This article appeared in this morning’s Undersea Warfare News.
USN Inspecting Block III Virginia-class Submarines for Defects
Grace Jean, Washington, DC – IHS Jane’s Navy International , Sep 3
•Navy officials are inspecting components on Block III Virginia-class submarines under construction
•A total of 58 components were investigated on board Block III lead boat North Dakota (SSN 784)
Programme officials are inspecting six more Virginia-class nuclear-powered attack submarines (SSNs) under construction following the discovery of materiel problems on board the lead Block III boat, US Navy (USN) acquisition command officials and industry representatives confirmed to IHS Jane’s on 27 August.
Issues found in the materiel of vendor-assembled and delivered components on North Dakota (SSN 784) – the first of eight Block III boats – caused the USN to delay the submarine’s planned May 2014 commissioning so that repairs could be completed and reviewed.
A total of 58 components, including stern planes and rudder rams, retractable bow plane cylinders, hydraulic accumulators, high-pressure air charging manifolds, torpedo tube interlocks and shaft/link assemblies, and weapons shipping and handling mechanisms were investigated on board the boat.
“To date, all necessary inboard and outboard components have been inspected and all required repairs have been completed,” said Naval Sea Systems Command (NAVSEA) spokesperson Colleen O’Rourke. “All other Block III submarines are being inspected and any issues found will be adjudicated.”
Being built under a teaming arrangement by General Dynamics Electric Boat (GDEB) and Huntington Ingalls Industries (HII) Newport News Shipbuilding, the third batch of Virginia-class boats were partially redesigned in an effort to reduce acquisition cost. The redesigned bow includes a new Large Aperture Bow array and two 87-inch Virginia Payload Tubes that each launch six Tomahawk land attack cruise missiles.
The issues discovered on board North Dakota are understood to be partly related to the redesigned bow introduced with the Block III design.
“There were two separate issues with PCU North Dakota ,” O’Rourke said. “The first was a materiel issue dealing specifically with vendor-assembled and delivered components and was not specifically associated with the bow redesign …. The second, unrelated, issue established the need for additional design and certification work on the submarine’s redesigned bow. Upon satisfactory completion of their independent investigation, NAVSEA concluded that North Dakota ‘s Virginia Payload Tube (VPT) system was fabricated in accordance with the approved design and satisfactorily tested in support of sea trials.”
According to a NAVSEA press release, the materiel issue in North Dakota ‘s vendor-assembled and delivered components needed an unplanned dry-docking to correct. The boat was first floated on 15 September 2013, with its handover at the time planned for February 2014 ahead of a May 2014 commissioning.
Products associated with the vendor-assembled and delivered components were delivered to the shipyards based upon installation timing, Kurt Hesch, vice-president and Virginia programme manager at GDEB, told IHS Jane’s on 27 August.
“Items that were already installed in Block III ships were inspected and repaired if necessary. These ships were earlier in the construction cycle and not yet in the water, making the re-work less disruptive,” he said.
“Vendor products not yet installed are being re-evaluated in the shops at the shipbuilder or at the supplier, with shipbuilder oversight. The work is continuing based on schedule priority and replacement part availability.”
Similar issues have been identified on other Block III submarines, but not to the same extent as those on North Dakota , O’Rourke told IHS Jane’s on 26 August. “To date, inspections have been completed on North Dakota and PCU John Warner (SSN 785). Inspections on all other Block III submarines are ongoing and will be completed before delivery,” she said.
Because the investigation is continuing, the navy declined to comment on accountability measures.
IHS Jane’s asked GDEB to comment on the additional design and certification work on North Dakota ‘s bow and how it might affect the remaining Block III boats, but company officials declined to comment further.
In mid-August all eight Block III boats were under construction, with North Dakota more than 99% complete. John Warner , the second Block III boat, is more than 90% complete, according to data provided by HII.
The remaining six boats in the batch are in build, with Illinois (SSN 786) 77.3% complete; Washington (SSN 787) 63.8%; Colorado (SSN 788) 53.7%; Indiana (SSN 789) 39.4%; South Dakota (SSN 790) 27.7%; and Delaware (SSN 791) 15.7% complete. Collectively, the third batch of boats is 60.4% complete.
North Dakota – the USN’s 11th Virginia-class submarine – was handed over to the USN on 29 August, two days before its contractual delivery date of 31 August 2014. Its commissioning is scheduled for 25 October.
The boat completed its second set of initial sea trials in the Atlantic in mid-August, according to GDEB in Groton, Connecticut, where it was assembled. As well, the navy’s Board of Inspection and Survey completed combined trials on 23 August, Hesch told IHS Jane’s . In a press release announcing the boat’s delivery, GDEB stated that North Dakota “received the highest quality score to date from the Navy Board of Inspection and Survey” and was delivered “on time and more than USD30 million below target cost”.
The USN is acquiring a 30-boat Virginia class to replace its Los Angeles-class fast-attack submarines; 10 Virginia-class boats are currently operating.
USN officials and the two shipbuilders signed a block-buy contract on 28 April 2014 for 10 Block IV Virginia-class submarines. Construction on the first boat, SSN 792, began on 1 May. Production of the second boat in the batch is expected to start on 30 September.