Nakajima A6M2-N "Rufe" pt. 8 - Kimikawa Maru

Before moving to warmer seas we would like to thank everybody for the kind and encouraging comments for this series. We also received some interesting questions we would like to address as best as possible. This posting is about the seaplane tender Kimikawa Maru which saw much action travelling to the Aleutian and Kuriles islands...and more.

 

 

 

Kimikawa Maru was completed on July 15, 1937 as a cargo ship for Kawasaki Kisen and was placed on the New York line but also travelled to Italy, according to some sources. It was one of the four sister cargo ships of -kawa (-river) Maru the others being Kamikawa Maru, Kiyokawa Maru and Kunikawa Maru.

With the outbreak of the Sino-Japanese war in 1937 a first group of cargo ships were converted to seaplane tenders, including Kagu Maru, Kinugasa Maru and Kamikawa Maru.

Between July and October 1941 a second group of merchant vessels started to be converted to seaplane tenders, including Sanyo Maru, Sagara Maru, Sanuki Maru, Kiyokawa Maru, Kimikawa Maru and others. The last was Kunikawa Maru which was completed as a seaplane tender in July 1942. Nevertheless, contrary to the first group, not all conversions of the second group were completed as planned.

Kimikawa Maru was to have 2X14cm cannons, 2X12cm a/a guns, 2X8cm a/a guns and 2Xtwin25mm a/a guns. Instead she got 2X15cm cannons, 2X8cm a/a guns and 2Xtwin25mm a/a guns, plus two 7.7mm machine guns. Two searchlights were also installed, one of 110cm the other 90cm. The derrick behind the funnel was removed and the rear of the ship was modified to be able to carry and operate seaplanes. A wooden deck was laid out with rails on the sides to handle the seaplanes and a single catapult was installed on the starboard side. The original plan called the seaplane tender to be able to carry a maximum of two "Jake" and two "Pete" on the front deck and two "Jake" and six "Pete" on the rear deck but upon completion on July 6, 1941 Kimikawa Maru had enough space to carry about eight seaplanes, usually six Mitsubishi F1M "Pete" and two Aichi E13A "Jake" on the rear deck and only on special occasions, if at all, on the front deck. 

As a seaplane tender she was accepted by the IJN on July 25, 1941, became part of the 5th Fleet and operated in the Northern Area.

In October 1943 she was converted back to transport and was finally sunk on October 23, 1944 by USS Sawfish. 

Kimikawa Maru took part in the Operation "AL" against the Aleutians on May 29, 1942 with the Northern Area Fleet and on June 8 unloaded eight "Jake" seaplanes and provisions on Kiska Island.

On July 3 while in her anchorage in Agattu Island she was attacked by USAF B-24 and suffered slight damage due to a near miss but had to return to Yokohama for repairs. 

 

As we saw in previous postings, Kimikawa Maru started ferrying seaplanes to Kiska from August 1942. Unfortunately aviation and naval sources don't always agree on the dates, the number and the type of the aircraft transported and this makes things very confusing.
The first occasion was on August 14 when five "Jake" seaplanes were transported to Kiska and again on August 31 when the same number and type of seaplanes were ferried.

On September 25, six "Rufe" and two "Jake" floatplanes were ferried to Kiska.

November.

Aviation sources (Izawa) mention that on November 6, Kimikawa Maru unloaded three reconnaissance seaplanes ("Jake") and six "Rufe" to Attu which were to fly the next day to Kiska. The reason for this was the strong presence of US bombers in the Kiska area and let's remember the unpleasant experience at Agattu island. But why didn't Kimikawa launch her seaplanes from the catapult and let them fly to Kiska? The distance between the two islands is less than 400km (240mi). The range of "Rufe" was 1,782 km (1,107 mi) and that of "Jake" was a staggering 2,100 km (1,300 mi). Well, the answer can be found in the page 68, middle caption, of "Maru Special #25" (March 1973): “In October Kimikawa Maru received orders to ferry five "Rufe" and three "Jake" seaplanes to Kiska but since the "Rufe" seaplanes could not be catapulted they were left back in Tateyama.”

The photo from Maru Special #25. Note the "Jake" on the right of the photo but also the three Kawanishi E7K "Alf" on the left. We have not discovered any reference of Kimikawa Maru ferrying "Alf" to the Aleutians or the Kuriles but the above caption could mean that the "Rufe" stayed back and were replaced by the "Alf" seaplanes. Note the tail code "X-2". 

