Manual Override Diablo III Guide
Last update: 11 May 2016
You may encounter Lieutenant Clyfton while exploring the Stonefort. Unlike two previous events described in this guide you won't have to protect anyone, because you and the lieutenant will be the only ones tasked with raising the third catapult.
Use the winch to raise the catapult
The objective isn't that simple, because aside from interacting with the winch you'll also have to defend yourself from hordes of demons. Keep fighting and interacting with the winch until the catapult is ready. This will cause the event to end.