U.S.S. TANG (SS 306) c/o Fleet Post Office San Francisco, California
A16-3 Serial 013 3 September, 1944
From: The Commanding Officer To : The Commander in Chief, United States Fleet Via : The Commander Submarine Division 141 The Commander Submarine Squadron 14 The Commander Submarine Force Pacific Fleet The Commander in Chief U.S. Pacific Fleet
Subject: U.S.S. TANG (SS 306), Report of Fourth War Patrol.
1. Enclosure (A), covering the fourth war patrol of this vessel conducted in Japanese Empire waters during the period 31 July 1944 to 3 September. 1944, is forwarded herewith.
R. H. O'KANE (A) PROLOGUE
Returned from third war patrol July fourteenth. The refit
by SubDiv 62 and Submarine Base, Midway, completed on the
twenty-fourth, is considered our finest to date. Conducted
normal training and departed July thirty-first.
July 31 (+12) - August 7 (-9)
1555 Underway for areas four and five at two engine speed.
Conducted usual training dives and fire control drills,
and enjoyed yachting weather.
August 8 (-9)
0950 Dived a half hour to avoid a bomber sighted at about
1410 Dived an hour for another bomber about ten miles
2351 Sighted MIKURA SHIMA in the NAMPO SHOTO, but because
of known radar installations nearby, proceeded to INAMBA
SHIMA, a small pinnacle, for checking our SJ.
August 9 (-9)
Conducted submerged patrol near INAMBA SHIMA in the
vicinity of numerous plotted contacts. Continuous
1900 periodic sweeps at forty feet finally located what
might have been smoke beyond ZENNI SU, so on surfacing
proceeded to the northwest to investigate. No contact was
made, but as all the surrounding areas were vacant, closed
the coast in the bight west of OMAE SAKI for submerged
patrol at dawn.
August 10 (-9)
0441 Dived six miles from the beach and continued closing
the coast. A few minutes later sighted single mast and
superstructure of an apparent patrol boat which continued
its sweep down the coast.
0903 Sighted a large engine-aft ship against the beach,
escorted by three bombers. We were already on his beam
six thousand yards away, so except for closing the traffic
route, our approach served only to impress our OOD's with
the necessity of sticking one's eyeballs on the beach to
pick out the shipping.
ATTACK NO. 1
1010 Within an hour of securing from battle stations for
this first ship, and having avoided another patrol by
continuing in, sighted an old type loaded tanker right
against the beach headed for OMAE SAKI. As four bombers
were the only escorts, took a sounding to find we were
still in forty fathoms. A standard speed approach closed
him to 1200 yards where with echo and stadimeter ranges
1034 three Mk 23 torpedoes spread his length by constant
bearings, 100 starboard track. speed 8.5, set at eight
feet, gyros near zero. No hits. No explosions on the
beach three thousand yards away. Two minutes after
firing, the tanker, alerted, reversed course away, so
commenced evasion, thoroughly expecting bombs or several
depth charges. We rolled on the bottom at eighty feet
during our turn to evade, but reached deep water and
commenced periscope patrol.
1500 Very distant counter attack commenced.
1920 surfaced north of DAIO SAKI, and staying clear of its
252 MC radar, proceeded down the 100 fathom curve past
MIKI SAKI searching for any night shipping.
August 11 (-9)
0418 Having doubled back to MIKI SAKI, dived three miles
west of the point, then closed intercept any morning
0515 When visibility was just becoming good through the
periscope, sighted smoke against the beach and the bow
wake of an escort. Before we could reach an approach
course, the escort and a large engine-aft freighter ducked
around MIKI SAKI and into KADA WAN, thence down the coast.
Patrol activity increased steadily with one pinger
generally in sight, an inshore patrol proceeding back and
forth a thousand yards off MIKI SAKI, and a motor boat
resembling a landing barge with six lookouts making a
nuisance of itself.
1244 After ducking for a modern looking gunboat loaded
with depth charges, heard extremely loud pinging coming up the coast. The A/S vessel was not as big as his ping, but coming straight to MIKI SAKI, then changing course to seaward, he forced us off the fifty fathom curve as we kept our stern to him. His method became apparent when a tanker came out of KADA WAN and ducked around MIKI SAKI with the TANG hopelessly out of position for attack. 1500 With changing tide, fogging periscopes nearly ruined the rest of our day for we were spotted by the motor boat when longer exposures became necessary. He was extremely difficult to shake, but on sighting smoke, a half hour run 1635 at standard speed into OKASE WAN left him out on the 80 fathom curve. This put us in about forty fathoms of water, on the route followed by the tanker, and on their most probable track.
