The U.S. Navy has its newest attack submarine in hand following its delivery by General Dynamics Electric Boat.

The submarine North Dakota, the 11th Virginia-class boat, was delivered late last week -- two days ahead of schedule and more than $30 million below target cost of $2.6 billion, the company said.

The Navy will commission the vessel next month and add it to its fleet.

The ship is the first of eight Block III Virginia-class submarines with a redesigned bow, which replaces a sonar sphere with a large aperture bow array and replaces the 12 individual vertical-launch missile tubes with two Virginia payload tubes.

The payload tubes initially will each carry six missiles. The missile tube replacement nearly doubles the payload space available.

General Dynamics Electric Boat said the new LAB Array eliminates hundreds of hull penetrations and replaces transducers with lower cost hydrophones.

"The full range of Block III improvements were successfully tested during North Dakota's sea trials," said Kurt Hesch, vice president and Virginia program manager. "This is an important accomplishment that reflects the skill and commitment of everyone involved in the Virginia-class submarine program."