Deck Log: April 2021

The USS Thresher (SSN 593) was the lead boat of her class of nuclear-powered attack submarines in the United States Navy. She was the U.S. Navy's second submarine to be named after the thresher shark.

On 9 April 1963, Thresher, commanded by Lieutenant Commander John Wesley Harvey, left from Kittery, Maine, at 08:00 a.m. and met with the submarine rescue ship Skylark at 11:00 a.m. to begin her initial post-overhaul dive trials, in an area some 190NM east of Cape Cod, Massachusetts. That afternoon, Thresher conducted an initial trim-dive test, surfaced, and then performed a second dive to half of test depth. She remained submerged overnight and re-established underwater communications with Skylark at 06:30 a.m. on 10 April to commence deep-dive trials. Following standard practice, Thresher slowly dove deeper as she traveled in circles under Skylark – to remain within communications distance – pausing every 100 ft of depth to check the integrity of all systems. As Thresher neared her test depth, Skylark received garbled communications over underwater telephone indicating " ...  minor difficulties, have positive up-angle, attempting to blow," and then a final, even more garbled message that included the number "900." When Skylark received no further communication, surface observers gradually realized Thresher had sunk.

By mid-afternoon, 15 Navy ships were en route to the search area. At 06:30 p.m., the commander of Submarine Force Atlantic sent word to Portsmouth Naval Shipyard to begin notifying the crew's family members, starting with Commander Harvey's wife Irene, that Thresher was missing.

By morning on 11 April, all hope of finding Thresher was abandoned, and at 10:30 a.m., Chief of Naval Operations Admiral George W. Anderson Jr. went before the press corps at the Pentagon to announce that the submarine was lost with all hands. President John F. Kennedy ordered all flags to be flown at half staff from 12 to 15 April in honor of the 129 lost submariners and shipyard personnel.

The loss of Thresher was a watershed moment for the U.S. Navy, leading to the implementation of a rigorous submarine safety program known as SUBSAFE. The first nuclear submarine lost at sea, Thresher was also one of only four submarines ever lost with more than 100 people aboard.

Created to find and destroy Soviet submarines, Thresher was the fastest and quietest submarine of her day, matching the smaller, contemporary Skipjack class. She also had the most advanced weapons system, including launchers for the U.S. Navy's newest anti-submarine missile, the SUBROC, as well as passive and active sonar that could detect vessels at unprecedented range. 

Following Navy tradition, this class of subs was originally named Thresher after the lead boat. But when Thresher was struck from the Naval Vessel Register on 16 April 1963, the class name was changed to that of the second boat, Permit, and Thresher is now officially referred to as a Permit-class submarine. Having been lost at sea, Thresher was not decommissioned by the U.S. Navy and remains on "Eternal Patrol."

We at Old Salt Coffee Company solemnly hoist a mug of Silent Service to the Old Salts of the USS Thresher.

It was the seventh crewed mission in the Apollo space program and the third meant to land on the Moon. The craft was launched from Kennedy Space Center on April 11, 1970, but the lunar landing was aborted after an oxygen tank in the service module (SM) failed two days into the mission. The crew instead looped around the Moon, and returned safely to Earth, splashing down on April 17, officially allowing us to call everyone on the crew an Old Salt. The mission was commanded by USN CAPT Jim Lovell with Jack Swigert as command module (CM) pilot and Fred Haise as Apollo Lunar Module (LM) pilot.

A routine stir of an oxygen tank ignited damaged wire insulation inside it, causing an explosion that vented the contents of both of the SM's oxygen tanks to space. Without oxygen, needed for breathing and for generating electric power, the SM's propulsion and life support systems could not operate. The CM's systems had to be shut down to conserve its remaining resources for reentry, forcing the crew to transfer to the LM as a lifeboat. With the lunar landing canceled, mission controllers worked to bring the crew home alive.

Although the LM was designed to support two men on the lunar surface for two days, Mission Control in Houston improvised new procedures so it could support three men for four days. The crew experienced great hardship caused by limited power, a chilly and wet cabin and a shortage of potable water. There was a critical need to adapt the CM's cartridges for the carbon dioxide scrubber system to work in the LM; the crew and mission controllers were successful in improvising a solution. The astronauts' peril briefly renewed public interest in the Apollo program; tens of millions watched the splashdown in the South Pacific Ocean on television.

An investigative review board found fault with preflight testing of the oxygen tank and the fact that Teflon was placed inside it. The story of Apollo 13 has been dramatized several times, most notably in the 1995 film Apollo 13 – based on the 1994 memoir co-authored by Lovell "Lost Moon" – and an episode of the 1998 miniseries "From the Earth to the Moon."

Although the mission didn't land on the moon, the successful return of these astronauts is to be celebrated. There have been 24 people who flew to the moon. Of the 12 that did not set foot on the moon, four were Navy. We'd also like to point out that of all 12 of the people who have actually walked on the moon, fully half represented the U.S. Navy, and two others (both Air Force) attended the U.S. Naval Academy. #HoistAMug of Brown Shoe Blend to the #Moonwalkers and crew of the Apollo missions!