The Railway Series
The Sodor and Mainland Railway owned a set of four-wheeled coaches, which were used on the line for passenger duties. After the Sodor and Mainland Railway went bankrupt and the North Western Railway was formed, it is unknown what happened to these coaches, but they were most likely scrapped.
Thomas & Friends
There are at least three coaches which are used by Stephen and Glynn to carry passengers around Ulfstead Castle. James and Diesel have also once pulled the coaches. Duck also shunted some of them once. Toby also used them when he helped out on the estate railway.
In the Railway Series, the coaches' livery are painted dark yellow and black, and appear to have "S&M" written on their sides in yellow and red lettering.
In the television series, these coaches are painted dark blue and cream with gold lining, as well as Sir Robert Norramby's crest on their sides. The wheels are black with blue lining.