Wahoo Video Commentary Part II

Here is the second installment of Chuck Thompson's assessment of the Russian Iskra Team video. He begins with an interpretation of Wahoo's loss based on known facts and review of the wreck footage. He then follows with a detailed description of the footage itself.

SINKING SCENARIO

Based on the examination of the available video of the wreck of the USS Wahoo, the following sequence of events is proposed.

Wahoo was in the process of transiting La Perouse Strait when she was detected by a Japanese aircraft looking for a submarine exiting the Sea of Japan. Wahoo was at periscope depth and had both scopes raise. During the first aerial attack, at least one of the bombs or depth charges scored a nearly direct hit to starboard at near main deck level in the area of the Control Room/After Battery Room bulkhead (frame 59). The result of this attack was severe damage to the main ballast tank 2C and fuel ballast tank 3A (hence the oil observed), and the conning tower fairwater. The pressure hull was ruptured on the starboard side near the junction of the Control Room/After Battery bulkhead, and possibly the conning tower (if not ruptured, the conning tower would have flooded through open lower conning tower hatch). The boat would have rolled severely to port, and experienced severe hull flexures which seem to travel along the hull and back again.

All personnel in the after battery room, control room and conning tower would have been incapacitated, and by the time they could recover, these spaces would have been flooded except for small air pockets and the top of the conning tower. The fact that the stern planes and probably the bow planes appear straight and level indicates that no attempt was made to surface. If the door to the forward battery room and forward engine room were open, they may also have flooded. It is probable that damage beyond these spaces was extensive, as there is no indication that any attempt was made by the surviving crew to escape from the forward or after spaces. Subsequent attacks and depth charging may have prevented the crew from trying to escape, and resulted in superficial superstructure damage, resulting in the superstructure damage visible today.

VIDEO SEQUENCE
(all times are from the video player, with time 0 at the beginning of the video)

The video begins with a brief Wahoo history, and information on the Russian dive team.

Eight (8) minutes into the tape, video of the wreck begins. The diver approaches the wreck from the starboard side, just aft of the conning tower fairwater (CTF), and the wreck is silhouetted. As the image comes into focus, extensive damage is apparent amidships as a break in the CTF silhouette and a dark area of the hull below the break in the CTF, extending downward around the hull.

At 08:10, as the diver approaches the wreck, a large chunk of debris is visible on the bottom, alongside the hull, immediately forward of the damaged area below the bridge. No detail is visible. The approach to Wahoo appears to be more zooming in than the diver getting closer to the hull, as detail does not improve.

At 08:25 image fades into swimming alongside the hull, mid level on ballast tanks, location unknown, possibly starboard side moving aft. The bilge keel is visible. No damage is visible.

At 08:36 film shifts to a different location, still swimming along the hull slightly higher. We are led by following sequence to believe this is starboard side moving aft. At the top of the ballast tanks, vertical superstructure is visible, with Government type limber holes. No damage is visible.

At 08:53 video shifts again, this time swimming along the starboard side, approaching the stern. The starboard propeller and shaft are visible. Footage continues around the stern, showing starboard (first) then both stern diving planes, and the rudder. Both planes are close to straight and level. The rudder is amidships. No damage is visible.

At 09:46 the diver is moving forward, and swims under the port stern plane and past the propeller. No damage is visible.

At 10:09 the diver continues to swim forward along the port side. Government type limber holes are visible. The hull appears to be in good shape, with many areas’s clear of marine growth. This is apparently the up current side, so there is less marine growth. No visible damage.

At 01:26 the port aft engine exhaust hole comes into view.

At 10:33 the port forward engine exhaust hole comes into view. Also the first of the “missing” superstructure is visible forward and aft of the exhaust. This appears to be corrosion damage, as the surrounding superstructure and supports do not appear damaged.

