a lot of automobiles have switched to using LED clusters for head and taillights. Is it concievavbly that locomotives could head on the same direction once the LEDs become cheap enough? The only real advantage cpuld be a minuscule reduction in maintenance and brighter head, marker ditch lights.
Amtrak uses led headlights/ditchlights in their new electrics.
I had thought the move toward LED lighting was well advanced, both in ‘new build’ locomotives (the ACS-64s for an immediate example have them) and in the retrofit market.
There are advantages other than first cost, and I suspect the reduction in maintenance cost is better than ‘minuscule’ especially including the reduction in cost to remediate a conventional headlight that has gone out ‘on the road’ and has to be replaced under applicable rules.
It has probably taken some time for the ‘cheaper’ LEDs and support circuitry to make it into the 64 to 72V, heavier-shock railroad world effectively. Remember that historical issues with LED high-power lighting involve the considerable heat-sink requirements and the inherent low resistance to voltage spikes – but once solutions to these have been costed down, or a price and reliability point reached which outperforms traditional (and often costed-down) solutions – expect to see it across the board.
One interesting issue with LED main lighting is that some of it is multiplexed, meaning that one ‘driver’ circuit works for many physical light-emitting diodes with some persistence-of-vision and internal phosphors making up the difference in continuous light. This shows up dramatically in digital photography of some of the units equipped with these lights. Digital photography can have extremely fast effective shutter speed (with the additional ‘exposure time’ involving post-processing and storage of the captured image) and it’s not uncommon to see pictures in which multiplexed lit LEDs have not registered as ‘on.’ I have been waiting with some amusement to see these sent to railroads as evidence of ‘rules violation’ or brought up in court by ambitious attorneys eager to show railroad 'negligence&#
A drawback of LED’s is they don’t generate enough heat to melt snow and would need constant cleaning when used in such conditions.
IIRC, some automotive LED fixtures actually include heaters for that very reason.
The city of LaGrange Ga is replacing mercury vapor & metal halide street lights with LEDs. The LEDs are very aimable and tend to place much more light on the street. we notice that the lights across street ( either way ) are pointed more toward us but once in the opposing lane for left turns they are very much brighter, The aiming certainly may be important. No one has indicated how the city is disposing the now surplus fixtures and to a lesser extent bulbs that still have life ? l
Some of the newer diesels seem to be using LED lighting on steps, and some of the ‘other’ lighting around the sides (manway(?) areas of newer locomotives.
Also have not noticed any of LED style on the headlamps or ditch lights.
I also wonder if itwill. Used in newer passenger cars. That could be a substantial reduction in HEP needed.
In Australia, Pacific National, one of the two biggest operators has refitted their main intermodal units (120 units altogether) with full LED lighting at their 15 year overhauls.
This includes headlights, marker lights and flashing ditch lights.
The blue white headlights show up more clearly at greater distances, but I can’t say what the view from the cab is like at night.
The LEDs are fitted into standard casings and are the same size as the sealed beams they replace. They are a dense matrix of hexagonal shape with maybe 50-100 individual LEDs. Two are fitted, like sealed beams.
The ditch lights consist of six larger LED units each arranged in a circle, again, fitted in the usual incandescent lamp casings.
Marker lights are similar to the headlights but smaller, and come in red and white, of course.
Many locomotives have been built with, or have had LED marker lamps fitted at overhaul.
The preserved Beyer-Garratt 6029 has LED headlights and ditch lights. The ditch lights, not being original, are quite small to reduce the impact in appearance, particularly when out od use. Since the locomotive is overall glossy black, the lights are important visual aids.
The Sydney “Waratah” trains (78 eight car sets) have full LED lighting inside and out. However, the power required for propulsion and air conditioning mean that there is little net power reduction. The long life of the LEDs is a cost reduction, maily in manpower to replace bulbs and tubes.
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FRA Locomotive lighting regulations
I put LED DRLs on my truck. They’re bright to look at, but you wouldn’t want to drive with them at night.
OTOH, the LED headlights on our new fire pumper are plenty bright for driving, and aren’t as blue as many of the LEDs you see. Given the proper optics, I suspect they’d be just fine on a locomotive. I have seen step lights, etc.
We’re starting to replace some of the light bulbs in our passenger cars with LEDs. There aren’t enough yet to make a major difference in HEP load, but time will change that.
There is nothing in the regulations that suggest the type of technology to be used. However, I’m not sure how you would dim an LED headlight - possibly just use a secondary light of lower power.
What did strike me was the regulations say nothing about how the headlight performs as a light for the operator. They are only concerned with how the light appears to those outside the train.
