Kurama-class Armored Cruiser/Battlecruiser (1909/1911): Neither Fish nor Fowl

[Admiral_Aruon 2,264]

So the Tsukuba-class and Kurama-class (alternately called the Ibuki-class as that was supposed to be the lead ship) ships are a pair of paired oddities i've had my eye on for a while, and since we now have one of the Tsukuba-class ships; the Ikoma; as a Battlecruiser (more on that situation later) alongside Dreadnought Battleships with the launch of the new patch, this is the perfect time for their successors, the Ibuki and Kurama of the Kurama-class Armored Cruiser/Battlecruiser.

 

This is a suggestion for the overcompensating redheaded stepchild of mid-1900s warship development, the Kurama-class Armored Cruiser.

 

Battlecruiser Kurama at anchor, 1913

 

Armored Cruiser Ibuki, circa 1910

 

 

MAJOR EDIT: original cross sections of Kurama-class ship from the Hiraga Archives, Kashiwa Library, University of Tokyo. many thanks to aizenns!

Spoiler

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DESIGN (both Kurama-class and Tsukuba-class):

 

I may as well mention both the Kurama-class and Tsukuba-class (keep in mind the Ikoma seen ingame now as WTs first battlecruiser is a Tsukuba-class ship), as the design for both classes are extremely close as the Kurama-class is very directly and with remarkable swiftness a back-to-back product-improved successor of the Tsukuba-class, with the swath of design modifications resulting in the Kurama-class only being made AFTER what would become the Ibuki and Kurama were ordered as Tsukuba-class cruisers.

 

The Kurama-class and Tsukuba-class Armored Cruisers are a unique oddity of warship development that could only have ever come about in the very brief window of time that they did, yet are not quite as bizarre or necessarily even forward thinking as you may expect.

 

when it comes to the design of these 4 ships across 2 consecutive classes, there are 4 general fields that explain their existence:

replacements, financial considerations, doctrine, and evolution.

 

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replacements:

this is the most mundane of the 4 corners of the 4 ships. what was originally the quartet of Tsukuba-class Armored Cruisers ordered were made to replace the lost pre-dreadnought battleships Hatsuse and Yashima, both of which ran into minefields in the leadup to the Battle of Yellow Sea in what was for the Japanese really the single worst day of the Russo-Japanese war...

...though unlike the Russians, Hatsuse and Yashima were not hosting admirals, so there were no admirals onboard to get decapitated by mine fragments, unlike the Russian flagship Petropavlovsk and its admiral Makarov in the previous days...

now on the surface, it may seem odd that even pre-dreadnought battleships were specifically replaced by non-capital ships, but the next 3 sections all explain why.

 

 

finances:

put bluntly, Japan was broke as **** after the war.

they had spent the vast majority of the ludicrous indemnity money of the 1st Sino-Japanese war (~6.4 times the size of the entire GDP of Japan in 1895) to crash build the IJN into a top 5 major world navy in the span of just a decade, and then the subsequent Russo-Japanese war and wartime emergency spending totaling roughly 2.15 billion yen in 1904-1905- which when run through a somewhat sketchy currency converter, converted 1905 yen rates to 2015 yen rates as: 3,277,284,088,930 yen (3 trillion, 277 billion, 284 million, 88 thousand, 930)... which makes for about 31.3 billion USD in today's money, with about 38% of this eye-popping amount being funded via loans from the UK, US, and Canada.

 

as you may have figured by now, building replacement battleships is costly for a nearly bankrupt nation fresh out of a major war, even as it's still running on emergency spending.

So Armored Cruisers with battleship-level armament (specifically on par with the Katori-class PDBB, keep in mind this is prior to the launch of HMS Dreadnought) made for a good fit in the meantime...

...and now if you know your 1900s naval warship history... that might seem eerily familiar...

