Ships are not very fast, compared to ground vehicles. Even an old beater car can easily go 130 km/h (or much faster) on the highway, while most ships travel four or five times slower. But what about submarines – what maximum speed can they reach?
Container ships and other large commercial ships should not be compared to submarines, because they need to be economical – they are money making tools. Meanwhile submarines usually perform military or scientific tasks. Military submarines must react quickly to the changing situation, they need to be powerful and tough. Money is less of an issue.
Submarines are very sleek and powerful, but are they very fast? Well, it’s hard to say.
This question is difficult to answer because the technology and capabilities of military submarines are kept secret. For example, Russian Akula-class (Russian: Щука-Б) submarine that can reach a speed of 28-35 knots (52-65 km/h) while under water, but there are rumours that it could do a staggering 75 km/h if it absolutely needed. Another class of Russian submarines, the Yasen, also officially reaches a speed of 35 knots, while others are slower.
In the US Navy, we would also find very fast submarines. The Ohio-class submarine can officially reach a speed of 20 knots (37 km/h), but according to unofficial data, a speed of 25 knots is not actually the limit. Los Angeles-class submarines on paper can do the same 20 knots, but are believed to be capable of pass the 33-knot (61.1 km/h) mark. Meanwhile, Virginia-class submarines can reach speeds of 25 knots (46.3 km/h). But none of them can match the 35 knots (65 km/h) on the Seawolf’s speedometre. This class of submarines was specially designed to act as quickly and as quietly as possible.
Of course, the US and Russia are not the only countries using submarines. HMS Astute, a British submarine, often considered to be one of the most technologically advanced in the world, reaches a top speed of 30 knots (56 km/h). The French Triomphant class submarines are also very modern, but only accelerate to 25 knots (46 km/h). Representatives of another class of French submarines, the Rubis, are slightly faster, but not by much. The Japanese Oyashio and Sōryū class submarines reach a top speed of 20 knots (37 km/h). The list could go on and on, but the truth is that the fastest submarines ever created are no longer sailing.
There once were efforts to make the fastest possible submarine. The USS Albacore, a research submarine of the US Navy that operated from 1953 to 1972, was much faster than the Ohio- and Los Angeles-class boats that were built later. It actually reached a speed of 33 knots (61 km/h). This was quite an achievement in those days. However, we would find the fastest submarines in the history of the Soviet Navy.
The Alfa-class submarine, technically one of the predecessors of the Akula-class, could reach speeds of up to 41 knots (76 km/h) underwater. In service between 1971 and 1996, the Alfa was officially the fastest submarine in the world at the time. It was said that it could reach a speed of 45 knots (83 km/h) if necessary. However, the speed record probably does not belong to the Alfa class either.
The Soviet Papa-class submarine (first designated K-162, then K-222) was a unique experimental vessel. It sailed in 1968-1984. Unofficially, it achieved its record during trials, when it accelerated to 44.7 knots (83 km/h). However, this is impossible to confirm.
In general, it is impossible to confirm all the numbers mentioned here. The true capabilities of military submarines may be incomparably higher, but they are concealed. The ability to quickly retreat after a successful or unsuccessful attack is very important, and the energy generated by nuclear reactors, combines with the the advanced shape of the hull, make it possible for military submarines to achieve very high speeds. We only know that no one can really catch the black marlin – this fish reaches 71.3 knots (132 km/h).
