in irons

(nautical) The "trapped" condition a sailing ship finds itself in when the bow of the ship is headed into the wind and the ship has stalled and is unable to maneuver.

The state of screw-powered ships which become stalled between crests of waves or swells during a typhoon, for instance, and the ship's rudder does not respond to the commands from the helm, leaving the ship at the mercy of the sea and in danger of capsizing.