 

 

evolution:

...and the reason why it seems eerily familiar in because this skirts right on the edge of the Dreadnought-Armored Cruiser concept; AKA Battlecruiser; though more like a Pre-Dreadnought-Armored Cruiser with its armament, and a mix of both versions of the Dreadnought-Armored Cruiser concept seen with SMS Blücher and the Invincible-class... so it really is a neither fish nor fowl situation.

Now it's worth keeping in mind that there's NO conceptual similarity to Battlecruisers outside of the idea of battleship guns on a cruiser hull. since the 1890s, various navies had flirted with the idea of fitting battleship secondary guns like 10-inch cannons in a single mount- in fact, the lead ship of the preceding class to the Kurama and Tsukuba classes; the Armored Cruiser Kasuga; had a single BL 10-inch cannon on the bow in place of a paired 8-inch cannons.

 

doctrine:

In addition to the above, the Russo-Japanese war had seen the IJN successfully use Armored Cruisers in the battle line to pummel individual battleships with overwhelming attacks; though the circumstances of which they were able to be effective make this success somewhat questionable as a matter of practicality; so the IJN doctrine evolved (briefly) to include up-gunned cruisers in the battle line, as packing the same armament as full battleships, while just lacking battleship-level armor is a easy concern to weigh when you have more and more all up firepower in the battle line to prevent a battle of attrition. classic case of the "best defense in a good offense" pattern of thinking.

-------------------------------------------------------

 

So with this all in mind, it makes sense why the Tsukuba-class and especially Kurama-class with their improved design and beefed up armament existed in the niche they did in the few years between the Russo-Japanese war and the reveal of what was then the Invincible-class Dreadnought-Armored Cruiser, and why the Kurama-class was succeeded not by an improved cruiser-killer or the IJN doctrine-unique Battle Line Armored Cruiser, but by the Kongo-class Battlecruiser.

 

Outside of all of that backstory, and 12-inch guns aside, the Kurama-class was actually a fairly normal cruiser design of the age. average speed, decent armor, and frequent long delays for Ibuki due to being a testbed for steam turbine engines in IJN service while Kurama retained the older VTE steam engines.

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RERATED AS BATTLECRUISERS?:

 

So on August 28, 1912, Tsukuba, Ikoma, Ibuki, and Kurama were rerated as Battlecruisers under the newly revised Japanese *coughcoughbritishcoughcough* warship classification system... but in practicality were they?

 

quite simply, no.

 

these are up-armed Armored Cruisers that can harass Pre-Dreadnoughts if there's already a friendly battleship or battlecruiser taking all the return fire... so in WT they are really in about as good a situation versing capital ships as they possibly could save for whenever pre-dreadnoughts are added to the game. (and a bunch of those have already been passed to developers)

they all lack the speed of true Battlecruisers, and they lack the all-big-gun armament to really make a difference... like battlecruisers.

now granted the Kurama-class (which had 4 pairs of 8-inch cannons as secondary armament instead of the Tsukubas plethora of 6-inch cannons) is certainly closer to being a BC than something like SMS Blücher; if only because the Kuramas and Tsukubas have 12-inch cannons at all; but fundamental aspects are missing- you're not winning any races in these ships, and your four 12-inch cannons can't hold a candle to the broadsides of 8, 9, 10, or even 12 seen on BCs or all-big-gun BBs. 

 

this reality was not lost on the IJN either, and at some point during/after 1920 but before the Washington Naval Treaty would come into practical effect in 1922, both Ibuki and Kurama were downgraded to 1st Class Cruiser.

 

So think of the Kurama and Tsukuba class ships as the pre-WWI counterparts of the Deutschland-class cruiser ingame.

 

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CONSTRUCTION:

Construction of both ships was initially delayed by a lack of open slipways at their shipyards, a shortage of trained workers and their low priority vs all the battleships under construction/reconstruction/repair.

 

Ibuki:

 

Ibuki had it's initial keel-laying delayed until the slipway used by the under construction Satsuma-class Semi-Dreadnought Aki was finished and launched. in this downtime the materials used to build Ibuki were stockpiled in advance in a process similar to that used to build HMS Dreadnought. And the same result was achieved- Ibuki was launched only 5 months after its keel was laid, a solid show for Kure Naval Arsenal considering the only faster keel-to-launch was HMS Dreadnought itself at the British shipyard known for being the fastest shipbuilders on earth, while KNA was still in the process of becoming Japan's second major naval shipyard behind Yokosuka Naval Arsenal.

