VDR-6,7 — upgraded bottom unloading trolleys were manufactured at the MICRON Design Bureau.

"Micronovtsy" sent the modernized trolleys — VDR-6,7 to the customer at Yakovlevsky GOK. The design department of the enterprise carried out a deep revision of the VDR-5,3 trolley. 
The main changes affected the design of the bowl — its volume was increased by 26.4%. As a result, the new trolley can carry 6.7 m3 of cargo instead of 5.3 m3, while all overall and working dimensions have been preserved. The trolleys do not differ in weight. This makes it possible to operate the new trolley together with the previous model in one composition without additional modification of the existing equipment. Thus, a train of new wagons can transport more ore at a time without increasing the cost of their maintenance.  

The power frame of the bowl was conceptually revised — the side and end walls with external reinforcement were redesigned in such a way as to maximize the use of the space included in the size of the trolley. At the same time, the resulting structure has a large margin of safety, therefore, a large service life. All this turned out to be realized without increasing the total weight of the trolley. 

Changes have also been made to the bottom frame to improve the manufacturability during manufacture. The top sheet of the bottom is lined with low-alloy hardened wear-resistant MAGSTRONG steel, as in the previous model. In addition, the designers changed the fastening of the wheel pairs to the bottom to facilitate the maintenance of the car during operation. 
The new trolleys are already being used at the customer's enterprise.