The Poseidon Deep Submergence Ventilated Supercavitating Vehicle
Since their invention many years ago, ocean-going vessels have always been plagued by the turbulence they create. Water is around 1000 times thicker than air, and logically induces 1000 times more drag on any object traveling through it.
The results are... Slow speeds. Conventional surface ships and submarine speed have always been limited to no more than 40 or 50 mph.
Supercavitation removes all these limits on speed...
Supercavitation occurs when an object moving though water reaches speeds in excess of 100 knots (110mph). If the object has a correctly shaped ‘cavitator’ on its nose, a bubble of air starts to form around the object... This extends to cover the entire object, and hence the object is no longer moving through water, but through air, which creates but a fraction of the friction. Hence Supercavitational craft are capable of racing at high speed on or below the surface of the ocean.
Traveling in a bubble kills off all traditional marine propulsion techniques. Propellers spinning in air isn’t much good after all… The only engines that work are the same ones, which power our ships to the stars… Rocket engines. Supercavitational craft are high speed, highly maneuverable rocket powered fighters.
Supercavitation utilizes the phenomena of cavitation, so it essential to understand what it is when looking at supercavitation.
Cavitation is an old problem, which has plagued ship designers for decades. It is caused by fast moving objects in water with sharp edges such as propellers spinning quickly and causing an actual change in the physical state of the water around them, leading to both damage and inefficiency.
This happens because the faster a propeller spins, the lower the water pressure around it becomes. If this pressure falls fast enough, then the water reaches its ‘vapor pressure’, at which, like boiling water, it vaporizes and forms small bubbles of gas. Unlike bubbles caused by heat though, the bubbles are unstable, and implode violently when their pressure changes. This implosion can cause extensive damage to vessels, and to a submarine which still runs in a world of ‘run silent run deep’ this kind of implosion can cause potentially deadly noise.
Supercavitation rather than fighting the process of cavitation exploits it to create a near frictionless environment for a craft to travel in. Instead of trying to avoid or minimize cavitation, it attempts to create a renewable large bubble, a ‘Supercavitational bubble’ that is designed to totally envelope the craft and thus make it travel within the bubble of air.
The breakthrough speed at which this occurs is 180 km/h, or some 110 mph or 100 knots. At this speed, with a correctly crafted nose the pressure of the water at the tip of the vessel drops sharply, and starts to change the water coming into contact with it from its liquid form to its gaseous one. As this happens a bubble begins to form, extending back along the craft.
A Supercavitational craft has a nose with a specially designed ‘cavitator’ which extends the bubble and makes it stable. The size and length of the bubble is dependant on speed, although its size can be increased by ‘ventilated supercavitation’. In ventilated supercavitation, air is pumped into the bubble to increase its size and ensure that it covers the entire supercavitating projectile. The Shkval for example, uses ventilated supercavitation by redirecting part of the exhaust gases from its rocket engines through outlets near the nose of the torpedo.
The Poseidon is the next step in the evolution of Submersible Warfare. Unlike the slow moving behemoth Boomers of today, the Poseidon is fast and stealthy, capable of traveling at high speed underwater for thousands of miles undetected. Crossing all the advantages of a Ground base and a submarine, and throwing in the speed of a jet fighter, the Poseidon keeps the Submarine relevant in the age of high speed underwater Travel.
Unlike a sub fighter, the Poseidon cannot be limited by range. To be effective it needs the ability to travel great distances underwater, and to complete tours without the need to refuel. Moving such a large object underwater would require vast amounts of rocket fuel. Luckily for the Poseidon, the fuel is all around it! Seawater is made up of Hydrogen and Oxygen. Hydrogen is the most energetic rocket fuel there is. The Poseidons’ nuclear reactor provides the energy to separate the hydrogen from the oxygen, allowing the Poseidon to burn hydrogen in its rocket engines and giving the Poseidon effectively unlimited range.
By its very revolutionary nature, supercavitation has presented an entire new range of problems to overcome in designing these new high-speed underwater craft, especially with regards to guiding them.