 

in addition to this light speed construction process, about 5 days after Ibuki was launched, both Ibuki (as well as Aki) had a major change in their design plans- Ibuki's planned engine machinery of 2 VTE steam engines and 28 Miyahara water tube boilers was changed to 2 Curtis geared steam turbine engines produced by, purchased from, and then licensed from Fore River Shipbuilding in the USA and 18 Miyahara boilers as a testbed for steam turbine engines in IJN use. To display how important this was to the IJN, construction of the Aki (which would also field a pair of Curtis STEs) was entirely halted and all focus diverted to Ibuki's engines for about 5 months.

 

 

Kurama:

 

Kurama's remarkably long two year building time at Yokosuka Naval Arsenal (but being launched first) was due to priority given to the building of the battleships Kawachi and Settsu and the repair and reconstruction of the captured Russian ships like Peresvet and Oryol captured after the Battle of Tsushima and the Battle of Port Arthur.

 

Unlike Ibuki, the Yokosuka-built Kurama would retain usage of the older, obsolescent 2 VTE steam engines and 28 Miyahara boilers due to issues with the steam turbine engines on Ibuki.

 

 

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HISTORY:

 

Ibuki, pre-WWI:

after the initial chaos (and engine problems) after commissioning and a short time as a reserve ship, Ibuki's original posting would be with 1st Fleet on December 1st, 1910.

in 1911 Ibuki would attend the coronation of king Rama VI Vajiravudh of Siam (Thailand)

in 1912, Ibuki was reclassed as a Battlecruiser.

 

WWI:

unlike Kurama, Ibuki would be present for one of the more interesting moments of WWI in the far east during the hunt for the light cruiser and merchant raider SMS Emden, the German light cruiser causing hell for British shipping in the eastern Indian Ocean. At this time the Ibuki and British Protected Cruiser HMS Pyramus and Armoured Cruiser HMS Minotaur would be protecting the 

New Zealand Expeditionary Force as it was crossing the Tasman Sea and then heading for the Cocos islands of the southwestern coast of Sumatra to cross the Indian Ocean from on their war to participate in the Gallipoli Campaign. as they neared the Cocos Islands, it became known that the SMS Emden and HMAS Sydney were both in the area, and while the Ibuki wanted to leave the convoy to support HMAS Sydney as Ibuki was practically twice its size, Ibuki was their only serious protection at that point.

this would be only major event the Ibuki would see during or after the war

 

post-WWI:

the only real event of note after WWI is when Ibuki; like so many others; fell victim to the Washington Naval Treaty.

 

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Kurama, pre-WWI:

after the initial chaos after commissioning, Kurama's original posting would be with the 2nd Fleet on March 1st, 1911.

the only action of note for Kurama during this period was attending the coronation of newly crowned British King George V and subsequent 1911 Spithead Naval Review.

in 1912, Kurama was reclassed as a Battlecruiser.

 

WWI:

After Japan declared war on Germany on August 23rd, 1914, Kurama would become flagship of the newly formed 1st Southern Expeditionary Fleet, the first of quite a few member/flagship roles in a variety of fleets and fleet divisions throughout the war.

the vast majority of active wartime service actions of Kurama were in trade protection of mainly British merchant vessels, as well as working alongside Battlecruisers Kongo and Hiei the landings and occupation of the German Mariana islands and Caroline islands.

on May 18th, 1918, Kurama ran over an uncharted reef off the coast of Geoje Island, shredding the bottom of the starboard bilge keel, tearing off rows of rivets, and putting a 6 inch hole in the bottom of the ship, flooding out the double bottom, requiring emergency repairs, and a return to the Sasebo Naval Arsenal. this was the only serious damage taken by Kurama during the war.

