Recognition and Equipment information

Another of the orders placed under the pilot scheme of the Modernisation Plan was for a small fleet of 10 type A (Type 1) Bo-Bo locos for which the construction contract was given to the North British Locomotive Co of Glasgow. This company had previously built the LMSR Bo-Bo prototype No.10800, and this fleet showed a remarkable resemblance to this machine. The power plant used was the Paxman 16YHXL which drove GEC traction equipment. Running numbers allocated were D8400-D8409.
Construction of the first loco commenced in late 1956 at the NBL Queen's Park Works, emerging for active testing in July 1958. This was initially around Glasgow, and later, after acceptance at Doncaster, in the London area where the entire fleet was shedded at Devons Road, Bow. The 10 examples of the fleet all emerged in just under a year, but before the last of the class entered service, some of the earlier delivered locos were suffering serious technical problems and failure, leading to several of them spending lengthy periods out of service.
The main problem was the diesel engine, which although the same as that fitted to the D8200 fleet, had a tendency to seize, caused by inadequate ventilation of the power unit due to fundamental design deficiencies. Another problem was water contamination of the oil, caused by cylinder head failure. Another problem area which caused major concern was the electro-magnetic control equipment which was not only non-standard but prone to failure. This also prevented the locos from operating in multiple with the more commonly found electro-pneumatic types.
After a short period of service the entire fleet was concentrated at Stratford depot from where they could be found operating light weight cross-London freights and trip working in the East London area - so, as to be close to Stratford shops for urgent attention if required! With the decline of freight traffic in the late 1960s and their poor operating history these locos were deemed as surplus to requirements in 1968. All were subsequently sold for scrap, with none being saved for preservation.
The livery applied when built was standard locomotive green, which remained with the addition of yellow warning ends until their withdrawal. Under the BR classification system this fleet were deemed as Class 16.

No. D8400, the first loco of the ill-fated fleet is seen from its nose or cooler group end, just after delivery from NBL to Doncaster. Access to engine room equipment was by six hinged side doors, while the generator group was behind the three grille doors just in front of the cab. Electrical equipment was housed in the small bonnet end. CJM Collection.

NBL Type 1 (Class 16) nose end layout. A-marker disks, with white light behind the lower section, B-red tail lights, C-coupling, D-red circle multiple jumper cable, E-red circle multiple jumper socket, F-steam heat pipe, G-vacuum brake pipe, H-engine control air pipes. CJM Collection.