Bruce
At the present time there are several hypotheses as to the loss of the sub. These in turn are based upon what might be called sub-hypotheses. For example “The hatch was blown open indirectly as a result of hydrostatic pressure.†That is not a fact. It is open for analysis, for questioning. Once it is labeled as a “fact” there is no more questioning.
We have been collecting a number of excellent photos and annotated drawings from various individuals that should help a group of experienced, skeptical and highly interested individuals agree on answers to these questions. However putting the material together in an organized manner so the we don’t waste their time is going to take time, perhaps a couple of months.
When this list of sub hypotheses is organized along with related evidence I plan to email everybody on the Attack Analysis list that this material is now ready for scrutiny.
In the meantime I expect there will be a number of discussions going on which will help in putting together the appropriate information.
TerryTerrass
October 16, 2007 at 1615 PST
A number of the the Attack Analysis comments continue to devote attention to the possibility that GRUNION may have fired one or more torpedoes from the After Torpedo Room. This is in spite of other comments which indicate that by the time of the KANO MARU attack GRUNION had only ten torpedoes, all forward. It is assumed that some individuals may have either missed or misconstrued these comments.
Having to consider the invalid possibilities of torpedoes fired from aft needlessly complicates the analyses of the six torpedoes which were fired from the forward tube nest..
In the hope that it will eliminate confusion and/or distractions I have copied extracts of two communications which should clearly confirm that all six of the torpedoes fired had to be from the forward tube nest. These communications were part of an effort in early 2006 to determine just when and how GRUNION may have been lost. This effort was complicated by the proximity to the International Date Line and uncertainty as to what time zones were being used, both by the U.S. and Japanese forces.
It was concluded that what Ned Beach considered to be GRUNION’s final message was, in fact, the next to last message. This may have some significance since there may be another version of Beach’s opinion which indicates that GRUNION had ten torpedoes but did not specify that they were all forward.
Terry
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From a Bruce Abele E-mail on
“This is from the Jim book
Page 4 Apparently, Grunion’s last transmission was heard on July 30, but there is some disagreement as to the content of that transmission. The official navy version has it that she reported heavy antisubmarine activity that day at the entrance to Kiska harbor and that she had ten torpedoes remaining. She was ordered to return to Dutch Harbor at that point. However, the author and submariner, Edward L. Beach, was the communications officer aboard the submarine, Trigger, which was in the vicinity of the Grunion that day. He recently wrote to me stating that he had decoded a message from Grunion out of curiosity, which was sent on the 30th of July. It seems that the communications officer of the Grunion was Ensign Willy Kornahrens who was a good friend of Beach’s and whose wedding Beach had attended a few months before. Beach reported the transmission as: “FROM GRUNION X ATTACKED TWO DESTROYERS OFF KISKA HARBOR X NIGHT PERISCOPE SUBMERGED X RESULTS INDEFINITE BELIEVE ONE SANK ONE DAMAGED X MINOR DAMAGE FROM COUNTERATTACK TWO HOUR LATER X ALL TORPOEDOES EXPENDED AFT … and then the message , which until that moment had decoded perfectly, turned into an unintelligible jumble.â€
Also
Page 11 I also learned that on that day the orders from ComTaskGroup 8.5 ordering the Grunion back to Dutch Harbor came in by radio message starting at 5:30 PM. The USS S-31 left its position in the general area near the Grunion at 8:00 PM that evening. On July 31 the visibility was “quite good,†but on August 1 it was very low east of Kiska and remained quite poor through the next day. By August 3rd, however, the visibility was once more “quite good.â€
I am having problems formulating a hypothesis that is consistent with everything I am reading. The one thing that seems OK is that everything happened on the 30th US date. Terry’s hypothesis that the transmission was at 0100 on the 30th seems to be the best though we have nothing to substantiate that time.
That hypothesis says that there was a transmission from the Grunion early in the morning of the 30. The confrontation with the Kana Maru at daybreak, and the transmission form Dutch Harbor at 5:30 in the afternoon telling Grunion to return was never received. Is this consistent with operating procedures???
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Extract from Submarine Task Force EIGHT War Diary for July 30, 1942 (from a WEB extract)
GCT 1335 LCT 0335 Received despatch from GRUNION to Comtaskgroup 8.3,
“WITH VISIBILITY FOUR HUNDRED YARDS HEARD ECHO RANGING SHIPS NEAR SIRIUS POINT WHICH DROPPED NUMEROUS DEPTH CHARGES X EVADED THESE VESSELS IN HOPES CONTACTING CONVOY X NOW BELIEVE VESSELS WERE MERELY ASSIGNED PROTECTION HARBOR X AT ONE FOUR THREE FIVE AND ONE FIVE ONE SIX HEARD MODERATELY HEAVY GUN FIRE TO NORTH OF KISKA X HAVE TEN TORPEDOES FORWARD REMAINING X FROM UNIT EIGHT FIVE SIXTEEN”
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END
TerryTerrass
October 20, 2007 at 1010 PDT
David Decrevel, on October 4, 2007, at 5:46 am, in the comment “An Opinion-Grunion Surfacing “, provided his opinion of a scenario as to how Captain Abele would have wanted to conduct his attack on KANO MARU and would NOT have wanted to surface for a gun action. This comment has many valid points but I take exception to three.
