The largest containership ever built in the United States was christened Saturday and soon will be on its way to Hawaii where it will regularly deliver merchandise from the mainland.

Honolulu-based ocean cargo transportation firm Matson Inc. blessed the new ship named after the state’s late U.S. Sen. Daniel K. Ino­uye during a ceremony at a Philadelphia shipyard.

Inouye’s widow, Irene Hirano Inouye, performed the honor of breaking a bottle of Champagne against the ship’s hull.

The 850-foot-long vessel, one of four new ships under construction for Matson, is expected to begin service in September after sea trials and a few finishing touches ahead of a passage through the Panama Canal.

“This is a proud day for all of us at Matson,” Matt Cox, company chairman and CEO, said in a statement. “Over our first 136 years, Matson’s fleet has evolved from sailing ships to larger steamers to diesel power, consistent with changes in technology and always evolving in step with the needs of a growing Hawaii economy.”

About 350 people attended the ceremony at Philly Shipyard Inc., including Cox, shipyard workers, U.S. Maritime Administration boss Mark Buzby and Peter Navarro, a trade adviser to President Donald Trump.

Matson’s new ship will become the company’s biggest and fastest. It will have the capacity to carry the equivalent of 3,600 20-foot containers and is designed to run at a maximum speed of nearly 24 knots on traditional fuel oil but also can be adapted to run on liquefied natural gas.

By comparison, Matson’s largest ships in service now are the Mahimahi and Manoa. They were built in 1982 and have a capacity equivalent to 2,824 20-foot containers. Matson’s youngest ship, the Maunalei, with a capacity equivalent to 1,992 20-foot containers, was built in 2006.

Philly Shipyard, a subsidiary of Norwegian-based Philly Shipyard ASA, is contracted to deliver two ships for Matson at a rough cost of $418 million. The second ship, named Kaimana Hila, is under construction and scheduled to be completed by March.

The shipbuilding company last year attempted to help start an ocean cargo transportation service to compete with Matson and rival Pasha Hawaii Transport Lines delivering goods from the mainland to Hawaii. But the effort to build up to four ships for New Jersey-based maritime cargo company TOTE Inc. for a new mainland-Hawaii serv­ice unraveled in January.

Matson also is having two other ships built at a San Diego shipyard operated by a subsidiary of General Dynamics. These two ships, named the Lurline and Matsonia, will be 870 feet long and capable of carrying the equivalent of 3,500 containers and 800 vehicles. These two ships are slated for delivery in late 2019 and mid-2020.