The sheriff of each county may appoint deputies and clerks to positions established in accordance with section 1623¹ for the transaction of the business of the sheriff's office, and may revoke the appointment of deputies in the same manner as the chief deputy. In counties of the third through eighth classes, the sheriff may also appoint necessary special deputies, when any emergency arises, to assist the sheriff in executing any civil or criminal process or court order or in preserving the peace, who shall serve only so long as they are absolutely needed.