[Bubblehead1980]

TMO Update BH V2.0
Donation Narwhal
100 difficult, cams and contacts off.



War Patrol Report
USS Nautilus SS-168
War Patrol TEN
24 January- 13 March 1944


PROLOGUE


Returned to Submarine Base Pearl Harbor, T.H. from War Patrol NINE on 12 December 1943, a special mission in support of the invasion of the Gilbert Islands. Conducted normal repair and refit for upcoming patrol. After three special missions in a row, NAUTILUS was assigned to a dedicated anti-shipping patrol in area CORN FIELD in the Philippine Sea, North of Palau. A mixed load of torpedoes were procured for this patrol. Forward torpedo room had eight of the MK 14-1A torpedoes with improved MK contact exploder, as well as six MK 23-1 torpedoes with the improved exploder as well. Aft torpedo room had four MK 18-1 electric torpedoes, and two MK 14-1A torpedoes with improved exploder as well. All torpedoes loaded on 23 January. Received word would be transferred to Australia in order to support operations in the Philippines , and thus would end this upcoming patrol in Brisbane. Ready for sea 24 January 1944.


NARRATIVE


Departed Submarine Base Pearl Harbor, T.H. at 0900 24 January and set course for Midway where would top off fuel prior to proceeding to assigned area. Conducted various drills en route to Midway over next few days and maintained a 14.5 knot speed of advanced.

Arrived Midway 0900 28 January and docked at sub tender for fuel top off, departing at 1400. Exited the reef and proceeded on course 255 a near strait line to assigned area some 3,200 nautical miles away. In order to conserve fuel, transit to area was made at 8 knots on the surface, diving as required.


At 0001 on 3 February, when NAUTILUS was approximately 250 nautical miles North of Wake Island, received ULTRA stating enemy submarine would arrive Wake Island between 0800-1200 4 January and to intercept. Proceeded to Wake Island, arriving off the channel to the North at 0400, making SJ contact with island at 29000 yards. Submerged ten miles north of Wake Island and conduct patrol. Sound soon contacts a small PC type boat which came out and swept the approaches to the channel, indicating expected arrival. At 0830 NAUTILUS had to 300 feet and rig for silent running to avoid the PC, which soon meandered about and clear area.

Sound reported possible submarine contact bearing 010 at 0900.. Rose periscope depth and soon spotted a surfaced submarine bearing 005 8000 yards. Went to General Quarters-Torpedo and began approach, turning off track to bring the stern tubes, loaded with MK 18 electric (wakeless ) torpedoes, to bear.0911 observation showed a Japanese I-Class Submarine on course 170 at 10.5 knots. Tubes were made ready to fire, set for a depth of 5 feet.

Torpedo Attack No.1

Fired tubes 5,6, from range of 1800 yards at 0914 and at 0916, both torpedoes hit the submarine, causing a massive series of secondary explosions. Submarine, on fire from amidships forward, sank less than 40 seconds. Went to 200 feet to depart area and avoid a PC closing on area.



Surfaced at dark and proceeded on course to assigned area.



February 5-10 was uneventful, en route patrol area. On February 11, and 12, forced to submerged twice each day to avoid long range air patrols (MAVIS /EMILY sighted) Transited North of Saipan on the 12/13th and into the Philippine Sea. On 14 February as passed through area FLOWER BED at position 15-20N 137-30E , spotted a surfaced submarine believed to be of Gato Class, but was unable but lost visual and SJ contact. Believing she submerged turned opposite direction and departed at flank speed, just in case.


At 0030 on 15 February arrived in assigned area (CORN FIELD). Submerged twice on 16 February to avoid SD contacts.


17 February

Torpedo Attack No.2


At 0748, SJ contacts bearing 006 27,545 yards,. position 15-50 N 132-30 E
APR-1 detected radar emissions same bearing as SJ contact.
Increased speed to close, and with rapid range/bearing changes and failure to close, along with radar emissions, deducted target was high speed vessel.


At 0831, spotted large warship, identified as a CA, possibly Takao Class. One DD escorting, on course 205 degrees at 21 knots. Unable to outpace the ship or keep up due to NAUTILUS's 17 knots max surface speed, readied torpedoes on low power setting for long range shot, depth eight feet.

At 0848 fired tubes 1,2,3,4 7800 yards, but at 0856 all torpedoes missed. CA took slight course change after launch, which opened range and changed angle, pushing target just out of reach of torpedoes max 9000 yard range.


Continued pursuit but the CA (now identified as Takao Class) pulled out of visual range and raced ahead. NAUTILUS continued shadowing to get visual at dawn and send up to date contact reports, hope for zig towards for another shot.


