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  • General discussion about locomotives, rolling stock, and equipment
General discussion about locomotives, rolling stock, and equipment

Moderator: John_Perkowski

 #923586  by eurorail
 
Hi guys,

Hope you can help me out with my quest for some information. As you can tell, I am quite new on this forum. Additionally, as you may have guessed already, I am originally from Europe. As a result, there are quite a few interesting railroad differences I have been observing between Europe and North America. One difference I find particularly intriguing is the use of headlights on locomotives.

Most, if not all, European countries have clear rules that a locomotive must display a triangular light pattern in the direction of travel. There's just those three lamps, all three lights are equal, of the same size and all three of them must be on at all times (i.e. there's no equivalent to "flashing ditch lights" or anything like that). The idea of the triangle, of course, is to allow for easy distinction between trains and cars at night time. Two headlights at the same hight = car or truck, three headlights in a triangle = train. (This goes as far as requiring that maintenance trucks travelling on railway tracks display the triangle pattern, also.)

There's no notion of ditch lights, and, as far as I know, there never was. Even if you go all the way back to steam locomotives, many of them already use the triangle light pattern. (See, for instance, this locomotive built in 1918: http://de.wikipedia.org/w/index.php?tit ... 1205225316.)

I am curious where the North American tradition comes from to mount the main headlights in the center, why they are always doubled up (horizontally or vertically) and why, for the longest time, the center headlights where the only ones being used. Even today, the ditch lights on locomotives are often smaller and nearly always not as bright as the main headlights and, depending on the circumstances, sometimes they may not even have to be switched on.

Thanks.
 #923821  by CN Sparky
 
I can't speak for Europe.. but over here in North America, if it's on a highway, it's not likely a locomotive. They tend to stick to those rails... at least, most of the time ;)

The bulb used in the ditch lights is exactly the same bulb used in the headlights... so I can't see how you see a difference. They are usually angled inwards at 15 degrees or so, so a straight-on shot might explain the perceived difference in brightness.
 #923864  by DutchRailnut
 
In USA the ditch lights ?? would be angled inwards, but todays lociomotives have Auxiliary Headlights in a patern mimmicking ditchlights.
as for rules see:
http://edocket.access.gpo.gov/cfr_2009/ ... 29.125.htm
 #923876  by 3rdrail
 
My understanding of the difference between American and European locomotive illumination is that in Europe, forward facing lights traditionally have been designed to merely mark the front end of the locomotive for those ahead whereas in America, "headlights" were designed earlier which would illuminate the roadbed ahead for the engineer. Actually, some early experiments proved to be too intense, blinding on-coming locomotives. I have a small collection of headlights. One of the lights in my collection, an early French steam locomotive light manufactured by Eug. Halard, Paris, the type which would be in pairs sitting side by side on the front end, proves to my satisfaction, this belief. At best, it would have only been sufficient for sighting the loco itself from a small distance. One, in my collection is a Golden Glow headlight, designed with polarized glass, for a 1951 installation on Pullman subway cars in Boston. If you take the glass from two lenses and turn them against each other, no light shines through. They were made this way to prevent blinding of an oncoming motorman.
 #923939  by eurorail
 
CN Sparky wrote:I can't speak for Europe.. but over here in North America, if it's on a highway, it's not likely a locomotive. They tend to stick to those rails... at least, most of the time ;)
They do now, do they? *lol*
 #951098  by GSC
 
Headlights on diesels up until the late 50s had one bulb mounted in a reflector. (Some guys today call them "old yellow headlights"). Once sealed beams became available (the same lamps as the auto industry used), the light housings were modified to hold two lamps - either horizontal or vertical to each other. The light from the sealed beams was brighter and whiter, and the sealed beam design itself held together better in vibrating situations. Plus, you had two lamps, nice if one burned out. The old single-bulb design left you in the dark (literally!) when the bulb went.

Ditch lights evolved from being "ditch lights" to flashing warning lights, to the now-steady "triangle" - an explosion of light. Some ditch lights still flash, but are going to become steady-burning eventually.

In cases where two separate headlights were mounted vertically (think of the nose of an E or F unit) the lower lamp was often used as it could be pointed almost horizontally ahead, increasing forward night vision for the crew.
 #971814  by davebdawg
 
I remember seeing on a tv show once on an E or F engine the headlight looked like a rolling eye from side to side while going along at speed, what the heck was that all about?
 #971845  by DutchRailnut
 
that was mars or gyra light, the second set of sealed beams was mounted in a gimbal type swivel with a motor, it was used as another attention getter at crossings/yards/stations.
 #974024  by 10more years
 
I'm basically guessing here, but: I would imagine that the reason for two headlights is as a back up. If one fails, then you would at least have a headlight. If you only had one and it went out, you'd be out of compliance with operating rules and dead in the water.

I think the ditch light are primarily a crossing protection device for the motoring public. We don't have to have working ditch lights to move a train (at least not on CSX). Our speed over road crossings is affected.

I wonder why our headlights are not brighter. Most of the time I run ditch lights just to improve my visibility. For those who are not aware of it, ditch lights are connected to the horn. Although you can cut them on with the headlight switch, or in some cases, a separate switch, they are activated (and flash) when the horn is activated so long as the ditch light circuit breaker is on.

And I think the oscillating headlight back in the old days was primarily another safety device to alert the public of oncoming train.