All these inspection saloons were built at Wolverton. They provided private, exclusive transport for the district inspectors and their senior staff, when visiting locations around the system, and to travel the lines. They were operated as a single vehicle, usually hauled by a small tender engine, an LMS 2P being typical. They were frequently propelled, thus allowing the staff more readily to observe the line from the leading saloon. Five of the coaches were built with inset door and grab handles, possibly for greater route availability, being slightly narrower.