The Navy took delivery yesterday of the most recent San Antonio-class (LPD-17) amphibious transport dock ship, a transfer that was postponed by nearly two months after the manufacturer discovered faulty bolts installed on the ship that had to be replaced.

The Navy accepted the future USS Anchorage (LPD-23) from Huntington Ingalls Industries [HII] at its shipyard in Avondale, La. Naval Sea Systems Command (NAVSEA) said. The Anchorage is the seventh in the class and is scheduled to be commissioned next spring in the Alaskan city of the same name.

The LPD-23 had been planned for delivery after acceptance trials in July, but HII discovered that defective bolts in propulsion system components, such as engines, main reduction gears and line shaft bearings, as well as steering and stern gate hardware, NAVSEA said Aug.1 (Defense Daily, Aug. 2, 2012).

There were concerns that bolts would not have been able to withstand shear forces during a shock event, NAVSEA said. The cost of replacing the bolts was carried by Huntington Ingalls Industries and amounted to less than $1 million, HII spokeswoman Beci Brenton said.

NAVSEA said the work was completed in August and of the 361 bolts inspected, 278 were accepted and 83 were replaced. The faulty bolts did not have the correct thread engagement and relief cuts to meet the ship’s underwater shock requirements, a NAVSEA spokesman said.

“The root cause of the deficiency was HII’s Avondale facility not following proper work procedures when fabricating the bolts,” the spokesman said.

HII said the bolt problem was discovered by a company machinist.