PORT TOWNSEND – A Coast Guard discovery of a large amount of pitting in the hull of the MV Quinault prompted the grounding of all four of the aged Steel Electric ferries, cutting off ferry service between Port Townsend and Keystone on Whidbey Island.

“If we find steel wasted more than 25 percent, then that’s when we tell them to cut it out and redo it,” said Lt. Cmdr. Todd Howard, chief of the Coast Guard Seattle Sector’s domestic vessel inspections branch.

“We want five-eights of an inches or better.”

The Quinault had areas of pitting and corrosion on the inside of the hull that were deteriorated by 30 percent or more, Howard said.

It was after a meeting Tuesday among Washington State Ferries and Coast Guard officials that state Transportation Secretary Paula Hammond halted ferry service between Port Townsend and Whidbey Island until early next year – while up to $4 million is spent fixing the Quinault.

On Tuesday night, Hammond announced a surprise decision to pull all of the ferry system’s four 80-year-old Steel Electric class vessels out of service to also examine the hulls of the Klickitat, Illahee and Nisqually.

State ferries system officials plan to have a passenger-only ferry on the Port Townsend-Keystone route in the interim, they said.

Howard said that the pitting, found along about 100 feet of the Quinault‘s keel, was made about 1½ weeks ago.

As a result, all steel plating four feet wide on both sides of the keel between the engineer’s compartments will have to be replaced, Howard said.

“It’s a significant amount of work to replace all the steel, but it must be replaced,” Howard said.

“The way these pits are being formed was, water was sitting on the bilge itself inside, because the hulls sweat from humidity,” he explained.

“If the paint coating isn’t good, then the water may eat into the steel.”

Last Friday and Saturday, Howard said, state ferries system preservation engineers rode on the Quinault‘s Steel Electric sister ferries, the Klickitat and Illahee.

“And while there, they were looking specifically at the [rusted] areas found on the Quinault,” he said.

Interior paint was chipped away to reveal pitting and corrosion.

“So by Monday, we learned there were concerns with the Klickitat and the Illahee.”

Despite the pitting uncovered, Howard said, “the boats weren’t out there ready to sink or anything.”

The Illahee was to join the Quinault in dry dock at Todd Shipyards in Seattle on Monday, he said.

The Klickitat will remain tied up at the Port Townsend ferry terminal until dry-dock space is freed up so that the hull can be inspected, he said.