At 10:42, shift to new film sequence. Diver aft of the CTF, moving forward along the port side, at the top of the ballast tanks, looking athwartship through the superstructure. Most of the vertical superstructure is missing, apparently from corrosion. The supports for the superstructure are in place and not distorted. The top of the pressure hull is frequently visible, with external hull reinforcements (ribs), along with other hull components/piping located below the aft deck. Sometimes you can see all the way through to the starboard side.

At 11:23 an intact section of vertical superstructure, with Government style limber hole, is visible. Superstructure fore and aft is missing, again because of corrosion?

At 11:47 the CTF comes into view from port aft, at deck level. The aft (tapered) end of the superstructure is visible, with side plating rusted out.

At 11:52 fade into diver swimming forward from aft of the CTF. Diver is to starboard and just above the level of the cigarette deck. As the diver approaches the CTF, the extensive damage becomes visible. The diver swims over the aft end of the cigarette deck, and the missing area becomes clear, although details are difficult to distinguish. It is apparent that much of the cigarette deck superstructure, as well as port and starboard deck are missing.

At 11:58 shift back to footage we left at 11:51, swimming forward along the port side just below deck level, with CTF coming into view. Aft end of CTF is in the foreground, bridge and sheers in background. Damage difficult to see.

At 12:02 shift to close up of the free standing aft end of the CTF. Plating is rusted out, although support structure is in place, and does not appear damaged.

At 12:05 camera pans to the left, and is looking at deck level, up the port side, alongside the CTF (to right). The missing port deck and center section of CTF is clearly visible. The forward edge of the missing deck appears to be a fairly sharp break, with teak decking visible. As the camera moves forward, the vertical CTF superstructure, including supports, is completely missing. The forward ballast tanks are not visible.

At 12:12 the camera is approaching the missing area of the CTF. Before any details of the damage can become clear, the image fades out.

At 12:14 video moves back to same sequence ended at 11:57, looking forward from above aft of the CTF. The sharp, clean break of the bridge deck (fwd part of cigarette deck) is visible. The D/F loop is in the center of the photo. Radio antenna supports, port & starboard are visible. A large piece of unknown debris sticks out to starboard at the level of the lookout platforms.

At 12:17 the bridge structure (from aft looking fwd) is visible, the lower sheers rising in the center of the superstructure from the cigarette deck to the lookout platforms. Immediately to the right of the lower sheers appear to be several large areas of marine growth blocking access to starboard. This does not appear to be ready service lockers.

At 12:18 video fades to looking forward along the port side. CTF fills right half of the photo. We are apparently immediately above the main damaged area, to port. The broken end of the D/F loop shaft is visible to the right. The camera pans to the right until both the port and starboard vertical sides of the CTF are visible. The camera is pointed directly at the aft end of the conning tower (could this be the cigarette deck pushed down and forward, covering the aft end of the conning tower?). The forward edge of the broken deck to port of the CTF is visible at left. While this is a good shot of the damaged area aft of the CTF, details are hard to distinguish.

At 12:20 what may be the bottom edge of the conning tower (or the aft end of the cigarette deck blown downward) is visible at the bottom of the picture. This appears as a sharp, horizontal but ragged edge. If this is the conning tower, it should be rounded. The absence of the starboard decking and superstructure is obvious – it is completely missing.

At 12:22 the camera is looking down and to starboard, right into the damaged area. It is obvious that all decking and supports are missing. The area shown would have been in the area of the starboard CTF manway. The damaged area visible must include the pressure hull.

At 12:25 the video shifts to looking at the primary area of damage. The video is looking aft, just forward from the main damage area, at the main deck level (stbd side), looking along the fore/aft axis of the fairwater. The location of this video is not discernible until the end of this sequence (12:43), when the ragged edge at the end of the conning tower (identifiable at 12:20), comes into view, at the lower right side of the video (this took me a very long time to understand). Close examination of this sequence does not answer any questions concerning loss, as the pressure hull is visible below the array of damaged structure,

At 12:32 a hand illustration of the damaged area, from starboard, comes into the picture, obscuring much of the picture. This is unfortunate as there is much to be seen. Although the hand illustration is a broadside view from starboard, nothing in the video can be correlated as being from that area.

