In May 2018, Hellenic Navy released a Request For Information letter (RFI), asking various companies for acquiring 533mm heavy torpedoes for its four Type 214 Papanikolis submarines plus one updated Type 209 AIP Okeanos. In October 2020, DM2A4 was chosen as the preferred solution, with a program consisting of 36 DM2A4, plus refurbishing of several older SUT Mod0 to Mod4 standard, plus extra batteries for older SST torpedoes / SUT Mod0 torpedoes, with a total cost of 105m euro. In September 2021, the contract was modified, with a program consisting of 44 DM2A4, without refurbishment of several older SUT Mod0 to Mod4 standard, plus extra batteries for older SST torpedoes / SUT Mod0 torpedoes, with a total cost of 110m euro.
German Atlas Elektronik was awarded a GDAEE (Greek Directorate-General for Defense Technology and Investment) contract for the modernization of the torpedo potential of the Hellenic Navy. The modernization consists of the supply and supporting role of new torpedo submarines of the Greek navy. In particular, the delivery of 44 modern DM-2A4 Seehecht torpedoes (export designation “SeaHake mod 4”) was approved at a total cost of nearly €112 million ($ 121 million). The SeaHake mod4 has a 21-inch (533 millimeters) standard caliber used for Heavyweight Torpedoes worldwide. It is capable of every common launching method such as swim-out, push-out, water steam, or ram. If Greece had accepted the German offer, then the delivery of 51 Black Sharks would have cost more than the delivery of German DM-2A4 torpedoes [€130,000,000 vs. €98,000,000]. Thus, the Greek submarines of the Navy finally acquired modern torpedoes, referring to bulgarianmilitary.com.
DM2A4 Seehecht (SeaHake mod 4) is the latest heavyweight torpedo developed by Atlas Elektronik for the German Navy, as a further update of the DM2 (Deutsches Modell 2) torpedo which was released in 1976. Being the successor of the DM2A3, it features an advanced electrical propulsion system and a fiber optic cable for torpedo guidance and communication, which, in conjunction with advanced signals processing and mission logic, makes the torpedo largely countermeasure resistant. The DM2A4/SeaHake mod 4 is the first torpedo ever to be guided by a fiber optic wire. With a fully digital system architecture, increased range and speed, and its new conformal array sonar with a very wide panoramic sensor angle as well as the additional wake homing sensor, the DM2A4/SeaHake mod 4 provides greatly advanced performance over its predecessor.
The homing headshell is a hydrodynamic optimized parabolic shape that aims to reduce torpedo self-noise and cavitation to an absolute minimum. The homing head’s conformal transducer array permits detection angles of +/-100° in the horizontal and +/-24° in the vertical, therefore supporting larger acquisition angles in comparison to traditional flat arrays. The wide-angle array is designed to reduce maneuvering when in search and reconnaissance stages, therefore also reducing self-noise and preserving battery power. The weapon has a modular design that includes up to four silver-zinc battery modules and can achieve a range of more than 50 km (27 mi) and a speed exceeding 92.6 km/h (50 kn) powered by a high-frequency permanent magnet motor, with a closed-loop cooling system independent from the environment.