At the first meeting of the Council in the year 1966 and at the first meeting of Council in each even numbered year thereafter, the Council shall elect from its own membership a President Pro Tem, who shall serve until a successor is elected from the Council as provided hereinabove. The President Pro Tem shall act as the presiding officer of the Council in the absence or disability of the President of Council and shall exercise all the powers and duties granted the President of Council by this Charter during the absence or disability of the President of Council. While presiding over special or regular meetings of the Council the President Pro Tem may vote upon all matters coming before the Council, but in no event shall the President Pro Tem, in his dual capacity as Council member and presiding officer of Council cast more than one vote on any action. In the event that the office of President of Council shall become vacant the President Pro Tem shall become President of Council for the unexpired term, and the Council shall elect a successor from among the membership of the Council to the office of President Pro Tem for that unexpired term.