Snorkel in the US Navy - 1945 onwards

APPENDIX F - US Navy Subvets Anecdotes

Anecdote No 1

James 'Pat' Patterson, US Navy Sub Vet, Docent, USS BLUEBACK exhibit at the Oregon Museum of Science and Industry. Deceased 2007.

Over quite a long period Pat graciously provided detailed notes about snorkelling aboard the USS BLUEBACK (SS581), a ‘tear drop’ BARBEL class submarine, commissioned 1959 and was in service for 31 years. These were the last diesel-electric submarines in the US Navy, but the design was taken over by the Dutch and developed into the modern submarines of today. It is believed the post war Japanese designs were also developed from the BARBEL class.

Before preparing, at my request, a full description of the snorkelling aboard BLUEBACK, Pat had already answered my various messages with specific questions about "shut down" if the snorkel head submerged and the boat could not recover before unacceptable conditions arose in the boat. I have included his several patient answers as a compilation, but the date order is not always clear as the original E-mails were lost in a computer crash. Fortunately the main content had been saved in a text file to disc and here it is. I trust readers will find much of interest.

SNORKEL PROCEDURES ABOARD THE USS BLUEBACK

When the word is passed to prepare to snorkel the submarine will come to periscope depth. In each compartment watch standers will rig the
compartments. This for most part means the right line up of ventilation and to line up the engines to run and if a battery charge is to be done the boat will rigged for that also.

In manoeuvring room the engine consul operator will put the snorkel safety switch in the bypass position and the junior controller will put the snorkel/surface switch in the snorkel position, this switch has four positions, snorkel, surface, and two trip positions.

Once the boat is rigged for snorkel the OOD (Officer of the deck) will order the snorkel mast raised by the COW (Chief of the watch). After the mast is raised the OOD will have the COW test the head valve while he checks the mechanical indicator thru the periscope. After the head valve is tested the word is passed to commence snorkelling.

The COW will then open the main induction valve. This valve is located at the bottom of the snorkel mast. The valve allows air to pass from the mast to the main induction pipe to the engine room. After the main induction valve is opened the engine operator will open the hull induction valve. This allows air into the engine room from the main induction pipe. The engine operator then starts the engine and opens the engine hull exhaust and the snorkel exhaust valves.

At 17psi of back pressure the main snorkel exhaust valve will open automatically. The high back pressure will blow the water from the free flooding snorkel exhaust mast. When they have all the engines started the engine operator will put the snorkel safety switch in the on position.

Once the boat is snorkelling and the order to secure snorkelling is given the junior controller will put the surface/snorkel switch to the tripped position. This will kick out the fuel racks; it also kicks off all generators and it shuts the main snorkel exhaust valve.

The engine operator shuts the engine hull exhaust and the snorkel exhaust valves and the hull induction valve. The COW shuts the main induction and the head valve and lowers the snorkel mast. This has been a normal light off and secure snorkel.

If there is over a 12psi back pressure or 6 inches of vacuum or the rpm of the fastest running engine goes below 400 rpm the snorkel safety circuit will shut the main snorkel exhaust valve and kick out the fuel racks and trip off the generators.

SNORKEL SHUT DOWN DUE TO UNINTENTIONAL SUBMERGENCE OF THE SNORKEL HEAD - USS BLUEBACK .

The snorkel head valve would shut when too much salt water would short out some electrodes and that would cause 100psi air to operate a valve we called the 'quick as a wink' valve. That valve would send 225psi air to the shut side of the head valve piston, this was all done automatically and was really quick as a wink. When the water washed off the head valve the quick as a wink valve would then apply the 225psi air to the open side of the head valve. Then the head valve would open automatically.

We could run all three engines while we were snorkelling. If the dive lost the bubble and the head valve shut the engines would suck the air out of the boat until we reached a 6 inch vacuum and then the main snorkel exhaust valve would shut automatically. At 12psi of engine back pressure the engines would shut down automatically.