 

post-WWI:

Kurama would take part in the Siberian intervention, aiding landings of Japanese soldiers in support of the White Russians throughout 1919 and 1920.

between 1920 and 1922, Kurama would return to normal peacetime duties.

in 1922, as the Washington Naval Treaty was finalized and started being adhered to, Kurama would become one of many ineligible ships. It would be put into reserve, stricken, and scrapped in 1923/24.

 

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GENERAL CHARACTERISTICS:

 

Ibuki:

Displacement:

Standard (1907): 14,636 long tons (14,871 metric tons)

Standard (1912): 15,088 long tons

Standard (1920): 14,600 long tons

Maximum (entire service life) 15,595 long tons

 

Length:

137 meters (450 ft) between perpendiculars

147.8 meters (485 ft) overall

 

Beam:

22.98 meters at waterline, 23.01 at widest (a classic slab sided ship)

 

Draft:

(1907-1911, 1920-1922) 7.92-7.97 meters depending on minor changes in weight over time

(most of the 1910s,) 8.09 meters

 

Propulsion:

8 single ended and 10 double ended superheater-equipped Miyahara water tube boilers fed through mixed coal and fuel oil spray jets,

feeding into 2 Curtis geared steam turbines,

producing 24,000 hp (on paper) for a top speed of 22 knots (on paper)

but in actuality, producing 28,977 hp for top speeds of 21.16 knots (39.17 km/h) by the time of the final speed trial (remember this was the first Japanese ship with turbines- and it had constant issues early on)

 

Range:

5,000 nmi (9,260 km; 5,800 mi) at 14 knots (26 km/h; 16 mph)

 

Fuel:

600 long tons of coal (normal)

2,000 long tons of coal (maximum)

250 long tons of Fuel Oil

 

Crew Complement:

844 as designed

841 as of 1909 commissioning

817 as of 1920

 

 

Kurama:

Displacement:

Standard (1907): 14,500 long tons

Standard (1912): 15,088 long tons

Standard (1920): 14,600 long tons

Maximum (entire service life) 15,595 long tons

 

Length:

137 meters (450 ft) between perpendiculars

147.8 meters (485 ft) overall

 

Beam:

22.98 meters at waterline, 23.01 at widest (a classic slab sided ship)

 

Draft:

(1907-1911, 1920-1922) 7.92-7.97 meters depending on minor changes in weight over time

(most of the 1910s,) 8.09 meters

 

Propulsion:

28 mixed single and double ended Miyahara water tube boilers fed through mixed coal and fuel oil spray jets,

feeding into 2 VTE steam engines, producing 22,500 hp (on paper)

but in actuality, producing 23,081 hp for top speeds of 21.25-21.5 knots (39.355-39.8 km/h)(depending on best sources) by the time of the final speed trial 

 

Range:

5,000 nmi (9,260 km; 6,000 mi) at 14 kn (26 km/h; 16 mph)

 

Fuel:

1,868 tons of coal, 288 tons of fuel oil

 

Crew Complement:

844 as designed

842 as of 1911 commissioning

817 as of 1920

 

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ARMOR:

armor used is Krupp Cemented Armor (KCA) steel

armor profile of the Kurama-class was improved compared to the earlier Tsukuba-class ships.

 

the armor belt extended to 1.2 meters below the waterline

at its thickest it was 178mm (7 in) between barbettes (wikipedia is completely wrong judging by every other source), thinning to 102mm (4 in) at ship ends.

The waterline armor belt of Krupp cemented armour was 7 inches (178mm) thick between the 12-inch gun turrets although it was only 4 inches (102mm) thick fore and aft of the turrets.

 

upper belt spanning from fore and after secondary cannon barbettes was 127mm (5 in)

Above it was a strake of 5-inch (127 mm) armor that extended between the eight-inch gun turrets and protected the two central 4.7-inch casemates.

In front of those turrets the armor was 6 inches (152 mm) thick, with the ends of the main armor belt connected to the main gun barbettes by 1-inch (25 mm) transverse bulkheads.

