1/350 Hasegawa IJN Submarine Depot Ship Heian Maru

Hey Everybody,


No, I have not completed the 1/350 Aoshima Tama as of yet, but I am getting to the point that I can venture out a little bit without distracting too much from that build. This build has been gnawing at me for quite a bit of time and to be honest I can no longer push it off.

So with that in mind, I decided I would begin the build log which will be follow-up later today with a post regarding the kit and accessories that I will use during the build. As per my usual practice here is some history of the IJN Submarine Depot Ship Heian Maru.

The following information is derived from Wikipedia

" Heian Maru entered regular service, delivering passengers, cargo, and mail, her initial route being Hong Kong, Shanghai, Moji, Kobe, Yokohama, Victoria and Seattle, with occasional stops at Yokkaichi, Nagoya Shimizu.

From early 1935 she served the Osaka to Seattle route, with calls at Kobe, Nagoya, and Shimizu. The return trip was to Yokohama, Kobe and Osaka. From April 1935 most voyages started and finished at Kobe, with stops at Yokohama, Vancouver, and Seattle. Due to the speed of Heian Maru and her two sister ships, NYK was able to maintain regular departures from Seattle for Yokohama every three weeks.[2]

Heian Maru was a fast, modern, mid-sized liner capable of taking 300 passengers across the Pacific in comfort. Her interiors were done in Old English style, and when opened for tours in Seattle she attracted thousands of visitors. One 1934 American passenger described the galley’s attempts at American-style food as poor, but was impressed by the vessel’s compactness of design, clever engineering, and professional crew.[3]

On 26 July 1941, President Roosevelt ordered the freezing of all Japanese assets in the United States. Heian Maru, en route to Seattle, was forced to spend two days sitting 150 miles off Cape Flattery while officials worked out a guarantee that the ship would not be seized once it entered American waters. Among the passengers, waiting anxiously, were numerous Jewish refugees from war-torn Europe, who had received transit visas from Chiune Sugihara, Japanese consul in Lithuania. Once in port the ship was refused permission to discharge its cargo of raw silk (valued at $1,000,000) bound for New Jersey mills. Only after five separate legal claims were initiated by the American customers of this cargo did the government relent and let it be offloaded. All passengers disembarked in Seattle, including 69 bound for Vancouver, B.C. Further diplomatic furor arose when, among 144 Japanese passengers preparing to board the ship for the return voyage to Yokohama, both men and women were stripped to their underwear and searched by American officials. The ship sailed in ballast from Seattle for the last time on 4 August 1941.

After Heian Maru returned to Japan in August 1941, NYK was informed that due to rising tension between Japan and the United States, the liner would be converted to military use. On 3 October the ship was formally requisitioned by the Imperial Japanese Navy, and designated as an auxiliary submarine tender with the Yokosuka Naval District. Two weeks later conversion was begun at Mitsubishi Heavy Industries in Kobe. Amongst numerous other alterations, four 15 cm/50 41st Year Type naval guns, two dual-mount 13 mm AA guns, two searchlights, and a rangefinder were installed.[1]

The outbreak of World War II in the Pacific on 7 December 1941 (8 December in Japan) found Heian Maru still being refitted, but by the end of the month she was on her way to Kwajalein to take up a new posting with IJN 6th Fleet. In early February 1942, while at Kwajalein, Heian Maru’s crew got their first experience in combat during raids launched from the American aircraft carrier USS Enterprise (CV-6).

Throughout 1942 and into the early months of 1943, the Heian Maru shuttled between Japanese bases at Truk (later known as Chuuk Atoll), Rabaul in the Solomon Islands, and Yokosuka and Kure, in Japan. She performed her designated task of supplying the dozen submarines of the IJN 6th Fleet with torpedoes, provisions, spare parts, and replacement crewmen, but, with her capacious holds, was also used as a troop and general cargo transport. At Rabaul in January 1943 Heian Maru was caught in two major Allied aerial attacks, during which she narrowly avoided bomb hits.[1]

Heian Maru with submarine I-171 at Paramushiro in the Kurile Islands in June 1943.
On 2 June 1943 Heian Maru was reassigned to the IJN 5th Fleet and arrived at Paramushiro in the Kuril Islands to support operations in the Aleutian Islands. She was used as a floating command post for the secret successful withdrawal of 5,000 Japanese troops from the island of Kiska, then returned to Yokosuka on 14 August and was returned to the IJN 6th Fleet.

