On Tuesday, right here on Everybody's Business, Port of Tacoma Communications Director Tara Mattina shared that the Port recently underwent an exercise to test the feasibility of a 13,000-TEU vessel calling at the Port of Tacoma.

At today's noon Port Commission meeting, Lou Paulsen, director of strategic operations and risk management at the Port, appeared to elaborate on that simulation.

He started with a happy declaration.

“The Port of Tacoma is ready to receive ultra large container ships,” Paulsen told the Port Commission, detailing the results of the study done by the port in conjunction with Puget Sound Pilots and involving representatives from various carriers.

“Earlier this year, we were approached by a number of our customers requesting information on the practicality of moving 13,000-TEU vessels in and out of Blair Waterway specifically. In response, we undertook during the beginning of August an operational assessment to simulate the transit of vessels of this size in and out of Blair Waterway. The conclusion of that assessment is that 13,000-TEU vessels can safely and reliably transit to and from Washington United Terminal specifically.”

The study specifically used as a model the 13,000-TEU M.V. Hamburg Express —actually closer to 13,200, Paulsen explained — which the study then tested under three different draft conditions representing different extents at which the vessel was loaded. To illustrate the size of the vessel in question, Paulsen went with a visual description.

“If you took the containers from this vessel and stretched them from this room, they would stretch from here to Lynnwood, Wash.,” Paulsen said. “A distance of 49 miles. … It is 20 containers high — 11 below deck, nine above — 19 containers wide and 20 feet long.”

The study's methodology was twofold, Paulsen explained. First, the study involved a simulation facility — the Pacific Maritime Institute in Seattle — where Blair Waterway was effectively recreated through computers and technology, as was the control room of the calling vessel. Assessment pilots from Puget Sound Pilots each piloted the simulated vessel via the recreated control room at PMI, then shared their experience and findings after the simulation.

The second part of the methodology involved pre-scripted transit scenarios, continued Paulsen, so that during each transit run, the study tested precisely the situation the team intended to evaluate. Wind speeds up to 25 knots were tested, and a variety of tug packages were evaluated, allowing the pilots to try alternative arrangements to secure safe passage.

Various system failures were also injected into the simulation, including vessel, tug, bow thruster and tow-line failures to simulate worst-case scenarios.

The assessment came to various conclusions regarding safe conditions for a vessel as large as the Hamburg Express calling at Washington United Terminal.

“Transits are safe and reliable in winds up to 20 knots, with a recommended tug package of two 90-ton tugs, one 50-ton tug, and the requirement of an operational bow thruster on the vessel, all of which is then to overcome to wind speeds of up to 20 knots” Paulsen said. “The transit speed of the vessel itself should be kept to two to two and a half knots.”

One of those tugs, Paulsen noted, would actually be used to slow the ship down.

“One of the 90-ton tugs is literally holding it back,” Paulsen said. “The dead slow ahead on this vessel is about 6 knots. They're made for speed and to slide quickly through the water. At two knots, which is a much safer speed to be transiting that waterway, one of those tugs is actually retarding the advance of the vessel.”

Commissioner Don Meyer complimented Paulsen and the assessment team on their work.

“Very very important to all of us in terms of being able to right-size our waterways,” said Meyer. “It's crucial for our future.”