Forklift Drum Lifter Design

I need a robust drum-handling attachment that can slip straight onto the forks of my lift truck through standard fork pockets. The unit must safely lift and tip 585 mm Ø × 885 mm steel drums weighing up to 300 kg. I’ll be working at mezzanine height, so the dumping point has to reach roughly 4 m from the warehouse floor.

Key operating requirements
• Rotation: rotate ith electric motor , two way rotation , with safety stop minimum 180 °, full 360 ° rotation strongly preferred for controlled pouring.
• Grip method: a chain or strap that wraps the body of the drum, tightening securely enough for repeated industrial use without damaging the drum wall.

What I expect from you
1. A complete mechanical design in 3D CAD (STEP or SolidWorks native) that shows fork pockets, rotating mechanism and the chain/strap restraint.
2. Basic strength calculations or FEA to prove it will handle 300 kg plus a sensible safety factor.
3. Fabrication drawings with material specs ready for a local shop to build.
4. A concise user/maintenance note so my operators understand safe attachment, rotation and release.

If you have prior experience with forklift attachments or drum tippers, please include a quick note and any relevant images; it will help me award the project faster.