New mass produced all-metal cab appeared on KrAZ trucks only in 1978. It has taken 15 years to launch its production. Wooden cab inherited from YaAZ did not meet requirements to ergonomics of driver’s working place at the end of 1960s.
The own cab had to be created after failed attempts in 1961/1964 to try Ural and ZiL cabs on KrAZ trucks at order from upstairs. Joint efforts have been taken to build the cab. How? Here is an account of eyewitness of the events, the then Head of Cab Bureau Yevgeniy Shirshonkov.
“Metal cab creation process was very painful. Any production is conservative with hostility towards new ideas. Target was hit to the disadvantage of research. A group of designers, at the moment we had no skilled designers, came from NAMI to design the cab before die making. We designed a structure and a hood, they improved the design a little, made it round and refined. Why was the fender square? It was a period of cubism: look at cars of that period, Japan-made ones, the Lada 2108, all of them are sharp-cornered.
The plant was not prepared for manufacture of new cab: tooling was not developed, the personnel could not design and make large size dies. Die tooling was made by Gorkovskiy Automobile Plant, a set of dies for hood by ZiL, drawing die for hood top panel by Tolyatti, die for hood reinforcement by Zaporozhye by the Decree of the Ministry. To make dies, standard patterns were required which were made of mahogany by highly-skilled cabinet-makers (surface finish accuracy of 0,015 mm). There were no such skilled workers at KrAZ. Methods were adopted at GAZ. All our aluminum molding lofts used to make patterns were delivered there. There, in Central Assemblability Laboratory, the cab was checked for assemblability. Very useful and serious work such as part modeling and their further joining by welding jig: pliers were used to check if there was access for welding. Parallel to manufacturing process, parts design study was made. Some changes had to be made to the design based on assemblability and study results. Modifications to drawing were made via phone because dies for some parts were in the process of designing at that moment at “KrAZ”. After all the works at GAZ were over, die making for fenders, hood, radiator grille, hood sides started at ZiL. 50 sets of parts, rigging for door, fenders, hood, radiator grille and hood sides were pressed. Die for inner panel of door was very complicated. Works on the hood were carried out in Tolyatti. Also the military put their foot in and we had to make changes to some cab parts. They did not allow using panoramic windshield. Their reason was that if the windshield breaks up, it could be replaced with plywood, cheap and easy. “
The new cab made with due regard for UNECE Regulations and CMEA was mounted on the KrAZ-250 truck. The cab was more advanced and featured better driver working environment. Bigger glass area and new spherical mirrors improved visibility. Noise level has been reduced from 91 to 88 dB, thus improving comfort for driver. The cab was heated by two fan blowers from radiator heater. Hot air warmed not only windshield but also door side glasses for visibility and comfort of driver at - 35 0С. Due to overdesign in most parameters the cab of the KrAZ-250 truck, even in 20 years, fully met requirements of new standard ОСТ 37.001.413-86: “Cab. Driver’s working place. Arrangement of controls of trucks, buses and trolleybuses”, and this ensured its long production life.
