User:Yiba/sandbox/Battlecruiser

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How Battlecruisers Came to Be
'Battlecruiser' is an English term describing a British concept. Equal or similar terms are used in other countries with different meanings, so it is fundamentally flawed trying to apply the term universally across individual navies. One such example is the term in Japanese 巡洋戦艦 (Jun'yō Senkan), which literally translates to 'cruiser-battleship' or 'battle-cruiser', meaning a warship with speed of a contemporary cruiser with the firepower and armor protection of a contemporary battleship. Another example is the German term Grosse Kreuzer (large cruiser), but this classification was not formally used until much later for German legal considerations on budgetary approval.

The term 'battlecruiser' is generally accepted to be coined by Admiral Jacky Fisher in 1908, who was the First Sea Lord of the UK at the time. The Royal Navy re-classified Invinsible from armoured cruiser to battlecruiser in November 1911. Imperial Japanese Navy likewise formally re-classified Tsukuba to "Jun'yō Senkan" in August 1912. However, the concept (not the term) was arguably born when Japanese cruisers Nisshin and Kasuga were successfully used in a battleship-fleet-to-battleship-fleet combat of Battle of Tsushima in 1905, when the common belief was "cruisers are not meant for the line of battle against a battleship fleet."

Battle of Tsushima
Although the news media coverage of the Battle of Tsushima on 27 May 1905 was very good for the time, Admiral Fisher was one of the first to receive the details of the combat from Captain Pakenham, who was assigned to the Imperial Japanese Navy as a military attaché and observed the battle first-hand onboard battleship Asahi. Asahi was led by three other Japanese battleships in front, and followed immediately behind by Kasuga and then Nisshin, in the main line of battle against five newest Russian battleships.

This very advantageous observation point was apparently secured in large part through personal efforts by Captain Pakenham, but active information flow in the courteous relationship in Anglo-Japanese Alliance likely played a role. Over forty officers were offered to Japan as naval attaché for the Russo-Japanese War by navies across the globe, but no other country had access to such an up-close viewpoint. Captain Manuel Domecq García of the Argentine Navy was an exception being onboard Nisshin at the tail end of the battle line during the engagement, but his appointment as a naval attaché had more to do with his government selling Kasuga and Nisshin to Japan at the beginning of the war. García was the head of the Argentine commission sent to Genoa to oversee the construction, and his background being a gunnery officer, he was placed in a secondary gun turret.

There were six more Russian battleships in the Russian fleet, but they were smaller and older, and were not a match against newer Japanese armored cruisers, like Izumo on the table. Consequently, four of the five newer Russian battleships along with three older battleships were sunk, and all others were captured, without the two cruisers being sunk in this most fierce and numerous exchange of large shells in the history of naval warfare up to 1905.

Kasuga and Nisshin
The two Italian-built armored cruisers incorporated Armstrong 10"/40 and 8"/45 guns, the latter in common with many of the Japanese cruisers at the time. These guns had a very long 18 km range combined with an excellent 1.5 (10") to 2 (8") rounds per minute rate of fire, which made it possible to shoot at the Russians from outside of the Russian gun range at more than twice or three-times faster rate of fire. Being in the line of battle led by four battleships, they did not stay outside of Russian gun range and were hit several times, but they survived this direct engagement with battleships while inflicting not-inconsequential damages to the enemy.

Although the two cruisers were temporary add-ons to the Japanese main line of battle, to take the places meant for battleships Hatsuse and Yashima that sank before this battle by striking mines, the use of the two cruisers in the line of battle opened the possibility for a new form of naval engagement for fast ships with long range guns. They would shoot the enemy ships from outside of the enemy gun-range while making it impossible for the enemy to close the distance by being faster.

Background
The idea of "large guns on a smaller ship" had been tried successfully in the form of Monitor during the American Civil War (1861–65), and the concept was revived in Humber-class by the Royal Navy in 1914 for bombarding shore targets. However, these vessels were made for shallow waters as coastal weapons, or for activities on rivers and in deltas, lacking seaworthiness.

Parsons and Cuniberti
Charles Parsons invented the steam turbine engine in 1884, and proved its power in his coal-firing yacht, Turbinia, which demonstrated a 34 knots speed at Queen Victoria's Diamond Jubilee in 1897.

Italian naval officer and architect, Vittorio Cuniberti, proposed an 'ideal' battleship with twelve 12-inch guns without secondary big guns, and 12" armor with the speed of 24 knots. After Regia Marina rejected the proposal, he published the idea on Jane's Fighting Ships in 1903.

Dreadnoughts
Japanese battleship Satsuma was laid down on 15 May 1905 with a Cuniberti-style "all big guns" design of twelve 12" guns. She was launched on 15 November 1906 as the largest battleship in the world with 19,683 tons of normal displacement, but her armament was changed to four 12" guns and six 10" guns due to a delay in the Japanese production of Armstrong 12"/45 guns under license. Being powered by two 4-cylinder triple-expansion engines, her maximum speed was 18.25 knots, and the range of the 12" guns was 17.24km at 15° elevation (rated at 21.12 km at 20° elevation, 27.43 km at 33°). This ship failed to meet the Cuniberti-standard on uniform guns, 12" armor, and the speed.

