Locomotive Headlight Angled Upwards

[dehusman]

rjemery

I assume a headlight and signal light here are the same. 

The signal light was an additional light.  It was a warning/announcement of the train coming at night.

[rhmilwroad]

I remember my uncle saying it was used for advertising, like search lights where used for a opening of a new store.

[Alan Robinson]

A stack light was different. It was a small light mounted directly in front of the stack and it was cowled with a lighted opening facing backward toward the cab. It was designed to allow the fireman to judge the density of the smoke coming out of the stack. Black smoke indicated inefficient combustion and a dirty fire, and it would block out the light. Light smoke, or barely visible smoke would allow the light to shine through.

This question is referring to an attempt to attract attention to the locomotive at grade crossings and thus avoid collisions. It didn't work very well unless it was pretty foggy as the beam wasn't bright enough to have much back-scatter in clear air. Only a few locomotives used such lights.

[dfandrews]

Sounds like a stack light, used by the fireman at night to monitor combustion conditions

by looking at the exhaust smoke/steam.

 

[rjemery]

That's called a sundog effect, usually seen when conditions are right looking in the direction of the sun on or near the horizon.

[Kootenay Central]

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[erikem]

 The UP tried a vertically aimed headlight on the M-1000 as an attempt to improve visibility of the train to cars - the idea was that drivers would see the vertical column of light moving towards the crossing. Didn't work very well.

[Last Chance]

Maybe the Mail Jennies or other planes used that light as a sort of night time navaid.

[rjemery]

 

In Jim Gribbins' The 400 Story, about Chicago & North Western's passenger trains, on page 12 is a photo of a steam locomotive with a headlight just in front of the smoke stack mounted on top of the boiler.  This headlight is angled 45 degrees upward.

The photo caption reads "Pacific 2908, normally assigned to the Chicago-Milwaukee segment of 400-401, appears in Minneapolis in this scene from August 22, 1935, sporting an original, non-gyrating signal light that beamed at the sky at a 45-degree angle."

I assume a headlight and signal light here are the same. 

Regardless, what was the purpose of this light? 

Whatever purpose it had, it apparently wasn't all that effective, as few steam locomotives of that era on C&NW or other roads made use of such a light.

One possible explanation:  The C&NW used semaphores, most often in threes mounted on poles jutting over the tracks from a signal bridge.  If the locomotive signal light was meant to help illuminate these semaphores at night, it would have had to be a fleeting encounter.  The locomotives averaged 60 mph, which would not have left much time to illuminate any overhead semaphore stack.