I believe the combination of the above offers a clear answer to the question whether the "Rufe" seaplanes could be launched by a catapult or not.
According to this Japanese site which features a diary of the Kimikawa Maru movement, on October 21 the ship departed Yokosuka with five "Rufe" and three "Jake" arrived at Paramushir on October 25, then left on November 2 arriving in Attu on November 6, unloaded the aircraft and returned to Ominato on November 6.
And this site mentions - 2 November 1942: Arrives at Kiska. Offloads her six A6M2-N and three E13A1, then moves to Attu the same day.
November 14 the ship departed after taking on board four reconnaissance seaplanes in Ominato and arrived in Kataoka Bay in Shumshu Island on November 18. The next day, November 19, departed again and at N52.50-E166 catapaulted the seaplanes to Kiska Island. On November 24 returned to Ominato.
Aviation sources and Combined Fleet mention nothing regarding this transport.

December.
Aviation sources mention that on December 25 Kimikawa Maru brought seven "Rufe" to Attu and three pilots also arrived as reinforcements.
The Japanese Navy site mentions that on December 8 departed Ominato arriving at Yokosuka the next day. While in Yokosuka the ship took on board five "Rufe" and eight reconnaissance seaplanes (type? Either "Pete" or "Dave", certainly not "Jake" as the ship could not carry more than four of these) and departed on December 16. After a stop at Kataoka Bay between December 20 and 23, arrived in Attu on the 26th returning to Ominato on January 1st.
Combined Fleet mentions:
18 December 1942: From the open sea at 52-50N, 166E, KIMIKAWA MARU launches four reconnaisance seaplanes bound for Kiska.
25 December 1942:
Arrives at Kiska with destroyer HATSUSHIMO. Debarks seven A6M2-Ns and departs same day.
 

January
The Japanese Navy site mentions that on January 19 Kimikawa Maru took on board ten "Rufe" departed from Yokosuka and after being escorted by the captured HMS Thracian until Inubosaki in Chiba prefecture sailed to Paramushir (nothing is mentioned regarding the fate of these ten "Rufe").
After that Kimikawa Maru joined the 10th convoy transporting seven "Rufe", one reconnaissance seaplane, two Tokuhatsu landing craft and four Daihatsu landing craft departing Paramushir around January 28.
Combined Fleet mentions:
13 January 1943: Departs Ominato. Arrives at Yokosuka that same day. Loads eight A6M2-Ns and one E13A1 for transport. Her cargo also includes four Daihatsu and two smaller barges.
31 January 1943: Arrives at Attu. Offloads her Rufes.
1 February 1943: Arrives at Kiska with USUGUMO. Departs the same day. Offloads her Jake.
Here's what we found from original Japanese sources. According to the official IJN plan dated January 22, Kimikawa Maru was to transport seven "Rufe", one reconnaissance seaplane, two Tokuhatsu and four Daihatsu landing craft as well as 700 soldiers. Together with Kimikawa Maru were to be Sakito Maru and escorted by the destroyer Usugumo and arrival date to Attu was to be January 27. On January 24 the Commander of the 5th Fleet ordered the captains of Kimikawa Maru and Usugumo to depart whenever possible without the soldiers. The ships were to be led by Usugumo and deliver the "Rufe" to Attu as soon as possible. On January 26 the captain of Kimikawa Maru radioed the headquarters that the bad weather in the area made impossible to deliver the aircraft and the landing ships by January 29. Therefore the ship was to return to Paramushir to get refueled and then make another effort to reach the Aleutians. On January 28 the captain of Kimikawa Maru radioed Attu explaining that the convoy will depart at 17:00 that day and is scheduled to arrive on the 30th at 19:00. There are no more cables but a report mentioned that after unloading their cargo at Attu, Kimikawa Maru will depart on January 31 at 21:00 to return to base escorted by Usugumo.
Aviation sources mention that on February 1, 1943 six "Rufe" and one "Jake" were delivered to Kiska, agreeing on the date but disagreeing on the location and the number of "Rufe" seaplanes.

