Old running lights

[Ed Waterman]

I have an old pair of running lights...probably from a ship of some size. The lights are about 5.5" high and 3.5" in diameter with cast aluminum housings.

The red light is red but the "green" light is actually blue. Might the green have changed over time to become blue or was there some situation where a blue light would be appropriate?

I seem to recall seeing other old green running lights that appear somewhat blue.

[nedL]

Especially on Ebay you see a lot of starboard running lights advertised as 'blue'. Put a bulb behind it and almost all the time it will actually be green. Starboard side lamps have always been green (last couple of hundred years anyway). (I believe the only blue lights allowed on vessels are law enforcement, and then it is an 'all around light' and not in the form of a side light.)

[Thorne]

Remember that non-LED bulbs have a distinct yellow cast, so a blue-ish green would be seen as green when illuminated.

http://www.yorku.ca/eye/blue-yel.gif
http://www.yorku.ca/eye/colormx3.htm

[Dave_C]

I have an old pair of running lights...probably from a ship of some size. The lights are about 5.5" high and 3.5" in diameter with cast aluminum housings.

The red light is red but the "green" light is actually blue. Might the green have changed over time to become blue or was there some situation where a blue light would be appropriate?

I seem to recall seeing other old green running lights that appear somewhat blue.


I have an antique oil burning port/starboard combo lamp. It is about 10 Inches high and has a brass shield brazed on the front so that you can only view one color or the other unless you are dead ahead. The "green" side is a definate blue and it was still blue after I cleaned all the old soot off the inside of the frensel lense. I have not stood back from it any further than several feet with it lit, but I presume it still looks like blue at a distance. It won't keep me from using it.

[Bob Cleek]

All blue running lights are green when lit and viewed from any distance... just like all cats are grey in the dark. Same with old time glass green traffic lights.

[paladin]

When designing with LED's things start getting weird. Certain color led's will have the light shift if the applied voltage is high or low, and will also have a bit of shift in spectrum if the current applied is higher or lower than specified.
I have a new software program....I really hesitated writing the check for, but the first two projects that I used it on saved me untold hours getting the specified luminosity and color shift. There is a library of almost 500 led's made by two dozen manufacturers, and it has all the specifications of each, and what to expect in color shift when voltage and current are out of specification. Proper lighting with the desired color spectrum is beginning to get a bit complicated.
The firsat design worked, so I can't complain.

[P.L.Lenihan]

A blue light was often used in the glory days of past to designate the owner was on-board as apposed to just the crew putting the vessel through its' paces.


Cheers!


Peter