[Bubblehead1980]

(TMO 2.5 Update BH V2.0 (2.0soon to be released)
Donation Narwhal mod
100 difficult, cams and contacts off. )


War Patrol Report
USS Nautilus SS-168
War Patrol TWO
30 January-17 March 1942
Area 4

PROLOGUE

Returned from first war patrol on 16 January 1942. Repairs made, provisions loaded, including twenty four MK 14 torpedoes.SD Air Search Radar installed on 27-28 January and tested. Ready for sea 29 January 1942.


NARRATIVE

Departed Submarine Base Pearl Harbor, T.H. at 0900 on 30 January for Area 4 in the Japanese Home Islands via Midway. Conducted dive, torpedo fire control, emergency, and gunnery drills en route.

Arrived Midway at 0830 3 February 1942 and docked at submarine tender. Fuel and provisions topped off, departed Midway at 1400 hours. Turned to course 270 at 10 knots until nightfall, turned to course 280 at 10 knots.


Maintained standard underway routine en route to patrol area, with daily trim dive from 0700-730 each day from 4 February until 11 February. At 1000 on 11 February, NAUTLIUS picked up a SD contact at 8 NM closing and submerged to avoid. Position was roughly 32-30 N 154-40 E, 530 NM N of Marcus Island, and thus it is believed the contact was a patrol aircraft from Marcus Island. Remained submerged until 1930, surfaced and continued on course 280.


Beginning at 0730 on 12 February, daily routine was to submerge in daylight as NAUTILUS was now within range of patrol aircraft from various locations. Typical submerged speed was 3.5 knots on course 280. A depth of 90 feet was maintained, with ventures to periscope depth for observation every half hour, and a vigilant sound watch was maintained as well.


Arrived in Area 4 at 0000 17 February and began standard operations, submerging at daylight and surfacing just after dusk. Patrol depth was 100 ft with periscope observations every half hour and sound watch maintained.

Each day at least two large flying boat types, believed to be H6K were observed. Multiple motor powered fishing boats were observed and avoided in daylight.

However, at 0200 on 20 February, two of these boats were spotted just 4000 yards off port bow. BATTLE SURFACE-GUN ACTION was called. At 0211, commenced firing on two fishing boats, estimated 200 tons each, from 2000 yards. Machine gun fire was returned from the lead boat, but was quickly silenced by two hits from six inch deck gun and multiple .50 cal machine guns hits. Ceased fire at 0214, as both ships were burning and adrift. Secured General Quarters and resumed course 000, arriving off the entrance to Sagami Way before dawn. NAUTILUS submerged just before dawn patrol, in hopes to interdict traffic coming and going from Tokyo Bay.

At 1131, spotted smoke of AK on course 180 in Sagami Wan. NAUTILUS went to GENERAL QUARTERS-TORPEDO and began approach on course 270. A low flying, twin engine flying boat (H6K) flew over, requiring NAUTILUS to submerged to 100 feet to avoid being spotted in the calm, glassy morning seas. The flying boat, likely on her way out for morning patrol, showed no signs of detecting NAUTILUS. Back at periscope depth, identified the AK as the 7590 ton AK ,DAITOKU MARU on course 170 at 9 knots. NAUTILUS continued to close at 3.5 knots. At 1158 periscope observation, the AK was observed turning to course 280, ruining the set approach. Increased speed and attempted to save the attack, but was unable. Enemy air and surface patrols and close proximity to shore prevented further pursuit. NAUTILUS went to 100 feet and secured from GQ.


At 1700, sound reported fast screws bearing 160. NAUTILUS went to periscope depth and observed a DD at estimated 7000 yards, closing on course 005. The ASASHIO Class Destroyer, was apparently heading for Tokyo Bay. Luck of proper position at contact provided ideal set up., and thus GENERAL QUARTERS-TORPEDO was ordered. Approach was made on course 090 at 3 knots. Enemy DD on course 005 at 16 knots. NAUTILUS closed to 1000 yards off the enemy's track. (TORPEDO ATTACK NO.2) At 1718, fired three MK 14 torpedoes from tubes 1,2,3 on ideal track, one that seemed could not miss.

At 1718:20, loud explosion, torpedo detonation was heard. Apparent that the first torpedo prematurely detonated twenty seconds after launch. Periscope was raised and observed DD slowing and changing course as they detonation apparently alerted the DD. The second torpedo appeared that it would hit, but the wake was observed running below target just aft of amidships, likely a "deep runner."

