harbor fender / pier / wheel
Roller Fenders are commonly used on the berth corners and dock entrances., also widely installed along the walls of dry docks and other restricted channels to help guide vessels and prevent hull damage.
The wheel(s) is mounted on a fixed axle supported by a special frame. And wheel(s) can be rotated freely when the ship hull contact / slid the along with the wheels. Roller Fenders combine reasonable energy absorption with low reaction at all berthing angles.
Roller fenders is low maintenance frame design and easy installation.