12:35 A note at the bottom of the video states that except for the rupture, the hull looks almost whole.

12:39 Same ragged edge visible at 12:20 comes into view, lower right hand corner of the picture, as the view shifts from aft to port.

At 12:43 the hand drawing fades away. It is not possible to identify anything in the photo, although the pressure hull and port deck edge must be there.

At 12:44 different video of the damaged area, this time looking from starboard to port, with the CTF superstructure at right and the missing deck superstructure at center. The forward and aft ends of the port deck are visible, the area in between missing due to damage. The camera backs up, and the ragged bottom edge of the conning tower (?) and the broken edge of the D/F loop shaft are visible. (the footage at this point is actually being run backwards, as the debris in the water is moving backwards, and the fish are swimming backwards.) The structure across the bottom of the picture must be the pressure hull.

At 12:53 camera shift to the same footage that faded out at 12:22. The camera is looking at the area under the cigarette deck with the ragged bottom of the conning tower visible across the bottom (same footage as before, even the same fish). The camera pans to port and up.

And by 12:58 we are looking at the port side of the CTF, forward of the damaged area, swimming forward.

Still images captured from the video are available on Legends of the Deep.
Part III coming soon...

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Wahoo Video Commentary

Legends recently received this thorough commentary by Wahoo aficionado Chuck Thompson on the Kartashev video made during the Russian dives on Wahoo in July 2006. It gives a good breakdown on content of the video and the findings to be made through watching it. As it is lengthy, I will post it in segments. Thanks, Chuck!

USS WAHOO (SS-238), LOSS OF
COMMENTARY ON VIDEO
By
C. A. Thompson

The following is a commentary on the video taken by Russian divers on the wreck of the USS Wahoo (SS-238).

COMMENTS

1. The Wahoo sits upright on the bottom, with little if any list, at a reported depth of approximately 230 feet of seawater (fsw)

2. Visibility in the water, although a little dark, is good, approximately 40+ feet. There is considerable small, organic marine debris in the water, flowing with the current.

3. The current appears to be from the Port Quarter.

4. Rudder is amidships, bow and stern planes appear to be “straight and level”.

5. Limber holes are visible from aft of amidships to the stern, both Port and Starboard. They are “Government” pattern limber holes.

6. Marine growth covers most of the hull shown. Some of the “up current” side (port) is clear of marine growth, and corrosion in these clean area’s is minimum, except where entire panels are missing or there is obvious damage (To be discussed later).

7. The video is obviously edited. It jumps around, and in some spots leaves a sequence, only to pick the same sequence up again later.

8. Much expected video is missing. There is no video of the hull forward of the CTF, only the deck and bow plating (bullnose). There is no video of the area inside the bridge area, except from a distance and directly astern, and only darkness is seen. While there is close up video of the damaged area, it is difficult to interpret without easily identifiable reference points. The view of the area of primary damage is obstructed by a drawing of the damaged area.

9. While there is significant video of the periscope shears, there is no good video of the bridge.

10. Both periscopes appear to be fully raised. According to O’Kane (WAHOO), this was standard procedure in Wahoo’s conning tower when on the hunt for ships.

11. The SJ radar is facing directly to Port.

12. Missing decking and superstructure plating. There are several areas, mostly aft of the CTF, where decking/deck panels and vertical superstructure side plating is missing. This is particularly evident: (1) aft of the after deck 20mm mount (over the engine rooms), and (2) superstructure plating above ballast tanks on the port side, aft of the CTF damage. Some adjacent plating shows no indication of damage, and little evidence of corrosion. In all cases (except for the area of major damage amidships), supporting structure/frames are visible, and show no damage.

13. All visible hatches appear to be closed. While none of the hatches is clearly seen because of marine growth, none are in the fully open position, and all appear to be closed. The only hatch that is not visible in some video is the upper conning tower hatch. The closed hatches are substantial proof that none of the crew made any attempt to escape after the loss. This is puzzling as Wahoo is in only 230 fsw.

