Another, more detailed list of AAR designations
Here's a long and detailed complilation or ARA/AAR freight car type
codes and how they changed over time.
After April, 1938 "TW" meant one or more wooden tanks. Before that
date, it doesn't say how many tanks there may be, but it/they are
definitely wooden and intended for pickles.
CNJ on one side, LV and RDG on the other.