 

the main 12-inch gun turrets and their barbettes were protected by armor plates 178mm (7 in) thick, with 37mm (1.5 in) turret roofs.

the secondary 8-inch gun turrets had 152mm (6 in) armor, and 127mm (5 in) barbettes, although the armor for those thinned to 51mm (2 in) behind the upper armor belt

 

casemates had 127mm (5 in) protection

 

The main conning tower/bridge had 203mm (8 in) armor all around with an armored communications tube connecting to the main deck that had (178mm) seven inches of armor

aft conning tower with 152mm sides.

 

deck armor was 51mm (2 in) amidships and increased to 76mm (3 in) at the ship ends

 

cross section of Ibuki-class from Brassey's naval annual 1915

 

_________________________________________________________________________

ARMAMENT:

 

EDIT: plethora of revisions thanks to @aizenns

Because of the complexity of Japanese naval weapon naming system before the 1917 switch to the metric system, most western-language sources use a technically incorrect naming

 

2×2 12-inch L/45 (305 mm) cannons-

on Ibuki: "45 caliber Type 41 12 inch" -  the licensed copy of the cannons on Kurama, locally produced by Kure Naval Arsenal

on Kurama: "45 caliber Armstrong 12 inch gun" - manufactured in the UK by Armstrong/EOC

 

both versions redesignated in 1917 as the "30 cm Gun"

http://www.navweaps.com/Weapons/WNJAP_12-45_EA.php https://en.wikipedia.org/wiki/EOC_12_inch_/45_naval_gun 

 

4×2 8-inch L/45 (203mm) cannons- 45 caliber Type 41 8 inch gun - the license-produced Kure Naval Arsenal copy of the EOC 8-inch 45 caliber

redesignated in 1917 as the "20 cm gun"

https://en.wikipedia.org/wiki/20.3_cm/45_Type_41_naval_gun http://www.navweaps.com/Weapons/WNJAP_8-45_EOC.php 

 

 

12×1 4.7-inch (120 mm) cannons-

on Ibuki: "45 caliber Armstrong 4.7 inch gun" - manufactured in the UK by Armstrong/EOC

on Kurama: "45 caliber Type 41 4.7 inch gun" - the licensed copy of the cannons on Kurama, locally produced by Kure Naval Arsenal

 

both versions redesignated in 1917 as the "12 cm gun"

the are specifically the Armstrong QF 4.7-inch Mark IV and its license-produced copy.

https://en.wikipedia.org/wiki/QF_4.7_inch_Gun_Mk_I_-_IV#Japanese_service http://www.navweaps.com/Weapons/WNBR_47-40_mk1.php 

 

4×1 QF 12-Pounder 12-cwt guns- in IJN service called "45 caliber Type 41 3-inch gun" as they were the license-produced copy of the Elswick Pattern N and Vickers Mark Z

the 12-pounders were mounted at the front of both 12-inch gun turrets on either side. if you look at the picture of Ibuki, you can just barely make out where they are on the bow turret

 

redesignated in 1917 as the "8 cm gun"

https://en.wikipedia.org/wiki/QF_12_pounder_12_cwt_naval_gun#Japanese_service http://www.navweaps.com/Weapons/WNBR_3-40_mk1.php 

 

4×1 short barrel QF 12-Pounder - in IJN service "Type 41 Short 3-inch gun"

 

these are 4 locally produced QF 12-Pounder 12-cwt guns whose barrels were chopped nearly in half to a fraction over 23 calibers long (either exactly 23.37 or 23.07) and rounded up to L/25 on paper.

as no changes were made to the breech mechanism, only the mounting and barrel length, both of these guns fired 12.5-pound (5.67 kg) Common shells with muzzle velocities of 2,300 fps (700 m/s) and a down-loaded version with 1,500 fps (450 m/s) respectively (the higher velocity shell though likely has a slightly slower exact muzzle velocity due to the shorter barrel)

