The ''Tridente''-class submarines, also designated as U 209PN, are diesel-electric

submarine A submarine (or sub) is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. The term is also sometimes used historically or colloquially to refer to remotely op ...

s based on the

Type 214 submarine The Type 214 is a diesel-electric submarine developed by Howaldtswerke-Deutsche Werft GmbH (HDW). It features diesel propulsion with an air-independent propulsion (AIP) system using Siemens polymer electrolyte membrane (PEM) hydrogen fuel cel ...

developed by Howaldtswerke-Deutsche Werft GmbH (HDW) for the

Portuguese Navy The Portuguese Navy ( pt, Marinha Portuguesa, also known as ''Marinha de Guerra Portuguesa'' or as ''Armada Portuguesa'') is the naval branch of the Portuguese Armed Forces which, in cooperation and integrated with the other branches of the Port ...

. This class of submarines was acquired by Portugal to replace the previous submarines of the , then being operated by the navy. Originally, HDW proposed the

Type 209 submarine The Type 209 is a class of diesel-electric attack submarine developed exclusively for export by Howaldtswerke-Deutsche Werft of Germany. The original variant (Type 209/1100) was designed in the late 1960s. The class is exclusively designed for ...

(U-209) during the competition, but decided to later enter a new proposal based on the Type 214. It is for this reason that the ''Tridente'' class is commonly designated as the U 209PN. The class and its ships are the first to not be named after marine animals, thus breaking a tradition retracing back to 1913, when the first submarine entered service with the Portuguese Navy.

Ships

The ''Tridente''-class submarines are wrongly classed in the "diesel-electric" class. Their propulsion is exclusively electric, with electric motors powered by batteries. These batteries may be charged while submerged by "fuel-cells" (inverse electrolysis) for which, this submarine carries a huge supply of liquid oxygen and hydrogen. Also, and solely as a second solution for recharging the batteries, this submarine carries two powerful diesel-electric generators (1,000 KVA) for use only when surfaced, or at snorkel depth. Submerged, from

Lisbon Lisbon (; pt, Lisboa ) is the capital and largest city of Portugal, with an estimated population of 544,851 within its administrative limits in an area of 100.05 km2. Grande Lisboa, Lisbon's urban area extends beyond the city's administr ...

, Portugal, submarines of the class may reach the

Cape of Good Hope The Cape of Good Hope ( af, Kaap die Goeie Hoop ) ;''Kaap'' in isolation: pt, Cabo da Boa Esperança is a rocky headland on the Atlantic coast of the Cape Peninsula in South Africa. A common misconception is that the Cape of Good Hope is t ...

and return, in 15 days.

Image gallery

File:Portuguese navy submarine NRP Tridente (S 160) arrives at Naval Station Norfolk.jpg,

submarine NRP ''Tridente'' at

Naval Station Norfolk Naval Station Norfolk is a United States Navy base in Norfolk, Virginia, that is the headquarters and home port of the U.S. Navy's Fleet Forces Command. The installation occupies about of waterfront space and of pier and wharf space of the Hamp ...

File:Submarino NRP Arpão.png, NRP ''Arpão'' at

Lisbon Naval Base The Lisbon Naval Base ( Portuguese: ''Base Naval de Lisboa''), is the main installation and operational base of the Portuguese Navy. Located at the former Royal Estate of Alfeite on the south bank of the Tagus river's estuary, near the city of A ...

File:NRP Tridente - S-120 Papanikolis 2.jpg, NRP ''Tridente'' under construction File:NRP Tridente - S-120 Papanikolis 1.jpg, NRP ''Tridente'' at

Howaldtswerke-Deutsche Werft Howaldtswerke-Deutsche Werft (often abbreviated HDW) is a German shipbuilding company, headquartered in Kiel. It is part of the ThyssenKrupp Marine Systems (TKMS) group, owned by ThyssenKrupp. The Howaldtswerke shipyard was founded in Kiel in 183 ...

Kiel Kiel () is the capital and most populous city in the northern Germany, German state of Schleswig-Holstein, with a population of 246,243 (2021). Kiel lies approximately north of Hamburg. Due to its geographic location in the southeast of the J ...

shipyard A shipyard, also called a dockyard or boatyard, is a place where ships are built and repaired. These can be yachts, military vessels, cruise liners or other cargo or passenger ships. Dockyards are sometimes more associated with maintenance a ...

External links

''Tridente'' class
information at the Portuguese Navy website (in Portuguese)
209PN profile
at the Portuguese Navy website (in Portuguese)
Submarino de ataque (SSK) classe Tridente (tipo U-214) - ''Área Militar''
(in Portuguese)
Acquisition history of the U-209PN class
(in Portuguese)
Article about the differences between the U209, U212, U214 and U209PN
(in Portuguese) {{Modern German submarines Attack submarines Submarine classes Submarines of the Portuguese Navy Type 214 submarines