If the Headlights were mounted right for the crew to see clearly in the dark, where would they be on the locomotives?
Which locomotive models have the headlights mounted for the best visibility in dark and hazy condtions?
Andrew
Good questions!
I’m sure that every railroad mounted their headlights where they did because they assumed that the chosen location was the best for the purpose. The fact that there were so many variants indicates to me that there was considerable difference of opinion on the subject.
Note that in the waning days of steam, the PRR swapped the headlight and turbogenerator, which raised the headlight by about a foot. Why?
Most mallet and simple articulated locos had headlights mounted on the front engine frame, but the D&H mounted theirs in the middle of the smokebox door…
Current Japanese practice for box-cab electrics seems to favor two headlights, at the extreme corners of the roof above the outer edges of the front end windows. DMU and EMU control cars follow the same pattern.
Only an engineman who had experience running many different locos (from several different railroads) at night can give a reasonably informed answer.
Chuck
I have read that the ATSF and now BNSF prefer low mounted headlights to eliminate the glare of the short hoods.
I have been told that the Pennsy switched the headlight and turbo positions to make the turbo more accessible for repair. I do not know if this is true but it makes some sense.
You mean ditchlights.
IIRC the Canadian roads, CN and CP had the headlights mounted on the nose to lessen the glare of falling snow(or rain on the wet coast). The CN 8000’s only have the headlights between the numberboards because they were tacked on to an NS order so CN could get them cheap.
My vote goes to nose mounted headlights.
How much reflection on the short hood do high mounted headlights create?
There would have to be black foam rubber on the low short hood to minimize refections.
Andrew
The reflection is not off the low nose. The glare comes from the headlight bouncing off rain/snow/fog/etc, and back into the cab.
Low headlights eliminate most of this. However, low mount lights can blind crew members standing on the front platform, and give them a nasty “sunburn”.
Nick
Given a preferamce of which to have they would have to be on the nose, glare from fog is bad with the high mounted headlights and that also goes for snow, the snow is not as bad durring the daylight hours but as soon as the it gets dark you can go bug eyed.
Rodney
enr what do you mean by they were tacked onto the NS order did NS pay for these locomotives or do they have similar features in comparison to the NS 70-2’s
They moved the generator to keep cinders and stuff from the stack out of it. This made it easier to maintain. It wasn’t a issuse of headlight position. But, if one thinks from moving the headlight up about a foot, you gain that much more of a sweep of the light. (Although not the reason for doing it, this is another advantage.) Mike
In a BN thread there is a mention that the BNSF Railway management is being practical and moving headlights down so that the crews have improved visibility.
Low mounted headlights might not be superficially pleasing to certain railfans, but it certainly will help the crews in low visibility conditions.
Andrew
Economy of scale. The most ocommon example, which applies here, is purchasing. The bulk buying of materials through long-term contracts. Locomotive manufacturers can order the materials they need at a lower cost cause the material provider can offer a lower bid and therefore the manufacturer can either keep the cost savings as profit or offer a lower cost to the railroad. Also keep in mind, the manufacturer may have offerred the locomotives at a discount price. The aviation industry, Boeing and Airbus do it all the time and I imagine that EMD and GE Transportation Systems does the same (well GE Avaition definately does, but that’s another story [:)]). And often, the larger the order, the bigger the discount.
NS probably paid for them and CN either paid there share to CN or to NS (and NS paid EMD). This means like you said, most likely CN and NS SD70M-2s has similar features with the exception of the paint scheme.
noselights are hopelessly ugly. helpful or not
and if BNSF claims it eliminates the glare on the nose (it’s not a “short hood” anymore. that was only a name applied to the high hood diesels), then why is it NS still orders all their power with cablights and never has problems with nose glares? this doesnt appear to be a serious problem. several other roads still order units with cablights
I used to work for the NS, no matter where the headlight was it was awfull in heavy fog, something common in the middle of the night in Indiana. You dont really even see much fo the nose in the new GE units. The EMD’s usualy had glare shields on the short hood headlights, ie the little visors on the bottom of each bulb. We would actualy switch off the ditch lights in heavy fog, set them so they only came on for grade crossings. Even being down low they made the glare worse than without them. Try watching for signals at 50mph in pea soup fog! With those nose mounted low headlights, you have to watch where you put your hands or what you lean against, them things get hot, even on low beam. The one problem with the ditch lights on the NS was the shops didnt really pay attention to how they were aimed when they welded the mounts to the pilot deck. One would be pointed skyward and the other in the ditch 20 feet in front of the unit. Cheers Mike
The misaimed Ditch Lights means that the shop employees must not be familiar with Canadian ditchlight practices or even automotive headlight applications.
The headlights must generate as much heat as light. It is amazing that the headlight do not have their own cooling system.
Andrew
The locomotive design engineers were probably analysed heat transfer from the headlights (or ditchlights) to the locomotive body to make sure that they don’t affect the locomotive body (cause damage to the hood/cowl when in use). This will undoubtly be more imporant in the future if they go the route of composites and such to make locomotives “lighter.”
And they do have their own cooling system provided by nature… convection.
This heat issue has me wondering about Amtrak P42s and a very recent rebuild. Take a look at a standard headlight on a P42:
197 Headlight (pre rebuild)
Notice the “glass” in front of the headlights. And now the new rebuild 197:
197 Headlight (post rebuild)
Note the new “open” headlight. I can see why 197 needed a rebuilt nose, but why change the headlight? Possibly due to heat? P42s do use a lot of composites.
Maybe. Is this something Amtrak is doing class wide (save a few cents on plastic covers)? From the pictures of what I’ve seen they still have the original design plastic covers. Also if these covers were fine before (without issues of melting/cracking/etc…) they should be fine now. Certain pastics do make excellent insulators.
But the thing is it looks like 197 hit something and the shop guys may not have been able to attach the new headlight cover either due to the repair work under the cowl.