Over the next several months, Heian Maru was busy transporting troops, vehicles, and other supplies of the IJA 17th Infantry Division from Shanghai to Truk and Rabaul. During a brief refit at the Yokosuka Naval Arsenal, her four 152-mm guns were replaced by two Type 10 120-mm guns, two Type 96 anti-aircraft guns and a Type 2 sonar. She was repainted in a dazzle camouflage pattern. Afterwards, she ferried torpedoes, distilled water, and other cargo to Truk, and, on 19 November, had a tense encounter with the American submarine USS Dace (SS-247) which tested her new commander, Captain Tamaki Toshiharu. She spent December 1943 and January 1944 disbursing supplies to submarines and other ships of the Combined Fleet at Truk lagoon.

The Japanese naval base at Truk was a large, sprawling complex, with hundreds of vessels anchored among dozens of islands, surrounded by a protective coral reef. The islands were studded with airfields, hospitals, repair shops, storage sheds, fuel depots, and command facilities. It was defended by coastal guns in concrete casemates, hundreds of fighter planes, and hundreds of anti-aircraft guns of all types, both on ship and shore.[10] Heian Maru was moored next to her sister ship Hikawa Maru (in wartime service as a hospital ship) on the leeward side of Dublon Island when, on the morning of 17 February 1944, the Americans launched Operation Hailstone.

Carried out by the US Navy’s Task Force 58, with nine aircraft carriers, under the command of Vice Admiral Marc A. Mitscher, Hailstone was a massive two-day combined air-surface-submarine raid. Although the IJN had moved its aircraft carriers and battleships from Truk a short time earlier, their defenses were unprepared for the scale of the attack, and the remaining navy and merchant vessels were devastated by wave after wave of American warplanes. Heian Maru quickly put to sea and went into evasive maneuvers north of Dublon Island - with Vice Admiral Takeo Takagi and his Sixth Fleet staff on board - but as one of the largest targets in the lagoon, enemy attacks were relentless. At mid-morning two bombs fell close astern, damaging one of her propeller shafts and flooding an aft hold. The crew managed to correct the trim by pumping fuel to her bow tanks, and after sunset Heian Maru returned to Dublon, where Admiral Takagi and some of the ship’s cargo of Type 95 torpedoes were offloaded.

Early the following morning, 18 February 1944, Heian Maru got underway as the American aerial attacks resumed. Shortly after 0300 she was struck, in quick succession, by two pairs of bombs; fire engulfed the bridge and threatened the hold containing the remaining torpedoes. The wounded ship began sinking, and at about 0500 Captain Tamaki gave the order to abandon ship. Most of the crew, including Tamaki, reached the shore safely, but a total of 18 men were killed, and 25 wounded.[1]

At 0900, Grumman TBF Avenger torpedo bombers from USS Bunker Hill (CV-17) attacked the still-burning Heian Maru, a torpedo striking her amidships on the port side. She sank soon after, coming to a rest on her port side in about 110 feet of water.

On 31 March 1944 the Heian Maru was officially removed from the navy list.

My intent is to build this into a diorama which will include a few submarines being reloaded. I will include a list of the submarines at a later time but to wet your appetite it will include the I-175, I-19, I-168 and some additional submarines. There will be a good mix of different classes of IJN Submarines.

Well that is it for now, I plan on putting the hull together this afternoon or later this evening and will post after that.

Thanks for stopping in and as always, comments, suggestions and criticism are always wlecome.



Hey everyone,

As promised, here is a list of the items that will be used during this build.

Artwox Wooden Deck

Hasegawa Hikawa Maru Detail Photo Etch Set Super

Hasegawa Hikawa Maru Detail Photo Etch Set Basic

Blackcat Models 120mm / 45 Single Mount (According to the Combined Fleet Webpage - the Heian Maru went through a refit in 1943 where in the 152mm main guns were removed and replaced with the 120mm single mount. Additionally the aft 152mm guns were replaced with twin Type 96 25mm AA guns)

Infini Model 13mm Twin Machine Guns

The Submarine kits that will accompany this build are

AFV Club I-19

Aoshima I-175 x 2

Aoshima I-168

Aoshima I-52

Pit Road I-54

And some photo etch for the subs

Not sure how this will all be laid out in the end but I am working on that as I move closer towards the build.

Thanks for stopping by,



Hey David, what a project! I also have this ship and some of this subs in my harbor stash and was thinking of a similar idea. I will closely watch your work :face_with_monocle: :+1:



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Glad to have you along for the ride. Really looking forward to getting deep into this build.




That is quite a project you are putting together, it will be most interesting to see how you pull it off…

Mark :beer:

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Oh man. This is going to be one epic build. Consider my butt firmly planted in the orchestra for this one!

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Thank you sir, I am glad to have you along for the journey.