Torpedo Attack No. 3

However, all was not lost as not long after losing contact with the Takao CA, atSJ made contact bearing 288 27000 yards at 1016. PPI showed disposition of a northbound convoy. Turned to course 095 to intercept.


Submerged for attack at 1115 and conducted approach on seven ship, three escort convoy. At 1138 fired two MK 18 electric torpedoes from tubes 5,6,, which hit the DAIKOKU MARU (7590 tons) amidships. Escorts closing, went to 300 feet, rigged silent running and depth charge. Multiple explosions and other sounds were heard of the vessel sinking at 1144.
Escorts came in and delivered a brief depth charge attack, losing NAUTILUS as leveled off at 350 feet. However, they remained in area to prevent from surfacing.


Torpedo Attack No. 4

NAUTILUS finally surfaced at 1900 and proceeded to regain contact which did at 2044. However, as was passing the port flank of convoy at 2344 for end around, APR-1 detected radar signals and soon a DD identified as Akatsuki Class peeled off at high speed. NAUTILUS turned away but had no hope outrunning the destroyer.


At 0101 fired tube 5 (MK 14-1A) from 3800 yards in a "down the throat " shot on the surface and prepared to dive. Torpedo hit target, but did not get the expected explosion, possible dud warhead. The DD however, did slow and turn away briefly before coming back at NAUTILUS. NAUTILUS submerged to 300 feet, rigged for silent running and depth charge. The Akatsuki was heard leaving the area, as another escort arrived, pinging, searching, dropping multiple DC patterns in area, none close.

Torpedo Attack No. 4A

NAUTILUS surfaced at 0235 and began another attempt at end around. However, soon the enemy radar was buzzing and again detected NAUTILUS, as two escorts rushed back our way. Again turned away and fired a down the throat shot, yet again on the Akatsuki DD from 4100 yards on surface. The torpedo hit, but with same result as last time. However, Akatsuki did slow, she was hurt. NAUTILUS submerged to avoid the second escort, as fast moving subchaser type as well as a SD contact. Apparently a night flyer had been called in.


Secured GQ and remained on silent running while escorts hunted area. Finally able to surface at 0800. Attempted end around to regain contact, but multiple aircraft prevented this. At 1234 while on surface, SD failed to detected incoming aircraft, which seemingly appeared out of no where and bombed NAUTILUS, fortunately her bombs fell short to the port side , no damage. Submerged and remained submerged for remainder of the day.
18-19 February were uneventful with some storms passing through the area.


20 February

Torpedo Attack No. 5


Made SJ contact on convoy at 1844 bearing 240 26000 yards. Set intercept course and at 2040 spotted smoke of eight ships, two escort convoy on course 025. Submerged at 2050 for attack.

Approaching target, spotted a SANRAKU MARU tanker of 3016 in column on
opposite side of convoy but with the spacing decided could fire through with
a solid chance of hits on the tanker. At 2107 fired spread of three MK 14-1A torpedoes from tubes 1,2,3 from 1700 yards and upon impact of first torpedo, tanker, erupted in massive fireball, second and third hits increased the conflagration, no doubt fueled by volatile northbound fuel oil. Tanker sunk at 2109.

Selected a large AK similar to MIIKE MARU of 11800 tons and fired tube no 4 as ideal set up presented itself. Torpedo hit and set off a massive chain reaction explosion, toppling masts and causing the large AK to list. With escorts closing, went deep rigged for silent running and depth charge. Soon heard the maru breaking up and sinking at 2116.

Depth charge attack which followed was prolonged and brutal, but believe thermal layer and heavy chop of seas protected NAUTILUS to a large degree. Lost sound contact at 0200 and surfaced at 0300, attempted to regain contact but unable. 21-27 February were uneventful as patrolled area searching, aside from diving to avoid occasional patrol aircraft.


28 February


Torpedo Attack No. 6


At 1104 SJ contact bearing 177 25000 yards turned into another northbound convoy. Repeated zigs made approaching target difficult but finally was able to submerged for attack at 1345. At 1418 from range of 1000 yards fired three MK 23 torpedoes at MADRAS MARU 3800 tons. All three hit and AK quickly slipped beneath the waves at 1421.


Two escorts closed in and although had initial trouble locating NAUTILUS, their search paid off and pinging began at 1454 NAUTILUS was shaken violently many times but no damaged. Finally, a close depth charge, likely below the amidships/control room caused heavy damage. (see damage section. Most serious of which is apparently destroyed bottles which contain compressed air reserve. Some minor flooding in control room was reported as well. The depth charge attack persisted for five hours until lost contact at 2059.