With three engines running it only takes about one minute to get to six inches of vacuum. With only one engine running it takes about six or seven minutes. If you are on one engine and the dive lost the bubble and went to deep the engine back pressure would build up and the engine would shut down at 12psi.

Also if the rpm of the fastest engine dropped below 400 rpm, the engines automatically shut down. They figured that an engine running only at 400 rpm would not have enough back pressure to keep water out of the engine.

All the engines were automatically shut down on high back pressure because the first thing to happen would be the main snorkel exhaust valve would automatically shut and this would always keep water out of the engines.

The main snorkel exhaust valve was always shut automatically by the snorkel safety circuits. The engine inboard and engine snorkel valves were shut by the crew. When I say the crew that means they flipped a switch. All the sea valves were electro-hydraulic.

QUESTION: Does the Tang class have the same snorkel set -up as the Barbel class?

Yes it does. The Tang class was the first class to have only have the single induction pipe. The guppy subs had the same safety circuits, 6 inches vacuum low rpm and back pressure cut out. They had a main induction valve for the engines. It was in the sail just above the main deck. The snorkel air would come into the snorkel head valve and then down the mast to the snorkel induction valve.

After passing thru the valve air would dump into the main induction pipe.

There was a change valve in the control room that the COW would give control of the main snorkel exhaust valve (also called ABLE valve) to the engine room, he could not open the valve but he could take control of the valve and then shut it.

When they started to snorkel the priority engine room would take control of able valve. They would open it when the engine started to run and they had enough back pressure to blow the mast.

Once the engine was running ok they would put able valve on the latch. This was a relay that would hold able valve open until the safety circuit was tripped and then the relay would shut the valve and the engines were also shut down.

I hope this helps you.
Pat

Hi Peter

I also was on a Guppy sub. It was the USS Sea Leopard SS 483 in 1969-1972.

On the Guppy boats you can snorkel with all engines. I thank the # 4 engine was removed on some Guppy boats.. That was the way it was on the two Guppy boats that I was on.

Hi Peter (referring to Barbel class)

The snorkel induction mast is a dry mast. However the IC man of watch would open a drain to negative tank in the control room. There is a sight glass so he could check and make sure the mast had not flooded. The drain would dump into negative tank and if you were snorkelling in bad weather a lot of water would wash down the mast and then into negative tank. Ever so often the COW would have to pump the tank back to the snorkel mark. He would pump the tank to sea.

Still looking for the drawings, I know I still have them.

I like the questions because it keeps me sharp and makes me think

Pat

Hi Peter

The Sea Leopard and the Blueback had a Prairie Masker and they worked good. One of the problems of using a Prairie Masker when snorkelling the boat would act very light aft and you had to flood in a lot of weight, I think we would have to flood in about 15k aft and in the center to snorkel more than about 9 knots.

Pat

Hi Peter

It was around the whole aft part of the boat and on the screws. Now that I think back it may have been #2 engine that was removed. Old age is sitting in. Never heard about any valve problems but that doesn't mean there wasn't any (referring to engine valves) I do know they had to shut down the compressor because of high temp a lot of tines, but the system would hide the noise from the engines very good.

We snorkelled about 1000 yards from a tin can and they said the boat sounded like rain water. We had all three engines on line. The system worked but was hard to keep on line.

Pat

Authors Note:

I understand one engine was removed from some of the GII GUPPY conversions to allow the Prairie Masker compressor to be installed. This was quite some time after the original GUPPY conversion.

Prairie Masker was a system where the hull was covered in a skin of bubbles and bubbles were used to reduce screw cavitation noise - the web has several useful references. The British experimental version was known as NIGHTSHIRT and as far as is known only the only British submarine so fitted was the trials submarine SCOTSMAN. Several destroyers had trial sets.

Answer to E-mail re performance legend plate.

The term 80/90 means 80% engine output and 90% gen output. The max rpm of the engines on snorkel was 725, this was set because they could not get enough air down the snorkel mast with the back pressure the engines run with on snorkel. This class of boat was to have different type of engines however they were found to be unsuited for sub service. The f/m engines were installed and it was found that the induction pipe was to small after losing some blowers.