1. In particular, I believe that Captain Abele was trying to surface GRUNION, not because he wanted to but because he felt that he had no other choice if he were to prevent her sinking. I still very much feel that the Forward Torpedo Room was flooding as a result of opening the inner door on a torpedo tube in which the gasket in the muzzle door had come at least partially out of its groove and prevented the outer door from being fully shut. (TANG, on its third war patrol, experienced the gasket problem and severe flooding when the gasket on the inner door also deformed. TANG’s experience is recounted on page 155-157 in the book Unrestricted Warfare, by James F. DeRose). As I noted in my comment on October 4, the air bubbles observed during GRUNION’s 180 degree turn came from the leaking muzzle door as the tube was being blown down in preparation for loading another torpedo. If, as I suspect, there was gunfire damage before the final 84th shot, this may also have contributed to a decision to surface and, quite possibly, to abandon ship. I am certain, given the circumstances, that he had less than perfect information upon which to make his decision. If my hypothesis is correct he made the proper decision and did the best that could be done in the situation.
2. GRUNION may not have had as much time to continue his attack on KANO MARU as Decreval assumes. It did not take long for the mine-layer Ishizaki and other ships to arrive to assist KANO MARU and recover the floating torpedoes so they were probably not too far away.
3. GRUNION had no torpedoes aft when KANO MARU was encountered . (See my earlier comment).
Terry,
See http://WWW.maritime.org/fleetsub/tubes for background/details of Torpedo Tube Interlock System and photos of Muzzle Door and Inner Door Seals.
I have not read (or at least recently) Unrestricted Warfare / J. De Rose re: the Tang incident. I am guessing that Tang at that time had recently suffered a depth charge attack which contributed to or caused the Muzzle Door damage, or displaced or unseated the multiple gasket/seals.
The Muzzle Door (and attached shutter door) is directly interlocked with Inner Tube Door and the Tube Drain Valve (to WRT Tank). This interlock system prevented communication between sea pressure and WRT Tank, and the other obvious complications of having the Inner Door open with Muzzle Door open.
Assuming (as your previous posts) that all six torpedoes fired that morning were fired from Tubes Forward, I assume that (going into the attack) all six loaded tubes were functioning normally, with no known damage or leaks.
Assume all six tubes fired normally, a muzzle door seal on one of the last three tubes to be fired was damaged or unseated during the torpedo launch.
(1) Assume that when the Muzzle Door/Shutter Door was closed that it came exactly closed (because if it didn’t exactly fully close, the Interlock System would absolutely prevent any further activities related to draining the tube to WRT).
(2) Assume that the seal/gasket failed in a manner which allowed the door to fully close but not effect a fully pressure tight seal against sea pressure.
The first step in draining the tube (or blowing down) to WRT is to close the outer door mechanically (degree of closure observed on an mechanical indicator attached to the Interlock System). With outer door fully closed. Torpedoman opens the Tube Vent Valve (an overhead lever in Blow and Vent Manifold) and ‘vent’ tube pressure (sea pressure) into the bilge, while observing the tube Pressure Gauge mounted on the inner door. At this point, even while the muzzle door may be fully closed, if it’s associated gasket/seal is not ‘water tight’ the tube would not fully equalize in pressure with the torpedo room. IE; water at sea pressure would continue to flow from the Tube Vent Valve into the bilge and the tube pressure gauge would continue to read sea pressure.
In this event the action taken would be to close the vent valve lever, thus isolating the tube. Next step would be to cycle the outer tube door open and closed a couple of times to see if that might clear the problem (or at least confirm the problem cause).
Steps to Drain (or blow down) the tube: Tube has been ‘vented’ to bilges and is equalized with torpedo room ambient pressure and vent valve closed (and tube pressure gage reads ‘zero’ pressure). (1) Torpedo man opens WRT Vent Valve and the Tube Drain valve (which will not operate if muzzle door is not exactly closed) (2) Torpedoman opens Air Supply valve (over head the tube directly above tube vent lever) which allows whatever flow of air (from 225 psig Ships Service Air) is required to boost the water from the flooded tube into WRT Tank. Torpedoman would be unlikely to use a force much more 50 psig or so to push the this water out of the tube into WRT (during this evolution WRT is itself venting into the torpedroom). Volume of water remaining in the tube is observed in the sight glasses. If the tube were reflooding to any major degree from a displaced gasket it would be readily apparent at this point.
