Bogie for subway train I. Core Technological Needs: Protection is the Only Criterion Bogie frame castings are certainly not normal Solid iron parts. They bear the whole weight in the car or truck system and travellers and constantly stand up to a variety of impacts and vibrations with the keep https://www.malikmobile.com/story/191998-rail-grinding-this-art-carried-out-amid-sparks-flying-quietly-safeguards-the-hea.html