Project Overview
Icy Strait Point (ISP) sees thousands of visitors annually as a popular cruise port of call. Transportation throughout the area, particularly to the top of Hoonah Mountain, is difficult due to the area’s dirt roads and mountainous terrain. As traffic increased after the second cruise ship dock opened, additional infrastructure was needed.
PND was part of a design-build team to resolve these issues, including assisting in design development for two gondola systems and support infrastructure. PND performed structural and geotechnical engineering for key improvements, including foundations for the ADA-accessible TRANSPORTER Gondola ― moving up to 2,800 passengers hourly over a half-mile between two cruise berths ― and the SKYGLIDER Mountaintop Gondola ― transporting visitors 1,600 feet up Hoonah Mountain in 6 minutes to ISP’s most popular attractions. PND also provided foundation and structural design of Wilderness Landing’s new streamlined 1,400-square-foot tour sales building and 3,200-square-foot gift shop. PND designed both buildings to resist heavy snowloads and lateral loads from high-wind and seismic events. Our team also designed two gondola storage buildings and a raised timber-framed plaza and foundation for a 26-foot bronze orca statue.
The new facilities have significantly streamlined visitor access and greatly reduced travel time between cruise ships and attractions, providing visitors more time to explore tours and local businesses. The local community of Hoonah makes up the majority of ISP’s staff and directly benefits from the project’s success.
Our Role
- Geotechnical Engineering: used rope access to navigate the steep slopes during investigations, including a helicopter-portable drill rig in winter weather conditions
- Structural Engineering: used variable foundations such as conventional spread footings, spread footings, and reinforced concrete foundations with micropiles to adapt to complex mountain topography, including steep terrain, weak overburden, complex rock features, large trees, and potential mass wasting hazards; PND designed the Wilderness Landing buildings with reinforced shallow concrete foundations and a light-frame timber construction with wood shear walls to ensure durability
- Construction Support Services: provided geotechnical and structural services for the gondola foundations during construction, as the means and methods were heavily governed by the capacity of contractors already on site; PND worked closely with the general contractor and subcontractors to develop adaptable solutions for each tower site with consideration for equipment and crew access limitations
Conquering Tough Terrain Through Variable Techniques
PND designed the tour sales building, gift shop, and gondola storage buildings to resist heavy snow and lateral loads from wind and seismic events. The gondola tower foundations included a variety of foundation and footing types, accommodating the difficult terrain while reducing costs. The gondola cars are hung on rails attached to repetitive, fabricated, welded steel roof trusses spanning the building’s width.
Hoonah Mountain’s complex topography and hazards required the team to rappel to tower locations and fly in construction materials with a helicopter and sling. PND’s geotechnical team used helicopter-portable drill rigs, oriented rock coring, and televiewer logging to assess subsurface conditions. The geotechnical team relayed information from their investigations to the designers as soon as it became available so they could quickly develop preliminary designs. PND also delivered completed design components in pieces, enabling construction to begin before the entire design was complete and proceed continuously through the limited summer work window.
Passengers
can travel in the gondolas every hour
Feet
elevation from the bottom of the SKYGLIDER system to the top of Hoonah Mountain
