Advertisements
One of the crew’s heads aboard the USS Blueback (SS-581). Note the sign above saying to leave a water seal.
The same episode on the Down Periscope, Up Periscope Podcast.

Note: The pictures in this post are of one of the heads on the USS Blueback (SS-581), a Barbel-class submarine in commission from 1959 to 1990, but the head is fairly representative of what you can expect to find on submarines of that era, and the system is tried and true. Blueback has 1 head for the eight officers to share and four heads for the 77 enlisted sailors to share.

They say that a toilet is a simple thing. That’s generally true for something like a flush toilet that uses water, valves, and gravity to accomplish its job. Barring a connection to a sewer line, whether on land, in the air, on the ocean surface, or below the surface, some form of holding tank is generally used. The difference in a submarine is in the operation of the head (nautical jargon for a toilet) itself.

Simply put: it’s a bit more involved than the one you use at home.

How it works

The long handle on the right side, near the deck, opens a ball valve at the bottom of the bowl to a holding tank below. The valve above the head allows seawater to “flush” the bowl.

Arguably, there’s nothing terribly complex or special about the heads on a submarine, but there is a process that needs to be successfully followed when answering the call of nature below the surface.

The Procedure

  1. Make sure there’s an inch or two of water already in the bowl.
  2. Do your business.
  3. Pull the handle to open up the ball valve to the tank below.
  4. Open the seawater valve above to “flush” the contents of the bowl.
  5. Close the ball valve.
  6. Close the seawater valve, making sure it leaves an inch or two of water in the bowl (so it forms a seal).

Where it all goes

Beneath the heads is a Collection, Holding, and Transfer (CHT) tank (AKA Sanitary tank). This is where your waste goes. On Blueback, every couple of days, the sanitary tank beneath the heads will be pressurized with air from the 400 lbs. air system, and the contents will be blown overboard. For U.S. vessel, this means anywhere greater than 3 nm from shore.1 Signs, such as the one above, will be hung to remind the crew that this is occurring. However, absent-minded crewmembers may forget to hang the signs or some may ignore the signs. (Some may even “misplace” the signs, perhaps as a cruel joke to break the monotony of submarine life or out of sheer maliciousness.)

Well, when you gotta go, you gotta go.

Whatever the case, anyone using the head at this time will not forget what is about to happen.

Getting crapped on by the Navy

Should you need to use the head when the tank is pressurized AND you happen to open up the ball valve…well, there’s only one place for the contents of that pressurized tank to now go. Straight up at you and all over the room. Such an event also produces a noticeable *bang* and everyone nearby knows exactly what happened. You’re now stuck cleaning up the mess you made.

A former U.S. Navy submariner (who will remain anonymous) relates the story of how one skipper created an honorary toilet seat for the most recent crewmember who committed this faux pas to ignominiously wear around their neck. The crew referred to this as “getting shitcanned.” The unlucky crewmember would then be counting the days until the next sailor committed the same mistake, upon which the honorary toilet seat would pass to that sailor.

The aforementioned former submariner also relates a story about how, as a young submarine sailor, he learned about the temperamental nature of submarine plumbing the hard way. Being fairly new to his diesel-electric boat, he was learning the ropes and being taught how to pressurize and blow the sanitary tank. One important step prior to pressurizing the tank with air is to close the valves to pipes that drain into the tank. So following those instructions, he indeed closed those valves, but what he failed to realize (and nobody told him) was that just because he closed the valves didn’t mean they were actually closed. What he needed to do was close the valves, then open them slightly, and then close them again. This was an old submarine, and the valves were old and sticky.

He proceeded to pressurize the tank and blow a fountain of shitty water back into the showers and the ice machine. Needless to say, he wasn’t the most popular sailor aboard that sub for a while…and nobody used the ice machine for the rest of the patrol. On Blueback, the various sinks, and showers, as well as the ice machine, water cooler, and coffee urn drain into the sanitary tanks!

Addendum

According to a tour guide who served on USS South Dakota (SSN-790), modern Virginia-class submarines use vacuum toilets (like those on aircraft). Waste initially goes into a vacuum tank before going into the sanitary holding tank. The toilet still has enough suction to flush into the vacuum tank, even when the sanitary tank is pressurized and being emptied, so blowing a fountain of sewage back into the submarine isn’t an issue anymore.

The dangers of submarine plumbing

The following story is an oldie, but a goldie.

During WWII, Allied submarines used a similar system of holding waste in a tank before discharging the sewage overboard. However, not all submarines had such a system. In fact, other systems were quite complex.

German U-boats also had a holding tank for waste, but given the way the system worked, the sewage could only be pumped overboard while the boat was on the surface or at relatively shallow depths given the lower water pressure. Additionally, these tanks took up space and added weight to the submarine. By late war, advances in Allied anti-submarine technology and tactics had made operations at shallow depths too risky for U-boats, so German engineers developed a new high-pressure system to allow waste to be discharged while at significant depths. Unfortunately, this system was so complex that it required specialist training just to use it properly. It involved opening a series of valves in a precise order to transfer the waste (in the right direction) through a series of chambers before isolating it in an airlock and using pressurized air to discharge it overboard.2

Reportedly, this complex plumbing system is what ultimately led to the sinking of the German submarine U-1206 on 14 April 1945. A mere eight days into its first combat patrol, U-1206 was lurking 200 feet below the surface of the North Sea off the coast of Peterhead, Scotland. The commanding officer, Karl-Adolf Schlitt, used the head, but not being trained in the proper procedure, called an engineer over to help him. The engineer apparently operated the valves in the wrong order and caused sewage and seawater to flood back into the U-boat. Things went from bad to worse as the water leaked down into the battery compartment and reacted to produce chlorine gas. With the boat filling with toxic fumes, Schlitt ordered the crew to blow ballast and even fire the torpedoes to produce positive buoyancy. When they surfaced, they were quickly spotted and attacked by British aircraft. With his boat taking damage, Schlitt ordered the men to scuttle her and abandon ship. The men reached the Scottish coast in rubber rafts, but three of them (Hans Berkhauer, Karl Koren, and Emil Kupper) were lost trying to climb the steep coastline in heavy seas.

The war in Europe ended several weeks later and Schlitt would actually deny his role in the sinking of his submarine. In his official statement, he noted that;

I was in the engine room, when at the front of the boat there was a water leak. What I have learned is that a mechanic had tried to repair the forward WC’s outboard vent. I would say — although I do not have any proof — that the outer vent indicator either gave false readings or none at all. The engineer who was in the control room at the time managed to make the boat buoyant and surfaced, despite severe flooding. Meanwhile the batteries were covered with sea water. Chlorine gas started to fill the boat. We were then incapable of diving or moving. At this point, British planes and patrols discovered us. I let the boat sink.3

While Schlitt may have disputed the cause of the sinking, what isn’t disputed is that his U-boat remains on the bottom of the North Sea, having been sunk, ultimately due to a failure in the proper use of a toilet. Schlitt would pass away in 2009, and in May 2012, divers located the wreck about 12 miles off the coast of Aberdeenshire (just south of Peterhead), where it lays in about 282 feet of water, reportedly in relatively good condition.4 No amount of complex plumbing will keep the head from overflowing this time.

Notes

  1. MARPOL Annex IV governs the discharge of sewage into the sea. Unless the sewage is treated, discharge is prohibited under 12 nm from shore. However, the U.S. is not a signatory of Annex IV. Instead, the Federal Water Pollution Control Act (FWPCA), amended by the Clean Water Act, regulates U.S. vessels discharging sewage into the sea. In the case of U.S. vessels, discharge is permitted beyond 3 nm from shore. When on international voyages, the vessel may obtain a Statement of Voluntary Compliance (SOVC), or else risk being detained in a port subject to MARPOL jurisdiction. See: https://www.dco.uscg.mil/Portals/9/DCO%20Documents/5p/5ps/NVIC/2009/NVIC_1-09(Ch1).pdf ↩︎
  2. Samantha Franco, “The Plumbing Disaster That Led to the Sinking of U-1206,” War History Online, February 1, 2023, https://www.warhistoryonline.com/world-war-ii/plumbing-disaster-u-1206.html. ↩︎
  3. Samantha Franco, “The Plumbing Disaster That Led to the Sinking of U-1206,” War History Online, February 1, 2023, https://www.warhistoryonline.com/world-war-ii/plumbing-disaster-u-1206.html. ↩︎
  4. Samantha Franco, “The Plumbing Disaster That Led to the Sinking of U-1206,” War History Online, February 1, 2023, https://www.warhistoryonline.com/world-war-ii/plumbing-disaster-u-1206.html. ↩︎

Bibliography

Franco, Samantha. “The Plumbing Disaster That Led to the Sinking of U-1206.” War History Online. February 1, 2023. https://www.warhistoryonline.com/world-war-ii/plumbing-disaster-u-1206.html.

Advertisements