A complication to viewers of LEDs. Had first cataract removed from left eye and wow what a difference. LEDs and CFLs that were perceived as yellow are now white. ( compared to right eye.) LEDs that were replacements for incadescent now do not need as much lumens as before. So will downsize LEDs where possible as higher lumens no longer needed.
This reminds me of the old mars lights. I always thought they were much more attention-getting than alternate flashing ditchlights.
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"A stranger's just a friend you ain't met yet." --- Dave Gardner
mudchickenThis old dinosaur prefers the constant-on rotating yellow light vs the strobe in certain conditions. We keep both in our inventory.
I've heard that pilots also prefer rotating lights on vehicles on an airfield - they are easier to track than strobes.
Many LED lights now feature flash patterns that provide a longer opportunity for recognition.
One of our firefighters pointed out a phenomenon that exists with rotating lights vs strobes or LEDs - the sealed beam of the rotating light bounces off other objects (like store windows "downtown"), something that neither strobes nor LEDs do.
Larry Resident Microferroequinologist (at least at my house) Everyone goes home; Safety begins with you My Opinion. Standard Disclaimers Apply. No Expiration Date Come ride the rails with me! There's one thing about humility - the moment you think you've got it, you've lost it...
This old dinosaur prefers the constant-on rotating yellow light vs the strobe in certain conditions. We keep both in our inventory.
(Have some really evil thoughts for some people that don't pay heed to signals and flagmen...at least I can throw my hardhat at the windshield of what's about to hit me.)
http://www.progressiverailroading.com/rail_product_news/details/GE-Lighting-LED-retrofit-for-wayside-incandescent-replacements--46475
Never too old to have a happy childhood!
tree68California Highway Patrol for many years just used the driver's side spotlight with a red lamp in it... It didn't even flash. The old "bubble gum machine" (or "Andy Griffith light") just doesn't do the job any more, though. Gotta have something to make people look up from their phones....
Yeah, but having a fully loaded Liberty on the roof, dash light, TIRs on the pushbar, LED hideaways in the headlights and corners is just excessive. Then you start mixing red and blue together and you get this ugly purplish-white thing. And people STILL won't notice it.
At least kick them down when stopped alongside the road. CHP also did the studies years ago with using just amber flashers to the rear. You're not doing any favors blinding passerbys when stopped along the road.
It's been fun. But it isn't much fun anymore. Signing off for now.
The opinions expressed here represent my own and not those of my employer, any other railroad, company, or person.t fun any
zugmannIt also doesn't help that many agencies use Disco patterns. And also put 15 auxillary LEDs on every spare inch of their cars and trucks. Used to be a simple rotator lightbar was sufficient. Now....I know they want to be seen, but being blinded isn't good either.
California Highway Patrol for many years just used the driver's side spotlight with a red lamp in it... It didn't even flash. The old "bubble gum machine" (or "Andy Griffith light") just doesn't do the job any more, though. Gotta have something to make people look up from their phones....
My light bar has, like, 16 potential patterns... I usually stick with one or two.
Another problem is the relative brightness of the colors. During the day, blue isn't very visible, one reason many police agencies use both red and blue.
LEDs are often "doped" to create the desired color (as opposed to mixing colors). That is, the amounts of the chemicals used are varied. This results in a very "pure" color. Almost too pure for those used to incandescent lights filtered by a lens.
This can be a plus for signals, as the all-wavelengths characteristic of an incandescent lamp can't overwhelm a fading lens.
One negative effect I've seen is that red lights placed at the top of the windshield (on the inside) are almost invisible if the top of the windshield is tinted (especially with a greenish tint). All the more reason for crews wearing neutral tinted sunglasses.
I am enjoying the reduction in my electric bill that's resulted from replacing almost all the bulbs in the house with LED's...
LEDs are great for distant "signaling", you can see them from miles away, but the narrow bands of the emitted light frequencies (color) are such that they are poor for illumination.
"White" LEDs do not give off "White" light, but are combinations of Red, Green and Blue such as to appear White to the human eye. If what the lights is shining on is not close in color to one of the frequency bands of the LED then little or no light is reflected off if it and it will just appear dark to the human eye.
LED design is getting better at giving off wider bands of the 3 colors and so are better at general illumination than they used to be, but are still not like an incandescent light that gives off a much broader band of colors.
I have LED bulbs in some fixtures in my house and they are really bright to look "AT", but I cannot read a newspaper easily from the light they give off.
If you happen to have an LED display on your computer, (at night so there is no other source of light) set the screen to just a white display (like start a blank document and make it full screen). Looking at the screen it will appear very bright (maybe even hurt your eyes), but it will be difficult to read a newspaper from the light available from the screen (or even navigate around the room!).
I have noticed that some cars have LED headlights and they are near blinding when they come at you, but they do not illuminate the road in front of the car nearly as well as an old incandescent bulb would.
