Compounds" Nos.59 and 62 to Class U1 4-4-0 locomotives. From this time on, with few exceptions, all boilers would be LMS standard ones (G6, G7, G8). Derby works could more economically deal with these boilers than York Road and so they would be sent to Derby for overhaul. The boilers would return some four or five months later with a new firebox fitted, ready for installing in the next suitable engine coming into the works. NCC locomotive classes The BNCR introduced class letters for its locomotive stock in 1897. The MR (NCC) and later the LMS (NCC) continued to use the system adding new classes as required. The following tables list details (where available) of NCC locomotive classes that were extant at the time of the amalgamation of the BNCR with the Midland Railway in 1903 and those classes which entered NCC stock subsequently. Broad gauge steam locomotives * Class T became extinct in 1913; the designation was reassigned to the ex-Ballycastle Railway 4-4-2T narrow gauge locomotives when they were acquired in 1924.† No class letter was assigned to No.91. Narrow gauge steam locomotives Diesel locomotives * No class letters were assigned to Nos.20, 22 and 28. The tabulated data in this section are mainly derived from a review of NCC locomotive diagrams. Coaching stock As with the locomotives, Midland Railway influence on NCC coaching stock design only became apparent after Bowman Malcolm retired in 1922. The NCC was a small railway and did not require the variety of coach types that its parent the LMS did. However, the NCC provided accommodation for three classes of passengers throughout its existence and this led to there being several coach designations that were unique to the NCC. Most LMS (NCC) coaches were similar to LMS Period I stock. This was perpetuated into the mid-1930s with repeat orders to existing designs. These coaches were mounted on steel under frames that were generally long, weighed between 28 and 31 tons depending on type, and ran on two four-wheeled bogies. They had wooden framed, fully panelled bodies with semi elliptical roofs and three-link screw couplings. Side corridor stock such as the J6 thirds and F2 composites had doors with adjacent quarter lights to all compartments and ventilation was by droplights set into the doors. G1 tea cars had a small dining saloon and kitchen set into one end of a composite coach. Although there were