Hydaburg Seaplane Base Refurbishment

Project # SFAPT00328

Purpose & Need

The purpose of this project is to re-establish strength, longevity, and safety at the Facility for its continued use. Deterioration of the facility is mainly due to several factors including: larger than predicted wave heights at the facility, float design details now performing under capacity due to the larger wave forces, and a gangway roller bearing detail at the float interface that prematurely seized and caused additional lateral forces on the float structure and support piling. The proposed action will replace the existing float with a new float designed for the wave environment in Hydaburg, as well as refurbish the gangway bearing components with a modern design that will minimize friction and prevent damage to the float.

This seaplane facility is the only seaplane base providing access to the remote City of Hydaburg and so it is essential to the community. Rebuilding will make it a safe and reliable air transportation hub for its residents to utilize for many decades.

Project Description

The facility was originally constructed in 1995 and is showing signs of severe deterioration due to wind and wave forces. The project would reconfigure the seaplane float and rehabilitate the remaining facility with a new single float built to meet the highest safety standards which include features such as a high-strength float design, a secure pipe-pile mooring system, and adequate tie-down points for the planes. The proposed project would involve the following:

• Refurbish the existing concrete approach
• Refurbish the existing steel gangway and bearings
• Remove and dispose of the existing cantilevered piles (4 total) and timber floats (2 total)
• Install a new 60 feet x 80 feet seaplane float
• Install two (2) new 24-inch diameter vertical piles and cap-beam for the gangway shoreward bearings
• Install one (1) new float restraint structure with four (4) new 24-inch diameter vertical piles and two (2) new 24-inch diameter batter piles
• Install rock sockets at all vertical piles
• Install tension anchors at two (2) vertical piles, and two (2) batter piles at the float restraint-structure

The project is anticipated to occur as early as spring 2026. The seaplane facility will need to be closed during construction for approximately three months in 2026. DOT&PF will provide more notice of the closure dates once a contractor is awarded the project and has prepared a project schedule.