Submarine classes

Submarines can be divided into a few classes depending on their powerplant systems and their use.

Submarine powerplants basically fall into two categories:
1. Diesel-electric powerplants
2. Nuclear powerplants

Diesel-electric powerplants were the first successful powerplants introduced in submarines. The system consists of diesel engines, electric motors and batteries.

Diesel-electric submarines obtain their power from diesel engines while running on the surface of the sea and batteries (charged by the diesel engines) powering electric motors while submerged. Since WW2 snorkels have allowed submarines to run their diesel engines submerged, thus giving them more stealth.

These subs come in two basic types:
1. Hunter-killer subs (SSKs), whose mission is to seek out and destroy enemy subs;
2. Ballistic-missile subs (SSBs, now obsolete), whose mission is to carry ballistic nuclear missiles(SLBMs) for deterrence.

Examples of SSKs are the Russian Kilo class, the French-Spanish Scorpene class, WW2 German U-boats and the WW2 USA Gato class.
An example of an SSB is the Russian Zulu-class.


A Russian Kilo SSK


The Scorpene-class SSK

Nuclear-powered submarines only came about during the 1950s-1960s period of the Cold War, with the first, USS Nautilus commissioned in 1954. These submarines draw power from a nuclear powerplant in the hull, which provides electricity to power electric motors which drive the propeller/pumpjet.


The USS Nautilus, the first nuclear sub

Performance-wise, these submarines surpass diesel-electric subs by a wide margin as they can travel much faster, longer and in some cases, deeper. They do not need to surface for air as nuclear powerplants do not need it. However, they are quite large, complicated and in some cases less stealthy than SSKs due to their nuclear reactor (SSKs can run silently with secured electrical and diesel motors whereas nuclear subs need to keep running coolant pumps to prevent the reactor from overheating).

These subs again can be divided into two types:
1. Attack submarines (SSNs) - same use as SSKs;
2. Ballistic nuclear submarines (SSBNs) - same use as SSBs

Examples of SSNs are the US Los-Angeles, Seawolf, and Virginia class, the Russian Alfa, Victor, and Akula class, the British Trafalgar class,the French Rubis class, and the Chinese Han class.


A US Seawolf-class SSN


A Russian Akula-class SSN

Examples of SSBNs are the US Ohio class, the Russian Typhoon and Delta class, the British Vanguard class, the French Le Redoutable and Le Triomphant class, and the Chinese Xia class.


Ohio-class SSBN


Typhoon-class SSBN


A SLBM launch


Note: SS means Submersible Ship; B means Ballistic(Missile); K means Killer (Hunter-Killer); N means Nuclear.
SSNs are already considered as attack submarines; there is no need for SSKN.