Timeline for fluorescent lighting on subways?

I've been around long enough to remember when both trains and stations were lit with dingy, dim incandescent bulbs. It seems a lot of the changeover to fluorescents occurred in the early to mid 1970s. Can anyone here point me to a more exact timeline? Even nycsubway.org didn't seem to offer much info one way or another. I guess it's easy to gloss over something like this in light of (no pun intended) all the other subway trivia. Still, I always thought it was a huge development because it suddenly made the subway so much more inviting. Before the change, stations resembled caves, and the trains weren't much better. The dim, yellowish incandescent lighting just made everything look dirty and old all the time.

Also, am I correct that the R10 was the first subway car to be delivered with fluorescent lighting, at least as far as I can tell by looking at pictures?

I'll hazard a guess that the next big change will be to LED lighting, perhaps starting in 10 to 15 years.

I'll hazard a guess that the next big change will be to LED lighting, perhaps starting in 10 to 15 years.

LED lighting? Please expound.

LED = Light Emitting Diode

Lighting systems using incandescent bulbs are cheap to buy but inefficient, generating from about 16 lumens per watt for a domestic tungsten bulb to 22 lm/W for a halogen bulb. Fluorescent tubes are more efficient, from 50 to 100 lm/W for domestic tubes (average 60lm/W), allowing large energy savings, but are bulky and fragile and require starter circuits. LEDs are robust and moderately efficient, up to 80 lumens per watt (but the average commercial LED outputs 32 lm/W). Thus LEDs are expensive, although their cost is falling. The technologies for LED production are developing rapidly. Because they are monochromatic, LED lights have great power advantages over white lights where a specific color is required. Unlike the white lights, the LED does not need a filter that absorbs most of the emitted white light.

http://en.wikipedia.org/wiki/LED_%28Lig ... g_diode%29

F40 wrote:LED lighting? Please expound.

To continue on the excellent description supplied by drewh the timeline for LED development has them reaching 150 lm/W by 2012 and 200 lm/W by 2020. Also, the installed costs will drop dramatically compared to today, making them competitive with incandescent in a few years, and with all other types of lighting in maybe 10 or 15. The subway seems a natural place to use LEDs. The greater efficiency will either mean less power for light (=less heat in the summers), or brighter stations/trains for the same amount of power. More importantly, LEDs have a service life in excess of 100,000 hours compared to 20,000 for fluorescent tubes. Further R&D may even increase this to 200,000 or 300,000 hours. In practical terms this may mean lights which last the service life of trains, and over 30 years in stations. This means decreased maintenance costs. The increased robustness of LEDs compared to fluorescent tubes means no more lights lost to vandalism (not that it seems to be a big problem any more).

BTW, any answers to my original inquiry?

The greater efficiency will either mean less power for light (=less heat in the summers)

How will it decrease heat in the summers? Fluorescent lights do not give off heat.

F40 wrote:

The greater efficiency will either mean less power for light (=less heat in the summers)

How will it decrease heat in the summers? Fluorescent lights do not give off heat.

Fluorescent lights don't get burning hot like incandescents but they do in fact produce waste heat. Roughly 25% of the power put into a fluorescent light is converted to visible light, with the other 75% producing heat. Ultimately in an enclosed station even the visible light is eventually converted to heat as it is absorbed by walls, so you can to a first approximation say 100% of the power put into lighting ends up as heat. LEDs will eventually have efficiencies of greater than 50%, or more than double that of fluorescent lights. This means for a given lighting level you'll be using less than half the power, and therefore generate less than half the heat. Less heat production isn't the only advantage of LEDs. In fact, for subway use the big attractions are really increased service life and increased durability. The energy savings plus associated heat reduction is just the icing on the cake.

Thanks for clarifying.