They were built in 1895. Even though it was called a gondola it is said to be one of the first "hopper" cars.
"Hopper-bottom" gondolas go back at least to 1881. N&W built one experimental car at that time. Between 1882 & 1883 N&W ordered and received 500 "hopper-bottom" cars from Bowers, Dure, & Co. for an avg cost of $530.50
They had a whopping 20 ton capacity.
Info above from Andrew Dow's N&W Coal Car book.
There is a photo from 1886 or 1887 in the book, but I was unable to find any pics online after 5 min of searching.