IJN Torpedo Boats TOMOZURU 1934 and HATSUKARI 1935 building process
PIT-ROAD SkyWave no.W40 model kit of IJN
CHIDORI Class Torpedo boats (2 in box) in scale
1/700 waterline series
The kit comes with a choice of building 2 ships of the 4 Chidori-Class ships . The TOMOZURU 1935 and HATSUKARI 1945, but firstly I had more interesting in building TOMOZURU as seen in 1934, because of the tragic and thrilling story of the capsize of the ship in bad weather general known as the "Tomozuru incident" this event was the direct cause to the Imperial Japanese Navy's rethinking of how to design and build future warship. Many already existing ships was modified to counter similar fate as TOMOZURU had on the 12th of March 1934. Secondly the kit of HATSUKARI will show the class of boats after the modification (Hull, super structure and armament) in 1935 as seen at the box art above.
Please read about the "Tomozuru incident" at the bottom of this page!
The ship-class had a heavy armament as in the "as build" configuration in fact they were more small destroyer than torpedo boats they carried two 5 inch turrets -one single and twin - they are not in the box but are on the spur of PIT-ROAD IJN vessel ordinance set. It's a surplus from my other builds and are attached many small SkyWave kit's. I know that the single 5 inch turrets is available, but is not in my inventory at the moment so I decided to "make" one of the twin turret, by cutting it in half, and sanding the inner sides down to just accomplish one gun barrel
Here is the two gun turrets -the single will be located in front of the ship and the twin will be at the quarterdeck at the back. The small protrusions at the right is a small gun director tower in the 5 inch turret (12.7 cm), 50 cal DP, 3 rd Year (1914) has a round shape instead of the sooner type.
The super structure is extended with an extra deck level under the commando bridge, and the additional vents is mounted. The windows is cut open and replaced with Lion Roar PE-set Ladders 1:350. Some windbreakers at the top and sides, is replaced with sheet metal plate (styrene plastic)
Firstly the break water is removed on the front deck -due to a bigger gun (the turrets act as break water itself) also note the two store rooms for spare torpedoes on each side of the funnel. A deck vent is also added on the foredeck. At the freeboard on the hull two bulges is added by a pair of styrene plastic strips they are also seen at picture.#4.
This picture show the different armament configuration in the "pre incident" and after the modification for the vessels.
I made new masts of silver tread (0.5mm and 0.3 mm) note also the higher superstructure on TOMOZURU in front and HATSUKARI in the back.
Picture #7 and #8:
HATSUKARI will have the single closed twin 53cm Torpedo launcher compared to TOMOZURU two open twins 53cm torpedo tubes. The four new cable drums is made of styrene plastic round bars with copper wire as ropes . On the platform just after the searchlight TOMOZURU will have a single 40mm AA gun here will HATSUKARI have a single 7.7 mm AA gun. The red chocolate colored linoleum deck, is painted and hereafter the small strips of brass dividers is shown by scratching (with a scalpel) the lines down to the light colored plastic below. an alternative would be to glue small copper wires upon the lines.
Capsize of torpedo boat IJN TOMOZURU
Author KOBAYASHI, Hideo (Yokohama National University)
|TOMOZURU was the third vessel of the Chidori
Class torpedo boats, and she was not yield to the London Naval Treaty. She
had three 12.7cm main guns and four torpedo tubes while her total
displacement was less than 600 tons and her maximum speed was
approximately 30 knots. Her performance was no less than that of a Second
Class Destroyer (Fig.2). TOMOZURU was completed on February 24, 1934 at
Maizuru, towed to Sasebo at the end of the month, and joined the 21st
torpedo fleet that was organized with her and two other boats of the same
type, Chidori and Manazuru. The fleet belonged to the Sasebo Guard
squadron whose flagship was light cruiser Tatsuta.
On March 12, 1934, a Japanese torpedo boat capsized. The
torpedo boat, named TOMOZURU, was heading north to Sasebo port. However,
during the navigation the weather turned to be rough, and TOMOZURU was
suddenly inclined by a strong wind and wave. Unfortunately she did not
have enough stability against the inclination so finally she capsized, and
one hundred officers, including the captain of TOMOZURU, died.
