Faulty bolts have been found on a new Navy amphibious transport dock ship and replacing the hardware has forced a six-week delay in the delivery of the San Antonio-class (LPD-17) vessel, Naval Sea Systems Command (NAVSEA) said yesterday.

The future USS Anchorage (LPD-23) was supposed to be delivered to the Navy on July 23, but now won’t come until early September, Lt. Kurt Larson, a NAVSEA spokesman, said. Manufacturer Huntington Ingalls Industries [HII] discovered the problem with the bolts in mid-July and reported it to the Navy, Larson said.

The delay allows time to inspect and replace the fitted bolts associated with propulsion system components, such as engines, main reduction gears and line shaft bearings, as well as steering and stern gate components, Larson said.

“The fitted bolt deficiencies are related to the ability to withstand shear forces during a shock event; there are no issues with fatigue loading or normal operation of the systems,” he said.

The Navy or HII could not say how many bolts were subject to replacement. The Navy said HII is footing the bill for the additional work.

The Navy is examining other LPD-17s built at HII’s Avondale, La., shipyard to determine if similar discrepancies exist.

The LPD-23 completed sea trials in June.

HII spokeswoman Beci Brenton said a company machinist discovered a dimensional issue with some of the bolts.

“Working closely with the Navy we have developed an inspection and replacement plan and we have begun the removal and replacement of non-compliant bolts which is expected to take about six weeks,” she said.

“We have all the material on hand to complete the repairs and we are currently evaluating the progress on bolt replacement,” she added.

The company is investigating how the faulty parts ended up on the ship, Brenton said.