Shelbert (The Little Engine That Could "2011 Film")

Mary is a "industrial work" diesel, Mary is seen doing more of the mechanical work on the railway, bringing new parts to other engines with workmen onboard to fit these parts on. So most engines call Mary "The Mender's Engine" for this. She's kind and feels sympathy for other engines who just have a bad day. She's known to be a quiet sort, but she does like a good chat with Humphrey every now and then.