A few questions first.
Does it need to be on/working while dragged about the
stage? Can the audience see the
fixture when it’s backlighting the ghost? Why does the
fixture need to be on a
dimmer? Why would you want to trash a
Fresnel when
halogen work lights are so cheap?
We are talking about something that’s possibly dangerous if the
fixture needs to be lit while dragged about the
stage, if it can be off that’s much safer in both an electrical and glass on
stage way. Your
Fresnel (
lens removed) with a BTN lamp could possibly survive a bunch of bouncing about the
stage, at least better than most other
fixture lamps, but if the lamp should break that’s fairly dangerous still, much less it could blow and shoot a hot glass
bulb across the
stage or into the audience. Should this be the way you want to do it, I would add at least 1/4"
hardware cloth into the
lens slot that's well supported. Better yet, use aluminum window screening. Won't keep all the glass particals out but it would prevent a hot lamp from hitting someone.
If the
fixture does not have to work, I would remove the glass and lamp from one of them dime a dozen work lights you find at home centers, figure out a way of attaching it to the chain, remove the lamp and
lens. Than have someone back
stage hold the
instrument as if the real
stage lighting
fixture that was a moment ago back lighting the
stage. When the actor pulls on the chain, the real
Stage Manager gives the lighting
cue to kill the back light
circuit, and a
stage hand throw/drops the simulated
fixture to be dragged about the
stage as if it were yanked off it's mounting. The old switcharoo given the audience does not ever see that back lighting
fixture in the first place.
If they are to see it, or if the
fixture is to be in use while dragged about than I would not use the security light. They use
safety glass that would explode all over the
stage and the lamps are more fragile plus pop out of their bases. Instead go back to the
Fresnel idea but take out the
lens of what ever you end up using.
You might go to a source like Grainger or McMaster Carr and get a silicone or Teflon coated
incandescent A-19 lamp. Mount a medium screw
base into the
fixture instead of the medium
prefocus one in it. Use something like a 2" square mounting
base - surface mounted plastic lamp
base over that of a
porcelain one. These silicone and Teflon lamps are shatter proof and if the rough service type might even survive some crashing about the
stage while lit. In other words, it might break, but it’s not going to spread glass all over the place. Such a lamp would also in anywhere from 60 to 100 Watts do a OK job of backlighting if supplemented by other fixtures.
With the proper lamp in the
fixture also, it given it even has to work would not need a
dimmer.
Only stipulation I would have is to have a
stage hand back
stage to
throw the
fixture rather than relying the actor to yank the
fixture off the wall and not take down the set. Could be as simple as some sort of trip
line to
release it from the wall if that
fixture needed to be seen ripped off the wall, but I would rely on hands back
stage over the magic of the night to get it right. Same with the
power cord. What’s to stop the
cord from coming loose in it’s
strain relief, getting caught in something or other wise breaking with a cut broken
cord live on
stage? Have a
stage hand with that
cord page it onstage than to
disconnect it given it needs to work. Much more reliable that way. You can place the
fixture on
stage dimmers for a secondary
safety factor so the people in the booth can shut it down should something go wrong, but the
stage hand should for the most part - especially if on headsets, be able to take care of most problems.
Avoid your some kind of
disconnect idea unless you go to a
Bates style
Stage Pin Plug that will have a hole within the
plug and
connector that can be used to screw the
plug to the scenery. On the male
plug you can
bend it’s spread pins together some to make it easier to yank free and have the female end attached to the wall. Otherwise with the
stage hand, unplugging while not nice is most effective with the
Edison cord than with some other possibly not
UL listed for your purpose equipment.
One last thing, you will want to ensure that the
fixture is grounded really well. Make sure no strain reliefs are loose or terminals holding any of much less the
ground wires are loose. Don't want anything to go spark in the night that's not in the program.
