21 NBHC built as 21 NBH. It was converted by the addition of a Guard's Van compartment and modified for Wheelchairs access by Puffing Billy Railway and re classed & numbered 21NBHC Puffing Billy Service History or Notes Between 1997 and 1998 the Puffing Billy railway built six more NBHs, numbered 18-23. These had steel frames, padded seats, and a wide "window sill". At first glance they look the same as the previous NBHs. There are other minor construction differences due to the use of steel framing. 21NBH entered traffic in 1998. The photo on the right shows the exterior of one such NBH. These have a seating capacity of 24 passengers. April 2016 - In for a lift, roller bearings replaced with standard bearings Historic - Puffing Billy Railway Narrow Gauge - Passenger Rolling Stock: Excursion Car 21 NBH which has been converted by the addition of a Guard's Van compartment and modified for Wheelchairs access by Puffing Billy Railway and re classed & numbered 21NBHC21 NBHC Passenger Carriage - Excursion Car - specially modified for Wheelchair access allowing it to carry wheelchairs and to have a Guard's Van compartment. made of wrought iron and timber21NBHCpuffing billy, pbr, rolling stock, 21 nbhc