A locking mechanism comprising: an S-shaped locking member (4; 104; 204) comprising respective locking hooks (6a, 6b) arranged at the end of opposed arms (8a, 8b; 108a, 108b; 208a, 208b) of the locking member (4; 104; 204); a pivot arranged between the arms (8a, 8b; 108a, 108b; 208a, 208b) of the locking member (4; 104; 204) and around whose axis the locking member (4; 104; 204) rotates; a coupling for coupling the locking member (4; 104; 204) to an actuator for rotating the locking member (4; 104; 204) around the pivot axis, and the coupling comprising: at least one coupling element (30, 32; 230); an actuator coupling (58; 258) for coupling the at least one coupling element (30; 32; 230) to the actuator; and first and second drive couplings (70, 72; 270; 272) for coupling the at least one coupling element (30, 32; 230) independently to each arm (8a, 8b; 108a, 108b; 208a, 208b) of the locking member (4; 104; 204) for transmitting rotational movement thereto, such that failure of one arm (8a; 108a; 208a) of the locking member (4; 104; 204) will not cause loss of drive to the other arm (8b; 108b; 208b) of the locking member (4; 104; 204); wherein: the first and second drive couplings (70, 72; 270, 272) each comprise a dog element (74, 76; 274, 276) engaging with the at least one coupling element (30, 32; 230) and the locking member (4; 104; 204); the dog element (74, 76; 274, 276) is a drive pin or bolt extending from the respective locking member arm (8a, 8b; 108a, 108b; 208a, 208b); and characterised in that the drive pin or bolt (74, 76; 274, 276) extends through the at least one coupling element (30, 32; 230) and the respective locking member arm (8a, 8b; 108a, 108b; 208a, 208b); and in that the dog element (74, 76; 274, 276) is received in an open ended slot (78; 278) formed in an end (80, 82) of the coupling element (30, 32; 230). an S-shaped locking member (4; 104; 204) comprising respective locking hooks (6a, 6b) arranged at the end of opposed arms (8a, 8b; 108a, 108b; 208a, 208b) of the locking member (4; 104; 204); a pivot arranged between the arms (8a, 8b; 108a, 108b; 208a, 208b) of the locking member (4; 104; 204) and around whose axis the locking member (4; 104; 204) rotates; a coupling for coupling the locking member (4; 104; 204) to an actuator for rotating the locking member (4; 104; 204) around the pivot axis, and the coupling comprising: at least one coupling element (30, 32; 230); an actuator coupling (58; 258) for coupling the at least one coupling element (30; 32; 230) to the actuator; and first and second drive couplings (70, 72; 270; 272) for coupling the at least one coupling element (30, 32; 230) independently to each arm (8a, 8b; 108a, 108b; 208a, 208b) of the locking member (4; 104; 204) for transmitting rotational movement thereto, such that failure of one arm (8a; 108a; 208a) of the locking member (4; 104; 204) will not cause loss of drive to the other arm (8b; 108b; 208b) of the locking member (4; 104; 204); at least one coupling element (30, 32; 230); an actuator coupling (58; 258) for coupling the at least one coupling element (30; 32; 230) to the actuator; and first and second drive couplings (70, 72; 270; 272) for coupling the at least one coupling element (30, 32; 230) independently to each arm (8a, 8b; 108a, 108b; 208a, 208b) of the locking member (4; 104; 204) for transmitting rotational movement thereto, such that failure of one arm (8a; 108a; 208a) of the locking member (4; 104; 204) will not cause loss of drive to the other arm (8b; 108b; 208b) of the locking member (4; 104; 204); wherein: the first and second drive couplings (70, 72; 270, 272) each comprise a dog element (74, 76; 274, 276) engaging with the at least one coupling element (30, 32; 230) and the locking member (4; 104; 204); the dog element (74, 76; 274, 276) is a drive pin or bolt extending from the respective locking member arm (8a, 8b; 108a, 108b; 208a, 208b); and characterised in that the drive pin or bolt (74, 76; 274, 276) extends through the at least one coupling element (30, 32; 230) and the respective locking member arm (8a, 8b; 108a, 108b; 208a, 208b); and in that the dog element (74, 76; 274, 276) is received in an open ended slot (78; 278) formed in an end (80, 82) of the coupling element (30, 32; 230). the first and second drive couplings (70, 72; 270, 272) each comprise a dog element (74, 76; 274, 276) engaging with the at least one coupling element (30, 32; 230) and the locking member (4; 104; 204); the dog element (74, 76; 274, 276) is a drive pin or bolt extending from the respective locking member arm (8a, 8b; 108a, 108b; 208a, 208b); and characterised in that the drive pin or bolt (74, 76; 274, 276) extends through the at least one coupling element (30, 32; 230) and the respective locking member arm (8a, 8b; 108a, 108b; 208a, 208b); and in that the dog element (74, 76; 274, 276) is received in an open ended slot (78; 278) formed in an end (80, 82) of the coupling element (30, 32; 230).