I think Pat is referring to the compact vertical 'pancake' engines that were fitted in the TANG class but were so troublesome they had to be removed and the hull lengthened to allow the fitting of conventional engines. This situation may well have impacted on the design of the BARBEL class.

Anecdote No 2

From Rik Nilsson US Navy Sub Vet in answer to E-mail question. (His web site is here)

Every time I reminisce snorkelling, I can remember the wrath of the enginemen against us planesmen who allowed the boat to drift down causing the engine cylinder relief valves to pop and fill the compartment with noxious fumes. I can almost smell them to this day.

In seas of long, heavy swells, it was sometimes hard sweaty work cranking the planes wheels (even in power mode!), keeping depth so the intake valve was as low as possible in the waves, yet not cycling closed frequently

Unlike the original Dutch and German implementations, which I believe were swing-up pipes with a float valve head, the final US Navy version consisted of hydraulically operated tandem vertical telescoping masts installed in the aft of the sail. The forward pipe was the intake and extended slightly more than 56 feet above the keel. The head valve was electro-hydraulic, closing automatically when doused with seawater. The exhaust stopped just short of the surface at snorkelling depth (52 to 54 feet keel depth), and ended in a perforated head under a plate to disperse the gases as a cloud of bubbles. This helped hide the diesel smoke, and reduced the noise signature.

The lower end of the intake mast connected to the existing main induction trunk through a water separating chamber. The engine intakes always drew their air directly from the interior of the boat, which was fed from the main induction in the forward engine room. For this reason, and due to the condition of compartment doors being closed while submerged, only the forward engines, engines one and two, were used for snorkelling.

Each engine exhaust connected to a snorkel exhaust header outside the hull through a swing check valve outboard of the engine exhaust cooling system. The exhaust mast was not test-depth rated, and free-flooded when diving. Any water in the intake mast was drained into one of the inboard tanks (possibly the negative tank), while the exhaust was purged upwards by the engine exhaust pressure. Snorkel start-up consisted of fully raising the masts, and when the head valve opened, the intake was drained to negative tank. The negative tank inboard vent was shut and the tank was pumped to sea. The inboard engine exhaust valves were released, draining any water to the bilge, and an attempt was made to start an engine to clear the snorkel exhaust. When exhaust pressure rose above sea pressure, about two atmospheres at snorkel depth, the snorkel check valve opened to purge the mast. Engine cylinder heads had back-pressure release valves to prevent engine damage if the depth was too great, or water was ingested.

The rush of fresh air after a long submergence was greatly appreciated, even though we knew we were less "stealthy" while snorkelling. The downside was that when we stopped snorkelling, our purged olfactory senses had to readjust to the normal stinky submarine atmosphere again. Also, most often in the Atlantic, the air at night is chilly. If you worked or slept next to an air conditioning vent, you might have to put on a jacket.

The oceans, even on "calm" days, are not perfectly still. Long-period swells as well as sea chop from wind can make snorkelling an unpleasant experience. When the automatic snorkel head valve closes, it's like someone applied a vacuum attachment to your face. Your ears pop, your tear ducts and sinuses drain, etc. It can be messy if you're asleep.

In medium to rough seas, the planesmen had to work hard to keep the head valve from closing too long. There was a vacuum safety sensor in the system that cut off fuel when the pressure in the boat dropped something like 7/10th of an inch of mercury (does that sound reasonable?). I seem to recall that if it stayed closed more than 15 or 20 seconds, the engines would shut down, both from lack of air and excess exhaust pressure. I've been in the engine rooms when this happens and remember the cylinder relief's filling the compartment with dark, choking, eye-burning fumes in a matter of seconds.

If the boat was steaming downwind at less than surface wind speed, it would be quite possible to suck engine exhaust into the snorkel intake. I can't remember that being an often occurrence, but then, I was only aboard Cubera for two years. It could be that we always changed courses when possible under the circumstances, so as to stay heading into the wind while charging batteries submerged.

