Sea of Iron:
By Mike Bennighof, Ph.D.
Finland first obtained a navy of sorts during
the Finnish Civil War of 1919, when a number
of elderly gunboats and torpedo boats of the
Tsarist Navy fell into White Finnish hands.
Almost all of these captures came in shipyards
and harbors where the vessels had been laid
up without crews, and not of active warships.
The only serious losses came when ice trapped
and crushed several torpedo boats in Viipuri
By the early 1920s, these ships had become
thoroughly worn out and most of them went
to the scrapyard in Turku. The fleet’s
first commander, Commodore Hjalmar von Bonsdorff,
presented a plan in 1919 for a navy base around
a division of armored coast defense ships,
with a squadron of large destroyers and 40
torpedo boats, plus submarines and minelayers.
It went nowhere, but the basic concept, heavy
guns supported by submarines and torpedo craft,
stayed with the next generation of Finnish
The Finns saw two threats requiring a fleet:
a possible Soviet landing around Helsinki,
and another Swedish attempt to seize the Åland
Islands (repeating their 1918 adventures in
the Finnish archipelago, driven off by German
threats). The Finnish parliament finally passed
an ambitious naval construction program in
September 1927 after two years of debate.
That didn’t stop the navy from signing
a contract for its first submarine a full
year before the Navy Act became law, and another
for two more in April 1927.
The program called for two armored gunboats,
three high-seas submarines, one tiny submarine
intended for operations on Lake Ladoga, and
four motor torpedo boats. A never-completed
second phase would have added four more armored
ships, six 1,000-ton destroyers, nine high-seas
submarines and three more tiny lake submarines.
Loading torpedoes aboard Vesikko.
Crichton-Vulcan of Turku, a conglomerate
(by Finnish standards) formed from the 1924
merger of two financially-troubled shipyards,
received most of the Navy’s contracts.
They built the submarines to a design from
the Dutch firm Ingenieurskantoor voor Scheepsbouw
(I.v.S), a front for the German shipyards
AG Vulkan and Krupp-Germaniawerft which under
the terms of the Versailles Treaty could not
participate in submarine construction. The Vetehinen, Vesihiisi and Iku-Tursu were 500-ton minelaying submarines that
became prototypes for the much larger German
Type VII u-boat, the backbone of the Kriegsmarine’s
submarine force during World War II.
Launch ceremonies for Iku-Tursu.
German engineers oversaw the construction,
which proceeded slowly. When the Finnish shipyard
workers went on strike, Crichton-Vulcan imported
German craftsmen to replace them. After delivery,
German officers (some of them active-duty
officers like Kapitan-Leutnant Karl Topp,
future commander of the battleship Tirpitz) remained on hand for “testing”
but in reality trained the new Finnish crews.
Meanwhile, the future Finnish submarine commanders
served on board Italian boats to gain experience.
The declining Hietalahden Laivatelakka yard
in Helsinki laid down the tiny submarine Saukko in 1930, with a claimed displacement of 99
tons. The Treaty of Dorpat signed in 1920
between Finland and the Soviet Union limited
warships on Lake Ladoga to 100 tons, but as
built Saukko actually displaced 114
tons. She had two torpedo tubes with no reloads,
and could be divided into two segments for
transport by rail. Saukko never actually
served on the lake, but was used in the Gulf
of Finland. Also an I.v.S. design, Saukko was to be the prototype for a coast-defense
submarine the Germans could build rapidly
and in large numbers. They discarded this
concept even before the Finns laid down Saukko,
and in service she proved a disappointment.
She was prone to break down, and her small
size made her very difficult to handle in
In 1932, Crichton-Vulcan laid down another I.v.S-designed
submarine “on speculation” (that
is, without a contracted buyer) but actually
at the secret request of the German Reichsmarine.
This boat, known initially as CV707, had almost
the same torpedo armament as the bigger Vetehinen (five torpedo tubes as opposed to six) but displaced
half as much, sacrificing most of her range.
She was based on the German World War One UBII
type, and became the basis for the Second World
War’s Type II German coastal submarine.
The tiny submarine Saukko.
She completed in 1933, and for the next
three years I.v.S. and Crichton “engineers”
(German submarine officers in civilian attire)
“tested” the submarine, undertaking
training cruises in the Baltic. Germany began
submarine construction in late 1934 and announced
the step in March 1935 with the first boats
commissioning that summer. With training moved
to CV707’s German-built sisters, the
secret training submarine was no longer needed
and Crichton sold her to the Finnish Navy
The Finns liked Vesikko, as they
named the boat, and hoped to build more of
the same type. Her relative lack of range
meant little in the congested waters of the
Gulf of Finland and Baltic Sea. Along with
a third armored gunboat and a half-dozen small
destroyers, the Finnish Navy hoped to build
at least three more of this type in the years
just before World War II but could not obtain
Finland’s five submarines all survived
the war, and Vesikko remains today
as a war memorial. They formed the fleet’s
offensive striking power, but during the Winter
War could not prevent Soviet battleships and
cruisers from shelling the Finnish lines.
Tiny Saukko made the first attempt,
stalking first the flotilla leader Minsk and
then the battleship Oktyabryskaya Revoluciya on 10 December 1939 but having to call
off the attack when her air vents froze.
Finnish submariners had little ice experience.
Ice proved a serious problem — despite
a design requirements that the Vetehinen class
hulls be strengthened to resist ice, the Finnish
Navy had not trained its submarine crews for
sub-zero operations. The minelaying submarines
began placing illegal offensive minefields
in neutral Estonian waters, the Finnish government
reasoning that since the Soviets were violating
Estonian neutrality, they would reply. But Vesihiisi and Vetehinen were both damaged by ice on these missions,
and on 15 January the fleet command ordered
a halt to all submarine operations.
The Finns opened the Continuation War in
June 1941 by laying heavy mine barrages across
the Gulf of Finland, and this kept Soviet
surface ships penned in until 1944. In the
summer of 1942 the Red Navy began a submarine
offensive in the Baltic, and the Finnish large
submarines were tasked with hunting them.
On 21 October Vesihiisi sank the
Soviet submarine S-7, on the 26th Iku-Tursu sank Shch-320, and on 5 November Vetehinen rammed and sank Shch-305.
These would be Finland’s first and last
submarine successes. After the war, Finland
was forced to give up her submarines, keeping
only Vesikko as a permanent memorial.
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Mike Bennighof is president of Avalanche Press and holds a doctorate in history from Emory University. A Fulbright Scholar and award-winning journalist, he has published over 100 books, games and articles on historical subjects.
He lives in Birmingham, Alabama with his wife, three children and his dog, Leopold.