USS Swordfish (SSN-579) - Final Casualty

Final Casualty

In late October 1985, Swordfish was delayed in departing Pearl Harbor due to the failure of the drain pump. A replacement was obtained from USS Skate (SSN-578), in the shipyard for decommissioning, but Swordfish put to sea before the pump was fully connected and tested, and the crew could not get the pump to operate. Since the engine room bilges could not be pumped, by the evening of 23 October, the first day at sea, the water in the engine room lower level bilge was over the deck plates (more than four feet). The crew tried to use a portable submersible pump, but were not successful.

When the water level got high enough to get up into the bottoms of the motors for the main lube oil pumps, causing grounds, the Captain came aft and saw the situation and decided to take the boat shallow to allow pumping bilges. When the planesmen put a slight up-angle on the boat to come shallow the water in the bilges instantly rushed aft, greatly increasing its effect on trim (this is known as "free surface effect", later classes of subs have flood control bulkheads in engineroom lower level to prevent this) and causing an up-angle of about 45 degrees.

When "fire in engineroom lower level" was announced, due to water in the main lube oil pump motors, a man in the aft end of engineroom upper level opened the watertight door into the stern room, which swung into the stern room, to retrieve a fire extinguisher. Just then the up-angle increased dramatically and the bilge water began pouring in. The door was shut before the boat surfaced. With the boat on an even keel, the water came up to the deadlight in the door.

The maneuvering watchstanders began to take the immediate actions for loss of shaft lube oil; the throttleman began to shut the throttles for the main engines. Without propulsion, the extreme up-angle caused the ship to quickly stop and begin moving backwards, sinking stern first. When the fire was announced, the Engineer had gone to Maneuvering (the control center of the engine room). He saw the depth gage indicating a rapid increase in depth, ordered "Ahead Full" on his own initiative, and opened the starboard forward throttle himself in an effort to drive the ship to the surface. In Control, the Captain saw similar indications, and ordered "Blow Aft!". Before the Chief of the Watch could initiate the blow on the aft group the up-angle became so steep that he was unable to maintain footing and slid to the rear of the Control compartment. He quickly climbed back up to the emergency blow "chicken switches" and opened the after group valve.

Swordfish surfaced successfully. However, during the up-angle the freshwater drain collecting tank vents were submerged and sucked contaminated water into the feed system. The steam generator water could not be analyzed immediately because nucleonics laboratory in the stern room had been inundated by the wave of bilgewater. After a while, the leading ELT found the necessary reagents and analyzed samples from both steam generators on the top hat in reactor compartment upper level. By this time the boat was in direct communication with Naval Reactors, which ordered the reactor shut down and cooled down and steam generators drained and refilled. The emergency diesel generator, located in engineroom lower level, initially had water in the generator from the incident but it was drained and the diesel was online before the reactor was shut down. The reactor was cooled down and steam generators were blown down with service air and refilled until all fresh water on the boat was exhausted, which was a couple of hours before arriving back in Pearl Harbor; the cooks broke out cans of juice and distributed them around the boat. Subsequent analysis of steam generator water revealed no leakage of reactor coolant into the steam generators.

Three of the boat's four air conditioning compressors were shut down as part of the rig for reduced electrical. The temperature in the ship exceeded 80°F (27C) with near 100% humidity for the several hours required for a tug to be dispatched from Pearl Harbor and tow Swordfish home. The tug, USS Reclaimer (ARS-42) arrived the next morning and began the tow around noon, arriving back in Pearl Harbor just after midnight.

The actions of the Chief of the Watch and the Engineer saved Swordfish and her crew. The boat spent the rest of 1985 in port making repairs and returned to sea in January, 1986, making a successful deployment to the western Pacific later in 1986.