Coalporter: When were they introduced?

[fullsteam88]

I am trying to hammer down a time period for my layout and I am stuck on these cars. I am between modeling CSX in 1992 or 1994. The problem is I don't know when the twin tub coalporter style cars came into use. If anyone has more information on them, I would really like to know when they came into heavy use on the CSX lines.

Thanks,
Ryan

[basementcalling]

The Confederate Grey paint scheme was run in early spring/summer 1995, as I was trackside the day they went into Newport News in numerical sequence order behind a couple Dash 8 locos, but without a camera of course.  The black scheme was an earlier paint job, so you are in the ball park.

[Chris1274]

Early 90's. If you watch the two Pentrex videos on CSX coal hauling operations, "Eastern Kentucky Coal" and "CSX Southern West Virginia Coal," you don't see any coal porters in the first video, which was produced in 1991, but the black and yellow ones are seen throughout the second video, which was produced in 1994.

[Robbman]

BethGon® Coalporters were made as early as 1978, when Bethlehem Steel Car introduced the design, these were all steel cars.

In December of 1984, BSC released the prototype aluminum BethGon® Coalporter with Georgia Power and Mississippi Power being first two test customers... utilizing the new design for two unit trains to their plants.

In 1986, the aluminum car was officially launched.

In 1994, a new variant was added, the BethGon® AeroFlo™. 

By 1995... BSC and successor Johnstown America (now FreightCar America) had built 20,000 aluminum cars, and by 1998 had built or provided kits for over 50,000 cars. 

In 2001, the design was revised and is now called the BethGon® II (along with the AeroFlo™ variant). 

In 2007, in conjunction with NS, FCA released another variant, the BethGon® II Hybrid car.