Multipurpose Land-Water Transfer Facility

The design solution for a land-water transfer facility with a diversity of functional requirements has provided a terminal that operates in accordance with design expectations. The terminal is owned by the Port of Seattle and is located at Pier 48, Seattle, WA. The principal user is the Alaska State Ferry System. The facility operates throughout a 20 ft. tidal range and receives vessels without ramps for stern loading, vessel with ramps for bow and stern loading, and barges. The plate girder transfer span has a hydraulic operated apron at the sea end. The span is balanced by counterweights in steel towers and is powered with electric motors. Hydraulic cylinder controls provide for either float or support as the particular vessel may demand. Span framing is connected to allow a transverse list in the sea end to match vessel or barge list. A special joint at the shore end provides a vertical transition between the fixed dock and the transfer span at extreme tides.