I do recall that in the lower Atlantic latitudes, we had water vapour "mist" form in the boat at times, due to warm inducted air condensing in our otherwise cool submerged atmosphere at the onset of snorkelling. Maybe that's what the Darter photographer caught on film ( No.3 below). The heady, oxygenated fresh air would temporarily purge our nostrils and make us more conscious of the ever-pervasive diesel (and other smells) in the boat.

Anecdote No 3

This picture came from the web. The comment recorded with the pictures was:

I had the luck to pull USS DARTER from early 1984 to early 1985. DARTER was one of four diesel boats at the time. They have all gone now. You can see how thick the diesel smoke got when you 'snorkel with a tailwind '.

The DARTER was a class of one submarine, a derivative of the TANG class.

Obviously exhaust gases in the atmosphere of a snorkelling submarines can only be seen as an undesirable health hazard and worthy of some comment, so Rik Nilsson being a US Navy SubVet was asked about this photograph, see his comments above in his anecdote No.2

There have been unsubstantiated web reports of Soviet submarine crews suffering serious illness due to snorkelling.

The author with service on Royal Navy 'A' and 'T' class submarines has no recollections of exhaust gases being drawn from the surface into the submarine, down the induction mast along with air and so checked with members of the Barrow Submariners Forum. In their responses most also wrote that they also had no recollection of exhaust gas in the submarine due to snorting. There were a number of comments on SSN similar that included in the anecdote reproduced below.

From a former Royal Navy watch keeping submarine officer on SSK and SSN in the late sixties/seventies. It is in fact a composite of a number of forum postings by the same person and brought together with the permission.

Certainly I remember it, you needed quite specific conditions, snorting down wind at the right speed so that your exhaust was gently blown forward to the induction mast. It was not a pleasant experience anyway, so most likely avoided whenever possible, hence the limited experience by other members of the Forum of getting 'one's own' back.

The reality is that any boat is at risk of 'getting it's own exhaust fumes back' if the conditions are right, and that is the boat going exactly down wind, at a speed slightly less than the wind speed, then the exhaust which is discharged but a few feet away from the induction mast must get sucked back. Boats with engines that have a higher back pressure capability and thus maintain a well submerged snort exhaust may do better as the exhaust is somewhat cleaned and diffused by bubbling through sea water. Those with poor back pressure performance which had non or slightly submerged exhausts (most soviet boats for example) would tend to suffer more.

It was also a problem on the surface even with the surface mufflers when going down wind at about wind speed where the exhaust would swirl around the fin. Remember the secondary purpose of snorting after charging the batteries was to replenish the oxygen in the boat. I am sure the ventilation system also drew from the area of the induction system and exhausted back into the engine room.

It was worst running on the surface on diesels on an SSN in those conditions because as they had no surface muffler you used the snort exhaust mast, and it needed cooling water injected into the exhaust, so going downwind you had a nice dieselly spray onto the bridge, did a whole watch like that after we has a SCRAM and surface after a main throttle steam leak, not nice.

My earlier comments on the poor back pressure performance of Soviet boats are a dim recollection from my days in the Navy, and applied to the Whisky/Romeo period boats, their more modern ones may have overcome the problem. Certainly back pressure was always reported as the reason we chose mechanical screamers (superchargers) on the P&O boats despite their noise. More recently I do believe the Germans have made turbo chargers work at higher back pressures.

POSTSCRIPT

On the 'getting your own back' problem, it has occurred to me that the ideal conditions for ingesting ones own exhaust are a wind speed similar to the boats and that the sea will be relatively calm so control problems would be minor. In general though it is highly unlikely any boat would persist in a course that was likely to asphyxiate the crew.

Anecdote No 4

This little anecdote originally came from here

On most Boats, the engine used to blow the stack, were the one's with the most running hours on them. Reason being, that if something went wrong and she flooded, what the hell, we have to overhaul her in 40 hours anyway.