ATTACKS NO.2 and 3
The smoke, which had been in two columns, developed into two mast-funnel-mast split superstructure freighters in column. They were escorted well to seaward by the gunboat previously sighted, and by a smaller escort on the other bow. During the remainder of the approach, the leading ship was identified (EC) as of the BIYO MARU class, page 220 ONI 208-J (rev'd), and the second about two thirds her size as similar (EU) to the AKASI MARU, page 230. Both ships were heavily loaded. 1740 When in position 1700 yards on the convoy's beam, just prior to firing a final set-up, sound showed our gunboat coming in fast about a thousand yards away, evidently warned by the motor boat of our presence. 1741 Fired three Mk 23 torpedoes at the leading freighter, range 1800, 110 starboard track, depth setting 6 feet, spread 150 ft of the targets length by constant bearings, followed by a similar spread at the second freighter on an 80 starboard track. Took a quick low power sweep to observe the gunboat filling the field boiling past our stern, evidently having misjudged our course and giving the wrong lead. Reassured, swung quickly to the leading target in time to see the first torpedo hit right in the middle, evidently in his Scotch Boilers, for he disintegrated with the explosion. 1743 On our way deep, timed our fourth and fifth torpedoes to hit the second freighter, followed by a tooth-shaking depth charge attack. As the gunboat's screws on our port bow showed his intent to turn us toward shallow water, make a full speed dash, assured by single ping soundings taken with each barrage. Even at this speed, the twisting, scrunching, breaking-up noises were loud in the direction of the targets. After twenty-two close ones, the depth charges drew aft and we were able to return to periscope depth 1821 in thirty-eight minutes. The gunboat was now about 4000 yards on our quarter, the other escort at the scene of the attacks apparently picking up survivors, and one plane was circling the area. Nothing else was in sight. 2005 Continued to seaward at five knots and surfaced at dark with depth charging still progressing and the area astern of us being swept by searchlights. 2010 Headed for INAMBA SHIMA at 18 knots.
August 12 (-9)
0420 Commenced submerged patrol between INAMBA SHIMA and MIKURA SHIMA back on our schedule. 0736 Maneuvered to avoid a patrol boat and proceeded south of MIKURA SHIMA as the Kuroshio was setting us on the island. 1505 Again the enemy had succeeded in chasing us from a likely spot, for after twenty-four depth charges and continuous planes and patrols, sighted distant smoke in the direction of our dawn position. 1918 As our attempts to maintain, and then to regain contact with the smoke had been futile, and even a six knot enemy ship would reach TOKYO BAY ahead of us, proceeded to the NOJIMA SAKI-INUBO SAKI area to intercept coastal traffic. 2300 Moved into KATSUURA WAN three miles from the beach to insure radar contact on any shipping.
August 13 (-9)
0312 As no contact was made and the visibility dropped to zero from wood smoke rolling from the beach, withdrew for submerged patrol at dawn. 0654 Sighted distant smoke to the southeast headed for NOJIMA SAKI and TOKYO. Four bombers and a patrol boat prevented a surface dash to get on his track, and our twelve mile approach fell short by six thousand yards of attaining a firing position. 1921 After surfacing, took one more turn up the 100 fathom curve to INUBO SAKI before proceeding south to the TORI SHIMA area of the southern islands.
August 14 (-9)
0429 When 40 miles east of HACHIJO SHIMA, dived to avoid detection by a patrol yacht. His maneuvering during the day prevented our usual surfacing for high periscope searches, so kept in sight for a 4" target if better shipping did not show up. Numerous planes indicated that he may have spotted us too. 1430 surfaced to regain contact but dived in twenty minutes on the approach of a plane.