Guidance presents one of the largest obstacles for supercavitating craft. Early versions of the Shkvals are thought to be ‘straight shooters’ capable only of flying in a straight line. Supercavitational bullets are also by their very nature unguided. The ability to successfully steer a Supercavitational craft presents perhaps the most difficult aspect of fully utilizing the technology. Any control surface within the bubble will have little or no affect on the direction of the craft.
Steering a Supercavitational craft creates the dual problems of both having to steer the bubble, and manipulating the bubble when turning to keep the craft in the supercavity. The latter is essential since if the fuselage were to come into contact with the ocean outside the bubble, then the force of suddenly hitting a wall of water would instantly crush it.
The solution to steer the bubble is accomplished using wing like ‘fins’, which extrude from the fuselage and extend beyond the Supercavitational bubble. Whilst these cause some increase in friction, they have the far greater benefit of allowing the Supercavitational bubble to be steered. The fins operate as control surfaces, which steer the bubble, and have the additional benefit of stabilizing the craft within the inherently unstable Supercavitational bubble.
The ability to control and manipulate the Supercavitational bubble is also essential in both increasing maneuverability and to stop the crushing of the craft as it turns. The bubble creating cavitator at the nose of the craft is capable of quickly changing its position and angle to both ensure the bubble is always encasing the craft and to compensate for varying water pressure as the craft’s depth changes.
Steering is aided through the use of thrust vectoring on the exhausts of the rocket engines, similar to current day proven systems used on the F-22 or SU-37 fighter jets. Thrust vectoring greatly increases the maneuverability of Supercavitational craft. The thrust vectored nozzles direct thrust both horizontally and vertically to allow much tighter turns and angles of attack, and assist the fins in effectively steering the bubble.
Cavitation in conventional marine craft is so dreaded because it can cause extensive damage to propellers as the bubbles implode. Fortunately, the decrease in the Supercavitational bubble, as long as it is controlled, would not have such an effect. A gradual slow down has the effect of progressively reducing the size of the Supercavitational bubble, gradually exposing the fuselage to greater amounts of friction.
As such as long as there is not a sudden collapse of the bubble, no damage is expected in leaving the Supercavitational bubble.
The Poseidon is powered by twin Saturn IX hydrogen breathing rocket engines. These produce massive amounts of thrust, enough to propel the Angelus to her top speed of over 750 Knots. Fuel for The immense rocket engines is sourced from hydrogen, which is extracted from seawater. Although silencers are fitted to the engines, the presence of transducers to create white noise allow the Angelus to be nearly as silent as a 20th century SSN submarine.
Amongst the most impressive areas of the ship is the bridge, which at over 100 feet in length contains the command centers for the ship itself as well as the air wing and sea wing. Set over numerous levels and brightly illuminated, it is the heart of the mighty Vessel.
Vessel Name: Poseidon
Type: Special Forces; Deep Submergence Ventilated Supercavitating Vehicle
Builder: Deep Angel Shipyards
Length: 1426 feet (434 meters)
Beam: 624 feet (190 meters) wingtip to wingtip
Height: 262 feet (79 meters)
Displacement: 326,000 tons
Cruising Speed: 40 Knots
Max Speed (Supercavitating): 750 Knots
Collapse Depth: Estimated at 13,000 feet.
Power plant: Fusion Nuclear Reactor
Primary: Rocket - Hydrogen Burning Engines (w/ hydra jet propulsion used to get it up to speed)
Secondary (Port) Engines: MHD “Caterpillar” Magneto-Hydro Drive
3x Capital-ship Class Trident Naval Rail guns (with supercavitating and conventional Ammunition)
8x 21inch Bow Torpedo tubes
4x 21inch Aft Torpedo tubes
50x Mk.41 Vertical Launch Tubes
25x SLBM Launch Tubes
18x The Arrow 2 Anti Tactical Ballistic Missile (ATBM) Tubes
15x A3 Asahi Tactical Armor Unit’s
Sea Wing (Sub-fighters)
20 x S/A-15 Hurricanes
5 x S-13 Fireblades (Special Ops)