visa for lithuanian citizen joining ship for repairs at shipyard and at sea

Good day,
our ship is planned for repairs at shipyard in China. A few service engineers including superintendents (all hold lithuanian passport) have to travel on board to stay during shipyard (ca. 3 weeks). Ship flies Antigua&Barbuda flag (registered in St John's). Managed Company is registered in Germany.
Kindly advise what type we should apply and how long the processing time and whether could be obtained in internet or personal attendance to consulate/embaussy is required.
thanks