As did this little ditty that follows. The expletive substitutes can make reading a little difficult for people not used to US swear words, but the substance of the text gives a deal of technical and operational information.

Thanks to Myron Howard EN1(SS) USS Bream SS243

A typical conversation from the "honoured" Engine Room went something like this:

Throttleman: "AW *****, not again, OK, lets line it up, light er off and pray it don't flood"

Oiler: uh, uh, uh, uh, (that's the sound he made opening the inboard exhaust valve 'cause the stem was all carboned up), UH, UH, UH, UH, (a total of 33 1/3 turns later) ********, thought I'as never gonna git the ******** open)

Throttleman: "hold that ****** by-pass this time, till I knock your ******* hand off of it, OR YOU'LL BE LIVING IN THE ********* BILGES".

Engine rolls 3 or 8 times, (depending on how cute the throttle was trying to be, showing off to the other Engine Room).

Throttleman: "OK, they finally gave me the ******** word to light off, grab that ******** by-pass switch, and remember, don't let go on your own.

Engine starts rattling and rolling, hacks, coughs, belches and starts firing, 2 or 3 cylinders at a time. Finally, it roars into life, the throttleman yanks the snorkel exhaust valve open, the oiler, trying to be cute yells "can I leggo, can I leggo, huh?" but remembers the previous threat and holds a death grip on it. About that time the Engine dies and starts rolling to a halt. The throttleman, in one smooth continuous motion shoves the snorkel exhaust valve lever back to the close position and knocks the oilers hand off just in time to keep it from flooding, but the airbox door springs are all shot and weak so they blow open and fill the engine room with that delightful, lung-searing, eye-watering black smoke we all loved so dearly.

Throttleman: "******* that was fun why in the **** don't they let me blow the stack with that other ****** of *****. Seems like the 1st in charge of the engine room always managed to be on the 8 to 12, and we never, never ever snorkelled on his watch, except during fleet opts and then it wasn't every ******* night, now was it.

I hear tell that the events for snorkelling on a FM (Fairbanks Morse) boat were a tad different.

Oiler: "Oh shoot, why couldn't they have waited until we finished our cookies and milk".

Throttleman: "Well just hurry up, when we shut down, you can go up to the Crews Dinette and get us some ice cream with whipped cream and cherries on top, OK?

Oiler: "Oh, I guess so. I just wish they wouldn't do this so often. It hurts my ears when those silly old planesmen dip the head valve.

Throttleman: " Well it hurts mine too but ya just have to learn to grit your teeth and put up with it. Remember, you could have been sent to one of those nasty EB boats with their dirty old Jimmy engines".

Oiler: Oh, I know and I am so thankful that didn't happen.

Anecdote No 5.

Admiral I Galantin (US Navy ret ) in his book SUBMARINE ADMIRAL, tells us more about the snorkel voyage of the USS PICKEREL (SS 524) mentioned in the opening of the main article.

Ingenuity and humour, two attributes of successful submariners, were not lacking on PICKEREL. In his report, Paul Schratz ( Captain) said "The most accurate and reliable indicator vacuum indicator aboard is almost too homely for mention in an official report. To alert the manoeuvring room controllerman to stand by to pull clear when the head valve is cycled, the electricians placed a red-painted condom over a mouth of a bottle. As soon as the vacuum increased, the condom stands up rigid, pointing a lurid finger of caution at the controllerman.

Anecdote No 6

Some years ago I had an E-mail exchange with a retired US Navy submarine officer. Unfortunately due to a computer crash and my failure to back up E-mails, I lost all the messages, however one item stayed in my mind so here is the gist.

The particular GUPPY submarine, relatively late in its service life, had a small diesel-generator fitted down the centreline on sound reducing mounts. Apparently its purpose was to a provide a quieter means of snorkelling at slow speeds while supplying the ship's electrical load. It was not a great success as the officer reported it spent more time in bits being repaired than in service. However it was an interesting idea that might have been pursued if the US Navy had persisted with diesel submarines.