In Australia, the ditch lights flash automatically when the horn is sounded.
The recent Chinese SDA-1 type locomotives in Australia also flash the ditch lights when they are powered up and when the brakes are released, handy for employees in yards and depots. They have LED ditch lights but incandescent headlights.
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The secondary diode core(s) approach will certainly work, and it has the secondary advantage that the ‘dim’ can be at a different reflector focus and/or aimed downward to carry well but provide less ‘dazzle’ to oncoming crews. It also ought to be compatible with existing switch arrangements.
However, I think it’s probably at least as good to dim by modulating the voltage to the diodes at very high frequency, similar to the way older triac dimmers worked. The net result is not only that fewer lumens are emitted at the diode in operation, but that the diode is not powered a considerable portion of the time, so the ‘net’ illumination is less.
The regulations mention incandescent and halogen lamps as well as specific wattages. They make no mention of LED’s.
The standard indicates that the quoted lamps meet the requirements of the standard.
It does not suggest that the quoted lamps are the only acceptable solution.
If a manufacturer offered LED lamps that could demonstrably meet the standard as laid out, I’m sure they would be accepted.
The SAE had similar standards for automobile headlights which has not prevented the proliferation of LED lights on private automobiles.
I expect that the standard was written to allow for future developments, hence the wording of the standard and the statement that certain existing lamps meet the standard.
While voltages and watt measurements are quoted in the examples, they are notably absent in the performance definition above.
As I’ve indicated, LED headlights meeting the standards used in the USA are already in use elsewhere, and apparently, on the Amtrak Siemens electric locomotives. If LEDs are acceptable for rail signal lamps, they will soon be adopted for headlights.
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But applicable laws, for many years, mandated ‘sealed beam’ lights without glass covers over them, specifically to get around excuses for using ‘bulb in reflector’ technologies which at the time produced inferior light, which had the effect of keeping clearly-better technologies – Cibie lights, in particular – from being “legal”. The 1965 Chrysler Imperial had glass plates over the headlights as designed (yes, how much better a designer Engel was compared to Exner!) but in many jurisdictions those were not allowed (and subsequent designs deleted them). New laws had to be passed to permit the halogen bulbs in permanent ‘streamlined’ enclosures (9000 series, etc.) and by extension xenon HIDs, and some of the associated light intensity and pattern requirements of state laws then became more of a limitation (hence the otherwise-inexplicable behavior of the high and low beams on 1994-era GMC trucks).
I do note that the FRA regulations – probably because they are nominally concerned with ‘safety’ and that not being the safety of crews because they are better able to see in front of them – are more concerned with the effect of the light on those outside the cab. I do find it strange that the standard, as BartACD describes it, apparently goes into detail with bulb type and wattage rather than defining compliance being thus-and-so an illumination (with an appropriate color temperature) at thus-and-so a distance in thus-and-so a pattern (as is incorporated, sometimes a bit defectively from an engineer’s point of view, in motor vehicle laws). I would think this is more a general guide to railroads as what to use in existing locomotives than a necessary choice of hardware. We obviously know LED headlights are FRA legal because they are currently in
Actually, there is a specific standard given:
I would opine that the specific bulbs portion was written against the technology of the moment, as opposed to potential changes in technology.
Recall that at one point there were headlight systems made up of five or six smaller lamps which fit into the form factor of the original headlights they replaced.
All the ones that had seven (six in a hexagon and one in the middle) were, I thought, built that way; all the ones I remember having seen were streamlined cab units, and I presumed when I was very young and first saw an example that the ‘idea’ was to have an enormous illumination directed forward, a bit like Euclid’s “light cannon” idea.
If that setup was in fact retrofitted to a unit that originally had a reflector bulb, I’d like to learn the details. This is one of those exotic areas like the UP’s/C&NW’s upward-facing light that deserves better ‘scholarly attention’.
Dual aimable sealed-beams in the space of an ordinary headlight, of course, are legion (behind the original glass, as in B&O E units, or in the headlight frame, as on the PRR T1, or in a special bolt-on cover, as on the NYC Niagara and some others), these providing the over-the-road redundancy and presumably the better aiming capability in the original Pyle-National patent for the ‘conversion’. But I think it is very rare to find more than two, and where an additional ‘clear headlight bulb’ is used, it’s in an explicitly oscillating light either as a different kind of warning or, as KCS used it, to spotlight areas outside the main headlight beam coverage.
There’s little chance they wouldn’t!
And this, indeed, is where I think the issue comes in. It was my distinct understanding (although I cannot produ
Or they could get a waiver if the law hasn’t caught up to the technology.
MILW seemed to like using 4 in their electrics.