The elevator and safety latch function tests were conducted successfully in accordance with the Elevator Product Manual. No abnormalities. The TDS HPU was operating in Auto mode, which includes a 5-minute timeout period. After 5 minutes of inactivity, the HPU system will automatically stop, and the system pressure drop to zero. The driller failed to notice that the HPU was off (display on screen + alarm activated on the display). The HSJE is equipped with a mechanical lock as a secondary barrier, but can not keep the elevator in a closed position in the event of a system pressure loss and a joint in an inclined position (weight loss). The Catwalk area has metal chain as a barrier (as per SP-2097 DROPS standard), the off-driller side chain was temporarily removed to allow the forklift to access the catwalk to remove the landing joint. The CCTV records shows that the crew complied with the red zone and the no-go zone requirement.