Sub dolphin propulsion system time to improve

Sub dolphin propulsion system time to improve


Air Independent Propulsion (AIP) system currently is the well known key component of a convention diesel‐electric submarine.

In fact, AIP system is a small power plant intended to provide operating of conventional submarine underwater (without supplying of atmospheric air) relatively for a long time. Any AIP system contains a fuel and liquid oxygen (as rule) storage and supplying systems, electro‐chemical or electro mechanical converter for transform of chemical energy of fuel into electricity and systems for dumping converter’s reaction products out of submarine board (in the sea water).

By tactic possibilities, the conventional submarines fitted with AIP system, take, as rule, the mean place between going out of day non‐AIP diesel‐electric and nuclear powered submarines. In littoral waters AIP‐DE submarines have minimal vulnerability. In littoral waters the boats are the most effective as compared with both NP and non‐AIP‐DE subs.

In particular:

  • Non‐AIP submarines have submerged endurance about 3 – 4 days at speed 4 knots (in real conditions it is about 2 – 3 days) that is limited by battery capacity. After that the submarine has to surface on snorkel depth to recharge battery and has to be on this depth during 7 hours as rule.
  • AIP submarines can provide submerged endurance of 14 – 18 days (in dependence on AIP type and submerged speed), and total endurance of 45 to 90 days, limited by oxygen storage.
  • Nuclear powered submarines typically have submerged endurance about 90 – 100 days that is limited by the food storage for the crew.
  • We can show advantages and disadvantages of AIP diesel‐electric (AIP‐DE) submarines as compared with non‐AIP and nuclear powered (NP) submarines.
Table. Nuclear Powered vs AIP diesel‐electric submarines. Comparison table.

Table. Nuclear Powered vs AIP diesel‐electric submarines. Comparison table

Table. AIP diesel‐electric vs Non‐AIP Diesel‐ electric submarines. Comparison table.

Table. AIP diesel‐electric vs Non‐AIP Diesel‐ electric submarines. Comparison table




SSK Dolphin‐I vs Type 209‐1200/1400 General Characteristics

SSK Dolphin‐I vs Type 209‐1200/1400 General Characteristics

SSK Dolphin‐I & Dolphin‐II General Characteristics

SSK Dolphin‐I & Dolphin‐II General Characteristics


Currently (2016) the Israeli Navy contains five submarines Dolphin‐class.

The Dolphin class is actually two different classes. They are: non‐AIP, SSK Dolphin‐I and AIP SSP Dolphin‐II sub‐classes of conventional diesel‐electric submarines.

Three Dolphin‐I class submarines were designed by Ingenieurkontor Lubeck Prof Gabler Nachf GmbH (IKL), a subsidiary of Howaldtswerke‐Deutche Werft AG (HDW) based in Lubeck, Germany. A schedule had originally been planned for the construction of the three submarines by an industrial team consisting of HDW and Thyssen Nordseewerke Gmbh (TNSW), lead by Litton Ingalls Shipbuilding. However, the project was cancelled in 1990 as result of Germany budget reallocation.

Following the Gulf crisis in 1990‐1991, contracts were placed for the construction of the first two boats, to proceed with funding support from the German government. Such decision was accepted in order to compensate for Israel the Gulf War (1990‐1991) damage and economic losses and, in the same time, to keep German shipyards occupied with a high profile projects. Deciding the both tasks and taking into account the post Cold War defense spending downturn the Chancellor of Germany Helmut Kohl approves an assistance package to German industry including the construction of two Dolphin‐I class submarines for Israel. Approval for construction of the third submarine was granted (50%) in 1994 only.


In other words, the first two Dolphin‐I class boats (Dolphin and Leviathan) were donated by Germany to Israel. The third boat (Tekumah) received a 50% of subsidy.

At the same time, early 1990s it was the very time when HDW, in fact, was ready to produce new up‐dated AIP submarines. In 1996 a Memorandum of Understanding (MOU) gave the start to the cooperation for building 4 vessels for German Navy and 4 vessels for Italian Navy. These boats in further will be designated as submarines SSP Type 212. These multi purpose well known AIP attack submarines (U31 – U34) were launched for German Navy in period from 2002 to 2006. The same as Dolphin, the boats Type 212 were constructed by Howaldswerke‐Deutsche Werft Gmbh (HDW) of Kiel and Thyssen Nordseewerke GmbH (TNSW) of Enden.

There are many causes why Israel did not obtain up‐dated AIP submarines.

