I have been wading through NP wheel reports from 1969 and now have over 1,000 cars interchanged to the Q in Minneapolis in 1969. What caught my attention was a high number of empty ACF 2,970 cu ft covered hoppers being interchanged. There were only 100 of these cars in number series 75000-75099 but dozens of these cars were interchanged with the Q. So I went back and checked the westbound NP wheel reports and found that these cars were heading west loaded with fly ash bound for and industry named "DWODAMCON". The interchange point was the Camas Prairie RR in Arrow, ID. Knowing fly ash is used in major concrete projects, a little industrial archeology turned up the Dworshak Dam project in Idaho which started in 1966 with major concrete work beginning in 1968. So I know now what all those covered hoppers were used for.
Here is the Q question: I also ran across a quote from the back of a photo from the Dworshak Dam project that says the fly ash came from Chicago. Which makes perfect sense then why the covered hoppers went to the Q. Anyone have any idea where there would be a major source of fly ash in Chicago for a project like the Dworshak Dam?
Tom Mack
Cincinnati, OH