Introduction.
Contrary to what some authors have suggested, the origin of the
design of the Bismarck Class battleships had nothing to do with the
Bayern Class of World War I except for the fact that they were also
equipped with eight 38cm guns in four twin turrets and a
three-shaft propulsion plant. The battleships of the Bismarck Class
were the product of a warship development that had begun with the
construction of the pocket battleships (Panzerschiffe) of the
Deutschland Class in the late 20's and early 30's under the
restrictions of the Treaty of Versailles.
Historical Background.
The Treaty of Versailles of 1919, stated in its Article 181 that
the German naval forces in commission could not exceed six
battleships, six light cruisers, twelve destroyers and twelve
torpedo boats, while Article 190 limited the displacement of
capital ships to 10,000 tons. On 6 February 1922, the United
States, the British Empire, France, Italy and Japan, signed the
Washington Naval Treaty. Under the terms of this treaty, the five
major naval powers agreed to limit the standard displacement of
their capital ships to 35,000 tons (35,560 metric tons), and the
calibre of their heavy guns to 16 inches (40.6cm). The total
capital ship standard tonnage was distributed as follows:
· United States 525,000 tons (533,400 mt).
· British Empire 525,000 tons (533,400 mt).
· France 175,000 tons (177,800 mt).
· Italy 175,000 tons (177,800 mt).
· Japan 315,000 tons (320,040 mt).
The London Naval Conference of January-April 1930 was intended to
review the Washington Naval Treaty, but France and Italy refused to
ratify it because of the low battleship tonnage ratios they were
assigned.
In the early 30's, German naval ship building was still restricted
by the Treaty of Versailles, and it was not until 18 June 1935 when
Britain's Foreign Minister Sir Samuel Hoare and the German
Ambassador Joachim von Ribbentrop signed the Anglo-German Naval
Agreement in London, that its restrictions were finally lifted.
Germany was then allowed to build a surface fleet of up to 35 per
cent of that of Britain, and up to 45 per cent in the case of
submarines. This meant that Germany could now build 184,000 tons of
battleships, in other words five 35,000-ton battleships. Between
December 1935 and March 1936 the five major powers met again in
London. Japan withdrew from the conference since her demands for
parity with the United States and the British Empire in capital
ship tonnage were not met. So, an escalator clause was added, and
allowed to build battleships of up to 45,000 tons in case a
non-signatory power was suspected of building ships outside the
treaty limits. Since Italy and Japan did not sign the Treaty, the
standard displacement of 45,000 tons was understood to be
acceptable by the other powers including Germany.
The Bismarck Class.
After the Anglo-German Naval Agreement was signed, the battleship
"F" (later Bismarck) was officially ordered, and the building
contract placed on 16 November 1935 with the shipbuilding firm
Blohm & Voss, founded by Hermann Blohm and Ernst Voss in 1877.
Designed by Dr. Hermann Burkhardt, the battleships "F" and "G"
(Bismarck and Tirpitz) were basically improved versions of the
battleships "D" and "E" (Scharnhorst and Gneisenau), and featured
many of the details of their predecessors. The Bismarck looked like
an enlarged Scharnhorst indeed. Officially listed as a 35,000-ton
battleship to comply with the London Treaty, Bismarck's real
displacement was actually some 7,000 tons higher. According to the
1937 escalator clause this was well within the 45,000-ton limit.
Moreover, none of the other naval powers kept themselves inside the
35,000-ton limit either, and all the battleships that came out of
the 1936 London Treaty (Vittorio Veneto, Richelieu, King George V,
and North Carolina) exceeded this limit.
More than 90% of the ships hull was electrically welded. Special
care was put to the stability of the ship, and one of the most
outstanding characteristic of the new Bismarck Class was its superb
capability to absorb damage due to the protected volume. The
subdivision was very extensive, and the hull was divided into 22
watertight compartments/sections (Abteilungen) numbered I-XXII from
stern to bows. 17 of those compartments were within the citadel;
this meant that 70% of the waterline length was protected by heavy
armour. The design required a very wide beam of 36 meters which
also contributed to maintain a high degree of stability. The ship
comprised 17 decks from the keel to the foretop:
· Foretop (Vormars).
· Searchlight deck (Scheinwerferdeck).
· Lower searchlight deck (Unteres Scheinwerferdeck).
· Admirals bridge (Admiralsbrücke).
· Upper mast deck (Oberes Mastdeck).
· Lower mast deck (Unteres Mastdeck).
· Bridge deck (Brückendeck).
· Lower bridge deck (Unteres Brückendeck).
· First deck (Aufbaudeck).
· Upper deck (Oberdeck).
· Battery deck (Batteriedeck).
· Main deck / Armour deck (Zwischendeck [tweendeck] /
Panzerdeck).
· Upper platform deck (Oberes Plattformdeck).
· Middle platform deck (Mittleres Plattformdeck).
· Lower platform deck (Unteres Plattformdeck).
· Stowing [stowage] (Stauung).
In contrast with the Scharnhorst, the lower main belt of the
Bismarck was reduced in thickness from 350 mm to 320 mm (Tirpitz
315 mm). A 320 mm belt backed by a 110-120 mm sloped armour deck
was considered more than enough to defeat any projectile at any
distance, and made the battleship practically immune in close range
engagements. The upper belt, was however, increased in thickness up
to 145 mm and had no portholes. Underwater, the thickness of the
torpedo bulkhead remained the same, but the distance between this
and the outer hull was increased from 4.5 to 5.5 meters
amidships.
The new design had to be longer due to the fourth battery turret.
The traditional arrangement of four twin turrets was selected.
Although 40.6cm main guns were permitted by the 1936 London Naval
Treaty, the new and powerful 38 cm SK C/34 with a high muzzle
velocity was considered more than adequate to fulfil its purposes.
Germany did not have 40.6cm guns available at that time anyway. The
secondary artillery was to be the same as in the Scharnhorst Class,
however the use of single turrets amidships was abandoned in favor
of twins.
