Post by ptc on Oct 25, 2019 18:00:50 GMT
What is weathering?
Weathering (from the hiekepedia) is the time weighted effect of the environment and mechanico - chemical interaction with a structured entity. ie: human body, train, auto, highway, outside structure. Terms like oxidation, corrosion particulate accumulation all come into play. Railroads are very "weathery" places. Everything is left out in the environment and then exposed to the most intense mechanico - chemical buffeting. I figure 1955-58 were the last couple of years when steam engines existed in quantity. You had to be 5-10 years old to produce lucid memories. There are many baby boomers who remember how nasty and dirty or really cool, trains really are. To the rest of you, sorry. Train weather from internal and external effects.
First internal. How come steam engines were always fired up, even when stopped like diesels? They are made of steel and steel expands and contracts when exposed to hot and cold. A Big Boy or Allegheny boiler would get several inches longer when heated,. A boiler and covering , pipes etc. are made in segments. These joints rub as they get hotter and cooler, the paint comes off, they are exposed to water or worse and BAM, rust, corrosion and it hasn't even moved yet! Smoke box and fire box areas appear silver. This was not for artistic purpose. These were insulated (unlagged in railroad terms) areas that got very hot. Untouchable to human tissue. The only paint or coating available was a graphic based compound and it did not work that well. These are the rustiest areas on an engine.
Coal Ash. A tender held 10-20 tons of coal and would be filled 2 or 3 times from NY to Chicago. That's a lot of grimy, grey black coating out of the stack and settling on top of the boiler and down the roofs of the cars. Gravity and water washed it downward. That's why engines are dirtier on top. By the way, mix water and coal ash and one byproduct is sulfuric acid. Acid, bad corrosive stuff on metal and paint surfaces.
Shale. Water, no matter how many times distilled contains mineral impurities. Worse in some area than others. When water leaks, aka steam from pipes and joints down a hot boiler, it evaporates (distills) leaving a white grey coating in its path or mineral impurities, shale. Railroads used water softening systems to some success. A large tender could hold 15-20,000 gallons and boiled if off quickly.
Track ballast quickly got covered with ash and granite dust etc. A train moving quickly displaces large amounts of air. Ride a subway and feel your ears pop and windows rattle. Bernoulli effect. That is how airplanes fly. Also a dust wave engulfs the lower aspect of a moving train.
Paint lettering. Paint industrially is know as a protective coating. Lettering was actually a paste hand applied by artisans. It faded and the lettering "ran" or chauked down the side of the tender.
Ok, there we have it. The basics of weathering. Rusting, ash coating, shale staining, dust bow wave covering and paint degradation.
How do we get this on our trains and layout structure? ie track and ballast and why? Stay tuned for the next segment, Why weather?
Weathering (from the hiekepedia) is the time weighted effect of the environment and mechanico - chemical interaction with a structured entity. ie: human body, train, auto, highway, outside structure. Terms like oxidation, corrosion particulate accumulation all come into play. Railroads are very "weathery" places. Everything is left out in the environment and then exposed to the most intense mechanico - chemical buffeting. I figure 1955-58 were the last couple of years when steam engines existed in quantity. You had to be 5-10 years old to produce lucid memories. There are many baby boomers who remember how nasty and dirty or really cool, trains really are. To the rest of you, sorry. Train weather from internal and external effects.
First internal. How come steam engines were always fired up, even when stopped like diesels? They are made of steel and steel expands and contracts when exposed to hot and cold. A Big Boy or Allegheny boiler would get several inches longer when heated,. A boiler and covering , pipes etc. are made in segments. These joints rub as they get hotter and cooler, the paint comes off, they are exposed to water or worse and BAM, rust, corrosion and it hasn't even moved yet! Smoke box and fire box areas appear silver. This was not for artistic purpose. These were insulated (unlagged in railroad terms) areas that got very hot. Untouchable to human tissue. The only paint or coating available was a graphic based compound and it did not work that well. These are the rustiest areas on an engine.
Coal Ash. A tender held 10-20 tons of coal and would be filled 2 or 3 times from NY to Chicago. That's a lot of grimy, grey black coating out of the stack and settling on top of the boiler and down the roofs of the cars. Gravity and water washed it downward. That's why engines are dirtier on top. By the way, mix water and coal ash and one byproduct is sulfuric acid. Acid, bad corrosive stuff on metal and paint surfaces.
Shale. Water, no matter how many times distilled contains mineral impurities. Worse in some area than others. When water leaks, aka steam from pipes and joints down a hot boiler, it evaporates (distills) leaving a white grey coating in its path or mineral impurities, shale. Railroads used water softening systems to some success. A large tender could hold 15-20,000 gallons and boiled if off quickly.
Track ballast quickly got covered with ash and granite dust etc. A train moving quickly displaces large amounts of air. Ride a subway and feel your ears pop and windows rattle. Bernoulli effect. That is how airplanes fly. Also a dust wave engulfs the lower aspect of a moving train.
Paint lettering. Paint industrially is know as a protective coating. Lettering was actually a paste hand applied by artisans. It faded and the lettering "ran" or chauked down the side of the tender.
Ok, there we have it. The basics of weathering. Rusting, ash coating, shale staining, dust bow wave covering and paint degradation.
How do we get this on our trains and layout structure? ie track and ballast and why? Stay tuned for the next segment, Why weather?
