What is Barracks ship?

A barracks ship or barracks barge or berthing barge, or in civilian use accommodation vessel or accommodation ship, is a ship or a non-self-propelled barge containing a superstructure of a type suitable for use as a temporary barracks for sailors or other military personnel. A barracks ship, a military form of a dormitory ship, may also be used as a receiving unit for sailors who need temporary residence prior to being assigned to their ship. The United States Navy used to call them Yard Repair Berthing and Messing with designations YRBM and YRBM and now classes them as either Auxiliary Personnel Barracks or Auxiliary Personnel Lighter.