TILX 16265 is an example of a typical tank car in limestone (calcium carbonate) clay slurry service. This particular car is one of a 100 car series built in 2000 by Trinity Industries and leased to Omya, a major producer of industrial minerals.

Calcium carbonate, like kaolinite (also shipped as a clay slurry, but a silicate mineral with a very different chemical composition), is often used in the paper industry as a pigment and binder for high-quality glossy papers. I’ve shared photos of a couple of different tanks in kaolin service for St. Marys Paper in previous “Freight Car Friday” posts. (I’ve been checking what photos I have of the mill, or show cars in the mill interchange tracks and the tanks around the paper mill definitely bore logos of kaolin companies – Dry Branch Kaolin in the 1990s, and Thiele Kaolin in the 2000s. I’m not sure if St. Marys used calcium carbonate.)

However, the car seen above is one of a pair of cars photographed in Sault Ste. Marie in July 2015 – eight years after the mill in the Sault was permanently shut down – and headed north over the former ACR line. An educated guess as to it’s destination would be one of the paper mills on the CP line along the north shore of Lake Superior or Thunder Bay region, via Franz.

UTLX 300400 below is a similar sort of car built by 1995 by Union Tank Car, and photographed in Sault Ste. Marie in June 2000.