At the Austin Train show this morning, a person asked me why many steam locomotives had ‘the front part’ painted silver. I made up an aw shucks answer with disclaimer that I might be wrong.
Seems I’ve read something about that on these forums lately but I can’t find it. Anyone know?
Southern Pacific’s smokebox fronts were painted silver as a reflection (no pun intended) of their “see and be seen” policy, in which the forward vilibility of their equipment was given first priority. Some folks may believe that is had to do with thermal efficiency; this is junk. The smokebox front had little, if anything to do with thermal efficiency. Southern Pacific painted the smokebox sides (the unjacketed portion of the boiler) and the firebox sides a graphite color. The boiler jacket and balance of the locomotive were painted black.
My understanding and experience is that high temp paint was only available in a limited amount of colors. Black, graphite and silver (aluminum) were the common colors. What I have seen on some locomotives is that the entire boiler was painted with the high temp paint, but most of it was hidden by the jacket which did not need high temp paint. This left only the smokebox and maybe some of the firebox sides visible. If the railroad used the silver high temp paint on the boiler but black on the jacket, it would appear that only the smokebox was painted silver.
I had never heard of it being done for thermal efficiency; the paint isn’t really an insulator and as 4merroad4men pointed out, the smokebox doesn’t really need insulation - at that point, the heat is pretty much waste and going out the stack anyway! The barrel of the boiler that does need insulation has it underneath the jacket, which is why the jacket can be painted with regular paint.
Two possibilities:
High temperature aluminum paint. I spread a few gallons of it around the boiler/engine room of the ship I served in almost sixty years ago.
Graphite in linseed oil rubs up to a silvery gloss, much used as a rust preventative on boilers. Heat and fly ash would cause it to darken rather quickly.
My own prototype jacketed the smokebox, so the whole shootin’ match was black from pilot beam to tender coupler housing.
Chuck (Modleing Central Japan in September, 1964)
I don’t beleive that aluminum paint was used for thermo protection. Having worked in small foundries we used EAF (electric arc furnace) to make alloy and in another foundry steel. The furnaces were painted with aluminum paint because regular paint would blister and peel from the heat. I was also a local level fire instructor and part of the class was to extnguish small flammable liquid fires with an extinguisher or with foam. I had two steel drums cut in half to use in this class. They were painted inside and out with aluminum paint, The outside for the same reason as above and the inside simply because I had five gallons given to me. They lasted for thirty years with no repainting and whan I retired I gave them to another instructor.
I would say the smoke boxes were silver for show as stated above.
To m
Tom, I think you nailed it with that explanation. Thank you!
There were many shades of graphite-based smoke box colors, from black to bright aluminum. In Europe, it appears that solid black (not graphite based) was favored, possibly because maintenance and “the look” was a higher priority.
I can’t speak for all RR’s, but at least on the CB&Q it wasn’t “paint” at all, but instead it was a mixture of oil and graphite brushed onto the bare surfaces of the boiler. It wasn’t nessesary to insulate and jacket things like the smoke box and fire box like it was the rest of the boiler, yet the sufaces got too hot to hold paint, therefore this graphite mixture was applied to protect the bare steel.
Some railroads Insulated and jacketed the smokebox and fire box sides as well, therefore they could be painted with the same paint as the rest of the engine. I don’t know if the extra jacketing had a purpose beside looks.
John.
I always believed it was quite simple. Painting the front of the locomotive silver made it more visible. It had nothing to do with thermal efficiency. The smokebox had to do with exhaust. Why would anyone think painting it silver would improve locomotive efficiency?
Mark
Aluminum paint was used because it was heat resistant. Thermal efficiency had nothing to do with it. Corrosion prevention had EVERYTHING to do with it. Paint that blisters and flakes off doesn’t do a very good job of preventing rust.
Chuck (Modeling Central Japan in September, 1964)
This all makes me wonder why some people choose automobiles colored like asphalt (dark grey) so they will be invisible to other drivers. Now if I were the judge …
Mark
Actually, if there is a heat-resistant aluminum paint, it would be a fairly recent development. I think everything I’ve seen on the topic has said that it generally wasn’t possible to paint the smokebox and firebox any color, because those areas got too hot and the paint would just peel off. So as John noted in his post, railroads protected those parts by applying a mixture of oil and graphite, which gave those parts a sort of medium-gray color (think graphite pencil gray).
It could be that towards the end of the steam era a heat-resistant aluminum paint came along and was used in those areas, which made them bright silver when new.
The odds that they would paint them a bright color for visibility would be pretty much zero. Those railroads that jacketed the smokebox generally painted it black like the rest of the engine. Painting things for visibility, like white handrails for example, didn’t become common until the very late steam era, and many railroads didn’t do it until they were well into the diesel era. So the idea that they painted steam engine fronts a light color 100 years ago for visibility seems unlikely to me.
See and be seen, after all SP had decks and perhaps other classes of steam with white fronts, a color never adopted as standard. SP begain to use silver smokebox fronts on non GS class power in 1946.
Dave
There’s another discussion going on about the same subject, some nice pics and examples…
I agree with Dave: See and be seen. Many western railroads painted the un-lagged portions of their boilers (smokeboxes and fireboxes) a lighter color to reflect heat, but also as a safety measure at grade crossings (which let’s face it, were far more numerous during the steam era than they are, now).
Rio Grande even painted silver striping or ‘sunbursts’ on the forward sand-boxes of their3700 series 4-6-6-4 and 3600 series 2-8-8-2 articulateds as a safety measure for their numerous unprotected grade crossings in Colorado and Utah. And during and after WWII, many of their other locomotives recieved a bright silver paint on both smokeboxes and fireboxes, especially their fast 1700 and 1800 series of 4-8-4’s.
Tom [:)]
The Missabe had some black and white striping on the pilot of their 2-8-8-4s…during the 1950’s. To me that’s the problem. Steam engines go back 200 years. If railroads in 1850 or 1910 were doing things like that, it might make sense to say they were painting / coloring smokeboxes light gray for safety reasons. But they weren’t. They were painting handrails black, engines black, etc. Using contrasting colors for safety didn’t come in until much later - certainly after WW2.
It might be a nice coincidence that a RR putting a mix of graphite and oil on the smokebox of their steam engines because the smokebox got too hot for the paint then available also made the front of the engine a little easier to see. But I’m afraid I won’t believe that a railroad in 1920 used gray graphite because it made their engines easier to see unless someone can come up with documentation. I’ve seen several sources (books, magazines) that said that the silver or gray was used to “paint” areas of the engine that got too hot for conventional paint. I’ve yet to see a similar published item of someone saying it was done to make the engines more visible.
If you haven’t yet done so, I’d encourage you to check out the similar questions being asked under a different post, the pics and comments help clarify the situation I believe:
http://cs.trains.com/trccs/forums/t/142157.aspx
BTW, if visibility was the issue, why weren’t the early diesels painted with a white or gray front?? [:)]
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