1. FREE FALL SOLUTION FOR CRAWLER CRANE

2. Comer Industries is currently supplying swing drives, travel drives and all types of hoist drives (boom, main, whip, jib luffing) with Free-Fall options, for cranes up to 2000 ton lifting capacity. GENERAL OVERVIEW FOR LATTICE CRAWLER CRANES

3. PGR3503 + RB Luffing Hoist PGA5003 + RB Travel Drive PGRF6503 Hoist Drive PG5003PR Swing Drive SOLUTIONS FOR LATTICE CRAWLER CRANES

4. FREE-FALL Description Why Free Fall option:  Time saving on descending operations (save up to 40 min descending time)  Increase the machine productivity  Comer could present two solution according to customer needs with different characteristics Comer solution A (brake on slow stage)Comer solution B (brake on fast stage)

5. FREE FALL Solution A (brake on slow stage) Working configurationFree Fall configuration Working brakeOpenClosed Free Fall BrakeClosedOpen Input Sun GearRotatingBlocked Working flow Free Fall flow FF Breaking flow

6. FREE FALL Solution A, technical drawing

7. FREE FALL Solution B (brake on fast stage) Working flow Free Fall flow FF Breaking flow Working configurationFree Fall configuration Working brakeOpenClosed Free Fall BrakeClosedOpen Input Sun GearRotatingBlocked Floating planetary carrier allows minimum braking torque

8. FREE FALL Solution B, technical drawing

9. FREE FALL Solution A vs. Solution B Comer solution A (brake on slow stage)Comer solution B (brake on fast stage) Comer current production Large Free-Fall brake is required to be effective on slow stage Free-Fall brake could work as safety brake in case of sun gear failure Comer project, still to be developed Smaller brake could lead to cost saving but investment are required to develop the project Additional safety Brake is required in case of sun gear failure