Appropriation ordinances, ordinances and resolutions pertaining to local improvements and assessments, ordinances and resolutions providing for or directing any investigation of City affairs, resolutions requesting information from administrative officers or directing administrative action, and emergency measures, shall be in effect from and after their passage by the Council unless some other time be specified therein. All other ordinances and resolutions passed by the Council shall be in effect from and after thirty days from the date of their passage except those in which a later date for taking effect is specified. Ordinances adopted by vote of the electors shall take effect at the time indicated therein or, if no time be specified, then thirty days after their adoption. An emergency measure is an ordinance or resolution to provide for the immediate preservation of the public peace, property, health or safety, in which the emergency claimed is set forth and defined in a preamble thereto. The affirmative vote of at least all of the members elected to Council less two of the Council shall be required to pass any ordinance or resolution as an emergency measure. No measure making or amending a grant, renewal or extension of a franchise or other special privilege shall ever be passed as an emergency measure. No situation shall be declared an emergency by the Council except as defined in this section, and it is the intention of this Charter that such definition shall be strictly construed by the courts.