{"id":17745,"date":"2024-03-14T22:19:21","date_gmt":"2024-03-14T20:19:21","guid":{"rendered":"https:\/\/www.liberalglobe.com\/?p=17745"},"modified":"2024-03-14T22:19:21","modified_gmt":"2024-03-14T20:19:21","slug":"french-scorpene-evolved-submarines-the-new-propulsion-technologies","status":"publish","type":"post","link":"https:\/\/www.liberalglobe.com\/?p=17745","title":{"rendered":"French Scorpene Evolved Submarines \u2013 The New Propulsion Technologies"},"content":{"rendered":"\n

The S-80 Scorp\u00e8ne is offered in three versions, the original CM-2000 which is the conventional diesel-electric version of the submarine, the AM-2000 which is the AIR version and the CA-2000 which is a diesel-electric version of smaller displacement and potential for coastal waters. To date, 14 units have been delivered or are under construction for four navies.<\/p>\n\n\n\n

It began in the 2000s with two submarines for the Chilean Navy and two for the Malaysian Navy jointly built between the two partners. Following Navantia’s withdrawal from the partnership, Naval Group has achieved sales for four submarines to the Brazilian Navy and six to the Indian Navy, all of which are built locally. At the same time, Navantia is building four S-80A submarines, derivatives of the French S-80 Scorp\u00e8ne adapted to Spanish operational requirements.<\/p>\n\n\n\n

According to the Scorp\u00e8ne manufacturer, it is ideal for action and has high operational efficiency. Robust and durable, it is an ocean-going submarine designed for shallow-water operations as well. Multipurpose, it fulfills the full range of missions, such as Anti-Surface and Anti-Submarine Warfare, special operations, offensive minelaying and intelligence gathering.<\/p>\n\n\n\n

The Scorp\u00e8ne’s hull design traces its lineage to the proposed diesel-electric version of the Amethyste-class nuclear attack submarine. The hull form has a hydrodynamically efficient design with an extended parallel midsection and a rounded bow. The stern is elongated and features cruciform steering fins that terminate in a low-noise seven-bladed propeller. The submarine has a length of 66-82 meters, a hull diameter of 6.2 meters, an overall height of 12.3 meters, a draft of 5.8 meters and a submerged displacement of 1600-2000 tons. The hull of the submarine is made of HLES 80 strength steel (equivalent to HY80) to optimize pressure hull weight in relation to strength. Consequently the submarine can carry a larger load of weapons and fuel on board than conventional designs.<\/p>\n\n\n\n

The French shipbuilding giant Naval Group has advanced in recent years in the development of new technologies for the Scorpene conventional propulsion submarines. In addition to the new electronic systems technology that is de facto being incorporated into new submarines under construction, the development of new propulsion systems also enhances a submarine’s mission capability. That is, increasing a submarine’s capabilities in terms of achieving greater speed, achieving greater underwater cruising duration, and achieving greater range all play a very important role in a submarine’s ability to accomplish a greater range of missions.<\/p>\n\n\n\n

The two new technology propulsion systems that Naval Group offers for its own design conventional propulsion submarines are the new technology lithium ion batteries (Li +ion, LIB) and the anaerobic propulsion system FC2G AIR type PEM (Proton Exchange Membrane).<\/p>\n\n\n\n

Lithium Ion Batteries<\/strong><\/p>\n\n\n\n

All conventionally powered submarines to date carry lead-acid batteries. The first rechargeable battery was a lead-acid battery, invented by Gaston Plant\u00e9 in 1859. Lead-acid batteries are very popular due to their low cost, robustness and low self-discharge. On the contrary, their disadvantages are their low energy density and their negative environmental effects. Lead-acid batteries consist of a lead metal anode and a lead dioxide cathode. The electrolyte consists of sulfuric acid. As the battery discharges, the two electrodes react to lead sulfate and the sulfuric acid reacts to water. During charging, hydrogen gas and oxygen are released due to the electrolysis of water, which is vented through openings in the top of the battery. This means that lead-acid batteries must be recharged, which requires regular maintenance. To address this, a new type of lead-acid batteries with adjustable valve (VRLA) have been designed, where the electrolyte is replaced by a gel. However, this type of battery is designed with a low potential for overvoltage to prevent gas generation during charging. Due to cathode corrosion, a lead-acid battery is capable of 200-300 cycles.<\/p>\n\n\n\n

Naval Group today offers a new version of the submarine, the Scorpene Evolved which is equipped with new generation lithium ion batteries. Lithium is the lightest of all metals and has one of the highest electrical potentials. In lithium-ion batteries, positively charged lithium ions (Li+) move from the anode to the cathode during discharge. These features provide the highest energy density in terms of volume and weight. Also, lithium-ion batteries are low-maintenance and do not require scheduled cycling to maintain their desired lifespan. Self-discharge is less than 50% compared to nickel-cadmium batteries. Aging occurs in lithium-ion batteries, resulting in the deterioration of battery capacity.<\/p>\n\n\n\n

In general, a very big disadvantage of a lithium-ion battery is the possibility of thermal runaway. This process can occur when exothermic chemical reactions are triggered due to physical or electrical abuse, such as short-circuiting, external heating, or excessive (dis)charging. The results of a thermal runaway are high temperatures, formation of toxic gases and the risk of explosion and fire.<\/p>\n\n\n\n

The main advantages of these batteries compared to lead-acid batteries are:<\/p>\n\n\n\n