Manta (paper project & mockup 1944)
Germany (1944), Fast Attack Craft
A daring concept born from desperation
At the end of the war, Nazi Germany desperately needed new technological ways to deal with the seemingly inexhaustible allied war machine, on land, air, and sea. This led to an engineering fest of epic proportion, spawning some of the most amazing and advanced projects and ideas ever seen. Some were impractical, yet others, while still rather unrealistic, were so advanced that they were realized twenty to fifty years afterward. Although there are tons of records for advanced missiles and jet planes, the comparatively fewer naval concepts are no less exciting to consider.
German naval secret weapons
The most advanced of these "secret weapons" were of course superfast submarines, originally to be powered by an advanced closed-loop propulsion system (Walter system). But as research dragged on, a cut was made by Albert Speer leading to the mass-production Type XXI, with the type being propelled by a hybrid system, combining conventional diesel with twice as many batteries to double the underwater speed, a brand new streamlined hull, and snorkel. Interesting also were the mass-built mini-subs Delphin, Hecht (53), Seehund (138), Biber (324), and Molch (393) as well as the human torpedoes like the Neger class (100), Marder (500) and Hai (the only prototype of a Marder enlarged by 36 meters).
German researches on hydrofoils
But one of the most amazing projects of that era (1944-45) was the array of fast surface ships using jets, catamaran hulls, or hydrofoils. Hans von Schertel worked before and during the war on many such prototypes and paper projects aimed at replacing the traditional S-boote and R-boote. The idea was that such kind of ship would be so fast they could not be destroyed, while they were either launching torpedoes or laying mines.
Attack Hydrofoil VS 6
These innovative fast attack craft were the brainchild of Baron Hanns von Schertel and realized by shipbuilder Sachsenberg. The prototype was tested in 1941. It was a 17-ton vessel, capable of 47 knots (80 kph) and laying mines. 52.5 feet in length, it was powered by two Hispano-Suiza gasoline engines of 560 hp each.
The Tietjens VS-7
followed, this time designed by Oscar Tietjens. It was largely based on a 1932 prototype with a patented surface-piercing hoop foil system, tested with success in the USA. The light vessel was able to reach 25 mph with a 5 hp outboard engine. The VS-7 largely emulated the previous VS-6, built at Schleswig, Germany, Vertens Yacht Yard. However, she was fitted with these revolutionary hoop foils. During trials, VS-7 reached a blazing 55 knots (101 kph) but was found slow to accelerate and had poor handling and maneuverability.
Transport Hydrofoil VS 8
One of the most remarkable projects of the time was the fast transport VS-8, which could carry and land a light tank anywhere between a Type 38T to a Panzer IV, stored on a tailored back deck, which was flooded as the self-propelled pontoon reached the beach (two 40 hp engines) with its load, in less than two minutes. However, the vessel was propelled by an 1800 hp Mercedes Benz diesel engine, which was found over time to be not up to the task. Other applications were to have been as a fast minelayer with 15-20 mines. The VS-8, ordered in 1940 was commissioned on January 3rd, 1943 but was found to be underpowered and the project was dropped after an incident in September of 1944 where during a trial, the VS-8 experienced a total engine failure, which was followed by a failed rescue, which was later attributed to sabotage. The VS-9 ordered in 1941 was never started.
Hydrofoil "VS 8" at Sachsenber-Shipyard- Picture from Fock Schnellboote Vol. 2
The following VS-10
was even larger, at 46-tons, 92 feet long, 60 knots, and torpedo-carrying. The prototype was completed and made ready for launch but completely destroyed in an air raid just a few days before it could happen.
The final TR5b or TRAGFLÜGELBOOT
was probably the most advanced of all of the previous designs. It combined a rather conventional hull twin turbojets Jumo 004s or He S 011s and three VS-type foils which housed the propellers. That way, the propellers were used to help the craft both during its final attack run and during its subsequent escape. Tests were performed in 1944 with a radio-controlled jet-powered boat, the Tornado, which showed calm sea was required for successful operation. K-Verband was planned for a production run starting in early 1945. However, it was set as low priority compared to more immediately useful and simpler vessels and thus never entered service.
Size comparison with a German SdKfz.234 reconnaissance car
Reconstruction in what-if camouflage
Second fictional livery, with periscopes up
UGS Manta: Origins
The Manta was an even more extreme prototype, that found its origins in the collaboration between the Walter facility and Versuchskommando 456. Named Untersee-Gleitflächen-Schnellboot Manta or UGS Manta, it was driven to overcome the limitations of midget submarines in both speed and range. The obvious solution was to have these in the air instead, the new philosophy leading to a completely new type of craft.
The Manta which resulted from this research looks stunning in its radical approach, and could only be compared to the 1960-1980s Ekranoplanes series built for the Soviet Navy. Indeed, that kind of hybrid between a plane and a ship used a well-known fluid property, the "wing-in-ground effect", which allowed for the construction of a very large plane (the "Caspian Monster" remains the largest "plane" ever built in that occurrence), much longer than the 747, C5 Galaxy or Antonov An-225 Mriya at 92.00 m (301 ft 10 in) and heavier at 240 tons. A small series of operational anti-ship and landing versions were operational in the 1980s and we will dig soon into these interesting crafts.
