I have fond memories of the Ballinacourty traffic. Just a shame I was quite young at the time, and photography or video equipment wasn't as everyday as it is now. The dolomite trains ran from Bennetsbridge, and consisted of a pair of 141/181's with approx 19 or 20 hoppers. 121's probably appeared on these trains too, but I personally never saw them. The oil/magnesite trains ran to Cork, as you say, loaded with oil into Ballinacourty and magnesite to Cork. They were the one train, with the loaded wagons running at the front of the rake. These were always hauled by 001's.