OT: anyone know what these are?

[Chewbacka]

34 minutes ago, WotEver said:

Cheers, I suspected that the top bit was a ballast for a discharge lamp.

If it is a metal halide lamp the ballast will output a few thousand volts to strike the arc, so don’t power it up without a lamp in the fitting.  

[WotEver]

12 minutes ago, Chewbacka said:

If it is a metal halide lamp the ballast will output a few thousand volts to strike the arc, so don’t power it up without a lamp in the fitting.  

No chance of that. We can’t find any switch that appears to operate them so the plan of action is to remove them soon (probably by standing on the forks of a Telehandler ?). 
 

Cheers,

Tony

When I was in theatre the follow spots were all Metal Halide. Actually when I first got involved in theatre some of them still used a lime arc which the operator had to steadily wind forward as it burned down. 

[billh]

High pressure sodium discharge lamps? The ballast gear for these is complex and heavy- be careful when taking them down. Usual lamp designation is SON-T, 250 or 400watt . Excellent general lighting in factory or car parks etc. Colour rendering poor but a lot better than those low pressure sodium  street lights that are still about. All  obsolete now with super efficient LED lighting.

In the picture there is a small depression in the end of the bulb, this is to fit a small spring metal bracket which supports the bulb in a horizontal  type fitting , but not necessary here where it is vertical.

Edited June 16, 2020 by billh

[WotEver]

24 minutes ago, billh said:

High pressure sodium discharge lamps? The ballast gear for these is complex and heavy- be careful when taking them down. Usual lamp designation is SON-T, 250 or 400watt . Excellent general lighting in factory or car parks etc. Colour rendering poor but a lot better than those low pressure sodium  street lights that are still about. All  obsolete now with super efficient LED lighting.

In the picture there is a small depression in the end of the bulb, this is to fit a small spring metal bracket which supports the bulb in a horizontal  type fitting , but not necessary here where it is vertical.

Thanks for the info