Here is a question that I believe Sammy King will know the answer to, as well as probably others.

While looking through the book Central American Holiday,I started to notice a particular, unique appliance on most of the locomotives pictured. It looks like, at least to me, a single light bulb mounted on a pipe just ahead of the stack. Some were pointed up, some back at a 45, and some had a deliberate P shaped pipe with the bulb pointing straight back. Some were just above the stack and some right at the rim.

I read an article a few years back describing oil firing a steam boat. They mentioned a window in the uptake with a light bulb shining through that could be seen in a mirror, letting the operator know how clean the flame was burning.

Is this the same purpose of the lightbulbs on the locos.

Thanks
Eric

Yes. Especially the National Railways of Mexico used this arrangement so the fireman could tell if he was making excess smoke at night. When I fired in Guatemala, I had to depend on the head end crew holding their noses and yelling Spanish obscenities at me if I was making too much nasty, filthy, black smoke after dark.

Some American roads also used these contraptions, such as the Katy and the Frisco.

FRISCO 1630 at IRM:
https://www.irm.org/gallery/Frisco-1630-Restoration/aoy

Back in 1971, I had the pleasure of riding for a few trips between Manhattan and Staten Island in the engine and boiler rooms of the ferryboat Mary Murray, which was the last double compound steam ferry running in New York (The newer boats had Skinner Uniflows or EMDs.) In the boiler room they had a periscope arrangement that went up alongside the stack, so the fireman could see just how much smoke they were making. I rode during the day, but I suspect there was a light opposite the periscope at the top of the stack for seeing the smoke at night, very similar to some locomotives. First time I ever heard the term 'Ringleman number'- After retirement, that boat sat alongside the NJ Turnpike for years, sadly was scrapped just a few years ago.

Umm, isn't SLSF 1630 a coal burner?

Howard P.

Coal firemen should also be interested in the amount of smoke being made in the course of their duties.

It is.

It seems to me that one of the differences between firing with coal or firing with oil is that we can control how much smoke we're making with an oil burner so much faster and easier than a coal fireman can. Usually all it takes for us is a slight adjustment of the atomizer or firing valve, so we are often held to a higher standard.

Many American locomotives had stack lights. Some were behind the stack, shining forward ; some were in front, shining back. I think part of it depended on the dynamo location or wiring routing, and part of it on how much the exhaust tended to foul the light enclosure over time.

They certainly make it easier to fire an oil-fueled locomotive at night!

There would be some value to stack lights on coal-fired engines if they operated in the dark anywhere subject to smoke ordinances.