February-March
According to the summary report of the 1st Destroyer Squadron there were two plans to reinforce the Aleutians. The 1st plan called for troop transport Sakito Maru and auxiliary transport Shunko Maru to ferry provisions to Kiska. They were to be escorted by cruisers Kiso and Abukuma, destroyers Wakaba and Hatsushimo, Kimikawa Maru and destroyer Inazuma (if possible cruiser Maya too). Kimikawa was first to launch her reconnaissance seaplanes to reconnoitre the area, then the planes to reach and stay in Kiska. If conditions were favourable the rest of the ships were to follow.
The 2nd plan called for Kimikawa Maru not to participate but only shipsto make a fast dash to Kiska without any air cover.
The 1st plan was preferable and ships were to depart on February 13 and arrive in Kiska on the 18th.
The two Navy sites agree that on February 9 Kimikawa Maru departed Ominato, made a stop at Paramushir and on February 12 launched (or catapulted) seven "Rufe" and five reconnaissance seaplanes (again "Pete" or "Dave") to Kiska from N52.55-E168 and returned to Yokosuka on February 21.
Nothing is mentioned regarding this transfer in Aviation sources. But the action report of the 1st DesSq mentions that on February 14 Kimikawa Maru and destroyer Inazuma delivered four reconnaissance seaplanes to Kiska. Two other seaplanes were damaged, and one more got lost.
According to the summary report of the 1st DesSq on February 12, the 2nd plan was decided to be put forward, i.e. two transports with escorts to make a dash to Kiska without Kimikawa Maru but from the movements of the various ships it seems that this plan was also scrapped and transports made fast runs separately to the Aleutians each escorted by light cruisers and destroyers.
The original plan needed to be rethought as was shown in the summary report of the 1st DesSq which mentions that the loss of Akagane Maru on February 19 and the elevated presence of enemy aircraft due to the completion of the airfield on Amchitka and also the presence of enemy ships in the area made it necessary to organize a transport convoy protected by the full force of the northern units. This was attempted in the end of February and the operation was named "A". The first group named "I" (1st) included Kimikawa Maru, Awata Maru, Sakito Maru and were protected by the 21st Sentai including heavy cruisers Maya and Nachi, light cruisers Tama and Kiso and destroyers Hibiki, Hatsuharu, Usugumo (there is a question on the presence of destroyers).
From February 27 to March 18 Combined Fleet mentions:
27 February 1943:
Departs Yokosuka in convoy I-21. KIMIKAWA MARU carries six float fighters and three reconnaisance seaplanes.
7 March 1943: Departs Paramushiro in fleet convoy 21 consisting of AWATA, KIMIKAWA and KASADO MARUs escorted by light cruisers TAMA and KISO. Heavy cruisers NACHI and MAYA provide distant cover.
10 March 1943: Arrives at Kiska at 1800. Disembarks 185 military personnel. Begins unloading ammunition and airfield materials, but at 2100 the convoy is forced to depart because of the threat of air raids. The ships depart with much cargo on board.
10 March 1943: Arrives at Attu. Offloads six A6M2-N Rufes. Departs same day.
18 March 1943: Arrives at Yokosuka.
The Japanese documents confirm the above information.
The second group named "RO" (2nd) including Awata Maru, Sakito Maru, Sanko Maru plus the escorts of the first group was to reinforce the Aleutians at a later date but this effort resulted in the Battle of the Komandorski Islands.
A review of the February-March events indicates that the Aleutians were in dire need of reinforcements, preferably "Rufe" seaplanes. Since these could not be catapulted in mid-sea, they had to be offloaded directly on Kiska or Attu and the presence of U.S. forces in Amchitka Island made that extremely precarious. So, it seems the seaplanes Kimikawa Maru carried changed depending on the situation. If they could dash and offload planes on Attu or Kiska they carried "Rufe". If they couldn't, they carried either "Jake" or "Pete" (probably) which they catapulted mid-way.

Below is a map included in the "Air Objective Folder on the Kurile Islands" of the US Army Air Force dated May 25, 1943, featuring the Kashiwabara Harbor on the island of Paramushir, right across Kataoka Bay on the Shumshu Island; the destination of Kimikawa Maru during her trips to the Kuriles.