 

considering this modified 12-Pounder design came around at about 1902/1903, it seems impossibly forward thinking that there was an AA cannon that literally predated the first air flight, but it becomes a lot more clear that this design was meant originally for gunboats and early submarines.

http://www.navweaps.com/Weapons/WNJAP_3-25_Short.php

https://en.wikipedia.org/wiki/Ibuki-class_battlecruiser#Armament

 

 

3 450mm torpedo tubes- one pointing forward at the stern, and one on each broadside, with one torpedo per launcher being a practice dummy, and two actual live torpedoes per launcher

no idea which torpedoes were used on the Ibuki-class and Tsukuba-class (especially since Ikoma seems to have been modeled in its i think 1920 version without them ingame), but navweaps has every possible option in the link below:

http://www.navweaps.com/Weapons/WTJAP_PreWWII.php#18"_(45_cm)_Torpedoes

 

according to the Japanese wiki pages, by 1920, both Ibuki and Kurama had picked up either 3 or 4 heavy machine guns for AA/point defense. Apparently these were Maxim guns chambered in 6.5mm Arisaka.

However according to original drawings, there were actually 4 Maxim guns, placed on both side of front and rear bridges.

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SOURCES:

 

online:

http://www.navypedia.org/ships/japan/jap_cr_kurama.htm

https://en.wikipedia.org/wiki/Ibuki-class_battlecruiser

https://en.wikipedia.org/wiki/Japanese_cruiser_Kurama

https://ja.wikipedia.org/wiki/鞍馬_(巡洋戦艦)

https://en.wikipedia.org/wiki/Japanese_cruiser_Ibuki_(1907)

https://ja.wikipedia.org/wiki/伊吹_(巡洋戦艦)

 

 

literary:

Conway's All the Worlds Fighting Ships 1906-1921, PDF/DjVu page 243

Warships of the Imperial Japanese Navy, 1869-1945, PDF page 74

 

防衛庁防衛研修所戦史室, 1969, ｢戦史叢書 海軍軍戦備<1> -昭和16年11月まで-｣ 付表第1 その1 大正9年3月調 艦艇要目等一覧表 軍艦
War History Room, NIDS, JDA, 1969 "Senshi Sosho [War History Series], vol.31, Navy’s preparation of the war <1> Until November 1941" Appendix 1 part 1, specification sheet of Warships, 1920

This appendix sheet is copy of Ministry of the Navy Annual Report in 1919

http://www.nids.mod.go.jp/military_history_search/SoshoView?kanno=031

 

Original sections of "Kurama" & "Ibuki" (scale 1/4 in = 1 ft)

original cross sections from the Hiraga Archives, Kashiwa Library, University of Tokyo

https://iiif.dl.itc.u-tokyo.ac.jp/repo/s/hiraga/document/a92f6efd-cdf6-4733-bec9-5d78b2c4e41a#?c=0&m=0&s=0&cv=0&xywh=3663%2C1097%2C1500%2C1129

Edited November 27, 2020 by Admiral_Aruon
major revisions part 3.01

[ItssLuBu 1,803]

Approved and open for discussion. 

[aizenns 3,591]

Nice suggestion! It will be interesting addition for game. +1

I find some problems.

 

 

10 hours ago, Admiral_Aruon said:

the Ibuki-class Armored Cruiser.

In Japanese Navy, this class was called "Kurama-class" because class leader of this class is Kurama. As I descripted in suggestion of Kaga, in Japanese criteria, class leader is decided by date of launch the ship. (Criteria of JMSDF is same as western navies)

Kurama launched October 21, and Ibuki launched November 21.

 

 

10 hours ago, Admiral_Aruon said:

ARMAMENT:

This section have a little problem. Because of complexity of Japanese naval weapon naming system before WWI era, almost all western books make mistake.

In case of old Japanese naval weapons, name of each guns were decided by manufactures of each gun.  For example, if it build by Armstrong, it was called Armstrong type (安式), if it build by Vickers, it was called Vickers type (毘式), if it build by Kure arsenal, it was called Type 41 (四一式) or Kure type (呉式), and if it came from captured Russian vessels, it was called Russia type (露式).