GUN ATTACK NO. 1
1753 Surfaced to maintain contact and check all guns, then closed 1832 to seven thousand yards and commenced firing. The enemy was tenacious and wary, twisting and turning and closing the range at every opportunity, and though he replied only with apparent 20 mm. machine guns, he was on in deflection and not far short with a range of 4500 yards, forcing us to haul out frequently. It was impossible with his movements and the 4" rate of fire to stay on for more than one or two hits, and only eight sure hits were observed. These were beauts, however, demolishing his deck house aft and exploding in his side and upper works. 1926 With eighty-eight rounds expended and the enemy still under control, perhaps from central station, proceeded to the south for patrol on the following day.
August 15 (-9)
Conducted submerged high periscope patrol east of TORI SHIMA surfacing periodically for high periscope searches.
August 16 (-9)
Patrolled on the surface, searching with seven lookouts and high periscope. 1339 Dived on sighting MAVIS, which dropped one depth charge thirty minutes later. 1532 Continued surface patrol.
August 17 (-9)
Patrolled as on previous day. 0736 Dived for an hour to avoid detection by a distant bomber. 1326 dived again for a bomber.
August 18 (-9)
Patrolled as on previous day. 1310 Dived an hour for a distant aircraft, then proceeded west at three engine speed to reach KANTORI SAKI by the following night.
August 19 (-9)
En route KANTORI SAKI for close in patrol. 1304 Submerged thirty miles from the coast and continued to close submerged. 1904 On surfacing closed the coast just short of KANTORI SAKI to intercept any night shipping. The numerous sampans and row of lights previously reported are still in evidence, but nothing interfered with our closing to 5000 yards from the beach, where contact with any shipping would be assured. 2347 Tracked a patrol boat as he came down the coast to seaward of us and then reversed course back toward MIKI SAKI.
August 20 (-9)
Continued close in radar search for shipping. 156 and 256 megacycle radar was in evidence, but it didn't seem to bite. 0450 Dived on the fifty fathom curve two miles from the beach where attack on any coastal traffic was assured. 0805 Avoided a patrol boat coming down the coast.
August 21 (-9)
0947 Sighted tops and smoke of a freighter coming out of the mist from the north. As the enemy was inside the ten fathom curve, we still had to close the coast a little and dodge numerous sampans, but his escorts, two SC's, were will clear on his beam and port bow to seaward. The freighter was a modern, medium sized, engine-aft ship. With range 900, 123 port track, speed 8, gyros around 30, fired two Mk 23 torpedoes at his stack and foremast by constant bearings, depth setting six feet. The first torpedo evidently missed astern and exploded on the beach, while the second torpedo left the tube with a clonk but did not run. We had to take our first eight depth charges at periscope depth, but had gained deep water for the next twenty-two. 2142 Surfaced and headed around SHIONO MISAKI to attack the constant traffic between this point and ICHIYE SAKI. Radar on 82, 99, and 261 megacycles was in evidence but nothing came of it.
August 21 (-9)
0456 Dived in deep water off OKINOKURO SHIMA and closed the beach slowly for an afternoon attack. 0855 A large ship and two escorts proceeding eastward and rounding SHIONO MISAKI out of reach changed our plan, and we closed the next freighter two hours later. She was a medium sized new engine-aft job with escorts well ahead, but with a 3000 yard torpedo run, broke off the attack, as a better shot was practically assured.
ATTACK NO. 5
After closing the beach to a twenty fathom spot off OKINIKURO SHIMA, headed west too buck a two knot easterly sea. 1243 Sighted smoke, then a medium mast-funnel-mast freighter coming up the coast unbelievably close to the beach. Our approach consisted mainly of ducking two sub chasers and whale killer escorts, and turning left for a stern shot. 1317 At a range of 1650 yards, fired three Mark 18-1 torpedoes spread 150 ft of the freighter's length by constant bearings, 110 port track, depth setting six feet, gyros around 20 left. All torpedoes exploded on the beach. We were at 200 feet, two fathoms off the bottom, when the first depth charges let go, and reached deep water twenty charges later. Our evasion at 100 turns kept everything aft including late arriving pingers. Checks on the firing bearings with our Mark 8, and plot of the firing showed everything in order. This left only the possibility of deep running torpedoes to explain our persistent misses, so decided to keep slugging and continue checking torpedoes. On our first trip to MIKI SAKI we were caught napping by a freighter and escort which rounded the point just after dawn. Radar searches had shown no night traffic, so felt sure shipping might wait at OWASE WAN just north of MIKI and KUKI SAKI. 1916 On surfacing, proceeded clear of KANTORI SAKI to probe above the bay.