Finally, the third torpedo missed just ahead of the bow perhaps by twenty feet or less as DD expertly maneuvered. DD then made a high speed turn, with one bow torpedo left in tube four, fired a "down the throat" shot from 600 yards and ordered a depth of 200 feet. A large torpedo explosion was heard as passed 85 feet, but believe was another premature explosion, not a hit. DD roared above, dropping four depth charges in close succession, shaking the boat.


Over the course of the next eleven and half hours, the DD hunted NAUTILUS making numerous attacks. (See ANTI-SUBMARINE TACTICS AND EVASION Section) . One particular attack came after two hours of silence, when DD suddenly rushed in pinging. NAUTILUS at 300 feet, rigged for silent running and depth charge, began a slow turn to port, and increased to standard speed for a "burst" of speed as DD roared above. Five splashes were audible as depth charges hit the water. Two detonated, slightly shaking the boat, but not close. After several seconds of silence, a loud , "CLANG" was heard, apparently the sound of a depth charge bouncing off the hull, aft of conning tower. Twelve seconds later, the depth charge exploded, shaking the boat but not damage reported.

Finally, contact was last with the destroyer. NAUTILUS secured GQ, but remained at 300 ft and under Silent Running and Depth Charge conditions until 2300 hours when came to periscope depth. All cleared, NAUTILUS surfaced into the fresh area.

NAUTILUS proceeded to western sector of Area 4 and submerged off Suruga Wan at dawn 21 February for patrol. No contacts were made and surfaced at 2200 hours, proceeding back to eastern portion of area off Chiba Peninsula.

During the morning trim dive at 0900( local) on 22 February, sound detected faint prop noises bearing 075. Turned to course 075 at 5 knots to investigate. By 0930, noise was strongly believed to be a merchant type vessel, but distance was not closing at rate desired, indicating vessel was heading away from NAUTILUS. Thus, after a careful SD sweep, surfaced at 0955 on course 080 at flank speed.

At 1016, lookouts spotted smoke of large AK on horizon bearing 354. NAUTILUS came about to parallel contact, pull ahead for dive and approach for attack. At 1024 SD detected a contact at nine miles, closing fast. Ordered a dive to 100 feet. NAUTILUS returned to periscope depth at 1045, extended the SD antenna for a sweep with no contact. The contacted vessel's smoke plume was visible in the light morning haze bearing 100. NAUTILUS surfaced at 1100 and went ahead flank.


At 1135, NAUTILUS submerged for approach and attack and GENERAL QUARTERS-TORPEDO was called. At 1150, identified the contact as a tanker of the ANJO MARU Class, 2,800 tons on course 030 at 9.5 knots. NAUTILUS
conducted a classic submerged approach at 3.5 knots and readied all four bow tubes, torpedo depth set to 15 feet, as target was believed to have draft of 14 feet. (TORPEDO ATTACK NO.2) At 1200 NAUTILUS fired tube No.1 from 1000 yards. Torpedo ran true and exploded beneath the keel. The tanker was likely empty of volatile fuel cargo was it did not explode was expected, but did lose its way, and sound confirmed engine noises ceased. After fifteen minutes, the stubborn little AO has not sunk, ordered Tube No.2 fired at 1215. Eleven seconds after firing and just yards from target, torpedo prematurely detonated, confirmed visually and acoustically. At 1217 fired tube No.3 and at 1217:44, observed torpedo impact side of vessel, but fail to explode. The "clang" of the impact was audible via sound gear and throughout the hull of NAUTILUS. At 1218 fired tube No.4, which veered off to port, suffering a possible gyro failure. Ordered immediate turn to port to bring stern tubes to bear on target.


At 1233, fired Tube No. 5, observed wake pass below target without detonation. Fired Tube No. 6 which again, detonated just yards from target, but after passing below target. With no desire to waste anymore torpedoes before could be checked out, nor to wait for enemy vessels in area to arrive, NAUTILUS surfaced for BATTLE SURFACE-GUN ACTION at 1246. Upon surfacing, immediately opened from 3500 yards on the unarmed tanker. Gun accuracy was excellent and effective as tanker was soon burning and at 1255, guns ceased fire as tanker settled in water. At 1300, fired four more rounds from each six inch gun at waterline, which finished off the tanker. ANYJO MARU 2800 tons sunk 1321 hours at 34-53N 141-14E 22 February. Two life boats were spotted as NAUTILUS cleared the area at flank speed and secured from GQ.

SD radar contacted was detected at 1342 hours, NAUTILUS submerged to avoid and remained so for rest of the day, surfacing at 2200 (local).