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Hey everyone,

So the build has started, nothing major at this point. Just wanted to get the hull put together. The fit was pretty good, minor adjustments and some clamping needed but other than that the IJN Submarine Depot Ship Heian Maru has made it to the yard and workers are swarming all over her.

Here are the two halves before joining

Here they are after joining.

To be honest she will sit in this configuration for a short period of time. I believe the next step will be priming followed by application of her dazzle camouflage.

The planned step after that will be cleaning up the initial deck levels. I am going to try and attempt to scratch build one of the cargo holds. There are no known pictures or plans of this area of the ship - that I know of - so I will use a little artistic license.

If anyone has any plans of picture please share - I would owe you tremendously.

Well that’s it for now - the next post coming shortly will be identification of the first submersible selected.

Thanks for stopping in.



Hey everyone,

So following some additional historical research I have found out that I will be removing the I-52 and I-54 from the list of submarines being built for this project. The historical record provided by the Combined Fleet webpage in combination with the individual vessel’s history illustrates no possible connection between the IJN Heian Maru and the I-52 or I-54 class of submarines.

Which highlights my first failure in that I started the I-52 on Sunday pictured below.

Oh well, live and learn. Luckily I have enough of the I-19 and I-175 to fill out this build.

More to come, hopefully in the near future.



It’s not a failure. You’re just getting an early start on a future build.


Wow David, what a project! I will be following this one closely. How many subs do you think will fill out the lineup then? Looking forward to forthcoming build updates…



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Is this the ship that was a liner and still exists in Japan as a museum ? If so perhaps you can glean details of her holds by searching in that direction.

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Canmedic - thank you sir for those words

Marty - right now I am projecting no less than 5 subs but that might expand.

RDT1953 - unfortunately the IJN Heian Maru was sunk in Truk Lagoon in early 1944, but she was a liner that was transitioned and the one in Japan your referring to maybe her sister ship. I appreciate the recommendation - I will take a look and see what I can find.

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Hey everyone - just a short update - since I realized my mistake with regards to the I-52 I decided to go ahead and get another option off the shelf. So I chose the 1/350 Aoshima I-175. She comes with decals for the I-175 and the I-174.

based on the Combined Fleet Tabluar of Movement for the IJN Heian Maru I can positively tie the I-175 with the ship during the timeframe which I am trying to represent.

Here is the I-175 with the hull clamped and resting.

I have tomorrow off so I am trying to decide between the Tama and the Heian Maru - hell I may work the Tama in the morning and the Heian Maru in the afternoon. In either case I have 5 days off next week so there will be significant movement on both build.

Hope to have more for you soon.

Thanks for stopping by



Hey all

Spent some time yesterday working on the I-168, added the deck

but more importantly I used this opportunity to look at the layout for the base.

I cracked open the AFV Club I-19 which requires adding the top of the hull to the bottom verse the Aoshima kits which have the hulls split in half.

Anyway, here are some pictorial thoughts regarding possible layouts.

From the looks of it I may need a wider board but will need to throw together a few more subs to figure that out.

Anyway, thanks for stopping in, as always comments, suggestions and criticism are always welcome.



Hey all

Not a whole lot was accomplished this weekend - with regards to the Heian Maru I spent time drilling out the portholes - still have a long way to go.

After discovering my error with regards to the I-52 I began working on the I-168. Ill provide a historical accounting for that sub once I determine if it will remain as the I-168 or another sub or that class.

In either case, I cracked open the Aoshima Upgrade set and laid down some photo etch and dry fitted the from wooden deck.

Pretty happy with it so far, with five days off starting Wednesday I am pretty sure that I will get the I-168 build completed through to the paint…fingers crossed

That is all for now, thanks for stopping in.



Hey all,

After doing some more historical research and trying to tie each sub the the Heian Maru I decided to build the I-168 kit as the I-169, granted a sister ship but there is a direct tie to the Heian Maru.

I-69, later I-169, was a Kaidai-class cruiser submarine of the KD6 sub-class built for the Imperial Japanese Navy during the 1930s. She served in World War II, and took part in operations supporting the attack on Pearl Harbor, the Battle of Midway, the Guadalcanal campaign, the Aleutians campaign, and the invasion of the Gilbert Islands. She sank in a diving accident in April 1944.

