Re: arc headlights and dynamos
Posted by skip on
URL: http://c-sng-discussion-forum.254.s1.nabble.com/arc-headlights-and-dynamos-tp15165p15171.html
John, Thanks for bringing this up. It's a good question and I've wondered about this as well.
The holes in the reflector of the headlight don't necessarily imply kerosene smoke venting. A carbon arc also produces lots of very hot air and some smoke and needs venting. So the typical "arc" headlight had a vent on the top that could have supported either kerosene or carbon arc. Check Coleman's Pictorial pages 66 and 67 showing the #13 in 1903 and 1922. The headlight seems the same. The earlier headlight is surely kerosene and the later has a generator and power wires implying carbon arc. The external headlight structure is the same in each.
Also, the B3B #21 and #22 have the "arc" headlights and have generators between the air tank and the steam dome. The B3A #11, #12, and #13 have the air tank moved back toward the steam dome and no apparent generator on the boiler top. BUT in the (1917) como spark arrestor era up through the early 1920s, the #13 shows a generator on the headlight platform between the headlight and stack as does the common photo of the #37 in Denver showing off its como spark arrestor (Coleman 86, 87). A few other B4Bs in that time frame show the headlight-platform generator and others don't. The #11 and #12 in this time frame show no such headlight-platform generator.
Note that there seems to be an electric line from the headlight on the #13 down to a tee on the handrail. I understand that the handrails were used as early electrical conduits. This would distribute the generator's power to the rest of the locomotive. But look behind the #13 at the front of the #12. It has no headlight-platform generator but does have the power line from the headlight to the tee on the handrail implying that the generator was somewhere else. So I wonder where it could be?
Skip Egdorf
Los Alamos, NM
URL: http://c-sng-discussion-forum.254.s1.nabble.com/arc-headlights-and-dynamos-tp15165p15171.html
John, Thanks for bringing this up. It's a good question and I've wondered about this as well.
The holes in the reflector of the headlight don't necessarily imply kerosene smoke venting. A carbon arc also produces lots of very hot air and some smoke and needs venting. So the typical "arc" headlight had a vent on the top that could have supported either kerosene or carbon arc. Check Coleman's Pictorial pages 66 and 67 showing the #13 in 1903 and 1922. The headlight seems the same. The earlier headlight is surely kerosene and the later has a generator and power wires implying carbon arc. The external headlight structure is the same in each.
Also, the B3B #21 and #22 have the "arc" headlights and have generators between the air tank and the steam dome. The B3A #11, #12, and #13 have the air tank moved back toward the steam dome and no apparent generator on the boiler top. BUT in the (1917) como spark arrestor era up through the early 1920s, the #13 shows a generator on the headlight platform between the headlight and stack as does the common photo of the #37 in Denver showing off its como spark arrestor (Coleman 86, 87). A few other B4Bs in that time frame show the headlight-platform generator and others don't. The #11 and #12 in this time frame show no such headlight-platform generator.
Note that there seems to be an electric line from the headlight on the #13 down to a tee on the handrail. I understand that the handrails were used as early electrical conduits. This would distribute the generator's power to the rest of the locomotive. But look behind the #13 at the front of the #12. It has no headlight-platform generator but does have the power line from the headlight to the tee on the handrail implying that the generator was somewhere else. So I wonder where it could be?
Skip Egdorf
Los Alamos, NM
Skip Egdorf
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