Other than just for looks was there a reason some railroads painted their smoke box and firebox (ash pit?) in a graphite (or silver) paint? I am assuming if it was strictly for aesthetic reasons, was it not unusual for several railroads to adopt similar paint schemes?

Same question but seemingly more obvious regarding aesthetics, why the red roof?

And, for the heck of it - how about a list of those that;
A) Had graphite smoke boxes
B) Had red cab roofs

/Mitch

The smokebox and firebox areas are exposed to high temperatures, and the mixture of graphite and linseed oil was able to withstand those high temps. Any normal paint would have burned off in a short period of time.

I don't know about the red cab roofs.

Since you asked, and for the record, steam locomotives on the Chicago, Burlington & Quincy had red cab roofs. I believe that their subsidiaries, the Fort Worth & Denver and the Colorado & Southern, did too.

Les

Although she never had a red roof while in service, Western Maryland Shay 6 at Cass does. I believe alot of the Western Maryland engines did.

The red roof might go back to the old days of "red lead" paint that would stand up to almost anything. Maybe the roof got a lot of abrasive ciders that would tear up regular paint.

Why red cab roofs?
....Because, on a hot sunny summer day, red will absorb less heat from the sun than black would.
It's all about crew comfort.

Jeff

I think that's a lot of it. Aesthetic reasons may be another one these days. Southern Railway never had red cab roofs in service, but everyone knows what color 4501 came out in 1966.

Mitch,

Any unlagged areas of the boiler/firebox were covered with the graphite/oil mix as a prior poster stated due to the heat that would burn off regular paint. Colors varied with the mix. In later days, for example, the CNJ used almost no graphite resulting in a back appearance.

It is my understanding that the reason for red cab roofs and in many cases red tops of the tender decks was that the paint used held up extremely well under the shower of cinders and other elements those areas are exposed to. What made this paint special? Not sure.

It's a pretty good bet that if the Pennsy did it, it had a purpose beyond looks. Same with the Rutland.

Rob

There has always been the observation that dark colors absorb and emit thermal radiation better that light colors, but surface texture also plays a role. Lately, I have read that surface texture plays a far greater role than color value from light to dark than was previously thought. I suspect that a gloss red surface would emit and absorb thermal radiation very similar to what a black surface would. As an example, I have checked aluminum sun shades with a black Kynar finish standing in bright sun, and found them to be 70 degrees F., the same as the air temperature. The reflective surface finish of the Kynar paint treatment completely overrides the ability of the color black to absorb thermal radiation.

The best emitter / absorber or thermal radiation is a textured, no gloss, black, and the poorest emitter / absorber is chrome or mirror finish. This raises a bit of a conundrum for using cab roof surface to reduce heat in a locomotive cab because that heat is not only coming from the sun, but also from the boiler.

A mirror surface on the cab roof would reflect all of the thermal radiation from the sun because such a surface is the poorest absorber (and the best reflector). But it is also the poorest emitter, so it cannot emit thermal radiation from boiler heat generated inside of the cab to the cooler body of deep space. To that heat source inside of the cab, the mirror finish on the roof would be an insulator.

On the contrary, a flat black surface on the cab roof would absorb heat from the sun, but emit the boiler heat being conducted to it from inside of the cab.

Here's a couple anecdotes that sum up my knowledge of heat radiation.

I once read a description of a Milwaukee Road rotary snow plow that implied that its Russia-iron boiler jacket contributed to heat retention. That was the only such reference I've ever seen, but it made sense, and might explain the builders' fondness for this polished material for jacketing before 1910 or so.

When I bought oxide-red vinyl siding for my house (the only one in the neighborhood that isn't beige, buff, or taupe), I had to pay extra for higher-quality material that wouldn't fail prematurely due to heat retention, which I suspect is very close to black's.

Aarne Frobom
Central Air, Michigan

That shiny metal jacket would indeed be insulation for the boiler, and it might be substantial because radiant loss plays a significant role. I recall that the Minneapolis & St. Louis RR jacketed one or two of their 2-8-2s in shiny stainless steel. As I recall, it was quite an extensive jacketing, including the cylinders, domes, etc. I assumed that it was done for appearance, and I never saw any reference to it being done for insulation, but it would have served that purpose.

.

With the logical follow on being; red lead primer, can't really be seen from the ground, so why bother with a coat of black? In other words, money. Just a completely wild guess.

Southern Railroad had red-painted tender bunkers when the locomotive was equipped with a stoker...this was information intended for the crew on coaling towers.

Not all SR locomotives had silver or graphite smoke boxes...it would appear to be a choice of the division as each division had special touches added for special needs and appearance. This will not answer all your questions but it might help get where you want to go.

T7 -

Well I'm stumped by this little bit of information. What difference would it make to the crew on a coaling tower as to whether the locomotive had a stoker or not?

Les