Anecdote No 7

From - LCDR Fritz Steiner US Navy (ret.)

I served in two snorkel boats, RAZORBACK (Engineer Officer in 1961-62). She was a Guppy IIA. BLUEGILL was a former SSK with a BQR-4 passive array sonar that wrapped around the bow. It was an amazing piece of gear. We could detect, classify and track ships and other submarines at astonishingly great ranges. Both were 3-engine boats.

We could snorkel at 7-8 knots. Anything faster than that and the masts and periscopes would would've vibrated so badly they'd probably have broken in the "up" position (not a desirable event). We could only snorkel on two engines anyhow - three would have pulled such a vacuum in the boat that we'd have shut down anytime the head valve shut. We used standard aircraft altimeters to keep visual track of what "altitude" we were at. It's been a long time since I did any snorkelling, but as I remember it, on two engines at 80/90 we'd "fly" at 1,800 feet. When the head valve shut we'd "climb" faster than an F-4. It was quite a sight watching the altimeter hands go around. Not to mention having your eardrums popping (if you were lucky) and your sinuses sucked dry (very messy). As best I can recall from nearly 50 years ago, the engines would shut down automatically at 6,500 feet.

One of the things that snorkelling forced was an increase in the lobe-to-lobe clearance in the engine scavenging blowers to compensate for their having to run in a partial vacuum. Without the increase, they'd have heated up and wiped (thereby ruining your whole patrol).

I can't think of a good reason for having to snorkel at high speeds anyway. You're noisy as hell when you snorkel - at any speed. You essentially render yourself deaf, passive sonar-wise. In an environment where other, unfriendly submarines might lurk, that's not a good way to be.

The worst kind of snorkelling was in a choppy sea and a heavy seaway. When the sea washed over the head valve electrodes, it would shut. The engines continued to suck air out of the boat, so we'd "climb." It was a strange sensation as the air would suddenly chill in the boat. Then just as fast as it shut the sea would pass and head valve would open. "Down" in 'altitude" we would go as the atmospheric air rushed back in through the snorkel induction. And the cycle would repeat itself over and over, We called it a "chattering head valve."

Pretty soon everybody would be annoyed. People sleeping would be waked up by their popping ears and draining sinuses. People already awake, would just bitch about it and endure it. Usually, because submariners LOVE to agitate their shipmates, several of them would walk through the Control Room (one-at-a time) and ask the Diving Officer if he couldn't control the depth a little better.

I made my very first dive as diving officer aboard IREX while an Officer Student in Submarine School in 1958. The year before, she had been fitted with the reinforced fibreglass, so-called "North Atlantic" sail.

I sounded the diving alarm and shouted "Clear the bridge!" The lookouts vanished. I found myself in a very lonely position high atop the sail of a ship that was sinking beneath my feet. The "clear the bridge" drill involved turning aft and going down a ladder to a platform deck halfway to the upper conning tower hatch. Then after a 90 degree turn to the right you'd go down another ladder, turn 180 and you'd be at the upper hatch, which before conversion would've been at your feet.

The ladders had stainless steel vertical hand rails. We had been advised by ship's company that the way down was speeded up by loosely gripping these rails and dropping down. Following their suggestion I did that and darned near wound up a casualty at the platform deck. A film of water unevenly distributed on each rail had become a lubricant between my hand and the rail, resulting in that hand's slipping while the other one held fast. I believe you can imagine how that torqued my body. I was lucky to land on both feet without breaking an ankle or separating a shoulder. I could easily have panicked, but I didn't. I turned and patiently descended the second ladder step-by-step. I dropped into the conning tower and yanked the hatch shut with plenty of time to spare The dive went well after that.

In 1961 as RAZORBACK's Engineer Officer in the shipyard I oversaw the installation of her North Atlantic sail, the first in the Pacific Fleet. By then I'd become a much "saltier" submariner and wasn't concerned about hurrying down the ladders. On sea trials the Engineer Officer always makes the first dive. Based on my IREX experience I simply took my time. After all the boat didn't submerge any faster than it did before.

