We now move from air to water in our exploration of anthropomorphic vehicles.
TUGS is a British television series created by some of the David Mitton and Robert Cardona, who were heavily involved with Thomas and Friends.
This was succeeded by Theodore Tugboat, a Canadian series by Robert Cardona. While Ringo Starr narrated Thomas in its early years, Denny Doherty (of the Mamas and Papas) narrated Theodore.
A YouTube of TUGS (not available on DVD despite an earnest campaign (a similar problem faced by Shining Time Station) is below. I must say, if you are not British, the Tug Boat characters are hard to understand.
On Thomas itself, Bulstrode the Barge is an unfortunate character whose utility is destroyed by Percy and is turned into a playground.