However, “don’t look a gift horse in the mouth”. At the same time to be just, it should be confessed that Dolphin‐I class submarines were outmoded already at the moment of their launching. In fact, submarines SSK Dolphin‐I class (Dolphin, Leviathan and Tekumah) are short‐endurance (<50 days) littoral water diesel‐electric submarines for coastal defense and limited regional influence. These submarines must periodically surface or lift snorkel to use diesel‐generators for recharging submarine’s battery.

SSK DOLPHIN‐I & SSP TYPE 212/212A. General Characteristics

SSK DOLPHIN‐I & SSP TYPE 212/212A. General Characteristics


Currently, boats Dolphin‐I are in service 16 – 17 years already. Taking into account that mean service life of conventional submarines is about 30 years, came time to think what fate waits for the boats in the future (in particular in 13 – 15 years).

There are some following outcomes:

  • Utilization (scrap). It should be remembered that boats contain expensive equipment and materials that hardly can be used for the second time. It is very pity, it is squandering. However, it is possible, real end of the boat’s service.
  • Sale. It will be very difficult to realize as it will be outmoded therewith old submarines.
  • Use these boats as training ships to train new submarine crews. One boat is enough to provide this aim.
  • Use these boats for solving civil tasks. The proposal is unreasonable economically. The boats have to be fully reconstructed whereas they do not suitable to implement such functions.
  • Equip boats with AIP systems and after reconstruction to proceed using them in service in Israel Navy. It is troublesome way therewith requiring investments. However, it is possible and real way that can extend the submarines life.

We consider that last way has priority. Why we think so you can read in the next slides.

Some important reasons why we should do it today.

  1. National Security. The State of Israel has a long maritime border and territorial extended along the coast of the Mediterranean Sea. The coastal cities are concentrated most of the population and industry of the country, as well as important administrative and political institutions. In the sea are Israeli offshore gas platforms. However, very from the sea, the State of Israel is the most vulnerable, both from the terrorist attacks, and in the case of large‐scale military conflict.
    The main tasks of the Navy of Israel can be summarized as follows:
  • the conduct of military operations against groups of ship and aircraft the enemy in order to gain dominance in the Mediterranean Sea adjacent to the sea border of Israel;
  • implementation of protection of territorial waters and the sea coast of Israel, including the important administrative and political centers of the country, economic regions, gas fields, naval bases, ports;
  • ensure protection of coastal marine communications and violation of maritime communications of the enemy;
  • control of the Aden and Aqaba bays, the Suez Canal and the Gibraltar and Dardanelles straits;
  • provide a direct support to ground forces and air forces during operations in the maritime areas, conducting amphibious operations, the fight against marine landing forces, conducting continuous reconnaissance on the sea.
    Obviously, to decide these problems a fairly large fleet is required. Since Israel is not able to support such fleet, the fleet objectives shifted to the Air Force clearly. However, the development and dissemination of advanced air defense systems, including the ship’s air defense system poses problems for the application of the Air Force, in particular, to address the strategic objectives. Under these conditions, AIP‐subs are simply irreplaceable.
    Of course, overall strength of the Israeli Navy and composition of surface ships is inferior to Iran, Turkey, Saudi Arabia and even Egypt.
    As for Israeli submarines, they are effective sufficiently and have reliable weapon as a deterrent to different enemies, especially taking into account the fact that these boats have the ability to carry nuclear weapons.
    Five modern submarines now (in the future it will be 9) ‐ it would be a serious force. However, if the three of them (it is 30%) are out‐of‐date ‐ it significantly reduces the power and possibility of the submarine flotilla,
  1. It is known that the service life of the submarine, is typically about 30 years. However, if the vessel’s technical condition is good enough, it can be served in the future, especially if it is possible (specifications) will meet modern requirements.
    Submarines Dolphin‐I class now are out‐dated. On other hand, design, construction, installation and different examinations takes not short time. Therefore, to improve these boats the works should begin today, whereas period 10 ‐ 14 years is not so long for such works.
    It will be pointless to start the reconstruction of the boats after their decommissioning,
    Hopefully, that for the next 15 years, Israel will obtain from Germany the remaining four submarines Dolphin‐II. Nevertheless, the case with French helicopter carriers for Russia Navy creates precedent.
    The decommissioning of three submarines from nine in the future (2030s) is a serious decline in combat capability of the Israeli Navy. It can be supposed that the Government of Israel and the leadership of the Israel Navy did not choose this path.

  2. Successful implementation of the Dolphin‐I submarines reconstruction creates possibility to use submarine after 30 years of their service if boats will meet modern requirements. Reconstructed boats can be sold later and the proceeds may be used for the purchasing new modern submarines.

  3. Implementation of these works in Israel creates the basis for the development of high‐tech naval facilities and systems in the future, and exclude dependence of Israeli Navy on foreign firms. It is very important requirement so far as it creates both work places and base for expending of maritime industry.


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