 

12-inch (30 cm) gun

• Kurama: 45 caliber Type 41 12 inch gun (四十五口径四一式十二吋砲)
• Ibuki: 45 caliber Armstrong 12 inch gun (四十五口径安式十二吋砲)

Note: later both gun were renamed to "30 cm gun"(三十糎砲).

 

8-inch (20 cm) gun

• Kurama & Ibuki: 45 caliber Type 41 8 inch gun (四十五口径四一式八吋砲)

Note: later it was renamed to "20 cm gun"(二十糎砲).

 

4.7-inch (12 cm) gun

• Kurama: 45 caliber Type 41 4.7 inch gun (四十五口径四一式四吋七砲)
• Ibuki: 45 caliber Armstrong 4.7 inch gun (四十五口径安式四吋七砲)

Note: later both gun were renamed to "12 cm gun"(十二糎砲).

 

3-inch (8 cm) gun on the main turrets

• Kurama & Ibuki: 45 caliber Type 41 3-inch gun (四十五口径四一式三吋砲)

Note: later it was renamed to "8 cm gun" (八糎砲). Both 30 cm gun turret have two 3-inch gun. Total number of 3-inch/50 guns were 4.

 

Short barrel 3-inch (8 cm) gun

• Kurama & Ibuki: Type 41 Short 3-inch gun (四一式短三吋砲)

Note: later renamed to "8 cm gun"(八糎砲). Total number of 3-inch/23.5 guns were 4.

This is NOT a High-Angle gun. High-angle gun version is "5th Year Type Short 8-cm high angle gun" (五年式短八糎高角砲). 5th Year Type were mounted on submarines and gunboats. Now, one gun is left on Thailand naval museum. 

Spoiler

Photo from suggestion of Converted Subchaser Fumi-Maru

 

Machine gun

• Kurama & Ibuki: Maxim 6.5 mm autocannon (麻式六粍五機砲)

"Maxim" machine gun with 6.5 mm rifle cartridge. Total number of Maxim machine guns were 3.

However, at least as far as I seen original drawing that I saw in library, she had 4 machine guns. Maxim machine guns were placed on both side of front and rear bridges.

 

 

Quote

 

Source:

防衛庁防衛研修所戦史室, 1969, ｢戦史叢書 海軍軍戦備<1> -昭和16年11月まで-｣ 付表第1 その1 大正9年3月調 艦艇要目等一覧表 軍艦
War History Room, NIDS, JDA, 1969 "Senshi Sosho [War History Series], vol.31, Navy’s preparation of the war <1> Until November 1941" Appendix 1 part 1, specification sheet of Warships, 1920

This appendix sheet is copy of Ministry of the Navy Annual Report in 1919

http://www.nids.mod.go.jp/military_history_search/SoshoView?kanno=031

 

 

 

I find original drawing of Kurama-class from Hiraga Archives (Tokyo Univ.). Perhaps it will be help.

 

Quote

Sections of "Kurama" & "Ibuki" (scale 1/4 in = 1 ft)

https://iiif.dl.itc.u-tokyo.ac.jp/repo/s/hiraga/document/a92f6efd-cdf6-4733-bec9-5d78b2c4e41a#?c=0&m=0&s=0&cv=0&xywh=3663%2C1097%2C1500%2C1129

 

[Milocat 4,857]

+1 for sure, this would now be a perfect addition.

[Admiral_Aruon 2,264]

On 21/11/2020 at 07:13, aizenns said:

Nice suggestion! It will be interesting addition for game. +1

I find some problems.

 

 

In Japanese Navy, this class was called "Kurama-class" because class leader of this class is Kurama. As I descripted in suggestion of Kaga, in Japanese criteria, class leader is decided by date of launch the ship. (Criteria of JMSDF is same as western navies)

Kurama launched October 21, and Ibuki launched November 21.

 

 

This section have a little problem. Because of complexity of Japanese naval weapon naming system before WWI era, almost all western books make mistake.

