A catalog of contemporary PD covered hoppers in North America. This is t a data book. 100+ color photos. US and metric dimensions. The purpose of this book is to introduce railway observers to the cars that today carry much of the flyash, cement, mortar, flour, starch, clay and talc. This is a basic catalog of those pressurised hoppers from the late 263,000 lbs GRL period through the current 286,000 lbs GRL period.