Under the direction and supervision of the City Manager there shall be made annually, as soon after the first of January as possible, a full and complete inventory of all City supplies, materials and equipment. Every such annual inventory shall be kept up to date until superseded by the next annual inventory so as to show at all times the amount and number of supplies, materials and equipment on hand. The equipment inventory shall be kept separate from that of supplies and materials, and such equipment inventory shall include a department transfer record of all equipment.