In case of old Japanese naval weapons, name of each guns were decided by manufactures of each gun.  For example, if it build by Armstrong, it was called Armstrong type (安式), if it build by Vickers, it was called Vickers type (毘式), if it build by Kure arsenal, it was called Type 41 (四一式) or Kure type (呉式), and if it came from captured Russian vessels, it was called Russia type (露式).

 

12-inch (30 cm) gun

• Kurama: 45 caliber Type 41 12 inch gun (四十五口径四一式十二吋砲)
• Ibuki: 45 caliber Armstrong 12 inch gun (四十五口径安式十二吋砲)

Note: later both gun were renamed to "30 cm gun"(三十糎砲).

 

8-inch (20 cm) gun

• Kurama & Ibuki: 45 caliber Type 41 8 inch gun (四十五口径四一式八吋砲)

Note: later it was renamed to "20 cm gun"(二十糎砲).

 

4.7-inch (12 cm) gun

• Kurama: 45 caliber Type 41 4.7 inch gun (四十五口径四一式四吋七砲)
• Ibuki: 45 caliber Armstrong 4.7 inch gun (四十五口径安式四吋七砲)

Note: later both gun were renamed to "12 cm gun"(十二糎砲).

 

3-inch (8 cm) gun on the main turrets

• Kurama & Ibuki: 45 caliber Type 41 3-inch gun (四十五口径四一式三吋砲)

Note: later it was renamed to "8 cm gun" (八糎砲). Both 30 cm gun turret have two 3-inch gun. Total number of 3-inch/50 guns were 4.

 

Short barrel 3-inch (8 cm) gun

• Kurama & Ibuki: Type 41 Short 3-inch gun (四一式短三吋砲)

Note: later renamed to "8 cm gun"(八糎砲). Total number of 3-inch/23.5 guns were 4.

This is NOT a High-Angle gun. High-angle gun version is "5th Year Type Short 8-cm high angle gun" (五年式短八糎高角砲). 5th Year Type were mounted on submarines and gunboats. Now, one gun is left on Thailand naval museum. 

Reveal hidden contents

Photo from suggestion of Converted Subchaser Fumi-Maru

 

Machine gun

• Kurama & Ibuki: Maxim 6.5 mm autocannon (麻式六粍五機砲)

"Maxim" machine gun with 6.5 mm rifle cartridge. Total number of Maxim machine guns were 3.

However, at least as far as I seen original drawing that I saw in library, she had 4 machine guns. Maxim machine guns were placed on both side of front and rear bridges.

 

 

 

 

I find original drawing of Kurama-class from Hiraga Archives (Tokyo Univ.). Perhaps it will be help.

 

 

 

thanks! especially for trustworthy sources I can add. i'll get these added to the revision once I have time.

[de Radio Demon@live 266]

+1

[Fireraid233 4,274]

+1

[aizenns 3,591]

I find some photos of Kurama and Ibuki at Kure-city Maritime Museum's database.

 

Interesting photos:

Spoiler

Rear 12-inch turret

Kurama, 1914

https://jmapps.ne.jp/yamatomuseum/det.html?data_id=89518

Spoiler

20-cm turret

Kurama, 1914

https://jmapps.ne.jp/yamatomuseum/det.html?data_id=89511

Spoiler

Stern walk

Kurama, 1911, Portland

("まらく" means Kurama)

https://jmapps.ne.jp/yamatomuseum/det.html?data_id=90712

Spoiler

Bow

Ibuki, 1909~1910, Kure

 

[aizenns 3,591]

Postcard about reception at HIMJS Kurama

You can see details of side of the ship.

https://iiif.dl.itc.u-tokyo.ac.jp/repo/s/hiraga/document/f2be80bb-23f4-42a6-8e1e-0948280a3d19#?c=0&m=0&s=0&cv=0&xywh=0%2C-552%2C1801%2C2285

[Miki_Hoshii 2,449]

+1 Would like to see this as soon as possible.