Solving A Shore Power Problem: 6,100 Feet of Cable Delivers Clean Energy to Pier 66 in Seattle

With the president of a leading cruise line committing to going green, offering shore power became essential for places like Pier 66. The purpose? For cruise ships to switch off their engines while docking and use electricity instead, conserving fuel and reducing emissions. This change would lead to cleaner air for Seattle and other ports adopting the same practice.

Procuring a Power Source for Pier 66

Pier 66 lacked a power source at that time, so the Port of Seattle began procuring one. The solution involved laying submarine cable on the seabed alongside Seattle's shore, linking Pier 66 to renewable energy from Seattle City Light. Here's how we did it.

Pier 66 Shore Power Cable Project Video — Seattle, Washington

Feasibility Studies and Permits

After 5 years of feasibility studies and permit planning, including consultations with the Department of Environmental Conservation and local fisheries, Pier 66 received the go-ahead. The Port of Seattle's studies determined that submarine cabling would be more cost-effective than terrestrial cabling, avoiding the need to construct a trench system through Seattle’s congested downtown area.

Laying Cable Outside Downtown Seattle

Nelosca Technologies (Nelosca) was contracted to place 6,100 feet of submarine across the seafloor outside downtown Seattle. Prime contractor Orion Marine Group handled the land-side elements while Nelosca installed, monitored, and secured the submarine cable from Terminal 46 to its endpoint at Pier 66.

Nelosca’s Advanced Equipment and Techniques

Such a project required specific safety measures and sophisticated tools to ensure success. During an interview, Nelosca’s subsea cable expert Cliff Center explained, “In the past, cables were pulled ashore by hand or with mules, using steam tugs and paddle wheelers.

"But today, with environmental regulations and quality expectations, state-of-the-art equipment is essential. This includes elaborate navigation suites, remote control vehicles, linear cable engines, cable counter systems, and shoot tension systems.”

Monitoring and Securing the Installation

Nelosca monitored the installation underwater with a remotely operated vehicle (ROV). The ROV’s ultra-short baseline (USBL) acoustic positioning system provided accurate real-time tracking, ensuring the cable was correctly placed and free from obstacles.

For the final step, we placed concrete mattresses and stone atop the nearshore ends of the submarine cable to secure them.

After years of preparation, the project was completed in 2024, allowing large vessels like cruise ships to adopt more environmentally friendly practices when docking at Seattle’s Pier 66.

Pier 66 Shore Power Cable Project — Seattle, Washington