While I'm at it, it was amazing what could be done to configure the Snorkel Exhaust System in ways that the original designers never imagined. As a submariner I'm sure you're well aware of the ingenuity that characterizes this unique breed.

"Hmmm look at this. Suppose we connected this to that and shut this valve. Then we could do this. Let's try it."

For example, while visiting Hong Kong, BLUEGILL was nested starboard side to a US destroyer that was moored to a buoy. The DD was preparing to depart HK and had all hands at quarters in their nice, clean white uniforms. As soon as it was ready to go, we were going cast off and to move to our berth at HMS TAMAR.

We had stationed the manoeuvring watch but hadn't yet warmed up the engines. I was standing topside aft when one of my leading enginemen popped his head up out of the after engine room hatch. With an evil grin he said, "Mr. Steiner, let's get them 'skimmers'." I asked him how. He said, "Let's cross connect #4 to the outboard exhausts for #1 and #2 through the Snorkel Exhaust System and roll the engines to make sure there's plenty of raw fuel in 'em. When we get the signal from manoeuvring we'll start all three together. When they're running we'll pop open the outboard exhausts for 1 and 2 and let the 'skimmers' have it." I told him that was fine with me. The destroyer was to leeward.

I stayed topside and watched with delight as our engines blasted a broadside of dense black smoke onto the DD. It was soon invisible. When the smoke finally cleared there wasn't a white-uniformed "skimmer" anywhere to be found on the DD's port side.

This was a classic display of the submariner's' ingenuity combined with his innate, puckish instinct to agitate. The "skimmers" no doubt were mad as hell, but the delight we took from this was that they had no idea we'd deliberately ruined their day and there was nothing they could do about it.

Hope this helps
Fritz

Peter, here's another personal anecdote you may find interesting:

The year before I became Engineer Officer in RAZORBACK her Chief Engineman came up with a brilliant idea.

All of our snorkel-capable submarines had retained their original configuration with respect to the mufflers that they had during WWII. These were a drowned-type with pressurized sea water pouring into them to dampen the diesels' roar - it would've been extremely bad form to be caught on the surface, by being heard.

These devices were eighteen feet long, flange-to-flange. They were connected to the individual engines' outboard exhaust risers at one end and to the overboard exhaust pipe on the other. Because of the doubly corrosive effect of sea water and diesel exhaust gasses, they had to be replaced on average every twenty-four months. As time passed the supply of replacement mufflers had dwindled. .

The Chief had a solution. He correctly reckoned that whenever we were doing "Sneaky Pete" operations, we snorkelled to charge the batteries, so the original purpose for the mufflers was moot. He suggested replacing the mufflers with a straight pipe through which the same "drowning" water would be forced.

COMSUBPAC approved the idea on a trial basis, and authorized the replacement of one of RAZORBACK's muffler with a straight pipe for evaluation purposes. The boat was in the San Francisco Naval Shipyard at Hunters Point. The shipyard manufactured an eighteen foot-long, circular straight pipe with appropriate flanges from 3/4-inch "black iron" and installed it between the outboard exhaust riser and tailpipe for the #3 engine. It wasn't appreciably louder than the muffler. COMSUBPAC bought it wholesale and recommended to the Chief of BUSHIPS that straight pipes become a standard SHIPALT to be accomplished Fleet wide at each submarine's next overall. It was so ordered with the proviso that they be made of 3/4-inch corrosion resistant steel, i.e., stainless steel that would never have to be replaced. The era of submarine muffers was history.

Fast forward to 1961. RAZORBACK was at Hunters point for a much-needed complete overhaul. We were to receive the reinforced fibreglass North Atlantic sail. We also were to replace all of the superstructure abaft the forward end of the sail with reinforced fibreglass "clam shell" sections. Naturally, we were also going to get three new stainless steel straight pipes.

