Internal Blackout Lamps

[Rangie]

Hello all,

 

I have one of these inside the rear of my Marshall Ambulance, and i've seen them fitted in Northern Ireland VPK/HVVPK Landies too.......

 

What is the function of the Red internal blackout lamps?

 

My idea: Is it for low-light to make it more difficult for the enemy to see people access/egress the vehicle at night?

 

Alec.

[fv1609]

Yes..

[Stone]

Red light was thought to harm one's night vision less than white light and so it was used at night just in case you needed to jump outside in a hurry and shoot someone. This is why some of the box bodies (ours included) have an interlock on the light switch unit - if the door is opened the main white lights cut out, but the red ones can stay on. (this is from memory as the switch broke long ago!)

 

In actual fact the colour has very little to do with it as it's more of a function of total luminance - as the eye can distinguish more shades of green than of other colours it's therefore best to use green lighting, as you can have it dimmer than other colours (i.e. less effect on vision and less likely to be spotted from afar) while still being able to make out the same amount of detail. All the maps used to be printed with special inks and carefully-arranged colour code to make all the important markings visible in red light - I suspect the cost of doing this again for green lights had something to do with the reason nobody seems to bother any more. Our most recent shelters only have white lights, in any case.

 

Of course in general it doesn't make a blind bit of difference, as when your squaddy nips out for a quick fag the flash of his lighter will completely f&*% his night vision up anyway! :nut:

 

Stone

[Tony B]

Red internal lights in an ambulance? That would be wrong. The internal night lights of ambulances are blue. Why? Because you can't see blood under red light.

[Rangie]

Thanks for the responses, food for thought indeed.

I have looked at two other ambulances and they have a red light in the saloon area as well.

 

I imagine its just for loading/unloading to preserve night-vision.

 

My circuit is wired as a feed from the dash to the rear red lamp, actuated by a limit switch on the right-rear first-opening door.

The saloon lights are switched independantly though, I thought they may have been actuated by the back door as well, in a changeover configuration. This may be a problem if the r/h rear door swung closed when the other is open though, the rear area being in full view bathed in light then!!

 

Any medics on the forum to answer the question?

Medic, we need a medic over here! :cool2:

[Tony B]

On the 101 there is a light switch attached to the top of the right rear door. Covered by a twist sheild. When open if the door opened the internals switch from white to blue.