May
Combined Fleet has the following:
1 May 1943: Departs Yokosuka. 
... 
5 May 1943: Arrives at Kataoka Bay. 
11 May 1943: American Operation "LANDCRAB" - The Invasion of Attu, Aleutians:...
That same day, KIMIKAWA MARU departs Paramushiro in Vice Admiral Kawase Shiro's Attu Task Force Escorted by cruisers MAYA and KISO, DesDiv 21's HATSUSHIMO and WAKABA. She is transporting eight F1M2 Petes and two A6M2-N Rufes of the No. 452 Naval Air Group. 
The plan calls for KIMIKAWA MARU to launch its floatplanes from a point 250 miles SW of Attu to fly to Kiska, but after the American landings on Attu, she and her escorts are ordered to return to Paramushiro. 
15 May 1943: Arrives at Kataoka Bay, Shimushu Island.
The Japanese Navy site agrees with the above with the exception of six "Pete" instead of eight.
This information is based to a large degree on a plan found in a document released by the 1st DesSq dated May 6.
But as we saw here, according to Izawa, the 452Ku had returned to Japan mainland on March 27 and reorganized on May 18. So the natural questions are: 1. what was the cargo of Kimikawa Maru when she departed Yokosuka on May 1?, 2. if she carried 452Ku "Pete" and "Rufe" seaplanes to be flown to Kiska, what was the point when the unit had already evacuated the Aleutians? Something's fishy here, right? The problem lies in that the Aviation guys check mainly aircraft related sources and the Navy guys mainly ship related and as a result the stories don't always agree.
Well, there are two complementing sources that agree between them in everything and clear completely the air adding on top many interesting details. The first is the book "Kiska - Nihon Kaigun no Eiko" (Kiska - The Glory of the Japanese Navy) by Ichikawa Konosuke who served on Kimikawa Maru as LCDR for accounting and provisions and the second, an article by Furukawa Akira in the book "Kaigun Suijoki-tai" who served as Chief Officer on Kimikawa Maru and as hikocho with the 452Ku.
According to them Kimikawa Maru left Yokosuka on May 1st. Stopped at Tateyama and took on-board eight "Pete" (NO "Rufe") floatplanes together with Hikotaicho Sakamoto Terumichi, pilots/observers and maintenance crew and headed to Paramushir area, where she arrived on May 5 and stayed for about six days. On May 11 Kimikawa Maru departed Paramushir to send aircraft reinforcements to the Aleutians. She was escorted by light cruiser Kiso and destroyers Shirakumo and Wakaba and the plan was to catapult the eight "Pete" floatplanes that she carried as close as possible to Attu Island, let them fly to the island and then on to Kiska. But on the way to the Aleutians they received message that U.S. Forces had landed on Attu. Considering that the Japanese forces on Kiska would be in very difficult position if the U.S. forces took Attu, an order was given the eight "Pete" of Kimikawa Maru to be catapulted and attack the enemy in the Attu area. The rest of the Northern fleet was to join in but the next day there was very heavy fog, the ships were sailing 200nmi west of Attu waiting for further orders and after relizing the strength of the US landing fleet and considering the bad weather that was to continue until the 15th, the order to attack was recalled and all the ships returned to Paramushir. Upon their return to Paramushir they found a number of ships waiting and "Betty" bombers on stand-by. More ships joined in and there were daily plans to attack the enemy forces in Attu but the weather didn't permit them to leave. Finally on April 18 rumours were received that Yamamoto Isoroku was killed and a mood of complete depression spread among the officers, some of them bursting into tears.
From the above, two things become clear: 1. Kimikawa Maru did not carry any "Rufe" seaplanes during that mission, 2. the "Pete" group of the 452Ku moved to Paramushir and then obviously to Shumshu at that time, not "around the end of May". Upon further research we discovered that although the whole unit had returned to Japan, at least three 452Ku "Jake" seaplanes were left back on Kiska and flew daily missions to Attu and back. That would mean that pilots and at least some ground crew were still present during that time and therefore, sending "Pete" seaplanes as reinforcements to provide some aerial cover would make sense.

According to Izawa, from July 1942 until March 1943 Kimikawa Maru and other ships transported to Kiska a total of 35 "Rufe" seaplanes.

Following the capture of Attu and the evacuation of Kiska, Kimikawa Maru was then assigned to support the forces in the Kuriles Islands transporting aircraft and material to Paramushir and Shumshu Islands.
Regarding the ship's movement during that period the "Combined fleet" site mentions:
25 May 1943: Departs Kashiwabara Bay.
26 May 1943: Arrives at Ominato. Resumes patrols along the Kurile Islands chain.
31 May 1943: Departs Ominato.
13 June 1943: Arrives at Kataoka Bay with six Type 95 Kawanishi E8N2 Daves.
But according to the above mentioned book "Kiska - Nihon Kaigun no Eiko", on May 25 an order arrived from the Commander of the 5th Fleet, Kimikawa Maru to unload all the "Pete" it carried at Paramushir, return to Ominato and load six 3-seat reconnaissance seaplanes ("Jake" or "Alf"; not "Dave"). Kimikawa Maru returned to Ominato on May 28, stayed for four days and took on board the 3-seat floatplanes, which belonged to the ship’s own flying compliment, i.e. they were not just replacement or aircraft transported for another unit (ex. 452 Ku). In other words on that date Kimikawa Maru took on-board her own aircraft, she did not carry the "Jake" group of the 452Ku. Apart from the floatplanes the ship was loaded with as many as possible provisions including fuel, food and more than 200 Kuriles based unit replacements and replacement sailors. She arrived in Paramushir on June 3 and this date is confirmed by the "Combat Diary of the 5th Fleet" which places the ship in Paramushir on June 3, Tokyo time/date; not June 13.

