Catastrophic lamp failures

derekleffew

Resident Curmudgeon
Senior Team
Premium Member
Re: Exploding 575 HPL

Thread re-named from "Epic fail (why FELs are bad)" to its current.

Agree with the screen concept. A 7.5" x 7.5" piece of 1/2" grid hardware cloth in the inner colorslot would work, but may cause color media to burn faster, even if it doesn't touch the screen.

Note that some sort of screen is required on all open-face (lens-less) fixtures, and I believe in Europe and other parts of the world, on ALL stage/studio luminaires.

...Was told that the lamp was a Pale Bright Blue right before it happened ...
I believe the technical term, around here at least, is super nova. The filament shorts, intensity and color temperature soars, and the lamp dies a valiant, spectacular death. Ninety-nine point something percent of the time, the envelope stays intact, however.
 

derekleffew

Resident Curmudgeon
Senior Team
Premium Member
Re: Exploding 575 HPL

Photo from a friend. HPL575. Heard a loud "pop", then went to investigate and found this.

HPL_bad.jpg
 

JD

Well-Known Member
Re: Exploding 575 HPL

I've had this happen a few times before. In old Altman's. It sounds like a shotgun going off. Scares the audience to death when it happens.
Oh yes, the good old FEL 1000ACP ... err... I mean Watt.
Best bass response is achieved in the Altman 1000Q followspot. The "chamber" is just large enough to make it sound a bit like a cannon. Had one go during a quiet, dramatic scene once. Had to wonder if some of the audience seats would need to be steam cleaned afterward.
 

Les

Well-Known Member
Got an interesting lamp failure for ya. I was cleaning up the technical storage area today and thought I'd investigate some NFG complaints of our "Starball" fixture.

MINI-STARBALL-II.jpg

Pulled out the little 100w halogen lamp and was greeted with this. A perfect little dimple on each side, with a glass straw connecting them, with the filament neatly draped over (couldn't blow air through it though - I tried). Seems like there was a mini implosion. One of the more artistic lamp failures I've seen in my career.

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GreyWyvern

Well-Known Member
Got an interesting lamp failure for ya. I was cleaning up the technical storage area today and thought I'd investigate some NFG complaints of our "Starball" fixture.

View attachment 14405

Pulled out the little 100w halogen lamp and was greeted with this. A perfect little dimple on each side, with a glass straw connecting them, with the filament neatly draped over (couldn't blow air through it though - I tried). Seems like there was a mini implosion. One of the more artistic lamp failures I've seen in my career.

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That is not a failure and is actually the way the lamp is made. The glass is what holds the filament up and in place. Notice that there isn't a wire post or anything else to hold it.
 

ship

Senior Team Emeritus
Premium Member
Dropped a wire rope with cotter pin retainer shackle into my bag one day after an install. Had to use it for a template length for shorter ones with turnbuckles to adjust for ceiling height. Hit the can of Coke on it's side in the bag in just such a way it made a firecracker pop sound. Literally, it was loud and hit in such a way my tool bag wasn't much filled up with exploded soda. Never seen or heard that before.

Somewhere on this website in the way back when' section - like 10 years ago is a "Killroy was there" proto of a lamp that when it's filament blew out of it, it both left a gunshot like freeze animation in the globe where the filament blew out of the other side. On the opposing side, there was this WWII graffiti like shape to the globe puckered in the shape of Kill Roy on the lamp when the gasses were sucked out.

On the other hand, what you present is "Pulled out the little 100w halogen lamp and was greeted with this. A perfect little dimple on each side, with a glass straw connecting them, with the filament neatly draped over (couldn't blow air through it though - I tried). Seems like there was a mini implosion. One of the more artistic lamp failures I've seen in my career." really interesting in that there is no halogen effect' silver tungsten buildup around the areas of the holes you note. Overall, the globe is clear and shoud not be a reason. There was no escaping silver tungsten elements deposited on the glass indicating that the "halogen effect" has been disturbed.

Initial suspect would be the filament hanger broke and let the filament brake thru the globe if say wiggling. If filament hanger not broken in allowing the filament to wander I would be really interesting. Any other answer short of BB" gun shot thru the cloud thru the lamp, it should have given an indidation as to your hole. Very interesting. One I have not seen before. Glass straw seen perhaps the filament hanger instead?

Perhaps in seeing it before, someone touched the upper hanger part of the inner capsule somehow. It retained heat and (how new is this lamp) did it's job in exploding. Problem is, normally one would see other than a clear lamp in failure. Voltage will blow a lamp - lightning strike blew it out? Doubting this. Perhaps a break somewhere in the capsule in causing a while operating pucker of the globe? This will have also sucked out the silver of the free halogen tungsten filament as to where it were located.

Fascinating given no indication of why it failed how it did I can see. Last chance, perhaps broken filament at the upper support burnt thru the outer globe and once thru it sealed up the hole in the glasss, than wiggled to the other side in crating the hole.

Would require a filament to loose itself from the upper hanger and free float between sides of the outer globe. Burn thru one side of the globe quick enough to pucker it in air coming in, than move to the other side of the globe in burning into it also,, peraps burning a hole thru it before failure. G

Interesting failure, short of seeing it in context I cannot guess further. Hope it helps.

