To provide a movable connection bridge capable of preventing breakage of both extension ladder and ship by automatically releasing the extension ladder from the ship in emergency that the movement of the extension ladder becomes abnormal.

On a lower side of a fixed ladder of the extension ladder, a motor 5, a rotary shaft 11 for supporting a fixed wheel 10 which receives transmission of output from the motor 5, and an engagement clutch 13 are equipped. The engagement clutch 13 comprises an action part 14 which is made rotatable integrally with the rotary shaft 11 and installed movably in the axial direction, and a follower part 15 freely rotatably pivoted to the rotary shaft 11 and engaged with the action part 14. The action part 14 and the follower part 15 are engaged with each other when the extension ladder is forcibly extended or contracted and when it is locked. In the other cases, the follower part 15 is made freely rotatable according to the movement of a movable ladder. The extension ladder is locked when the action part 14 is operated on the basis of detection of abnormal movement of the extension ladder and is engaged with the follower part 15.