Semper Vaporo
Pkgs.
avonlea22Yes, very good point. I used to work for Whelen Engineering, the company that makes many of the emergency lights. I know the old strobe style had a day/night option and I heard that the LED's do as well. I tend to think those that use the lights don't care to or don't think to switch to night mode. Unless the technology has changed, this had to be done manually from inside the vehicle rather than, say, a sensor on the bar.
It also doesn't help that many agencies use Disco patterns. And also put 15 auxillary LEDs on every spare inch of their cars and trucks. Used to be a simple rotator lightbar was suffiecient. Now....I know they want to be seen, but being blinded isn't good either.
tree68 Emergency service agencies have had a similar problem with the LED light bars now in use. Some light bars include a day/night option.
Emergency service agencies have had a similar problem with the LED light bars now in use. Some light bars include a day/night option.
Yes, very good point. I used to work for Whelen Engineering, the company that makes many of the emergency lights. I know the old strobe style had a day/night option and I heard that the LED's do as well. I tend to think those that use the lights don't care to or don't think to switch to night mode. Unless the technology has changed, this had to be done manually from inside the vehicle rather than, say, a sensor on the bar.
jeffhergertIncandescent bulbs on approach-lit signals have the same problem. Snow builds up, even on hooded signals when snow is blowing around, and the bulbs aren't on long enough to get hot to melt the snow.
Especially the green bulbs which are almost NEVER lit.
zugmann Fred Boyer South Shore is all LED signals. Initally the train crews were upset with them. They are much brighter then the bulbs. I'm waiting to see what happens with a good snow storm. LED's do not generate enough heat to melt the ice. Even covered in snow, the LEDs are bright enough to shine right through it. These aren't sissy little auto tailights.
Fred Boyer South Shore is all LED signals. Initally the train crews were upset with them. They are much brighter then the bulbs. I'm waiting to see what happens with a good snow storm. LED's do not generate enough heat to melt the ice.
Even covered in snow, the LEDs are bright enough to shine right through it. These aren't sissy little auto tailights.
Incandescent bulbs on approach-lit signals have the same problem. Snow builds up, even on hooded signals when snow is blowing around, and the bulbs aren't on long enough to get hot to melt the snow.
Jeff
Fred BoyerSouth Shore is all LED signals. Initally the train crews were upset with them. They are much brighter then the bulbs. I'm waiting to see what happens with a good snow storm. LED's do not generate enough heat to melt the ice.
avonlea22 cefinkjr I hope LED replacements are better for railroads than they have been locally for highway traffic lights. Cities in this area switched pretty quickly as soon as LEDs became available and they seemed to start failing within a couple of months. The failure was that as many as 40% of the LEDs in any one array would be dark. I suspect the whole array was replaced when it got any worse than that. I haven't heard whether the failures have been caused by faulty LEDs or the circuitry behind them. I noticed this as well when they first started switching to LED's. Now that you bring it up, I havent seen any like that in a while. One problem I DO have with LED's in traffic lights is their brightness at night. Approach an intersection that has no streetlights but three or four LED's, you can be blinded by them, especially the green. Thanks everyone for your input. Apparently the technology has been used in some areas. Like I said, I'm mostly in the Harrisburg, PA area and not much, has been done here. Doi the new Tier 4 units have LED lighting?
cefinkjr I hope LED replacements are better for railroads than they have been locally for highway traffic lights. Cities in this area switched pretty quickly as soon as LEDs became available and they seemed to start failing within a couple of months. The failure was that as many as 40% of the LEDs in any one array would be dark. I suspect the whole array was replaced when it got any worse than that. I haven't heard whether the failures have been caused by faulty LEDs or the circuitry behind them.
I hope LED replacements are better for railroads than they have been locally for highway traffic lights. Cities in this area switched pretty quickly as soon as LEDs became available and they seemed to start failing within a couple of months. The failure was that as many as 40% of the LEDs in any one array would be dark. I suspect the whole array was replaced when it got any worse than that. I haven't heard whether the failures have been caused by faulty LEDs or the circuitry behind them.
I noticed this as well when they first started switching to LED's. Now that you bring it up, I havent seen any like that in a while.
One problem I DO have with LED's in traffic lights is their brightness at night. Approach an intersection that has no streetlights but three or four LED's, you can be blinded by them, especially the green.
Thanks everyone for your input. Apparently the technology has been used in some areas. Like I said, I'm mostly in the Harrisburg, PA area and not much, has been done here. Doi the new Tier 4 units have LED lighting?
Some police and emergency vehicles are using LED's for their 'Light Bars'. As mentioned - their light output at night is absolutely BLINDING. While you may be able to see them flashing from a further distance, when you get closer they are overpowering. I will be interested to see the accident statistics for these units over time as I suspect some drivers will get 'attracted' to the source of the light and end up hitting the source (target fixation).
avonlea22One problem I DO have with LED's in traffic lights is their brightness at night. Approach an intersection that has no streetlights but three or four LED's, you can be blinded by them, especially the green.
