B757-200
Flight Crew Air Transport Pilot (ATP)
Situational Awareness
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Aircraft Aircraft Damaged; Flight Crew Overcame Equipment Problem; General Maintenance Action
Company Policy; Aircraft; Incorrect / Not Installed / Unavailable Part
Maintenance ferry flight to ZZZ with ALL flight attendant's and three mechanics on board. On landing (which was smooth) in ZZZ; upon rollout; my Captain and I heard a loud bang (very loud) upon roll out (with the smell of smoke). We cleared the runway and after the landing check list was completed; I picked up the intercom and asked 'What was that noise'? I was informed that it was a service cart that broke loose from the back and traveled down the aisle and hit the cockpit door. I asked if everyone was ok and the answer was yes. After parking and shut down check lists were complete; the Captain and I found the cockpit door was jammed. The mechanics on board used tools to open the door. With my assistance (kicking) we were able to get the door open. Door hinge was broken from bulkhead at bottom. Uneventful from there.  Approach was stable; Auto brakes 2; smooth landing and normal rollout.
Boeing 757 First Officer performing a ferry flight with Flight Attendants and Maintenance personnel on board reported hearing a loud sound and then smelled smoke while on the landing roll out. The noise was caused by a service cart coming loose rolling down the aisle and damaging the flight deck door.