29 February

Torpedo Attack No. 7

NAUTILUS, struggled, but managed to surface at 2200 to assess her situation. Fortunately, compressor was intact and able to produce some air into reserves, although a limited amount. Although damage, it was decided could mount a surface attack with last three MK 23 torpedoes and proceeded on pursuit course. Contact was regained at 0031 and pulled ahead of convoy, closing from starboard. Convoy was on course 330 at 8 knots. Slightly illuminated by the faint sliver of moon lowering over the horizon.

Spotted a large AK believed to be 7000 ton HIYAMA MARU. At 0054 fired Tubes 1,2,3 (MK 23-1 torpedoes) from 2500 yards on surface. All three torpedoes hit, crippling the freighter. NAUTILUS came under heavy gunfire from damaged AK and her cohorts while swinging, away but no hits were scored. Star shells and spotlights illuminated our stern as raced away under fire, and both escorts were closing fast. Merchants soon ceased fire as lost visual but one DE type escort astern fired several times before ceasing, apparently losing contact. Not wanting to dive unless forced, continued on surface. Soon both escorts converged and began dropping depth charges, convinced we had submerged, as NAUTILUS slipped into the night.


With all torpedoes expended, set course for Brisbane, passing East of Palau, West of of Admiralty Islands and East of New Guinea through the Vitiaz Strait. NAUTILUS opted not to stop at Milne Bay for fuel as had enough to reach Brisbane. Transited the Jomard Passage, spotting a Australian DD after exiting at 0800 9 March.


At 1726 on 9 March 135 NM South of Jomard Passage at 13-17S 152-27E,
SD made contact at 15000 yards. Believing contact to be friendly given location, did no submerged. However, lookouts soon spotting a large four engine flying boat, believed to be a EMILY, closing fast. Ordered dive. As passed 70 feet, heard plane roar above but no bombs were dropped. Possibly a recon patrol from Rabaul. Remained submerged until dusk, the surfaced and continued on to Brisbane.


10- March was uneventful as transited to Brisbane. Rendezvoused with Australian DD escort outside Moreton Bay entrance, navigated the minefield (new feature in V2.0, always a escort to show player the way through the minefield) at 0830 13 March. Docked at Brisbane at 0955 , terminated war patrol.


SHIPS SUNK


I-Class Submarine 1800b tons

AK DAITOKU MARU 7590 tons

AO SANRAKU MARU 3000 tons

AK MIIKE MARU 11800 tons

AK MADRAS MARU 3790 tons

AK HIYAMA MARU 7145 tons

Total tonnage sunk for patrol: 35,239 tons.


SHIPS DAMAGED


DD Akatsuki Class 2000+ tons




MAJOR DAMAGE AND DEFECTS

February 29 1944 Depth Charge Attack

All damage repaired at sea unless otherwise noted.


1.Compressed air banks severely damaged. Limited to just 12 percent of normal capacity for remainder of patrol.

2.Compressor

3.Trim Pump

4. Hydraulic pumps

5. Piping leaks

6. High pressure air line leaks

7. Flooding- Control Room-minor.

8. Busted light bulbs and glass fixtures throughout the boat.



CASUALTIES

CTM H.B. Bell, USN. (Chief of the Boat) injured in control room by depth charge. Recovered.

S1c V.D. Pitt suffered severe combat fatigue during/after depth charge attack of 28 February. Detached for treatment.



ANTI SUBMARINE COUNTERMEASURES AND EVASION

Enemy appears to use using a more powerful depth charge that encountered on past patrols. Heavier charge appears to have a improved sink rate, providing less time to get out from under a pattern when dropped. Believe charge has a improved exploder permitting increased depth setting as well.

Enemy escorts, especially full fledge destroyers seem to regularly equipped with radar now.

Evasion was conducted by course, speed, and depth variations. Operation below thermal layers when available assisted in evasion as well. NAUTILUS reached a depth of 395 feet to evade enemy. A strong pattern above pushed the boat to 400 feet at one point.


REMARKS

A successful but challenging and busy patrol. This was NAUTILUS's first dedicated anti shipping patrol since early 1943 and first engagement with enemy vessels since May 1943, as three previous patrols were all dedicated special missions, along with a overhaul period in summer 1943.

While still a capable vessel, improved enemy equipment and tactics revealed NAUTILUS's age, vulnerability, she is not as well suited for front line anti-shipping operations compared to newer boats. However, in spite of this a impressive number of ships, including a enemy submarine and valuable tanker were sunk on this patrol.

W.D. Irvin