Note: This can be a noisy operation, and may have subtle effects on ships trim. Conning Officers may elect not to carry out this operation immediately after firing for various tactical reasons.
Note: One function of the Interlock System and this sequence of actions/events is largely designed to ‘isolate’ WRT from full sea pressure at any/all times. WRT lives inside the pressure hull and is not a full pressure vessel like negative tank.
Given that (1) the three torpedo tubes involved had starting conditions at 06:07 that were something like ‘normal’ and (2) Grunion did not suffer ‘depth charge’ or other abuse during the next few minutes which would have caused some additional failure other than a single displaced or damaged muzzle door gasket/seal (3) I do not see the ‘bubbles’ mentioned by R. Nakagawa as very likely coming from a torpedo tube actively being ‘blown down’.
The only air ‘bubble path’ mentioned in the after action documents/reports (that I am aware of) are from R. Nakagawa.
The narrative notes; “bubble running on surface figuring half circle†and “at head-end of bubble running, big black-brown water arose,…oily on surface†The sketch notes; ‘Bubble Path’ and ‘Torpedo Path’ adjacent and with the same symbols.
I do see as very likely the ‘..half circle’ bubble path being the hot exhaust gases and steam wake of a circular run, as depicted in his sketch directly next to the two other Torpedo Paths. The reason I say very likely is: During this specific 2-4 minute time frame we have a 100% known bubble emitter running in the immediate area and it was eventually accounted for.
I think CO Grunion assumed (1) that Kanu Maru had sent ‘Mayday’s twenty minutes earlier with their position (2) If Grunion had visibility enough to shoot Kanu, that ASW had visibility enough to come out and pick up their escort duty at least at first light, and were probably on their way. (3) If the 0335 message was the correct date, CO Grunion had heard echo range and depth charge and heavy gun fire very close to this area the previous night. Which would mean that ASW was already outside the harbor and much closer.
I think Grunion at this time was opening out to NE or E (050*) and taking a good look at the horizon behind Kanu Maru for ASW. To reload 4 x remaining torpedoes is probably an intense 1 hour or maybe more, and would not be done on the surface. The boat would likely go deep and sort out a very fine, stable trim before starting that evolution.
Terry Terrass comments #1 of 24 October
In his comment of 21 October at 9:38PM Ed Walston expresses a number of views regarding flooding of the forward torpedo room as well as the hypothesis that none of the torpedoes fired was a circular run. I disagree with a number of his views, not because of any desire to fuel a controversy but because I feel strongly that we need to determine as accurately as possible what really happened.
Although I will admit that there may be room for some doubt about the torpedo room flooding I do not think that to be the case relative to the circular run. Consider the following points:
A. Relative to a Circular Run:
1. The most specific evidence cited for there having been a circular run was the semi-circular stream of bubbles.observed by the Army medical officer. Although their paths would have been different, would not the tracks of the five straight running torpedoes been identical in appearance to the so-called “circular runâ€:?
2. Although Ed considers that this torpedo was “eventually accounted forâ€, is there any definitive evidence that the loss of the bow section was due to torpedo #6 exploding at GRUNION? In other words, if there was no circular run, is there any other explanation of the extensive damage observed in the pictures? Per the book “The Fleet Type Submarine†(NavPers 16160, pg 9) a submarine hull has very good strength to sea pressure forces but is not particularly strong when it come to rigidity. The key words from this reference are as follows:
“Pressure vessels, while capable of withstanding great pressure, do not in themselves possess great rigidity. Being subject to mechanical action (leverage), they must be secured to each other by one common strength member (the keel), as well as by watertight connections (bulkheads).â€
If the FTR was nearly full of water while the rest of ship was still buoyant, I think it quite possible for the bending moment to have fractured or greatly weakened the bow section while the ship was in the process of sinking. The bending moment would have been even greater if the ballast tanks were blown in an effort to avoid sinking.
The topside damage observed could very possibly have been due, at least in part, to 8cm gun shells which hit but were not observed by KANO MARU.
B. Relative to Flooding of Forward Torpedo Room
1. Ed accepts, correctly, that TANG on its third patrol had received significant depth charging prior to suffering the deformed muzzle door gasket problem. Tang’s problem had originated as a result of hitting one of its targets, quite possibly an ammunition ship, which blew up with a tremendous explosion.
GRUNION reported in its’ next to last message that it had received “minor damage†in an unsuccessful attack two days earlier. Notwithstanding Ed’s conclusion that there was “No known damage. Tubes were functioning normallyâ€, is it possible that this damage could have caused the outer door gasket problem but in such a manner that it would not have been detectable and/or detrimental until the outer door was opened for the attack on KANO MARU?
