We’re well conscious of the consequences of a navigation error in an airplane. Even in visual conditions, you can put yourself in a position where you have a fuel issue and no suitable landing spot, and in instrument flying conditions you can find yourself on the non-survivable edge of the airspace, where it meets mountains and things like that.
The protagonist in our tale — USS Seawolf, SSN 575.
Submarines are, in effect, flying on instruments all the time. While we’re probably the last generation of pilots to ever see “Elevation data unreliable but believed to be no more than 17,000 feet” on a grid square, the charting of subsea terrain is much less complete than that of terrain that juts out into the air. So even if a sub skipper never errs, he may thwack an uncharted wreck or seamount. And if he errs, well, submarines don’t do well at the edges of the water — they like to stay in the middle. Anything near the edges, whether it’s seabed, coastline, wrecks, fishnets and other bottom debris, not to mention the surface of the sea itself, is inimical to your boat’s stealth, if not your survival.
And while an airplane crew has many resources that can help them stay in the middle of the air, the sub crew is alone. They have no calm voice of traffic control, watching them on radar. (Sure, someone might be watching them on sonar, but they have no way to call). And when they’re operational, they can’t even use all the resources they have — when you’re engaging in an ASW exercise, you can’t really map the bottom with your sonar. The navigation tools used on submarine include an inertial navigation system, in which an error on any one waypoint ruins every subsequent waypoint.
Patch of Seawolf’s 1957 commissioning crew, or “plankholders.”
It was a navigational error during a tactical exercise that nearly destroyed USS Seawolf (SSN-575) on 30 January, 1968. This Seawolf was the second sub to bear the name; the first was a fleet sub whose fate is unknown, but did not return from a 1944 war patrol. By 1968, Seawolf was old as nuke subs of the day went — laid down in the early fifties, launched in 1955 and commissioned in 1957, she was only the second nuclear-powered vessel in the world, and originally the only American sub powered by a liquid metal reactor.(pdf). Due to a shipyard cock-up, the reactor never made full power and was replaced later by the spare pressurized water reactor from USS Nautilus (SSN-571)1; the Soviets would later use liquid metal reactors, although different ones (lead-bismuth rather than Seawolf‘s sodium).
Seawolf lacked the Albacore-tested hull streamlining and the noise reduction of later submarines, and she was, by 1968 standards, one of the noisiest nuke boats the US Navy had — which made her a good stand-in for the noisy Soviet boats of the day.
USS Sturgeon (SSN-637) crewman Gannon McHale remembered the mishap, which occurred when Seawolf was giving Sturgeon and other subs a sonar and fire-control system workout:
The idea was for the Seawolf to make high speed runs through the deep narrow canyon, which would pose a real test for our sonar men. A serious echo existed in Georges Basin, but our sonar guys were up to the task. Finding Seawolf was not a problem – she was noisy, and we were not.
… Seawolf made her high speed runs through the basin, and we tracked her. [XO Bruce] DeMars recalled, “I believe it was the third run. We had a very nice tracking solution, and I was about to recommend we shoot when the solution rapidly fell apart. I thought he [the captain of the Seawolf] could not have turned south, as that was shallow water, so he must have turned north.”
This spawned a dispute in the control room of Sturgeon, as the experienced ship-handlers, including the XO and the commander(Curtis B. Shellman) simply couldn’t believe that the skipper of Seawolf would have done anything that stupid, and Sturgeon’s sonarmen insisting that, stupid or not, that’s exactly what Seawolf did.
The dispute was resolved by what DeMars remembered as “the most horrendous sound on the sonar,” followed by the unmistakeable sound of an emergency ballast tank blow.
Seawolf had grounded at approximately 20 knots. Dealing with the emergency, the crew never sounded an alarm, but sailors and officers throughout the boat felt the impact — as a bounce, when the bow hit sloping ground, and then a shake, as the stern struck and slid. This was followed by the sound of the emergency blow and watertight doors slamming. For the crewmen dealing with the emergency, there was no time for terror; for the men in other stations, there was.
Seawolf took a huge nose-up bow angle and zoomed to the surface, bursting out of the water to 1/3 of its length, then plunged back down underwater before oscillating back to the surface again. It was grievously damaged; the sonar dome was gone, as was the sub-surface phone; the screws were ruined. Hydraulics were out. MM1 Chauncey Leach remembered:
All the main and the vital hydraulic oil was on the floor in the stern, and you could see the after bulkhead moving back-and-forth with the wave action top side. The rudder and the planes were hanging on by a thread. The whole turtleback section back there was just swinging.
Hasty repairs were made — Leach would be one of the sailors decorated for his actions doing that — and watches set, as the sub wallowed in the Atlantic for a day until a rescue ship arrived and took Seawolf under tow. Fortunately the mishap location was only 65 NM from the nearest point of the US Atlantic coast, which explains why the tug (USS Skylark ASR-20) was able to ge there so quickly.
Despite the severe damage to the sub, the blow was glancing enough that none of the crew received a serious injury. The Navy apparently reported the incident but numerous sites report erroneously that Seawolf made it back to her home base at New London or Electric Boat at Groton under her own power. That was, as we have seen, out of the question. Repairs took over a year and Seawolf now went to the Pacific Fleet.
Within a couple of years, the Navy decided to add a section of the hull enabling certain special projects. Its special operations included wiretap servicing in the Sea of Ohkotsk, and participation in attempts to recover material of intelligence value from the sunken Soviet sub, K-129. For the K-129 operation its noisy nature didn’t matter, but it is surprising to see it associated with Sea of Okhotsk operations, as the sea was (and is) considered to be home territory, and aggressively patrolled, by Soviet/Russian naval forces. Seawolf continued in service until 1986, and was scrapped in 1997-98, with her reactor section being buried (as is customary for retired US subs).
There were immediate consequences to this accident. An upcoming Med deployment for Seawolf was out of the question, so a new boat was substituted. As it happened, she would never reach the Mediterranean, either: USS Scorpion, which sank 22 May with 99 souls on board. (It was a hard year in the underwater racket: early 1968 also saw the accidental loss of French, Israeli, and Soviet boats).
It’s just been announced that the Glomar Explorer, formerly the Hughes Glomar Explorer, a ship that, like Seawolf, was involved in the CIA-managed K-129 salvage efforts, is now headed to the scrapyard. It had a post-service career in oil drilling, but falling oil prices made it uneconomical.
- The original reactor and its components were dumped in the ocean on 18 May 1959, at
38-30N, 72-06W. See: http://skeptictank.org/treasure/GP3/NEP4TEXT.TXT
- McHale, pages 53-54.
- McHale, page 55.
Loewen, Eric P. The USS Seawolf Sodium-Cooled Reactor Submarine. Retrieved from: http://www.ans.org/about/officers/docs/seawolf_sfr_sea_story_051712.pdf
McHale, Gannon. Stealth Boat: Fighting the Cold War in a Fast-Attack Submarine. Annapolis: Naval Institute Press, 2008. (Page numbers are from the 2013 Naval Institute Press paperback).
Naval History and Heritage Command: Seawolf II (SSN-575). Retrieved from: http://www.history.navy.mil/research/histories/ship-histories/danfs/s/seawolf-ii.html
NavSource Online: Submarine Photo Archive: USS Seawolf SSN-575. Retrieved from: http://navsource.org/archives/08/08575.htm