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With the end of the First
World War the French navy was in a much weakened state. 40% of its ships
had been lost during the war, and not replaced due to priority being given
to the army. In the immediate post-war years financial constraints
prevented any large ships from being built, and construction focused on
destroyers and cruisers.
Tentative approval to the
construction of new battleships as part of an overall naval programme was
given in 1924, and design studies began in 1926. Germany's announcement of
the construction of pocket battleships in 1928 provided a focus for
designers, and the new French battleships were intended to counter this
threat. Approval for construction was finally given in late 1931.
The main guns were chosen
to be 330 mm (13 in), and it was decided to mount them in two quadruple
turrets forward of the superstructure. This gave considerable weight
saving over a quadruple turret design by reducing the length that needed
armour protection and reducing the total number of turrets. It also had
the advantage of allowing the full weight of fire to be used in a chase
situation, as it was expected that the pocket battleships would attempt to
flee when confronted with such an obviously superior vessel. The potential
vulnerability of this arrangement was reduced by having an armoured
bulkhead between the two turret halves, and by having separate magazines
for each turret half. To address the potential weakness to attacks from
astern the superstructure was designed to maximise the arc of fire
available to the guns.
The selection of secondary
armament was somewhat revolutionary. They were the first capital ships to
choose HA/LA (high-angle / low angle) dual-purpose secondary armament, for
use both as anti-aircraft and anti-surface weapons in stead of the
traditional separate secondary guns for surface targets and smaller
tertiary guns for air targets. This had the advantage of giving more guns
for either air defence or surface defence, provided that both were not
required at the same time. As with the main guns, these were placed in
quadruple mounts and separated in to half-turrets by an armoured bulkhead.
The guns were 130 mm (5.1 in) calibre and were placed at the stern of the
ship to provide some protection in that area from surface attack. Close
range protection against aircraft was provided by ten 37 mm (1.5 in)
cannon in five double mounts, as well as machineguns.
The armour gave the ship a
theoretical immunity zone of 16,600 to 28,400 m (18,160 to 31,060 yds)
against a 280 mm (11 in) gun, meaning that at ranges below 16,600 m a 280
mm shell could be expected to penetrate the side armour, and above 28,400
m a 280 mm shell could be expected to penetrate the deck armour. It must
be stressed that this is a theoretical calculation, as in practice several
factors (particularly the sea state) affect the actual resistance to
shells at the instant they hit, and the immunity zone is constantly
changing as the ship heaves, rolls and pitches. It's also worth noting
that the armour for the Dunkerque was designed to resist the relatively
small calibre guns of the pocket battleships, rather than the much larger
guns of true battleships.
The ship was designed for
29.5 kts at 'normal' (design) displacement, following the normal design
principle that the ship should be able to out-run anything that it could
not out-fight. This gave a 2 kt advantage over the German pocket
battleships, and matched the speed of contemporary cruisers. The design
was very fuel efficient, and sufficient fuel was provided to allow over
16,000 nautical miles at 17 knots, enabling the navy to meet its worldwide
colonial commitments.
Hangar space for two Loire
130 seaplanes was provided, along with a single catapult and a single
crane, on the stern of the vessel. A third aircraft could be carried on
the catapult, however this is not believed to have occurred in practice.
The Dunkerque was the first capital ship to have aircraft included as part
of their initial design, and they were intended for reconnaissance and to
spot the fall of shot.
These ships were well
suited to their chosen role of protecting French commerce worldwide from
the German pocket battleships. Faster, better armed and better protected
than the pocket battleships there is little doubt that they would have
overwhelmed them in an engagement. There were some minor shortcomings,
however: the action at Mers el Kébir confirmed their vulnerability to
battleship-calibre guns (although it confirmed the wisdom of the armoured
bulkhead dividing the turret halves), and the loading arrangement of the
secondary armament was not a success. Nevertheless, many of the design
concepts were brought forward in to later classes of French battleships,
and they influenced the design of both the British and the Italian ships
of the time. |
|
|
|
Dunkerque |
Builder |
Laid
Down |
Launched |
Completed |
Left
Service |
| Navy
Yard (Brest) |
24
December 1931 |
2
October 1935 |
1
February 1936 |
27
November 1942 |
|
The Dunkerque was
based in Brest when Germany invaded Poland, and her first task was
to cover the movements of French cruisers from Brest. The Atlantic
fleet was then reorganized, and the Dunkerque became part of the
1čre Escadre de Ligne, which also contained the most modern
cruisers and destroyers. This force was primarily intended to
counter the two German pocket battleships known to be at sea, as
well as being available to provide a covering force for convoys. The
force put to sea to on 22 October protect convoy KJ3 from the pocket
battleship Deutschland, although the threat never materialized.
The force next left
port on 25 November to operate with the British searching for what
was believed to be the Deutschland, although in fact the ships were
the Scharnhorst and the Gneisenau. This search took place in very
poor weather conditions, which caused some damage to the Dunkerque.
Nothing was found, and she was ordered back to Brest on 30 November.
In December she carried gold to Halifax (Canada), then returned as
part of the escort for a Canadian troop convoy.