2. Ed indicates that if there were a gasket problem, it would have occurred on the firing of the last three torpedoes. I see no reason why it could not have occurred on any of the six firings
3.. Ed states that the torpedo tube muzzle door/WRT tank interlock insures that the outer door is “exactly closed†before the tube can be drained down. Although that was undoubtedly the design objective, there are a number of factors which could preclude it from being a reality. Ordnance Pamphlet 1085 (OP 1085),. which is available on-line from Google, has much information about submarine torpedo tubes. These include, among others,
(a) “Lost motion†(Pg 136)
(b)“Certain mechanical clearances are necessary†(Pg 142)
(c) A “Spanner†tool for adjusting the coupling of the muzzle door coupling and interlock mechanism.
(d) The amount of “give†in the outer door gasket.
4. .. Ed describes a torpedo tube draining procedure which differs, not just from that described on Page 119 but from what would be most expeditious to perform. In his description he includes venting the tube before draining it down and includes, “if necessaryâ€, cycling the outer doors several times. Not only should this be unnecessary for the purpose he envisions, cycling a hand operated outer door would not be easy nor expeditious. Ed implies that it would be easy to tell if the tube is drained by looking at the gage glass and pressure gage mounted on each inner door I suspect that the tube being blown down would have been either #5 or #6 because reloading with a torpedo stored in the pit would have been faster and easier because it would have required less movement than torpedoes stored in other positions. Because the inner doors on these two tubes are below the platform level, it would be much harder (and perhaps less reliable) to check the indications on these two particular doors than Ed believes.
Per OP 1085,. to drain the tube, after positioning the muzzle door interlock, the tube is blown down before venting it. If this is done, the air in the upper part of the tube could easily escape to the surface from an opening at the muzzle door and could continue for as long as compressed air is being blown into the tube. Given that GRUNION would have wanted to reload as quickly as possible but not wanting to interfere with the firing, they would have started blowing down the first tube they wanted to reload very shortly after the last torpedo was launched.. If that tube was the one with the gasket problem, the bubbles would have started very soon after torpedo #6 was on its way. Since the diagram by the Medical Officer does not really seem very realistically match his verbal report (torpedo tracks vs water column circle, black bar fall down), I am very strongly inclined to take the version and diagram provided by Aiura as to where the various torpedoes ran even though I think that his ship positions and times may be somewhat suspect. The idea that Aiura’s attention remained focused on his starboard side while the periscope remained visible “moving calmly†on the port side seems highly unlikely even though there was not much that he could have done.
5. Delaying a torpedo reload to avoid making the noise required to blow down the reload tube does not seem likely given that there were no ASW craft to hear the noise in close proximity. Actually sinking the KANO MARU would have been a very important and priority task for a variety of reasons.
6. Whether or not the gasket problem existed it would have been vitally important to vent the drained torpedo tube to the FTR before attempting to open the inner door. Even with a small pressure in the tube the inner door could slam open quite violently as soon as it was unlocked with a high probability of injuring personnel and damaging torpedo tube parts. Having this happen with the outer door gasket problem could very well hamper efforts to cope effectively with the gasket problem.
END
Terry,
I haven`t read about Tang`s experience so I have more doubts than facts there, but I`d like to make a couple of comments to your post.
Point #2: the existence of different pressure bulkheads along the sub´s length makes me believe that the designers had taken into account the increase of weight (or loss of buoyancy, however you want to see it) and would have calculated the hull`s strength to withstand it.
About the reference, it is correct in that the single longitudinal strength member is the keel. Surface ships have many other members running along the hull, but I don`t know the name in english, sorry. However, the flooding of the forward end would not produce a “bending moment”, that would occur if the hull was fixed in a horizontal position and the bow left to hang. The actual result of the flooding would be a “turning moment” aroung the center of buoyancy, which is where the sub is “resting” (where the upward force is applied), and the boat`s bow would simply move downwards.
Furthermore, any ballast tank blown in the area of the FTR would have tended to alliviate that moment, providing an upwards force opposite to the flooded FTR`s weight.
Point #6: this is the part I like the most of these posts, learning from you guys. I didn`t know the exact position of the tubes, but what you say about two of them being very low would probably make seeing the visual indicators a bit difficult. However even if the inner tube door was opened with the tube still flooded, it seems to me there should be no reason for an uncontrolled flooding of the whole room. The exterior door would be closed and even with a damaged gasket the amount of water entering through it would not have been too high. Even in that case, the FTR bulkhead hatch could have been shut and the compartment pressurized with the “salvage air” valve, thus slowing down the water ingress.
What I realize as I write is that in this case about 3000 pounds of water would suddenly travel about 20ft towards the stern… MAKING THE SUB BROACH??