August 22 (-9)
ATTACK NO. 6
0020 After passing MIKI SAKI, slowed, crossed the 100 fathom curve and proceeded around KUKI SAKI into OWASE WAN. Side lobes were confusing, but we soon found a "pip where no pip ought to be". The night was black and only the long shape of the enemy could be seen until we circled him to get him away from the land background. There he was quite visible, identified as the gunboat who had harassed us during our first visit, topping it off then with those tooth-shakers. He tracked at zero speed and was obviously anchored in about 20 fathoms two miles northwest of KUKI SAKI. Holding our breath, we moved in slowly to twelve hundred yards, twisted, then steadied for a straight stern shot, and 0142 fired one Mark 18-1 torpedo at his middle set on three feet. The phosphorescent wake petered out after a hundred yard run with the torpedo evidently headed down, and hit bottom with a loud rumble, timed half way to the enemy, where there should have been 250 feet of water. It was tracked by sound to this moment, but after the rumble cleared away, nothing more was heard. 0144 Fired a second Mark 18-1 torpedo set on three feet, feeling sure the enemy had been alerted by the first. It's wake was dimly visible directly to the target, tracked also by sound, but it passed underneath, apparently running on the deep side too. With one salvo of three left aft, circled for a 1058 bow shot, and with range 900, fired a Mark 23 torpedo from number 5 tube at his middle, set on zero feet. Though we were stopped and absolutely steady and the gyro angle zero, it took a thirty yard jog to the left before settling towards the target and missed astern. 0200 Still whispering, though the last two torpedoes must have roared past him, fired a second Mark 23 torpedo from number 6 tube set on zero aimed at his gun forward. It took a jog to the left also, but settled down right for his middle. The explosion forty seconds later was the most spectacular we've ever seen, topped by a pillar of fire and more explosions about five hundred feet in the air. There was absolutely nothing left of the gunboat. This vessel was observed at close hand previously during daylight. She was new in appearance, flush deck, with raised gun platforms forward and amidships mounting estimated 3" double purpose guns. Aft of the midships platform was a goalpost structure, possibly for use in sweeping, topped by a lookout or director platform. Her stern had very long almost horizontal depth charge racks holding fourteen counted depth charges a side, and what appeared to by Y-guns on the centerline. On observation before firing she measured between 225' and 250' in length and is estimated to have a standard displacement of 1500 tons. Feeling that our difficulties had been mainly in sluggish steering and depth engines, withdrew at full power to spend the day checking afterbodies of our remaining torpedoes. After giving the steering engines a good workout to insure they were free, checked our rudder throws. On three of the six torpedoes they were three quarters to one degree heavy. With a careful trim and no pressure in the boat, swung all torpedoes and calibrated depth springs. 1900 Now confident that our last two salvos would count, headed for OKAI SAKI and the scene of our first attack of the patrol.
August 23 (-9)
0100 In position on the fifty fathom curve west of OMAI SAKI, moved slowly to the bight of FUKUDA. We were six thousand yard from the beach and it is certain that no shipping passed, though navigational lights were burning. 0417 Submerged, this time in our desired position, and commenced a cautious periscope patrol. Plane activity started right after daylight followed by the first patrol a half hour later. 0803 Sighted smoke of two freighters as they rounded OMAI SAKI and commenced closing their track. As expected, they were practically aground, so closed to 1000 yards from a wreck off FUKUDA, undoubtedly one of our sub's handy-work. Though the escorts were clear, an unexpected zip and a third previously unobserved small freighter put us underfoot. A full speed dash succeeded only in getting us clear as they boiled by our bow and stern about two hundred yards off. 0923 We had been secured from battle stations less than a half hour when an old type destroyer, four bombers, and a float plane commenced searching down the coast. At first it appeared that we'd been spotted, but his circling tactics resembled the routine sweep we'd observed of MIKI SAKI. Though we had our torpedoes set at two feet and he came very close, we could secure nothing but sharp[ tracks or large angle shots. Why his ear-splitting pinger didn't pick us up will remain a pleasant mystery.