Conscious of the
potential for war with Italy, the Dunkerque was moved to Mers el
Kébir, in North Africa, at the start of 1940. When this threat did
not materialize she returned to Brest in preparation for an
operation to Norway in conjunction with the British, but this was
cancelled when the Germans invaded Norway and she was sent back to
Mers el Kébir. On 23 June, after Italy had declared war on France,
she left port in company with the Strasbourg to intercept Italian
cruisers which were threatening a French convoy. The Italians
withdrew before battle could be joined, and she returned to port.
She was still there when the armistice was declared on 25 June 1940.
On 3 July the forces
in Mers el Kébir were fired on by British warships after they
refused to accept British terms for disablement or surrender. The
Dunkerque was hit by three shells whilst heading out of port, and
she had to be beached. On 6 July she was attacked by British torpedo
bombers, which hit the ship alongside her, setting off depth charges
and ripping a huge hole in the side of the ship. She was slowly
repaired, and moved to Toulon on 20 February 1942. She was scuttled
there on 27 November 1942 to prevent her being captured by Germany. |
| Strasbourg |
Builder |
Laid
Down |
Launched |
Completed |
Left
Service |
| Penhoët
and Loire (St. Nazaire) |
25
November 1934 |
12
December 1936 |
December
1938 |
27
November 1942 |
|
The Strasbourg was
based in Brest with the Dunkerque at the outbreak of hostilities,
where she operated with the 1čre Escadre de Ligne (see above). As
the German pocket battleship Admiral Graf Spee was known to be
operating in the South Atlantic she was transferred to Dakar in
early October to form part of an Anglo-French force. She returned to
Brest at the end of November when searches failed to find the German
ship.
In January 1940 she
joined the Dunkerque for joint operations, moving with her to Mers
el Kébir. She managed to escape from port during the British attack
on 3 July, and made for Toulon. She was attacked by British aircraft
on the way, shooting down one and damaging two, and arrived in
Toulon on 4 July. She became the flagship of the French fleet,
although operations were rare due to lack of fuel.
She was disabled and
scuttled in Toulon on 27 November 1942 to prevent her capture by
Germany. The Italians subsequently stripped her, and later the hulk
was refloated by the French. In 1944 she was bombed by the Americans
whilst being used by the Germans to block the port's shipping
channel, and had to be grounded. |
|
|
|
|
Dunkerque |
Strasbourg |
| Vessel Particulars |
|
|
| Displacement |
|
|
| - Standard |
30,264
tons |
31,687
tons |
| - Full Load |
34,884
tons |
Unknown,
but greater than Dunkerque |
| Length (OA) |
215.14
m (705 ft 10 in) |
215.50
m (707 ft 0 in) |
| Length (WL) |
209.00
m (685 ft 8 in) |
209.00
m (685 ft 8 in) |
| Beam |
31.10
m (102 ft 0 in) |
31.10
m (102 ft 0 in) |
| Draft (Standard) |
8.55
m (28 ft 1 in) |
8.58
m (28 ft 1 in) at 30,280 tons |
| Draft (Full Load) |
9.63
m (31 ft 7 in) |
Unknown,
but greater than Dunkerque |
| Block Coefficient |
0.54 |
0.54 |
| Propulsion |
133,730
hp |
No
data, but very similar to Dunkerque |
| Speed |
31
kts |
No
data, but probably less than Dunkerque |
| Weapons |
|
|
| Main Guns |
8 x 330 mm
(13 in) guns in two quadruple mounts |
8 x 330 mm
(13 in) guns in two quadruple mounts |
| Other Guns |
12 x 130 mm
(5.1 in) in four quadruple mounts
10 x 37 mm (1.5 in) cannon in five twin mounts
32 x 0.52 in (13.2 mm) machineguns in eight quadruple mounts |
12 x 130 mm
(5.1 in) in four quadruple mounts
10 x 37 mm (1.5 in) cannon in five twin mounts
32 x 0.52 in (13.2 mm) machineguns in eight quadruple mounts |
| Magazine |
800 rounds of
330 mm
7,865 rounds of 130 mm
20,200 rounds of 37 mm |
800 rounds of
330 mm
7,865 rounds of 130 mm
20,200 rounds of 37 mm |
| Armour |
|
|
|
Side Belt |
225
mm (8.9 in) tapering to 125 mm (0.6 in) |
283
mm (11.1 in) |
|
End Bulkheads |
210
mm (8.3 in) forward
210 - 150 mm (8.3 - 5.9 in) aft |
260
mm (10.2 in) forward
210 - 150 mm (8.3 - 5.9 in) aft |
|
Magazine |
125
mm (4.9 in) upper
40 mm (1.6 in) lower |
125
mm (4.9 in) upper
40 mm (1.6 in) lower |
|
Barbette |
310
mm (12.2 in) |
340
mm (13.4 in) |
|
Turret |
330
mm (13.0 in) face
250 mm (9.8 in) sides
345 mm (13.6 in) back
150 mm (5.9 in) top |
360
mm (14.2 in) face
250 mm (9.8 in) sides
355 mm (14.0 in) back
160 mm (6.3 in) top |
|
Deck |
115
mm (4.4 in) upper
40 mm (1.6 in) lower |
115
mm (4.4 in) upper
40 mm (1.6 in) lower |
|
Miscellaneous |
|
|
|
Aircraft |
3 x Loire 130
seaplanes (normally 2) |
3 x Loire 130
seaplanes (normally 2) |
|
Compliment |
1,381 |
1,400
(approx) |
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