The spinning process for the production of prestressed concrete poles for energy distribution and street lighting : flow chart and video
literature : https://mega.nz/#!YUFXlSLL!H80ZHGNyjqEFckrOrvVqRAx1u-0asn-cQZAfORExBQA
video : https://mega.nz/#!9FVi1ATK!E7a2UUij4gOONX6EMeBdxUUdZZWLyeK5eoum4TCkEro