At 1:00 a.m. on March 12, 1934, TOMOZURU following
Chidori left the Terashima Channel, Sasebo port and headed for the seas
south of Otateshima Island for an approach and attack training against
flagship Tatsuta. The three boats kept training despite the rough weather,
but as the winds and waves got rougher and rougher the training was
suspended at 3:25 a.m. On the way back to Sasebo port, the sway of TOMOZURU
intensified and her radio fell down from the desk and died. She contacted
the other boats with a light signal, but at 4:12 a.m. TOMOZURU's light
signal suddenly ceased.
It was obvious that the lack of TOMOZURU's stability caused the capsize, that is to say that bad design led to her capsize. In 1931, a supply plan of auxiliary ships under the restriction of the London Naval Treaty was formed, and the Headquarters presented some requirements for the new ships. But they demanded too heavy armaments for two types of destroyers (1,000-tons and 1,400-tons) in spite of the limited budget and under restriction of the number of destroyers. Although 1,400-tons class destroyers was constructed as Hatsuharu Class, the construction of the 1,000-ton class destroyers was cancelled due to the restriction of the total vessel tonnage possessed, and they decided instead to construct Chidori Class torpedo boats, which were smaller than the 1,000-ton class destroyers and therefore not under the restriction of the treaty. The Chidori Class was intended to be used in place of the Second Class Destroyers in the seas near the Japanese coast. The required performance for the Chidori Class was far greater than that of a torpedo boat in the age of the Russo-Japanese War (1904~05). Requirements included 600 tons basic displacement, 30 knots maximum speed, 3,000 miles range at 14 knots, three 12.7cm main guns and four 53cm torpedo tubes. To reduce the weight, light alloys and welding were widely used, and they cut down the weight of the engines and armaments as much as possible. However, the main gun was the same turret type gun as was used by a destroyer, and some additional equipment was added so that the weight became heavier than they had expected. The freeboards were enlarged in order to improve the vessel's seaworthiness, and livability was better than that of conventional destroyers. In addition to all of this, armament planners of each department in the Headquarters demanded armament having complex and elaborate mechanics. As a result, the center of gravity of the Chidori Class torpedo boats rose, and her basic displacement was held down to only 527 tons.
The cause of the capsize of TOMOZURU was the lack of stability that resulted from the so called "Top Heavy Structure". The Navy who demanded excessively heavy armaments and the shipbuilders who accepted these demands were responsible for this incident.
TOMOZURU's capsize forced the Japanese Navy to fundamentally rethink the stability of their vessels. A remodeling plan was made individually for every vessel, and shipbuilders carried out all of the remodeling plans during 1934~35 (Fig.5). The designs of all of the vessels under construction at that time were reconsidered from scratch.
* The torpedo boat TOMOZURU capsized due to her
top-heavy structure. Current shipbuilders have valuable experience and
confidence in their knowledge of stability. However, we must remember the
difficulties of shipbuilders in the past and make the best use of the
knowledge that our predecessors gave us.
One background issue of TOMOZURU's case was a severe
demand for increasing the fighting power of each vessel under the
restrictions of the disarmament treaty. In November 1921, the US, the
British Empire, France, Italy and Japan formed a disarmament committee in
Washington D.C. In this committee, they decided that each nation should
restrict the total weight of her vessels. The US, the British Empire,
France, Italy and Japan agreed to restrict the total weight of each
country's vessels according to the ratios 5, 5, 1.75, 1.75, and 3.
From October 23 to 26 in 1944, the Japanese Navy was
soundly defeated by the US in the battle of the Philippine Sea. After the
battle, the US 3rd fleet under the control of Admiral Halsey was assigned
to attack Leyte Island. The 3rd fleet appeared east of the Philippines and
attacked Luzon Airfield after two weeks resting in Ulithi on December 13.
Task Group 38 carried out the attack under the control of Vice Admiral
Kindly loan from Mr. KOBAYASHI, Hideo rapport at (Yokohama National University)