Oheka II

An E-boat flying the white flag of surrender at the coastal forces base HMS Beehive, Felixstowe, May 1945
Class overview
Name	S-100
General characteristics
Type	motor torpedo boat
Displacement	100 tons (max) 78.9 tons (standard)
Length	32.76 m
Beam	5.06 m
Draught	1.47 m
Propulsion	3: Daimler Benz twenty-cylinder diesel engines MB 501; 3,960 hp
Speed	43.8 knots
Range	800 nm at 30 knots
Complement	24–30
Armament	2 × 533 mm torpedo tubes (4 torpedoes) 1 × twin 20 mm C/30 cannon, 1 × single 20 mm cannon 1 × 37 mm Flak 42 cannon

Lürssen Oheka II 22.5m built 1927

22.5 m long, Displacement 22.5 tons. Speed of 34 knots

Pictureand information was taken from:

Lürssen Oheka II 22.5m built 1927

22.5 m long, Displacement 22.5 tons. Speed of 34 knots

Picture was taken from:

http://www.richardstokowski.de/luerssen1.html

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The attention of the German Navy was drawn to Oheka II , a highly innovative luxury motor yacht built in 1927 by the German boatyard Luerssen for a Jewish banking tycoon who emmigrated to the United States from Germany. The name "Oheka" originated from a monogram of its owner's name, Otto HErmann KAhn. It's round bottomed hull was 22.5 m long, and displaced 22.5 tons. It reached a top speed of 34 knots, making it the world's fastest boat in its class. There is no basis in fact for the common misconception that Oheka II was a "rum runner" used for smuggling.

In Oheka II, Luerrsen overcame many of the drawbacks of the round bottomed displacement hull. The boat ploughed through the water by the brute force of three 550hp Maybach engines. The composite use of wood planks over alloy frames reduced weight. The innefficient tendency for round hulls to "squat" stern-down in the water at high speeds was counterbalanced by a hull form that flattened towards the stern, providing hydrodynamic lift where it was needed.

Oheka II's combination of speed, strength and seaworthyness was exactly what Naval command wanted. In November 1929, Luerssen was given a contract to build a boat to the same basic design, but with two torpedo tubes on the forecastle, and a slightly improved top speed. It was to become S-1, the Kriegsmarine's first Schnellboot and the basis for the all other S-Boats built during World War 2.

Oheka II was powered by 3 Maybach VL2 engines. These were V-12 engines also used in Zeppelins.

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The technical history of the S-Boat is a tribute to the imagination, determination and resourcefulness of German engineers. Although the treaty of Versailles was meant to prevent Germany from taking up arms in a war of aggression, its practical effect was to stimulate an ingenious and modernistic arms development program. Turning obstacles into advantages, German engineers designed weapons which both outwitted the restrictions of the Versailles treaty and capitalized on new technologies and tactics that could enable a small, lightly equipped nation to defeat a more powerful but anachronistic enemy. The rapid defeat of France in 1940, despite its overwhelming numerical superiority over Germany in weapons and troops, was total vindication of this program.

The S-Boat is a classic example of Germany's Versailles-influenced weapons engineering. Focusing on a boat considered too insignificant by the Allies to be regulated by the treaty, the Germans created a scaled down warship well-suited for naval Blitzkrieg. Heavily armed and fast, it could inflict great damage on a larger enemy and escape unharmed. Its sturdy design showed great foresight into its future operational role and emphasised high quality over mass production.

From very the beginning of the torpedo boat program, German Naval Command required boats suited for combat in North Sea conditions. A series of trials with a broad variety of designs began in 1920 under cover of developing a fast "submarine chaser," Most initial programs concentrated on short planing hulls commonly used for speedboats. This surface skimming design is ideal for fast boats in calm waters but loses its chief advantage of effiency when waves slam the flat hull bottom. Furthermore, weight is a critical issue, and the irridescent plume of water created by a planing boat moving at high speed is visible over great distances at night.

In 1928, in light of these limitations and the dismal North Sea weather, Naval command elected to concentrate strictly on a round bottomed displacement hull. Their attention was drawn to Oheka II , a highly innovative luxury motor yacht built in 1927 by the German boatyard Luerssen for a Jewish banking tycoon who emmigrated to the United States from Germany. The name "Oheka" originated from a monogram of its owner's name, Otto HErmann KAhn. It's round bottomed hull was 22.5 m long, and displaced 22.5 tons. It reached a top speed of 34 knots, making it the world's fastest boat in its class. There is no basis in fact for the common misconception that Oheka II was a "rum runner" used for smuggling.

In Oheka II, Luerrsen overcame many of the drawbacks of the round bottomed displacement hull. The boat ploughed through the water by the brute force of three 550hp Maybach engines. The composite use of wood planks over alloy frames reduced weight. The innefficient tendency for round hulls to "squat" stern-down in the water at high speeds was counterbalanced by a hull form that flattened towards the stern, providing hydrodynamic lift where it was needed.

Oheka II's combination of speed, strength and seaworthyness was exactly what Naval command wanted. In November 1929, Luerssen was given a contract to build a boat to the same basic design, but with two torpedo tubes on the forecastle, and a slightly improved top speed. It was to become S-1, the Kriegsmarine's first Schnellboot and the basis for the all other S-Boats built during World War 2.