ATTACK NO. 7
1017 With the destroyer just clear the reason for the activity became apparent with the sighting of masts and high superstructure of a ship coming down the coast toward OMAI SAKI. He was escorted by a large PC or DE ahead, an SC on his bow, our aircraft previously sighted overhead, and an LST and a PC astern. We had been forced out a little by the destroyer, and a high speed approach was necessary to insure a short firing range. It was therefore not until the angle on the bow opened ten minutes before firing that the full import of our enemy became apparent. The decks of his long superstructure were lined with men in white uniforms, as was his upper bridge. 1110 Made another five minute dash to close the track, slowed and 1118 took two echo ranges, and fired three Mark 23 torpedoes spread his length by constant bearings, 105 starboard track, range 800 yards, speed 8, depth setting six feet, then commenced swinging for a stern shot at the LST. The first and third torpedoes hit beautifully in his short well deck forward, and the after part of his long superstructure, giving him a twenty degree down angle which he maintained as he went under with naval ensign flying. There is no ship resembling this in any of the ONI publications, though if the BUENOS AIRES MARU on page 45 were give a raked bow and her stack cut down level with her superstructure, she would be a close approximation. She was not, however, a hospital ship. The gross tonnage of this vessel would be in the neighborhood of 10000 tons and her standard displacement 15000. 1121 Our LST headed for the beach and someone dropped two depth charges, not close, which permitted us to get two soundings and clear out at 100 turns. For once, depth charging the submarine seemed to take second priority, undoubtedly as survivors were picked up, for it was ten minutes before they started to rain. We had then reached deep water, and two hours at high speed, then gradual slowing, kept everything astern, including a multi-ship echo ranging search during the remainder of the day. 1907 Following our hit and run policy, commenced a full power dash to round SHIOKO MISAKI for another crack at the coastal traffic before a waxing moon made evasion difficult.
August 24 (-9)
Radar on 82, 96, and 256 megacycles was again in evidence near SHIONO MISAKI, but it appears to be poor, or in part early warning installations. 0336 Sighted a ship on the SJ at 10000 yards about on the 100 fathom curve. After tracking it at six knots and gaining position ahead, picked up and sighted another ship close to the beach. As this latter seemed to be the larger and the 0428 former probably an escort, switched approach and dived for a periscope attack in the dawn that was breaking. When the generated range was 3000 he commenced signalling with yardarm blinkers, then turned away displaying a super load of depth charges and efficient looking guns. Though we had our tubes ready for this patrol, he wandered shoreward, never giving us a setup. It appeared that he had been relieved by a second patrol which occupied our attention for the next two hours, 0950 and too late we saw him lead a modern medium sized diesel tanker out of KAZAMPO, just east of ICHIYE SAKI, and head for SHIONO MISAKI hugging the coast. Activity increased toward noon with the passage down the coast of a HISKUN MARU class patrol with two stripes on his stack. Within an hour sighted smoke beyond ATAKI SAKI, and assuming our escort commander would soon be back with the freighter, moved in to the forty fathom curve. He was there all right on the next observation with two large freighters astern. They were both riding high and practically on the beach, escorted astern by a similar patrol, on their beam by two worming destroyers, and five PC's fanned our to the 100 fathom curve. Their echo ranging frequencies varied from about 500 cycles, nicely audible on the JP and sounding like a pile driver on the lowest limit of the JK, to above the upper limit of the JK at 37 KCS. Convinced that this was a little too much for a twenty fathom shot with our last three torpedoes, slithered under the inboard PC, a fathom or two off the bottom, and reached deep water with only one token depth charge. 1930 As our presence was at least suspected in this location, commenced a high speed run around SHIONO and KANTORIU SAKI to attack off NIGISHIMA SAKI after daylight. This point lies about five miles southwest of MIKI SAKI and is tipped by a small island three hundred yards off the beach around which shipping must pass. Our previous observations showed that the motorboat patrols did not range this far from MIKI SAKI. If the echo ranging patrols could be avoided below the gradients in the fifty fathoms available without moving off their track, position for attack would be assured. 2342 Closing NIGISHIMA was not without incident however, for with lookout and radar efficiency poor in frequent rain squalls, suddenly sighted a submarine on our beam parallel to us, unbelievably close at 1100 yards. Put him astern and moved out to five thousand yards where tracking showed he had changed away also. We then commenced an end around for dawn observation and attack if enemy. Positive enemy identification would have been impossible at night. Shortly after we changed course for our end around his pip at five thousand yards grew smaller and disappeared apparently as he dived. After ranging ahead on his original course, clear of his possible submerged positions, and searching for an hour, proceeded to NIGISHIMA SAKI. As this is the same area in which four torpedoes missed the TAUTOG, it will be interesting to know if any friendly submarine was in this position thirty miles southeast of KANTORI SAKI. His diving as soon as we reversed course suggests radar, though no interference on SJ or detector was noted.