The Manta only used this effect when on the surface to lower drag at its minimum, thanks to a trimaran configuration: Three cylindrical hulls and large vertical keels/tanks captured the airflow under the main wing when the craft was raised. However the acronym is loosely translated as "Submarine sliding speedboat", in fact, these were indeed submarines unlike the Soviet Ekranoplanes, and only raised above the surface thanks to the keel/tanks that provided buoyancy. When above water (final phase of the attack), the Manta could reach 50 knots (93 kph) which made it difficult to hit, in addition to presenting a rather hollow frontal target. Once in range, it could then launch up to eight torpedoes.
Mockup model of the UCS Manta
The Manta was made of three tube-like hulls linked by the main wing and two vertical keels. The central tube housed the two-men crew cabin (each had a bubble-like canopy) and contained the diesel-electric propulsion and diesel-hydraulic transmission to link these to the lower keels propeller. The outer cylinders are Schwertwal-I type and held the batteries, fuel tanks filled with Ingolin, trim tanks, and compensating tanks. The wing was divided into an upper and lower part and sandwiched in between were located the two to eight torpedoes, or 8 TMA or 12 TMB mines. These were the same as the rest of the midget submarine fleet, aviation type, 450 mm in diameter, or the larger marine type (four carried). mines. They could also carry 4 "projectiles"* which are not precisely described but would have been likely heavy rockets.
Three-view drawing of the Manta, from the model.
The Manta was about 15 m long, 6 m wide, with 1.5 m diameter cylinders, and weighed 15 tons empty/ 50 tons loaded. This was compensated by two 600 hp engines or 800 hp Walter turbines coupled with 440 Kw electric motors. The maximum surface speed was noted as 50 kts, and the maximum submerged speed: 30 kts (55 kph) which was impressive enough. The range was 200 nm @50 kts/600 nm @20 kts on the surface, and 120 nm @30 kts/500 nm @10 kts when submerged. Navigation equipment was similar to that of the Schwertwal, and safety equipment was well-thought-out with a marker buoy with an antenna, a self-inflating dinghy, and special diving suits. In addition, the crew could jettison the two very heavy electric batteries from the keels, providing extra buoyancy, to help the craft reach more easily the surface in an emergency.
Navigation equipment was similar to that of the Schwertwal, and safety equipment was well-thought with marker buoy with an antenna, self-inflating dinghy and special diving suits. In addition, the crew could jettison the two very heavy electric batteries from the keels, providing extra buoyancy, and helping the craft when submerged, to reach more easily the surface in emergency.
When surfacing, the propulsion mode is even more exotic you can think: With less drag, the speed was to be in excess of 90 kph and the keels where not even supposed to surf, but to roll over the waves
thanks to four encased massive aviation wheels. This way, the drag was even more limited and at that speed the water surface was hard enough for the Manta to roll over. For extra lift there were two extra pairs of foils, for and aft of the keels before the wheels took over.
The ultimate naval V-weapon
The Manta was a submarine/flying/fast attack craft way ahead of its time. While it left the blueprint phase, it only existed as a small mockup. All documents produced after the Kleinst-U-Bootwaffe (Miniature Submarine Command) blessed this project has been burnt. Only the model remained, which was used to draw 3-view blueprints after the war.
Should the Manta have been built in numbers prior to June 1944, they could have disabled or destroyed many allied ships assembled during the D-Day landings. Only AA anti-artillery would have been fast enough to catch these when surfaced, provided they had the right depression. Does this idea still mean something today? The Russian Ekranoplanes are mothballed and FAC hydrofoils have been retired for the most part due to the fact that hydrocraft are known gas-guzzlers. This kind of submarine/wing-in-ground craft was only meant to attack the enemy with torpedoes and in the modern-day, due to radar and modern weapons systems like CIWS and surface-to-surface missiles, this form of attack is simply too risky.
However, the same concept applied to a missile-launching craft is much more appealing. Indeed, these could approach the enemy's inner radar/outer sonar detection limits and try a saturation fire after surfacing. The enemy ships could launch missiles in return, but MACH 3 missiles in large numbers within reach would have left little time to respond, especially if the attacking crafts are coated and stealthy shaped.
|Dimensions||15 x6 m, hull diam. 1.5 m|
|Displacement||15 - 50t FL|
|Propulsion||2 props, 2x 600 hp diesels, 2x 440 Kw elect. mot.|
|Speed||50 knots/sub 30 knots (90 km/h; 55 mph)|
|Range||200 nm @50 kts/600 nm @20 kts, 500 nm @10 kts sub|
|Diving depth||50-60 m|
|Armament||2-8 Torpedoes or 8/12 TMA/TMB mines or 4 rockets|
Reminds something ?