World Maritime News Staff, August 26, 2014 zoom The largest floating drydock in the USA, the Vigorous, arrived aboard the world’s largest heavy-lift ship Blue Marlin in Portland on Monday for final assembly at Vigor Industrial’s shipyard.Fully assembled, the drydock will be 960-feet long. However, it is currently in three parts, which are stacked aboard the 738-foot heavy lift ship for delivery. Vigor is investing more than USD 50 million to build and deliver the Vigorous. The drydock will allow Vigor to service vessels such as cruise ships, tankers and cargo ships. It also will free the company to send another drydock from Portland to Seattle, expanding capacity there.Your browser does not support the video tag.Two large vessels, Maritime Administration cargo ships, are already booked for repairs when the drydock enters service in November.“The Vigorous is a symbol of the resurgence of the maritime industry in Portland and the wider Pacific Northwest,” said Vigor Industrial CEO Frank Foti.“Back in 2000, the shipyard was struggling. Today, we’re growing across the region, and I’m proud and profoundly grateful that we’re in a place to make this kind of investment.”A floating drydock is a U-shaped marine vessel used to repair and build ships.Operators let water into the drydock through valves to submerge it, which allows other vessels to drive in and out of the drydock.When the water is pumped out the drydock rises, lifting docked vessels out of the water. This allows workers to service and repair parts of the vessel usually under the waterline.