The LST carried tanks and other rolling stock, and had the ability to discharge its cargo directly onto the beach.
The destroyer-like APD provided limited gunfire support and fast defense of the squadron.
When the ships of a PHIBRON are loaded up with the forces of a Marine Expeditionary Unit and some additional Navy units (including a Tactical Air Control Squadron (TACRON) detachment and landing craft from a Naval Beach Group two or more of either a Assault Craft Units (ACU), Beachmaster Units (BMU), Special Warfare Group (SWG), Explosive Ordinance Disposal Team (EOD), and Fleet Surgical Team (FST).
The unit is designated as an Amphibious ready group(ARG) for deployment capability.
The officer in charge of a PHIBRON is designated COMPHIBRON (#) or Commander Amphibious Squadron (#) and acts as the commodore for all ships in the ARG.