DAMAGE

1. The most obvious damage is in the area at the control room/after battery room bulkhead (frame 58), primarily on the starboard side.

a. A large section of the conning tower fairwater is missing, it appears to be from the two (port & starboard) fairwater access manways located just aft of the DF antenna, to about 5-8 feet from the end of the fairwater.

b. A small section of the aft end of the fairwater, though badly corroded, is still free standing.

c. On the starboard side, the major damage extends to the deck, the superstructure plating adjacent to the fairwater, and the ballast tanks, possibly all the way to at least the bilge keel (the lower hull in this area is visible only in the opening footage, and not very clearly).

d. On the port side, a section of decking and superstructure is missing, but the ballast tanks cannot be seen in any of the video provided.

e. It is probable that much of the superstructure/tank plating may have been damaged and distorted, but in place, immediately after Wahoo’s loss, but 60 years of storms and corrosion has caused it to fall away (metal which has been exposed to bending, such as an explosion, suffers minute cracking, loss of paint, and is easily corroded).

f. Damage to the pressure hull amidships, below the fairwater, is difficult to interpreted from the video provided. Examination of this area shows a jumble of debris. The Russian drawing seems to indicate that a large section of the pressure hull is missing, but the fact that debris is visible indicates that the pressure hull must still be there. This is not to say the pressure hull is not ruptured, as it most probably is, but that it is not completely destroyed, as the sketch seems to imply. All of the video showing this area has identifiable debris, so location can be established, but no actual penetrations of the pressure hull are identifiable.

g. Examining the damaged open end of the fairwater looking forward, one would expect to see the after end of the conning tower. While there is clear footage of this area, the after conning tower bulkhead cannot be distinguished. What is visible, extending atwartship from port to starboard, is what appears to be a ragged edge of plate just above the pressure hull. It is possible that the cigarette deck was blown (or collapsed) downward, and now covers the aft conning tower bulkhead.

i. There is no visible damage to the periscope shears, and this area is extensively photographed. The SJ antenna is intact, and the SD antenna shows only damage consistent with the fishing trawls covering the periscopes.

j. At the bridge (lookout) level, in a number of views, appears a large piece of wreckage which extends away from the bridge to starboard. No clear footage of this debris is available and it cannot be identified.

2. In the video provided, no significant damage is visible to the forward part of the boat. However, available footage shows only the main deck. Only a couple of deck plates, and possibly a tank manway cover are missing. The 4” gun is trained fore and aft, as it should be. The forward 20mm mount has been rotated, but this is likely the result of fishing trawls. There is no video of the hull forward of the conning tower, and as a result, any damage cannot be seen. There is no distortion in the forward deck to indicate that there may be serious damage to the hull.

3. There is lots of video of the hull aft of the conning tower fairwater. The hull, including propellers and shafts, both diving planes and the rudder, appear undamaged. However there is noticeable minor damage to the aft deck and superstructure in the form of missing deck plates and superstructure panels. One area immediately aft of the after 20mm mount (over the forward engine room) is missing deck plates from port to starboard, and adjacent vertical superstructure plating. However, the supporting framework for this decking/superstructure is visible and appears undamaged. There is also a significant section of vertical superstructure missing on the port side above the ballast tanks, extending from the damaged/missing area of the CTF, aft. In this area all the superstructure plating is corroded away, with the support structure visible and apparently undamaged. It is possible that the missing deck plates and hull panels are the result of the depth charging that Wahoo endured after she was sunk. Close depth charging may not cause rupture of the hull, or destroy deck and superstructure, but it can flex/bend plate and cause loss of paint, both of which would result in more rapid corrosion, and after 60+ years, these areas probably deteriorated (rusted) and fell away. This is illustrated in the vertical side and fairwater plating which shows just the corroded edges of plate, with most of the plate missing.

Part II will address sinking scenarios.

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