HMS Dreadnought was laid down on 2 October 1905, launched on 10 February 1906 with 10 Vickers 12"/45 guns with the displacement of 18,410 tons. She was the first battleship to have two Parsons steam turbine engines for a maximum speed of 21.6 knots.  Due to the Vickers B.VIII turret design allowing only +13.5°  elevation, the range was limited to about 16,450 yards (15.04 km with 2CRH AP projectiles) although Vickers later rated the gun itself at 25,000 yards (22.86 km at 45° elevation possible with land-based artillery, with 4CRH AP shell).  This ship, while being hailed to have revolutionized the battleship design, also failed on the speed standard.  Admiral Fisher later claimed to have argued for the cancellation of building this ship in favor of the Invincible-class, which shared the same gun and the turret. Later during World War I, this turret was upgraded to enable 16° elevation, for the range of 20,435 yards (18.69km) with 4CRH AP projectiles.

1904-1916
The period covered in the following table is marked by a very fast technological advancement combined with fierce competition among the navies in the world. Some inventions in the period, like the Japanese Shimose Powder and German trinitrotoluene (TNT), the strongest high explosives at the time, were tightly guarded secrets, but in general, navies stole each other's technical advancements with relative ease. Combined with the public perception to hold the largest battleship as national pride, the navies had different philosophies and approaches to an ideal fighting ship.

The concept for a warship in battles to have: 1. Longer gun range, and 2. Faster speed, obviously requires the enemy ships to have a shorter gun range and slower speed. So in the period of rapidly advancing naval warfare technology, it was a matter of shooting for a moving target. To illustrate what ship was better than others in what respect in what year, the speed target in 1904 is arbitrarily set at 21 knots, 30 knots for 1916, and the 9 knots improvement is equally divided in the 12 years in between. Similarly, the gun range target is arbitrarily set at 15 km for 1904 and 25 km for 1916, and the 10 km improvement in the period is equally divided over the 12 years. By using these arbitrary end-points for the period, 9 ships out of 26 exceeded the moving target on the speed scale, and also 7 ships on the gun range scale at the time of their commission.

Exceptional figures in other relevant elements, namely, number of guns, rate of fire, and armor thickness are also indicated in pink. *: These rows are for reference purposes only. Not included in the comparison. Keys:

The two Italian ships on the table, Napoli and Pisa, while never being called a battlecruiser, show amazingly well-balanced attributes for the time. The German armored cruiser Blücher almost meeting or exceeding both speed and gun range targets, while having a large number of guns and excellent rate of fire is remarkable. Note that none of the ships exceeded both speed and range targets, except the Blücher, Lion-class and Kongō-class ships which came very close to meeting both.

The US Navy apparently did not see much in the prospect for a battlecruiser as their designs tended to polarize between a fast and lightly-protected cruiser and a strong but slow battleship in the period. When the US Navy finally decided on building the 'battlecruisers', Lexington-class (commissioned in 1927 instead as aircraft carriers), they displaced 44,200 tons and had a top speed of 33.25knots. By that time, battlecruisers grew so large it became difficult to distinguish them from a fast battleship.

The Royal Navy commissioned the largest number of warships in the period. They apparently preferred Vickers guns and turrets over Elswick guns/mounts/turrets for most of the period, which tended to limit the maximum elevation. Elswick's close ties with the Imperial Japanese Navy may have had some effect on this tendency, which continued well into 1914-1918 World War I period when the Royal Navy ships went through upgrades to increase the maximum elevation of the turrets. HMS Invincible had two Vickers BIX and two Elswick BX turrets for the main Vickers-designed Mark X guns.

Battle of Heligoland Bight (1914), Battle of Dogger Bank (1915) and Battle of Jutland on 31 May to 1 June 1916

SMS Derfflinger, commissioned in 1914, and HMS Hood, commissioned in 1920, were both intended to replace battlecruisers and fast battleships.

The range of naval guns improved so much that "fall of shot observation" became impossible at the far end of the range, as the shells flew much beyond the 20-25km horizon observable from high on the mast. Consequently, 1920-1927 may have been the end of life for the Battlecruiser concept.

Propulsion
Primary engines of warships progressed from coal burning 3-cylinder triple-expansion steam engines to coal/oil burning 4-cylinder triple-expansion engines, and the number of main engines grew from the normal 2 in the past to 3 on SMS Blücher in 1909 along with the same number of screws.

Then, more powerful and efficient oil-burning steam turbine engines replaced them, first on HMS Invincible in 1909, driving 4 screws.

Firepower
'Firepower' is generally determined by:

Shell Weight x Impact Velocity x Rate of Fire x Number of Guns or, more simply put: Bore Size x Barrel Length x Rate of Fire x Number of Guns

Armor
The stronger protective armor plate Harvey armor in the 1890s was replaced by Krupp Cemented Armor by 1902-1908, which enabled lighter and stronger warship protection. Notes: