Submarines operate for extended periods of time under the ocean. This ability gives them the advantage of stealth in performing her missions. Since even the most modern submarine requires people to operate it, providing the basics of life while submerged has always been a challenge.

sub duty

Think about those World War 2 movies where the Destroyer had forced the U-boat to the bottom. The destroyer captain could be patient since all he had to do was ride around on top and wait for the air on the inside of the submarine to become so horrible it could no longer sustain life. At some point, the boat would have to come to the surface.

When the idea of using nuclear submarines as launching platforms became a reality, something different needed to be done. So the Treadwell corporation proposed building a new type of “Oxygen Generator” that would ensure a high rate of oxygen production from pure water. The process is called electrolysis.

Direct current is passed through a KOH (Potassium Hydroxide) solution, which electrolyzes the water to H2 and O2. The water has been treated by an ion exchange system to eliminate other electrolytes. Sixteen electrolytic cells at about 1000 amps are required to produce 120 SCFH of O2 (sufficient for 120 men) at 11 of 16 pressures up to 3000 psig. The gases are removed from the cells and distributed (O2) or disposed of (H2). Hydrogen is discharged overboard. (or at least that’s the plan”

The early model had 7 foot cells inside and had a nick-name: “The Bomb”.


Picture of a 6’ Generator. Ask any sub sailor what the most dangerous thing is on a submarine and you might get a lot of different answers. Obviously anything that can explode and potentially kill you will probably rise to the top of most people’s list. While my first patrol on the George Washington was spent mess-cooking and driving the boat, my second and subsequent patrols were spent in the atmosphere control room.

I had heard about the Bomb ever since sub school. Stories from the early days talked about how unstable it could be. Even if you don’t know anything about science, you have to believe that any machine that has that much pressure and that much electricity running through it could be a bit of a problem if things went wrong. Add to that the fact that Oxygen in high concentrations will feed a pretty good fire and hydrogen… well, let’s just say that hydrogen was not our friend.

The bomb sat in the forward starboard corner of the machinery room on the GW and you had six or seven other pieces of equipment to monitor at any given time. Everything on the early models was manual except for one or two automated devices. There were rows of indicator lights that would flash in series to tell you that all was well inside the box. Gages also told you that the correct balance between the oxygen side and the hydrogen side was being maintained. If either of those stopped being normal, the loudest alarm you would ever hear in your life would tell you that you have fifteen seconds to close a series of blocking valves to prevent an uncontrolled release of something that could just ruin your day.

Not only was the O2 and H2 pretty dicey if released, but the potassium hydroxide itself would eat through paint and at 3000 PSI, could shoot around corners with ease and blind you. Legend had it that in a few early models, the force of the explosive events was so strong that it blew off the metal panels and cut a guy’s head clear off. (okay it’s a legend and they did teach it to us in O2 Generator school but who wants to take a chance of that happening?)

Did I mention how many parts this thing had? I will tell you that during the upkeep before I made my first “Room watch” I had to order all of the parts to completely rebuild the beast. I got writers cramp after one day. O-rings, penton seals, gaskets, and on and on were required since the bomb had an “event” on the previous patrol with the Gold Crew. Any leaks on the inside of the box would result in KOH being sprayed on components and creating more leaks. If the H2 and O2 sides became unstable, the rapid depressurization would result in an explosion. So putting it back together with no flaws was absolutely critical. We were still finishing the job as we got underway for Patrol 43.

SSBN 598 A gang

Auxiliary Division from Patrol 43

I still dream about Patrol 43. If there was ever a thing that could go wrong on a submarine, it happened on that patrol. Most of those stories will come at a different time but this one stands out among the most memorable.

We were submerged and the Bomb was running. It was my first time by myself running it and I was pretty intimidated. In the first hour or two, I must have reviewed the emergency shut down procedure a hundred times in my head. I could see every flicker of every light and every tiny movement on the gages that would tell me a leak was developing. I practiced evacuating the room a few times but quickly realized there wasn’t a great place to hide. You see, just on the other side of a very thin bulkhead was the upper level of the missile compartment. Yep, the perfect place to put something that could blow up was right next to the warheads of nuclear missiles.

Go in the other direction and you find yourself staring into the hatch that leads to the reactor compartment passage. Now that part is a bit safer since there is so much safety shielding around a reactor. But you still thought about the potentials.

After a six hour watch, I was never so glad to see my relief, Dewey Watson. Dewey was a young guy from Ohio and seemed a lot more confident than I was about his new duties. (Yes, we both graduated from O2 Generator school at the same time). I had work to do in the engine room so I signed everything over to him and left. I was laying on top of a condenser in lower level fixing a pump when I heard the most dreaded announcement followed by the General Alarm “Fire in the Machinery Room”

It was the Bomb. I later found out that shortly after taking the watch, Dewey had an uncontrolled release of pressure which caused the machine to become unstable. He was trying to get all of the emergency shut down valves so the machine could be blocked out. The machine started spraying caustic and the roving watch in the missile house saw a cloud of “smoke” and called it in.