August 25 (-9)
0420 Dived three thousand yards from NIGISHIMA SAKI and moved to within fifteen hundred yards of the beach. Patrol activity started within a half hour, but turned back short of us for some time, probably as a continuous stream of cargo sampans was the only escorting necessary. We did not remain at ease, 0805 however, for on a return sweep down the coast, a PC continued directly for us. We were two fathoms off the bottom at 275 feet, rigged for silent running, and depth charge too, when he passed directly overhead. He gave no indication of suspecting our presence, and we were able to come to periscope depth as soon as he passed. Two repeat performances by the PC, sweeps by a HISHUN MARU class patrol, and planes on every observation, indicated coming shipping, by they also prevented sufficient observations to fix our position, and we were off ADASHIKA WAN, 1135 a mile down the coast when smoke appeared around MINI SAKI. The tops, now visible, developed into a medium mast- funnel-mast and a small engine-aft freighter. Guessing they would continue across ADASHIKA WAN, swung left for a stern shot with our last torpedoes. They turned into the narrow bay however, giving us a 130 port track with a range between 1500 and 2000 yards. Confident we could do better, and influenced a little by an escort about to take off our periscope, broke off the attack. We had been back abreast of our island off NIMISHIMA 1429 but an hour when more smoke came in sight. This proved to be a patrol with a deep throated pinger again sounding like a pile driver on the JP. The JP was too realistic where the noise appeared to scrape and klonk along the bottom. It was almost reassuring when he shifted to short scale on passing 1530 250 feet above us, and especially so when he commenced driving piles again.
Attacks NOS. 8 & 9
During the next hour, two and then three patrols swept 1715 the area, followed by distant high frequency echo ranging from down the coast. though its peak was above the range of our receivers, it grew steadily louder until four escort vessels were in sight. The coast was obscured by passing rain, but 1743 soon the enemy ship came in sight very close to the beach. She presented a starboard angle, so closed the beach to get on her track before turning off for a stern shot. Ont he next observation we were on her port bow, so came to the 1800 reverse of her course for low parallax firing. The enemy was now identified as a modern medium sized diesel tanker, heavily loaded. She was identical to the vessel that slipped by us out of KAZAMPO on the previous morning. Her quarter escort slipped astern as she came on, three others remained fanned out on her starboard bow, while the fifth ranged ahead. Our Navigator was correct when he tabooed turning for a straight stern shot, for our first echo range, inadvertently taken 180 degrees out, showed 800 yards to the beach. The second, on the enemy, checked with the periscope stadimeter at 600 yards, so using constant 1805 bearings, fired the first Mark 18-1 torpedo at his stern, the second amidships, and the last a third ship length ahead, right for the middle of the three escorts nearly in line of bearing on his starboard bow. Though the depth setting was six feet and the gyros around 60 degrees, the first two hit exactly as aimed and the third just blew hell out of the leading escort. Though observed sparsely this latter is believed to have been of the KUSKIRO MARU class with standard displacement of 600 tons. 1808 What was left of the tanker had now sunk and the stern escort was making a run toward where his quarter would have been. Expecting some close ones, put him on our port bow and headed for deep water. The initial barrages permitted high speed and single ping soundings, and in fifteen minutes we reached deep submergence. The enemy obviously never knew where the torpedoes had come from, and though his search became systematic with a total of sixty-eight depth charges, our 100 turn evasion outflanked him. 2039 With the moon hidden in clouds and the radar detector coupled to the SD antenna giving only strength two signals on 142, 242, and 306 megacycles, surfaced and cleared the area at full speed. the signal strength decreased rapidly as we withdrew, and searchlights astern disappeared in gathering rain squalls.