Patrol of the area on 23-27 February brought no contacts, other than daily patrol aircraft. However, at 0200 on 28 February, lookouts spotted the silhouette of a ship on the horizon at bearing 065. Contact was tentatively identified as a AK of 5000+ tons. Low visibility necessitated a shadowing before attacking submerged at dawn. NAUTILUS matched course 030 at 9 knots of next few hours. Finally at 0915 local, with the AK astern, NAUTILUS submerged for attack. GENERAL QUARTERS-TORPEDO was called and approach was conducted on course 095 at 4 knots. Upon observation at 0936, it was revealed target had slightly course course. NAUTILUS compensated for this by speeding up to 6 knots to close range. Upon next observation, set up was ideal. Target was identified as AK of the KENJYO MARU Class, 7,627 tons. Tubes 1,2,3,4 made ready for firing. Torpedo No.1 was set to a depth of 25 feet, as target draft was 24 feet. Torpedo No. 2 was set to ten feet, aiming to take advantage of the backup contact exploder. A keel shot and side impact on such a large ship was believed to be best solution for sinking.

(TORPEDO ATTACK NO.4) At 0951, fired tubes 1,2, from 1000 yards, AOB 90, ideal track. Just after raising scope, observed Torpedo No.1, at 20 feet or less from target, prematurely detonate. Torpedo No.2 hit target right under stack, causing a large explosion, likely of the boilers. Ship went dead in water, sound reported engine noises ceased. At 0954, fired tube 3 , set for depth of 25 feet. Torpedo wake again observed passing below target. Fired tube 4, set to depth of 5 feet. Torpedo hit as aimed, but failed to detonate. The audible "clang" of the impact of the torpedo with target hull was audible aboard NAUTILUS and on sound gear. With forward tubes empty, turned NAUTILUS to bring stern tubes to bear, while forward tubes were reloaded.

Tubes 5,6 and were fired, on minimum depth setting from 800 yards at ten second intervals. Both torpedoes prematurely exploded en route to target. NAUTILUS again turned to bring bow tubes to bear as last three bow torpedoes were loaded into tubes. Tubes 2 and 3 were fired at 1041 hours, torpedo 2 prematurely detonated less than 10 yards from target, after passing below the keel. Torpedo 3, set to minimum depth, ran true and exploded, just forward of the amidships, starting a fire.

However, the large AK refused to sink. Fired tube 4 (final bow torpedo) which after launch, jogged to starboard, before going into a circular run. NAUTILUS, as it did when experienced this malfunction on War Patrol One, went to 100 feet and waited until torpedo reached its end of run.

Back at periscope depth, with stern tubes brought to bear, fired final two stern torpedoes, set for minimum depth from 700 yards. Both torpedoes hit as aimed, but failed to detonate, the clang again clearly audible through hull and on sound. NAUTILUS, out of torpedoes opened the range.

After some contemplation, decided to open range to 6000 yards and utilize the six inch deck guns. The KENJO MARU was heavily armed with what happened to be four inch guns in the bow and stern. However, the risk was considered worth the reward, for this was a large important cargo vessel.


NAUTILUS went to 100 feet and passed below the AK and opened range to 6000 yards. BATTLE SURFACE-GUN ACTION was called at 1120 and after a SD sweep , NAUTILUS surfaced parallel to the target. At 1122, NAUTILUS opened fire with fore and aft deck guns from 6200 yards off targets starboard side. Target returned fire, with a few shell splashes observed in our vicinity but not close. Thirteen hits from NAUTILUS's six inch guns, left the AK burning and sinking, when suddenly a large explosion happened Four minutes after last six inch gun hit. The AK split into two sections at amidships. KENJO MARU 7627 tons sunk at 34-20N 140-10E, 1159 hours.


NAUTILUS submerged at 1204 for SD contact at 8 miles and remained so for rest of day due to heavy enemy ASW air and surface activity in area. Surfaced at 2230 and set course for Pearl Harbor, as all torpedoes were expended. NAUTILUS proceeding at 10 knots had enough fuel to make Pearl Harbor and did not stop at Midway en route. On the morning of 17 March, 1942, NAUTILUS arrived Submarine Base, Pearl Harbor, T.H. and terminated war patrol.


ATTACKS

Three torpedo and the gunnery actions occurred on this patrol. Twenty torpedoes were fired, for four hits. Several "can't miss" shots were in facted missed, due to repeated torpedo malfunctions. Malfunctions include premature detonation of torpedoes before reaching the target, failure to detonate when impacting the target, running deeper than set and thus running too far below target, failing to actuate the magnetic exploder, apparent gyro failures, and circular run. These failures, aside from serving as a source of great frustration, put NAUTILUS and her crew in grave danger. Failures in Attack No.1 led to NAUTILUS enduring a eleven and half hour counter attack. The circular run Attack No. 3 presented grave danger as well.

