An FYI from Port of Seattle spokesperson Peter McGraw:

The THORCO ROYAL will be berthed at Terminal 5 in West Seattle for about three weeks starting tomorrow (Friday) to undergo vessel repairs prior to returning to sea.

It will be berthed from mid-dock (1500 foot mark) north to about the 2200 foot mark. There will not be any cargo activities associated with its layberthing at T-5.

MarineTraffic.com shows the cargo ship is already in West Seattle, currently at a dock on the Duwamish River.