PS. I have seen a lot of T-3 RSC lamps going dimpled outer globe filament support hanger "T" type globe lamps out there. They have dimples in the outer globe to support hangers for the filament.

Is it possible you have a dimple for the upper filament support hanger and some other cause of the failure? Just wondering in not having seen a dimpled upper support before but possible as a concept for science of cooling the lamp.
 
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microstar

Well-Known Member
It appears this thread about catastrophic lamp failures has resonated at one high school performing arts center. From a Chauvet LED installation blurb:
"LAS CRUCES, NM – Joe Price, the manager of Oñate High School’s Performing Arts Center, knew that the time had come to replace the facility’s incandescent lighting rig with an all-LED system. The 20-year-old incandescent fixtures used at the school’s theater in Las Cruces, NM, were not only inefficient and costly, they also posed a potential hazard. This was made abundantly clear one day when an overhead lamp exploded."
Sounds like one lamp exploding in 20 years resulted in a brand new all-LED lighting system! Good job Joe!
 

TNasty

Active Member
I see a bunch of these pictures, and I can't help but to think that this is why I put a box of blue nitrile gloves in my tool box. Paper towels can be a risk, since oils can sit on them from people grabbing the roll.

Anyways, it's interesting seeing how each bulb dies- some go black, some blue, others rainbow, and some... explode! I've got some rather "vintage" bulbs marked 'dead' in some drawers in my booth- big spherical 500w bulbs. One of them has the most amusing little blister on it (not even an inch in diameter).
 

JD

Well-Known Member
You know, I'm going to to miss all this when the world goes 100% LED. LED's die in the most boring way.
It's sometimes fun to sort through old boxes of lamps just to see the new and unique ways they all died.
 

Les

Well-Known Member
I'm going to miss the smell from hot dusty lights. These days, I only ever experience it when I'm focusing the front lighting. We traded a few dozen Par 64's for Elation Sixpar 200's a few years ago.

Not that I miss the par cans - at all. And I really should clean out the dust in the ellipsoidals...
 

TheaterEd

Renaissance Man
Fight Leukemia
I once had a 135w incandescent screw base house light just decide it was done and the glass bulb portion came free from the socket and fell to the floor. It was pretty cool to see, just glad no one was sitting there and it was after most of the audience had left from a concert.
 

GreyWyvern

Well-Known Member
I once had a 135w incandescent screw base house light just decide it was done and the glass bulb portion came free from the socket and fell to the floor. It was pretty cool to see, just glad no one was sitting there and it was after most of the audience had left from a concert.
I had this happen to me at home a few months ago. I got home from work, and saw a light bulb laying on the floor beneath the living room ceiling fan. On looking closer, I saw that it was just the glass part. I use the GE Reveal at home. A year or two ago, they switched to a halogen version of it to be more energy efficent, fewer watts for the same lumens. The halogen lamp is inside of a regular glass bulb so it looks the same. So, although the outer glass is missing now, it still works fine and I haven't replaced it. I'll try to remember to post a picture. The only thing that bugs me is that it is now a bit brighter than the other three due to the missing outer glass.
 

sk8rsdad

Well-Known Member
Premium Member
Fight Leukemia
although the outer glass is missing now, it still works fine

[HIJACK]
The outer glass might be a safety feature. I know some residential halogen lighting fixtures require a glass shield over the halogen lamp to prevent flammable materials from contacting the envelope of the halogen lamp.
[/HIJACK]

My most recent lamp failure led to a $400 repair bill. A Philips MSR Gold 300/2 MiniFastFit decided it was tired of life after 50 hours and went out with a bang, blowing it's top and taking out the glass diffusion on the shutters before coming to rest in the CMY blade assembly.
 

venuetech

Well-Known Member
Departed Member
I think that the outer glass is both a safety feature and a color filter/enhancement on the reveal lamps.
The outer glass is (in theory) to contain a violent failure of the halogen envelope.

On a side note: I was once told by my lighting professor that the quartz envelope when broken and embedded in a person. Does not show up on x-rays in the same way ordinary glass would. Does anyone have experience or further knowledge?
 

GreyWyvern

Well-Known Member
[HIJACK]
The outer glass might be a safety feature. I know some residential halogen lighting fixtures require a glass shield over the halogen lamp to prevent flammable materials from contacting the envelope of the halogen lamp.
[/HIJACK]
That would make sense. The lamp is somewhat protected as the is a decorative glass around it and it is 10' in the air. The end is open though.

I think that the outer glass is both a safety feature and a color filter/enhancement on the reveal lamps.
The outer glass is (in theory) to contain a violent failure of the halogen envelope.
The color is a bit different now too. Hmm, didn't think about it containing a violent failure, though I should have. Part of the reason I have just left it as is, is because I've been to lazy to haul the ladder into the house to deal with it! So far, the halogen version seems to fail sooner than the old style, but none have been violent.
 