Gunnery performance, of both crew and equipment was excellent and finished off both vessels damaged by torpedoes that managed to work. A total of 52 6' 53 caliber shells were expended for 36 confirmed hits.

SHIPS SUNK

AO ANJO MARU
2800 tons
1942-02-22 1321
34-53N 141-14E
Sunk by torpedo and gunfire

AK KENJO MARU
1942-02-28 1159
34-20N 140-10E
Sunk by torpedo and gunfire.


Fishing Boat #1 (Armed)
200 tons
1942-02-20 0215
34-34N 139-46E
Sunk by gunfire

Fishing Boat #2
200 tons
1942-02-20 0215
Sunk by gunfire
34-34N 139-46E

Contacted and/or Attacked (Not Damaged)

DD Asashio
1200 tons
1942-02-20 1700
35-3N 139-44E


NAVIGATIONAL AIDS

Cape Taibusa, Boso Peninula and Oshima Island aided in navigation
while in patrol area.



AIRCRAFT CONTACTED

Multiple twin engine patrol planes, believed to be H6K type were observed in patrol area. Enemy patrols the Tokyo area and offshore fairly extensively with aircraft and armed picket vessels, such as fishing boats sunk on 20 February.



ANTI-SUBMARINE COUNTERMEASURES AND EVASION


Enemy aircraft appear to form the backbone of ASW patrol in Area 4, along with pickets. However, it is believed area is patrolled by Destroyers on a regular basis.


The depth charge attack of 20 February was intense, persistent, and accurate. Pinging of active sonar was dominant through attack, enemy did go silent for periods of time to listen for contact. Enemy sonar effectiveness appeared to wane once NAUTILUS reached 250 feet. Although, their persistence allowed apparent intermittent contact, resulting a prolonged pursuit.

Should be noted that most depth charges appeared to be set too shallow to do more than rattle the boat and crew, with the exception of one lucky charge, which bounced off the aft deck. The audible "CLANG" which broke the silence, was a bit disconcerting. The charge exploded about eleven seconds after bouncing off the deck, shaking the boat.


Evasion was conducted by silent running, with frequent course changes. Initial depth for evasion was 150 feet, working down to 300 feet. Speed "bursts" were used as required when enemy passed above or close aboard.


MAJOR DEFECTS AND DAMAGE


Depth charge attack of 20 February caused minor damage. All damage repaired at sea unless otherwise indicated.


1. Trim Pump

2. Hydraulic Pump

3. Piping Leaks

4. High Pressure Air Line Leaks

5.Busted light bulbs-All compartments

6. Aft Battery


RADAR

SD Air Search Radar performed well with typical detection range of eight nautical miles.



SOUND CONDITIONS AND SOUND GEAR

Sound conditions were general mediocre throughout the patrol area.

Sound gear functioned above average considering conditions.


THERMAL LAYERS

Thermal Layers were detected at 200 and 160 feet.


RADIO

Radio performance was normal throughout patrol.


PERSONNEL

Crew performance was excellent throughout patrol, even under trying conditions such as the prolonged depth charge attack of 20 February and repeated torpedo failures.

Eight men and two Officers qualified on this patrol.



HEALTH AND HABITABILITY

Crew health was overall satisfactory. Three delayed cases of venereal disease arose shortly after departing Midway, likely acquired from last shore leave following first patrol. Cases were successfully treated.

Conditions aboard the boat remained overall satisfactory with well prepared meals, mostly calm sea conditions, and overall favorable weather.


MILES STEAMED/FUEL CONSUMED


Pearl Harbor-Midway
Miles 1,325
Gallons 20,244

Midway-Area
Miles 2,750
Gallons 40,650


In Area
Miles 5,250
Gallons 55,221


Area-Pearl
Miles 4095
Gallons 52,288


DURATION

DAYS

Pearl-Midway 4

Midway-Area 14

In Area 11

Area-Pearl 17



FACTORS IN ENDURANCE


FUEL 11,554 gallons

TORPEDOES 0

PROVISIONS 29 days

PERSONNEL Indefinite

Reason for Termination of Patrol- All Torpedoes Expended



REMARKS


A successful patrol with a tanker and large merchant sunk, plus two fishing boats for a total of 10, 827 tons tons. While proud of this accomplishment, results of patrol could have been better with more time on station, but this was preempted by repeated torpedo malfunctions and thus it is sincerely hoped this issues are resolved as soon as possible.



J.P. Thew, CDR, USN.