Groton, Conn. – While floating partially submerged in icy waters along a dock at a General Dynamics’ Electric Boat facility here, the Navy’s first Block III Virginia-Class attack submarine is being readied for sea-trials, certifications and delivery.

As a key step prior to formally handing the boat over to the Navy to begin service, Electric Boat engineers and Navy professionals are testing the electronics, wiring, missile tubes and propulsion system on-board the submarine, among other things, said Kurt Hesch, vice president of Virginia-Class submarines, Electric Boat.

The USS North Dakota, the first Block III Virginia-Class submarine slated for delivery, is expected to be handed over to the Navy for service by April of this year. An April or May delivery is several months in advance of its contracted arrival in August, Navy and Electric Boat officials said.

“The fact we're delivering early to the contract delivery date demonstrates we did the re-design right, something clearly demonstrated in North Dakota’s bow taking two fewer months and 8,000 fewer mandays to build than the previous ship, USS Minnesota,” Capt. Dave Goggins, program manager, Virginia-Class submarines told Military.com in a written statement.

Christened in November, the USS North Dakota will be the first of eight Block III Virginia-Class boats delivered to the Navy, submarines engineered with a series of technological upgrades and innovations compared to earlier Blocks I and II boats, Navy officials said. Blocks I and II, totaling 10 ships, have already been delivered to the Navy.

All eight Block III boats are being built under a $14 billion Navy deal with General Dynamics’ Electric Boat in December of 2008.

Hesch and Navy officials explained that the sea trials involve three phases. They begin with an alpha-phase which assesses the ship’s ability to dive to depth and conduct emergency surfacing operations. The alpha trials also assess the submarines propulsion plant and many of the technologies.

The bravo-phase tests the acoustics and combat systems and looks to correct any problems, followed by the Navy Board of Inspection and Survey trials where an independent board comes to inspect the boat prior to certification. The idea is to identify and address any potential issues with the boat well before it enters service with the Navy.

“The first trial is very rigorous. We are making sure we understand the water tightness and ensuring we understand the propulsion capabilities and understand the emergency systems are working. We take these incremental steps to make sure it is a fully functional and safe ship,” Hesch said in an interview with Military.com

Sea trials can last anywhere for eight to 12 weeks depending upon what issues are discovered, Hesch said.

There is a lot of testing that can only happen once the ship is underwater, such as an assessment of the nuclear-reactor, propulsion plant and dive and stern planes, Hesch explained.

“You start off going to a shallow depth to make sure everything is good, then you kind of work your way through the systems, making sure the propulsion plant is working the way it should,” he said.

The sea trials will assess everything from the sonar systems and missile tubes to on-board electronics, command and control technologies, navigation systems, sensors and submarine computer systems.

“We know what we want to test. We go out there and it is a very carefully orchestrated agenda that we follow without waiver,” said Michael Nowak, USS North Dakota ship manager, Electric Boat.

Nowak said his crew will assemble the requisite repair materials and mechanics in the event that sea trials reveal the need for changes. Some of the dockside testing includes shooting launch vehicles from torpedo tubes in order to verify that the launch lines are completed and ready, Nowak added.

The Block III subs, now under construction, are being built with new so-called Virginia Payload Tubes designed to lower costs and increase missile-firing payload possibilities, Navy officials explained.

Instead of building what most existing Virginia-class submarines have -- 12 individual 21-inch in diameter vertical launch tubes able to fire Tomahawk missiles -- the Block III submarines are being built with two-larger 87-inch diameter tubes able to house six Tomahawk missiles each.

While primarily done to lower costs for the boat, this technical change will allow the possibility of future missiles and off-board sensors to be launched from the tubes, Navy officials said.

All Virginia-Class submarines are also engineered with a computerized fly-by-wire touchscreen control system wherein boat operators use a joystick to navigate, unlike the mechanical hydraulic controls uses on prior models.

The Block III boats also have a Large Aperture Bow array which places a conformal sonar system in the bow of the boat, Hesch said.

While all Block III submarines are currently under construction, planning for 10 Block IV Virginia Class submarines is already underway. A Navy, General Dynamics’ Electric Boat contract for 10 submarines is currently being finalized and is expected to be finished in coming months, Navy officials said.

General Dynamics’ Electric Boat says they are planning a series of additional innovations for Block IV, such as a new radar and oxygen system. The Block IV deal will span years 2014 to 2018.

Hesch explained that one of the goals with Block IV is to increase the number of deployments for the submarines over their 33-year service life from 14 to 15. This can primarily be accomplished by engineering the boat with longer-lasting parts and increasing the efficiency of the ship’s maintenance availability, Electric Boat officials said.

Also, for Block V construction, the Navy is planning to insert a new 70-foot-long section designed to house additional missile capability. In fact, the Navy's Capabilities Development Document, or CDD, for what's called the Virginia Payload Modules is finished up and approved by the Pentagon’s Joint Requirements Oversight Council, Goggins said.

The Block V Virginia Payload Modules will add a new module or section of the submarine, increasing its Tomahawk missile firing capability from 12 to 40, Navy officials said. The idea is to have additional Tomahawk or other missile capability increased by 2026, when the SSGN Ohio-Class Guided Missile Submarines start retiring, he explained.

Hesch said that General Dynamics’ Electric Boat officials plan to work closely with the Navy to refine and solidify requirements in anticipation of doing early prototyping in 2015 and 2016.

The new module will add 28 missiles to the pressure hull section of the boat, using four large tubes each filled with 7 missiles. This will cause a slight, two-foot-long protrusion on the hull of the submarine to allow for a hatch to open, Hesch said.

In fact, the most recent Congressionally-passed budget deal approves $59 million for the Virginia Payload Modules, money which will move the developmental effort along.

The last six Virginia-class submarines have been delivered ahead of schedule, Navy officials said. The six submarines were Block I and Block II Virginia-class submarines.