These vans were the first type built out of a one-piece plywood bodies. They were built on reclaimed PHG underframes and the first two vans were extensively tested before a contract was let for their construction in large numbers. The 2 prototype vans were built with a roller-shutter door on the end platform wall. This feature was later removed from these vans and a sliding door was used instead. The internal layout of the van consisted of a central guards compartment with adjoining toilet cubicle. At one end of the van there is a 2.9m long goods compartment.
In 1977, 12 vans were modified with strengthened underframe and drawgear for use on some Hunter Valley coal trains. The trains operated to locations where there wasn’t a balloon loop, and therefore the locomotives had to runaround. To speed up turnaround times, a van was marshalled at each end of the train. The vans were also fitted with a main reservoir pipe to supply air from the loco’s to the pneumatic discharge doors equipment on the coal hoppers. The last 3 vans of the JHG contract, 34098-100, were built as a UHG. The remaining 9 were converted from in service JHG’s.