Bogie for subway practice I. Main Technological Demands: Protection is the Only Criterion Bogie frame castings are usually not regular Solid iron pieces. They bear the complete fat of your vehicle entire body and passengers and continually face up to many impacts and vibrations from the track. Their technical needs https://socialcreditu.com/post/9248_with-the-development-of-big-data-the-internet-of-things-and-artificial-intellige.html