I saw a post where someone said they saw the "160" roll thru. I have seen other posts where they are talking about other numbered engines. Are these certain types of engines where there are more than one which run on different lines, or is it the name of one engine where theres no others called "160"? Does every engine have its own numbered name? For instance if I say, "these cars are being pulled by "42", is that the only engine with that number, or is there another engine with that number on another line. I hope I asked these questions so they are understood. Thanks. Just trying to see if every engine has its own unique number.