybe less than 30 hours per year? So why switch till it got to the point no one knew how or run or maintain them anymore and they were no longer reliably able to get through a show. I had worked on some xenons that were 15 years old at the time that had under 500 hours on em. I think they tend to get used even less these days because they have so many other lighting options.

[Ryan Gallagher]

We still have early xenon super troopers... I'll have to take a look at our lamp house hours now out of curiosity. It is true that "spots" are far less commonly spec'd in a touring show rider (broadway's aside) these days.

Plenty of rock/band shows and even some headlining comics just ignore spots now... plenty of movers in a rig to cover all the specials, solos, and other call outs, plus there is the labor savings. Traditional theatre productions still uses them heavily.... but a lot of "road house" theatres don't host a ton of that unless they are home for some local/civic companies too.

[Rick Raskin]

I worked may water cooled lamps both Futura II and Ashcraft Super Core-lites. Most had water recirculators behind the lamphouse but one I worked had direct connect to the main water supply. I don't recall ever seeing any kind of flow monitors or fail-safe switches. That's me in 1965 at the Beltway Plaza -- no recirculator. The other is the Apex in DC -- with recirculators.
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