August 26 (-9)
0800 In overcast, scuddy weather, continued past AOGASHIMA and set course for PEARL.
September 3 (+9 1/2)
(D) TIDAL INFORMATION
West of OMAI SAKI, a current counter to the Kursohio was persistently encountered.
(E) NAVIGATIONAL AIDS
In general all navigational lights were burning, but with varying characteristics. In addition, observed fixed dimmed navigational lights which are visible less than three miles.
(F) SHIP CONTACTS
(G) AIRCRAFT CONTACTS
(H) ATTACK DATA
The possible defensive minefield between SHIONO MISAKI and ICHIYE SAKI, noted in JICPOA information, is not considered to exist.
(J) ANTI-SUBMARINE MEASURES AND EVASION TACTICS
Speeds up to full under the initial depth charge barrages with soundings taken during explosions facilitated hugging the bottom and clearing the area to deep water. further evasion at 100 turns for at least two hours invariable left all opposition behind.
(K) MAJOR DEFECTS AND DAMAGES
It is considered that the design of the drum type controller for trim pump, drain pump, turbo-blow, and hydraulic plant, is both poor and antiquated. The unreliability of this controller approaches a major defect in the trim pump installation, where it will not stand up under frequent us and fails repeatedly. This is essentially the same controller that was installed in USS ARGONAUT and improved in the WAHOO by addition of a stainless steel cover, which had to be left off to make the frequent repairs. It could well be classed with the Model T Ford, and has the same characteristic crank and choke. Its failures are not traceable to inexperienced operators, as it fails as readily for old hands. Its peak performance occurred on this patrol when its failures put the trim pump out of commission while an enemy sound screen pinged overhead. The silver soldering outfit for convenience is now kept handy by. The following list of failures for this patrol alone should help to illustrate the situation, and need for replacement by a CUTLER-HAMMER type as installed in EB boats: August 7, 1944 Tripping out. Replaced carbon contacts and loosened metal cover. August 9, 1944 Tripping out. Reversing the metal cover helped temporarily. August 10, 1944 Carbon holder broke. Silver soldered holder and renewed carbons. August 11, 1944 Zero ground. The top of the overload coil was found caked with carbon dust. August 14, 1944 Tripping out. Adjusted holding coil. August 17, 1944 Tripping out. Removed metal cover entirely. August 19, 1944 Tripping out. Tightened loose screws on drum contact and carbon holders. August 21, 1944 Tripping out. Carbons were found to be making only 10% contact. August 22, 1944 Carbon holder broke. Silver soldered holder and renewed carbons. August 26, 1944 Tripping out. Tightened shoes and adjusted carbon contacts.
Satisfactory. (M) RADAR
SD - Not used SJ - No interference was noted
It is believed that the transmitter failures of this particular SJ radar continue to be excessive, compared to other similar units. It is serial number 11, probably constructed under pressure and not up to par. As suggested previously by the Force Electronic Mat‚riel Officer, this transmitter should be replaced by another. The part failures for this patrol are listed below:
(N) SOUND GEAR AND SOUND CONDITIONS
Sound conditions were fair. Of interest is the wide frequency range of enemy pinging. It is considered quite probable that many patrols previously considered to be listening only, are actually echo ranging on frequencies higher than can be covered by our receivers. A higher frequency receiver to determine this alone would be valuable.
(O) DENSITY LAYERS
Excellent layers were encountered south of HONSHU, generally beginning between 100 and 150 feet.
(P) HEALTH, FOOD, AND HABITABILITY
(a) Number of men on board during patrol - - - - - - - - - 78 (b) Number of men qualified at start of patrol - - - - - - 47 (c) Number of men qualified at end of patrol - - - - - - - 65 (d) Number of unqualified men making their first patrol- - 8 (e) Number of men advanced in rating during patrol - - - - 15
(R) MILES STEAMED, FUEL USED
Midway to area 2425 mi. 22500 gal. In area 3350 mi. 38000 gal. Areal to Pearl 3325 mi. 53000 gal.
Days enroute to area 7 Days in area 17 Days enroute base 9 Days submerged 12
(T) FACTORS OF ENDURANCE REMAINING
Torpedoes Fuel Provisions Personnel 0 7500 60 days indefinite
(V) MARK EIGHTEEN TORPEDOES
The routine followed was similar to that of other boats except that it was not found necessary to interchange torpedoes between tube and racks.