Pre-World War II
Upon commissioning, I-69 was assigned to Submarine Division 12 in the Kure Naval District.[2] She was decommissioned and placed in reserve on 1 May 1939.[2] She was recommissioned on or about 1 September 1939.[2] On 12 May 1941, she suffered bow damage in a collision with the submarine I-70 at Yokosuka, Japan.[2]

As the Imperial Japanese Navy began to deploy in preparation for the impending conflict in the Pacific, I-69 was assigned to Operation Z, the planned Japanese attack on Pearl Harbor.[2] Submarine Division 12, consisting of I-69 and I-70, was assigned to Submarine Squadron 3, which in turn was assigned to the 6th Fleet′s Advanced Expeditionary Force, for the attack.[2] On 11 November 1941, I-69 departed Saeki, Japan, with the commander of Submarine Division 12 embarked, bound for Kwajalein in company with I-68, I-70, I-71, I-72, and I-73.[2]

First War Patrol
On 23 November 1941, I-69 departed Kwajalein to begin what would become her first war patrol.[2] She received the message “Climb Mount Niitaka 1208” (Japanese: Niitakayama nobore 1208) from the Combined Fleet on 2 December 1941, indicating that war with the Allies would commence on 8 December 1941 Japan time (7 December 1941 in Hawaii).[2]

On 7 December 1941, I-69 and I-68 took up station off the entrance to Pearl Harbor, Hawaii, to rescue the crews of midget submarines attempting to penetrate the harbor’s defenses during the Japanese attack that brought Japan and the United States into World War II that morning.[2] At 21:01, I-69′s commanding officer witnessed what he reported as “a massive explosion in Pearl Harbor. There are several explosions, followed by high columns of fire (probably a detonating warship magazine). This must have been some capital ship sunk by our midget submarines”.[2] On the evening of 7 December 1941, I-69 fired a torpedo at a destroyer south-southeast of Barbers Point, Oahu.[2] Apparently sighting the torpedo’s wake, the destroyer turned away, avoiding the torpedo, then counterattacked with depth charges.[2]

I-69 and I-68 spent 8 December 1941 off the entrance of Pearl Harbor awaiting the return of midget submarine crews, but none returned.[2] On 9 December 1941, I-69 attacked a cargo ship south of Oahu without success and was again depth-charged.[2] Later that day, she became entangled in an anti-submarine net off Barbers Point.[2] After several hours, she freed herself, damaging a periscope in the process, and finally surfaced after remaining submerged for about 39 hours.[2] When all hope of rescuing aircrews shot down during the 7 December attack was abandoned, she left Hawaiian waters, arriving at Kwajalein on 27 December 1941.[2]

Operations from Truk
With her overhaul complete, I-169 got underway from Kure on 25 September 1943 bound for Truk, which she reached on 3 October 1943.[2] She departed Truk on 14 October 1943 and while at sea was ordered to join the submarines I-19, I-35, and I-175 in attacking a large westbound Allied convoy that the submarine I-36 had sighted south of the Hawaiian Islands.[2]

On 19 November 1943, I-169 was on patrol in the Pacific Ocean between Hawaii and the Marshall Islands when she, I-19, I-35, I-39, and I-175 received orders to proceed to Tarawa Atoll in the Gilbert Islands, where an invasion fleet of some 200 Allied ships was gathering.[2] On 20 November 1943, U.S. forces landed on Tarawa Atoll and Makin Atoll in the Gilberts. In the Battle of Tarawa, the Japanese garrison was destroyed by 23 November, while the Battle of Makin ended with the annihilation of Japanese forces there on 24 November. On 26 November 1943, I-169 received orders to form a picket line with the submarines I-19, I-40, and Ro-38 north of Makin Atoll.[2] While I-169 was running on the surface on 1 December 1943, an American plane detected her, but she was able to dive and escape.[2] While running submerged, she made sound contact on a heavily escorted U.S. convoy but was unable to break through the escort screen and attack.[2] She returned to Truk on 9 December 1943.[2]

While at Truk during December 1943 and January 1944, I-169 took torpedoes and stores aboard from Heian Maru, and on 1 January 1944 she was assigned to the Truk-based Submarine Division 12, a part of Submarine Squadron 3, along with the submarines I-171, I-174, I-175 and I-176.[2] On 27 January 1944 she departed Truk bound for Rabaul, then got underway from Rabaul on a supply mission to Buka and Buin on 27 January 1944.[2] She returned to Truk on 11 March 1944.[2] She left Truk again on 18 March, but returned on 22 March 1944.[2]

On 4 April 1944, I-169 was at her anchorage in Truk Lagoon northwest of Dublon, taking on supplies with some workmen aboard and her commanding officer and 20 other members of her crew ashore.[2] At about 09:00 Japan Standard Time, an air raid warning sounded.[2] I-169′s watch officer ordered her to dive immediately to avoid attack by approaching U.S. Navy PB4Y-1 Liberator patrol bombers.[2] She submerged with most of her deck hatches still open and her main induction valve unsecured, causing her after compartments to flood immediately.[2] An immediate attempt to resurface failed, and although surviving crewmen sealed off the flooded compartments, I-169 sank to the bottom in 125 feet (38 m) of water.[2]

