An international First Officer reported being fatigued because he woke early for an afternoon departure which was delayed over 3 hours. Then he could not sleep during his inflight break and on arrival felt he was unsafe to fly.

Narrative

Due to a maintenance delay our flight departed 3 hours and 6 minutes late and into the night. I was acting as the First Officer and the non-flying pilot. Crew Scheduling did not call the crew to advise of a delayed departure due to maintenance. I signed in at approximately 4 hours and 40 minutes before departure. I woke in the early [morning] that morning unable to sleep any longer. After the late departure; I finally took my rest break at approximately 5 hours and 30 minutes after takeoff; approximately 21 hours after awakening the previous morning. My break was for about two [hours] and twenty minutes. I was unable to get any rest at all during my break due to a variety of reasons. The main reasons were excessive galley noise; passenger noise; a meal service in progress; window shades opened and bright sunlight entering the cabin; the light from a video monitor directly in front of the crew rest seat; location of the crew rest seat near the galley; the opening and closing of the closet directly in front of the crew rest seat; and the opening and closing of overhead bins. As a result I returned to the cockpit extremely fatigued. I mentioned this to both the Captain and the Relief Pilot. The Captain had slept on his break; but the Relief Pilot was also fatigued. I had now been awake for approximately for 24 hours. We descended and landed without incident. The entire descent; approach; and landing were unsafe in my opinion as two of the three pilots were very fatigued due to a lack of crew rest in flight. I feel my performance was seriously downgraded and that I was operating in almost a fog. I would have switched positions with the Relief Pilot; but it was clear he was in the same or worse condition. Weather was not a factor and we experienced no abnormal or emergency conditions. If we had; I am not sure I could have performed in a manner that would have resulted in a safe outcome due to the serious fatigue I [was] experiencing. Had I been able to sleep for even two hours of my break; the fatigue I experienced would not have occurred.