RonHebbard

Well-Known Member
Premium Member
I once had a 135w incandescent screw base house light just decide it was done and the glass bulb portion came free from the socket and fell to the floor. It was pretty cool to see, just glad no one was sitting there and it was after most of the audience had left from a concert.
TLDR Warning firmly in place;
1968 or 9; Multi-year renovation and expansion of a local hospital. They added a new, much larger, staff cafeteria. Ceiling fixtures were each about 2' square, mirrored glass, approximately 16 clear, candelabra based, globular, ornate 15 or 25 Watt lamps per fixture and about 30 fixtures in the room. Finished ceiling height maybe 10'. When we were about two days away from turning over that wing, the foreman sent two of us in to remove all protective materials, polish all of the mirrored surfaces and lamp all of the fixtures warning us to be sure our hands were clean and not to leave grubby fingerprints all over the place. Roughly 480 lamps. It took a while.
We were given lots of Windex and clean cloths and the other guys harangued us for grabbing the "white glove" work. Maybe an hour in, my journeyman decided we should power up one of the dimmers and see how things were looking. He noticed we had several lamps 'DOA' and suffering 'infant mortality'. One of the sub-foremen came by and suggested we'd save time by setting all of the dimmers at 25-30% and leave them there so we'd know if we had a 'DOA' lamp the instant we installed it and could save the time of dragging the ladder back. It was pretty slow going, the day was rolling by, things were looking good and we figured we had enough lamps within the 10% mandatory spares to complete the room then have the lamp supplier supply additional lamps to turn over to the client. Got to the end of the day and we were asked to put in an hour of O.T. to reach completion so the cleaning contractor's overnight crew could do a final construction cleanup and the furnishings contractor could load in his snazzy new cafeteria tables and chairs the next morning.
Got it finished, looked dazzlingly elegant. Journeyman sent me for the sub-foreman. Sub-foreman sent me for the foreman. Much patting of backs and happiness all around. Foreman announced his approval and told us to turn 'em off and call it a day. Someone shut 'em down and within seconds clear glass envelopes rained down on the floor with the majority of them shattering having just fallen 10' to the tile. Many had hit the floor while others were hanging wobbling, hung on the exposed filament structures. Much unhappiness. Much pointing of fingers. It was after dinner hour and getting darker so someone began turning on the remaining lights. 'Nova-ing' of exposed filaments. Several globes that had been hanging were now plummeting. More unhappiness. Even more finger pointing. crap moved slowly up hill. The lamp supplier's rep' was phoned at home mid-dinner. We were finally sent home. First thing next morning, while the furnishings were loading in and making ladder access problematic, various levels of management from owner's rep's to architects, yada, yada, arrived to flog the lamp supplier. The remaining lamps were once again lit, initially at reduced levels, and then raised slowly over a period of time to full under the supplier's rep's direction. Much speculation as to the cause of the problem. The semi-knowledgeable all had an opinion. The most knowledgeable kept their mouths closed. The mystery became why did so many die while others refused to fail no matter how bright or how long? We had to move tables and collect various samples, both of functioning lamps and globe-less candelabra bases. The supplier, Sylvania possibly, needed time to analyze the remnants in their labs and conjure an answer / solution. The immediate problem became what are we to re-lamp the fixtures with in time for the grand soire only days away. The supplier did not have enough stock in the area to re-lamp the room and no one wanted to eat the cost of the re-lamping even if they did. The supplier wanted at least a week. The owners and their fundraisers wanted their show-piece room for their fancy opening for their financial contributors.
I can't remember the exact details but I believe we lamped every second socket (as it was all they could provide in time) with frosted lamps which the supplier had in stock, and felt could be trusted to not fall in the caviar, then went back to that wing more than a month later to re-lamp the entire room with the specified, clear, lamps. It took longer this time with all of the furnishings in the room and having to do a portion of the room at a time so the doctors and surgeons could eat their meals while we were working.
Joseph Brant Hospital in Burlington, Ontario with one entire wall glass from floor to ceiling and overlooking Lake Ontario. The hospital's still there. It's been renovated at least twice more over the years and they're expanding again as I type. Unfortunately I've been seeing too much of it lately, these last few times as a patient.
Oh, the lamps!? They deemed it dissimilar rates of expansion / contraction when heating and cooling. Some lamps bases had been formed from brass, or similar, while others had been formed from aluminum. They found both base materials had held up when initially tested but cooled / contracted at different rates. They had the base, the glue and the glass. One material / combination worked as designed / expected while the other combination cut perfect little circular holes in the clear glass globes upon cooling. I believe that particular room disappeared in one of the successive renovations.
I still remember the sounds of those initial lamps hitting the tiles like a hail storm.
With apologies for droning on.
Toodleoo!
Ron Hebbard.
 

venuetech

Well-Known Member
Departed Member
A sales agent once convinced me to buy inexpensive replacement lamps for the houselights.
When it came time to change them the base would remain stuck in the mogul screw socket. Leaving me holding just the glass, with the crumbling glue or whatever falling out as I stood on the ladder under it.
 

firewater88

Active Member

Found this one today when changing over for another show. Never heard it and no one told me about it. Swapped out the fixture with a spare until I can clean this one out. Have had issues with a few batch's of USHIO's in recent past.
 

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