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PRR T1 "Headlinght In Front Grill"

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PRR T1 "Headlinght In Front Grill"
Posted by BEAUSABRE on Friday, September 16, 2022 8:37 PM

Were the PRR T1's lights in the "front grill"  a second headlight or a signal (such as Mars) light?

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Posted by Overmod on Saturday, September 17, 2022 7:38 AM

It's a fixed auxiliary light.  The drawings are preserved in the Pennsylvania State Archives and copies are in the T1 Trust repository.

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Posted by BaltACD on Saturday, September 17, 2022 7:58 AM

Overmod
It's a fixed auxiliary light.  The drawings are preserved in the Pennsylvania State Archives and copies are in the T1 Trust repository.

Did it have some designated purpose within the framework of PRR Rules? Operating, Train Handling or Safety?

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Posted by Overmod on Saturday, September 17, 2022 8:02 AM

I'd think there would have been, and there has been some discussion of this including on PRR-FAX, but I don't remember anything definitive.

It's a sealed-beam light.  I have only seen one example of a dual-sealed-beam conversion of a T1 headlight (circa 1948) and there may be some requirement comparable to automobile lighting in the '30s involving sealed-beam lights or redundancy.

It is not red, and it is not rigged to flash.  I do not remember how it's wired.

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Posted by pennytrains on Saturday, September 17, 2022 6:16 PM

Huh.  Maybe someone came up with a form of "ditch light" way ahead of their time.

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Posted by kgbw49 on Saturday, September 17, 2022 7:49 PM

Perhaps its a "laser".

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Posted by Overmod on Sunday, September 18, 2022 1:03 PM

The original assumption (which really is to say, my assumption) was that this light was slightly angled so it would spin or 'walk' in a circle, like an experimental KCS light I observed, which would sweep around the areas out of the headlight cone.  Persistence of vision would alert to anything looming up or potentially endangered.

In a sense this is a version of ditch lighting but would not have the effective raw candlepower of two 'cross-eyed' low-mounted lights converging at headlight aiming distance... a little over 400' IIRC.

Incidentally, regarding convergence, it is interesting to note that older headlights often did not shine 'straight ahead' like vehicle high beams do.  They angle sharply down to throw a pool of light ahead of the engine, and you can see this in some contemporary illustrations showing engines operating at night.

(And yes, the subject of grade-crossing laser from that lens did come up, but as a structured-light source rather than deadly grade-crossing light show... and no, the two little circles either side of the light don't light up in red.)

The discussion of the emergency light included its use as a fog light or in places with significant local air opacity such as Pittsburgh.  If I recall correctly the drawings have it on a comparatively cheap bracket without precision 'collimation'.

 

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Posted by BEAUSABRE on Sunday, September 18, 2022 1:59 PM

I hope people who are bandying about the term laser are in jest as the first laser wasn't built until 1960 - well after the T1's demise. The first laser was built in 1960 by Theodore H. Maiman at Hughes Research Laboratories, based on theoretical work by Charles Hard Townes and Arthur Leonard Schawlow.[6]

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Posted by zugmann on Sunday, September 18, 2022 2:05 PM

Overmod
Incidentally, regarding convergence, it is interesting to note that older headlights often did not shine 'straight ahead' like vehicle high beams do.  They angle sharply down to throw a pool of light ahead of the engine, and you can see this in some contemporary illustrations showing engines operating at night.

Current locomotive headlight bulbs have a little arrow embossed on them.  I was told the arrow should be pointed up when installed. 

  

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Posted by Overmod on Sunday, September 18, 2022 2:06 PM

We were referring of course to what the auxiliary light would do on replica T1 5550, which could easily use femtosecond lasers or COILs if there were any reason, or lack of reason, involved...

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Posted by BEAUSABRE on Sunday, September 18, 2022 2:21 PM

Digging around,  including the PPRT&HS, I have found the following 1) The claim that Lines West (Western Region?) wanted them 2) The claim they were fog lights - does that mean they were not on constantly? 3)The claim that they swept back and forth in a horizontal pattern acting as a beacon like some early diesel streamliners had 4) The fact that some K4s that got the "beauty treatment" got them as well, below the turbogenerator  "curious and curiouser" he said

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Posted by zugmann on Sunday, September 18, 2022 3:17 PM

I could see the T1 light for fog, but that K4s?  That's pretty high up still. 

  

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Posted by BEAUSABRE on Sunday, September 18, 2022 9:17 PM

I've got a hunch that Railway Age or The Locomotive Cyclopedia in the late Forties might well have an article about these lights, but not having access to either, I can only guess. The fan community seems to draw a blank on "Why?"

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Posted by kgbw49 on Sunday, September 18, 2022 9:50 PM

BEAUSABRE

I hope people who are bandying about the term laser are in jest as the first laser wasn't built until 1960 - well after the T1's demise. The first laser was built in 1960 by Theodore H. Maiman at Hughes Research Laboratories, based on theoretical work by Charles Hard Townes and Arthur Leonard Schawlow.[6]

 

It was in jest. A light-hearted nod to Mike Myers as "Dr. Evil".

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Posted by Overmod on Monday, September 19, 2022 12:08 PM

No mention in the '47, '50, or '52 Cycs.  I'd bet the point was moot after then as I've never seen a PRR diesel equipped with one.

Trust me when I say we found out how the light was constructed.  Only its intended purpose remains in play.

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