 , the only mainline operator of this type of carriages are Great Western Railway on the "Night Riviera", whose fleet was refurbished in 2017.With the decline of overnight sleeper services in the United Kingdom shortly after their introduction at the end of the 1980s, many of the carriages later were moved to heritage railways to provide sleeping accommodation for heritage staff and volunteers.Mk3 sleeper vehicles remain in use on the Great Western Railway's "Night Riviera" from London Paddington to Penzance in Cornwall.