After I-169 submerged, it was not immediately apparent that she was in distress.[2] Only after she did not surface after the air raid and attempts to contact her were unsuccessful did concern grow that she had sunk.[2] A diver sent down to investigate found her on the bottom and contacted the surviving crewmen trapped on board by tapping on her hull.[2]

Sixth Fleet headquarters issued orders on 5 April 1944 to rescue the trapped survivors.[2] A repair ship with a 30-ton crane and the tug Futagami arrived on the scene to attempt to lift I-169′s bow to the surface.[2] They initially had difficulty finding I-169, and once they located her and attempted to lift her, the crane’s cable broke due to the flooded submarine’s great weight.[2]

Tapping later died away except from the aft compartment.[2] Salvage crews lowered air hoses and drilled holes in I-169′s ballast tanks but found it impossible to signal the surviving crewmen to open the air valves to the ballast tanks from the inside.[2] The trapped crewmen fell silent by 23:00 on 5 April 1944 and air raids on Truk prevented further work on the wreck overnight on 5–6 April 1944.[2] All the trapped men who survived the initial flooding suffocated.[2]

So as not to drag this pot on further I will end here and start another focused on the build itself.

Thanks for stopping and I hope that you enjoyed reading about the I-169.


Hey everyone,

Thanks for sticking around and reading through my second post. I had a rare opportunity this past week to spend 5 days at home. My initial thoughts were to break the time up between the I-169 build and the Tama, but after getting into the I-169 build I ended up neglecting the Tama and spent all five days working on the I-169 and the Heian Maru.

So as mentioned before this build is based on the 1/350 Aoshima IJN Submarine I-168 kit, the kit was nice with good detail. I had no issues with putting her together, well at least not until I started using the 1/350 Aoshima detail set.

After adding the initial PE to the kit I marched forward with replacing the deck hatches. These are all from the Aoshima detail set. Hind sight being what it is I should have added hand wheels to each of the hatches as the detail is lacking on the PE. I think I will still add them but without paint…hmmmm

Anyway, once I decided to focus on the I-169 the build went pretty quick.

After adding all the PE it was on to painting. I primed the kit with Mr. Finisher 1500. Once that dried I used Tamiya Kure Arsenal Grey due to the I-169 having gone through refit at Kure prior to arriving in Truk.

After that I added a layer of Alcad High Gloss.

Some side notes, I replaced the kits 13.7mm machine gun with one from Fine Molds - looks a lot better in my opinion and I added a hand wheel to the main gun just to give it some detail. I also replaced the kit range finder located on the aft of the sail with a Veteran Range Finder and removed the molded bollards and replaced them with small bollards from Rainbow.

There were a couple of issues with the PE, one piece was a little oversized and needed to be sanded down but the bigger issue was the wooden deck - it is too long on the after portion and need some surgery to get it to fit between the molded detail. All in all it is a decent upgrade kit.

The I-169 will be displayed as either arriving or departing the side of the Heian Maru, therefore I did not open any hatches as I will on other builds.

That is where I stopped, I figured I would move on to decals, weathering and rigging once I complete the other subs that will accompany the Heian Maru.

Thanks for stopping in and as always comments, suggestions and criticism are always welcome.


Hey all,

I’m sure everyone is tired of reading my post by now but I ask you bear with me a little more. While I was waiting for paint to dry on the I-169 I took the opportunity to continue drilling out port holes on the Heian Maru, at this point I would say I am about 75% complete.

When my fingers got worn out from the drill I moved on the the deck.

The first step was removing all the molded on detail for the deck winches and bollards, if I remember correctly there are places for 5 winches. In either case that portion of the destruction was pretty quick and painless.

I want to display the Heian Maru as a working ship resupplying the submarines that moored alongside, so with that in mind I decided to remove the cover to the ships hold. This was a little more difficult than the winches but I like the final result. There are four ships holds divided between the fore and aft portions of the ship.

My intention is to scratch build a hold with equipment and supplies. I order some catwalks from Five Star along with some oil barrels, wooden boxes and other odds and ends to use to fill the holds.

While taking a trip to Lowes with my wife I grabbed the opportunity to buy a base for the diorama, here are some updated photos of final placement - thoughts?

Anyway, that is all for this long weekend, thanks for stopping in and reading though my posts, as always comments, suggestions nd criticism are always welcome.


Not tired at all of your posts. They are a treat. Looking forward to more.

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