Enter Fritz, the ever curious, "Why is it like that?" Engineer Officer. I asked the shipyard man (one Cal Woolley) who was responsible for installing the straight pipes why they had to be so long. Was there some acoustic reason? No, there was no reason for it other than to fit between the flanges so the exhaust could pass through the tailpipe which itself passed through the hole in the sheet metal superstructure that had been there since conversion. (This was a manifestation of the "We've always done it this way" syndrome.)

I said. "Cal, we're getting an entire new superstructure, so the yard's going to have to cut holes in it for the exhausts, right?"

"Right."

"Okay, design a pipe for me that attaches to the outboard exhaust flange and then simply turns in the shortest possible radius to pass through the hole in the superstructure. I'll take it to my CO and if he agrees we'll march it up the hill."

He agreed. The shipyard couldn't have cared less. COMSUBPAC loved it and told BUSHIPS who also bought it and issued a new SHIPALT replacing the previous one. RAZORBACK got the first three new short pipes. Every other diesel boat in the Fleet that didn't already have the long straight pipes by then got them, too.

The short pipes consisted of a flange welded to a 3/4-inch transition section about a foot long on its shortest dimension and about three feet on its longest creating a forty-five degree angle. This was welded to another section which turned the direction of flow another forty-five degrees. i.e. directly to starboard or port, where a final straight section a couple of feet long went through the superstructure.

A residual benefit for RAZORBACK was that COMSUBPAC allowed us to keep the substantial savings from the funds that had already been allocated for a long pipe replacement. We applied these savings to lots of desirable projects that we otherwise would have never accomplished

Best,
Fritz

FOOTNOTE

Fritz, after reading the completed article added to his already very informative anecdote and made a review comment that is most welcome from an experienced US Navy submarine officer.

It meets with my approval and EARNS MY praise. WELL DONE! One minor item caught my attention:

"However in the GUPPY GIIA conversions, one diesel-generator was removed to make equipment space, detail of the lay-out and operation is not known."

 RAZORBACK (SS394) was a GUPPY IIA. Regarding the above uncertainty, I believe that this should clear thing up. The #2 Engine (Port) was removed from the Forward Engine Room. The air compressors, trim and drain pumps, vacuum pump, IMO pump, and Hydraulic Accumulator, air conditioners, Refrigeration unit, and ICMGs were moved from the Pump Room (under the Control Room deck) into the space vacated by the engine, both above and below the deck plates. The ICMGs were relocated to the Manoeuvring Room. The vacated space in the former Pump Room became the Sonar Room.

As has been stated elsewhere in the article, we could snorkel on two engines only. A third engine would have created too great a vacuum in the boat, which in turn, would've left too little margin before reaching "flameout altitude." No preference was given to running only the After Engine Room's engines while snorkelling. Keeping the engines' accumulated running times more or less equal was more of a deciding factor in determining which two would be run at any given time.

USS BLUEGILL (SS-242)  formerly (SSK-242) was a GATO class conversion that also removed the #2 engine. She was one of about a dozen GATO's that got converted. I was "Ole Blue's" Engineer Officer for 15 months, then became her Operations Officer and Navigator.

In 1960 during my Submarine Officer Qualification final exam, I went to sea in USS CAIMAN (SS-323), She demonstrated the great, albeit unintended, versatility of the snorkel system by, are your ready for this, diving on the snorkel.

During this evolution she submerged in the usual fashion, shutting the main induction valve while raising the snorkel mast, shutting the main engine overboard exhaust valves, and opening the snorkel exhaust valves. By the time the boat reached periscope depth the snorkel mast was fully raised, the head valve was open and air induction was being taken through it. The engines never stopped running. The main snorkel exhaust opened easily since the snorkel exhaust mast was never completely flooded. CAIMAN did this routinely.

I was dazzled, to say the least. This proved that it could be done, but not that it should be done. Once was enough for me.

Best regards,
Fritz

< BACK

Comment by torres1944 on 2009-10-15 08:19:11
Excellent article! Thank the author for post it!