Now let's turn our attention to the Kimikawa Maru photos featured in the publication "Maru Special #25".
The photo further higher in this posting with the "Alf" and "Jake" floatplanes is not dated but the caption mentions that the photo was taken when the ship was heading to the North Area. I think it is possible that the photo was taken during the above mentioned May 28~June 3 trip to Paramushir.
Two photos featured on page 65 and one on 67 (also featured on the back cover), show Kimikawa Maru loaded with seven or eight "Pete" and one or two "Rufe" floatplanes. The date given in the caption is April 1943 and the place Ominato. Here are close-ups focusing on the aircraft.

 

 

 

There are two problems, one with the date. All of April the ship was in Yokosuka undergoing repairs. The other problem is with the seaplanes and their markings. While in the top photo the tail markings cannot be discerned, in the other two photos they seem to be "V2-" indicating aircraft belonging to the 452Ku. So, the natural conclusion would be that these photos were taken when the 452Ku moved from Japan mainland to the Kuriles. Let's see when this happened.
According to the "Combat Diary of the 12th Air Fleet" on May 18 the "Pete" group of the 452Ku was on-board the Kimikawa Maru (information that confirms the "Kiska" book naration), the "Jake" and "Rufe" groups are in Yokosuka undergoing training and repairs. These last two groups were to relocate to Yokohama from May 29.
On June 6 six "Rufe" seaplanes of the 452Ku relocated to Ominato and on June 11 these were followed by six more "Rufe" with three "Jake" and two "Pete" seaplanes.
On June 24 ten "Rufe" relocated to Betobinuma in Shumshu.
Another source is the Kodochosho of the 452Ku. Here are all the entries of that period:
May 20 - four "Pete" seaplanes are on anti-submarine patrol in Paramushir. This entry confirms that a number of "Pete" floatplanes were already in the Kuriles. These arrived with the May 11 trip of Kimikawa Maru.
June 11 - Two "Pete" seaplanes on anti-submarine patrol in Ominato. This entry confirms the "Combat Diary of the 12th Air Fleet" and shows that at least one seaplane, probably two, of the 452Ku "Pete" group was still in Ominato.
June 18 - one "Pete" anti-submarine patrol in Ominato.
June 28 - "Rufe" in Betobinuma take-off ten times on patrol or ten aircraft took-off on patrol. This entry confirms the above entry of the "Combat Diary of the 12th Air Fleet" that the 452Ku "Rufe" moved to Shumshu island on June 24.

 

A most interesting photo is featured in Akimoto's “Nihon Kaigun Kokutai Shashin-shu”, Shupan Kyodo 1960. According to the caption "Rufe" seaplanes are ferried to the 452Ku by Kimikawa Maru in February 1943.

There are a couple of very interesting details to turn our attention to. First is the very worn looking main float but notice also that the stabilizing float has a solid green paint. The green of the main float looks more like it has been haphazardly airbrushed than the paint has just peeled off. Compare it if you like with the main float close-up here.

 

The other major point is the tail and the marking. A closer inspection reveals that the rudder looks to have been overall gray with a number 2 in red, then the area around the 2 is camouflaged with a quick hand of green paint by paintbrush and airbrush. Compare the dark number 2 with the bright colored, probably yellow, marking on the rest of the tail.

One suggestion that would explain the look and the markings of this "Rufe" is that it's a spare aircraft, in overall gray, camouflaged in haste and sent to the Aleutians and/or that it has replacement parts like the rudder and the main float.
As we previously saw the 452Ku during their time in Kiska used the tail marking "M1-". Therefore the date Akimoto-san mentions in the caption is not correct, unless this is a spare aircraft that would get the "M1" marking once delivered in Kiska.
Devlin Chouinard created artwork based on our interpretation of the above photo.

 

While updating the past "Rufe" posts with entries from the daily reports entitled "Japanese Naval Activities" issued by the Navy Department, Office of the Chief of Naval Operations in Washington, I came across a couple "mysterious" ones!!!!
The first mentioned: "U. S. surface vessels shelled 3 radar targets about 70 miles SW by S. of Kiska for half an hour beginning at 0016 X on 26 July [1943]. The targets, shelled at ranges from 12,000 to 23,000-yards were not seen before they vanished."
And the second: "Early 29 July, at 0850 X, a plane made a radar contact on 7 unidentified objects about 180 miles W. of Attu. The contact was lost and a search begun." 

[cue music]