All the watertight doors were shut and I ran to the hatch in the reactor tunnel. The Engineer was standing there with a CO2 fire extinguisher in his hand. I looked through the observers hole and Dewey was jumping back and fourth trying to get the machine blocked while the spray continued.

Just at that moment, another announcement came across the 1MC that chilled me to the bone… “The atmosphere monitoring station has reported that Hydrogen level in the boat is 4% and rising”  4% is the level where Hydrogen becomes so unstable, it could possibly explode! You could feel the boat taking a very strong up angle as the control room crew tried to drive us to the surface. Dewey had a look on his face that looked like it was his last few moments. The engineer handed me the CO2 extinguisher and said “Get in there and help him” as he pushed me through the hatch he had just opened. He shut it behind me.

“Dewey, what do you want me to do?” “I don’t know Mac, it’s blocked but it keeps spraying” “Shut the power off, its not helping now anyway”

Just then, the boat leveled off and the 1MC announcing system came on.

“All hands this is the captain. Disregard the previous announcement about the hydrogen level in the boat. There was a mistake reading the instruments and hydrogen was at .04 % not 4 percent. Damage control teams are assembling to help combat the casualty. There is no fire.”

The bomb, hissing and crackling, slowly settled to atmospheric pressure. We had a heck of a mess to clean up over the next few weeks but we had dodged a bullet.

When we went back in to repair, it turns out that one of the penton seals had not been placed correctly. It would not show up immediately but at higher pressure and heat, it allowed the leak to slowly become a bigger problem.

I learned a lot about built in quality after that day. You can never assume that any test or inspection will save your butt down the road. The whole spirit of BIQ is that you do the job absolutely the right way with the absolute right parts every time.

Now some people might be saying that this is a life and death thing that rarely ever happens in their job. Really? Who do you think designs the parts that go into the cars, trucks, boats, planes and so on? People. And who do you think can be effected if just one percent of the airbags fail on a car series that will include over a hundred thousand cars? Maybe your family member?



Picture of the sail from the USS George Washington… flowers in memory of MM2/SS Dewey Watson

Mister Mac

9 thoughts on “Boom

  1. Ran the Bomb on the 602 and was LCPO on the 750 with a 7 Ft. Always treated her with more respect than the reactor including being put on report during an ORSE board for blocking her up during a reactor scram after 45 minute limit.

    1. Good story, I was Instructor on 7 ft o2 gen. In pearl.Ablown seal at top of cell was my worst case emergency shut down during training. Impossible to isolate. All you could do was emergency purge . Sounds like Dewey did all he could.

  2. Wow so cool to learn about subs I served on board the USS Alamo LSD 33 I dont think I could of handled being under the water for so long Im alittle closterphobic i think

  3. Good story, I was Instructor on 7 ft o2 gen. In pearl.Ablown seal at top of cell was my worst case emergency shut down during training. Impossible to isolate. All you could do was emergency purge . Sounds like Dewey did all he could.

  4. During a refit on the 616 I was bringing the #2 O2 generator up for it’s drop test after doing the 1500hr PMS and a cell replacement. Just got it up to 3000psi when a seal blew out in one of the cells. Blew KOH all over the outboard side of the machine. Had to rip the entire cell area apart, get all the piping cleaned, replaced all the insulators and check valves, repainted the inside of the cell area AND the lagging outboard the machine. Turned out a Penton seal went out. Squadron generator inspectors claimed they had never seen one do that before, thankfully the Treadwell rep confirmed it. It took forever to burn all the grounds off the machine. Thankfully it happened during upkeep and not underway with the machine in electrolysis.

  5. Mr. Mister MAC, that was a great story for those of us SEABEES who were never underway on a sub. In fact, the only one I was ever on was tied up to the Proteus in Holy Loch, Scotland. Working to build the AFDB 7, a friend and I, after waiting over a month for our request to board the sub, took matters into our own hands. We jumped aboard from a Mike boat and scrambled up the side. Getting to a level position, to be met by a 3rd Class Petty Officer with a drawn gun, I said,”Take us to your leader”. The Officer of the Day let us see around after learning that we were working 12 hours a day to provide a floating dry-dock FOR THEM and just wanted to” see what we were working for” !!!

  6. I remember being told about the O2 gen. that took the top of the watches head off. One of my shipmates had served on the boat and had the sad duty of trying to keep the poor soul alive. I do not remember which boat it was, trying to think which one Mike had served on. He told me how hard it was to sit with this guy knowing there wasn’t much anyone could do for him.

Leave a Reply to mstrmac711 Cancel reply

Please log in using one of these methods to post your comment: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s