South Shore is all LED signals. Initally the train crews were upset with them. They are much brighter then the bulbs. I'm waiting to see what happens with a good snow storm. LED's do not generate enough heat to melt the ice.
One problem you'll see with LEDs is ganging. Rather than install a dropping resistor on each LED, manufacturers often hook three LEDs up in series. So when one fails, three are now dark.
cefinkjr The failure was that as many as 40% of the LEDs in any one array would be dark. I suspect the whole array was replaced when it got any worse than that. I haven't heard whether the failures have been caused by faulty LEDs or the circuitry behind them. I have noticed, however, that newer installations seem to be much more reliable.
The failure was that as many as 40% of the LEDs in any one array would be dark. I suspect the whole array was replaced when it got any worse than that. I haven't heard whether the failures have been caused by faulty LEDs or the circuitry behind them.
I have noticed, however, that newer installations seem to be much more reliable.
Our local traffic department tells us that it is manufcturing defects by a certain company ( unknown ). LEDs use DC and it may be that the rectifiers do not work well. As well some company in parts pipeline may have gone bankrupt ?
I have noticed, however, that newer installations seem to be much more reliable. They're still only marginally better than incandescent when driving into the Texas sun. Even good-sized black sun shields behind the lights don't help all that much; wise drivers approach any signal with extreme caution when driving into the sun and, with the sun at your back, assume the other fellow is not so wise.
ChuckAllen, TX
basementdwellerOne down fall to LED's is the lack of heat allows snow to cover the lens. I see this problem every winter on our traffic lights.
It's a problem for vehicle lights as well.
While the visible range may be reduced, at night it shouldn't be a problem short of a serious blizzard of sticky snow. On a sunny day, however, it could be an issue.
Perhaps that's one reason for the length/depth of the hoods on the "Darth Vader" signals.
Did a Chicago Detroit trip last week, most of the signals I noted were LED. Most of the grade crossing flashers around where I live are LED. The industry, FRA, and the University of Illinois conducted a visibility/ conspicuous study of conventional vs LED grade crossing flasher study in the late 9Os. The goal was to preempt FRA from fighting LEDs in that application. Needless to say the LEDs were as good as or better than conventional.
tree68You may see new locomotives with LED headlights, but I doubt the far-less-expensive incadescents will be replaced wholesale unless someone can demonstrate significant savings.
There's at least one NS engine running around with LED headlights installed. Most of the other lights on the engines (numberboard and running) are being replaced as the engines get shopped. Many of the newer RCO engines are getting amber LED beacons instead of the normal strobes.
Lanterns are LED now. Signals are still mostly incandesent yet, but LEDs are slowly being worked in. Amtrak has been more proactive in using them. Neat to see an old PRR dwarf signal with LED upgrades.
The Class 1 railroads have replaced or are replacing all the signals with LEDs.
The regional railroads would not be able to change all their signals as quickly.
Watch my videos on-line at https://www.youtube.com/user/AndrewNeilFalconer
In Australia, Pacific National has replaced the headlights on their Cv40-9i units as they go through major overhaul. The fitting seems to be a standard twin unit with the sealed beams replaced by a hexagonal array slightly smaller than the old bulb and reflector.
Those LED lights are very bright and are visible from further away than the standard headlight. The ditch lights on those units are LED too, but a different pattern with fewer larger LED elements, possibly because they now flash (alternately) when the horn is sounded, a feature added along with new cab electronics and a new 7FDL-16....
EMD said that the SD70ACe-T4 uses LEDs for evereything EXCEPT the head and ditch lights. Since these are available, there might be a USA standard requiring conventional sealed beams....?
M636C
For a while, green LEDs weren't as green as one might desire - more yellowish, instead.
Nowadays, they can "dope" them pretty precisely, so green is really green, etc.
JC UPTON There was a story recently (on Trains, 3 months or so..) about the NTSB findings that mixing LED style track side signals with conventional incandescent type caused an accident; the farther (LED) signal was showing a more permissive aspect than the nearer (non-LED) signal & caused the engineer to run through the closer signal....
There was a story recently (on Trains, 3 months or so..) about the NTSB findings that mixing LED style track side signals with conventional incandescent type caused an accident; the farther (LED) signal was showing a more permissive aspect than the nearer (non-LED) signal & caused the engineer to run through the closer signal....
That type of accident has happened with totally incandescent signals in the past - there are many elements involved in how individual signals are viewed from approaching trains.
Storey was from Jan. 2015
Was a NTSB Safety alert
from the Far East of the Sunset Route
(In the shadow of the Huey P Long bridge)
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