Modern warships represent the cutting edge of naval engineering, designed to conduct variety of duties at sea. Warships are generally classified based on size, capabilities, and mission profiles. To better gauge the naval capability of any nation, it is important to understand the broader spectrum of modern warship classifications.
Aircraft carriers can be categorized based on their size, displacement, aviation wing, and propulsion systems. Super-carriers, like United States Nimitz and Gerald R. Ford classes, are the largest with displacement approximately 100,000 tons. These carriers are nuclear powered, equipped with CATOBAR system, and can support carrier aviation wing of 90 fixed-wing and rotary-wing aircrafts. Conventional powered ski-jump carriers, equipped with STOBAR system, are medium carriers and usually have displacement between 40,000 to 60,000 tons. China’s Liaoning and Shandong, Russia’s Admiral Kuznetsov, and India’s INS Vikrant and INS Vikramaditya are known examples. British HMS Queen Elizabeth and Prince of Wales can also be included in this list. Few exceptions are there. French Charles De Gaulle is mid-sized carrier but is nuclear powered. Similarly China’s newly launched Shandong carrier is conventionally powered but displaces more than 80,000 tons. Beside aforementioned examples, various amphibious warships with flight decks, commonly dubbed as Landing Helicopter Dock (LHD), are operational with navies of Japan, Turkey, Brazil, Italy, and Spain. These vessels are not purpose-built carriers. But with necessary upgrades and by operating V/STOL aircrafts like, F-35B, these vessels can be function as light carriers.
Submarines are also relatively easy to categorize based on mission-profile, propulsion systems, and on-board-weapons. Submarines can be nuclear powered or conventionally powered. Nuclear powered submarines are nuclear-powered attack submarine (SSN), nuclear ballistic missile submarine (SSBN), and nuclear guided (cruise) missile submarine (SSGN). With exception of SSBNs which are nuclear deterrent and custodian of sea-based nuclear strike capability, SSNs and SSGNs are offensive platforms and are used for striking enemy surface as well as under-surface targets at long-ranges. Conventional submarines can either be traditional hunter-killer submarines (SSK), or AIP equipped hunter-killer submarines (SSP). These submarines are potent sea-denial assets. Air-Independent Propulsion System (AIP) ensures submarine’s superior endurance which subsequently translates into high survivability rate. Small submarines, called midget submarines, with displacement of few hundred tons are also operated by some navies. These submarines have shorter ranges and are used for lying mines and conducting special operations.
There exists no universally acknowledged criteria exists to classify different warships based on their size. But in concept, when size and firepower are taken into account, cruisers are the biggest, heaviest and most heavily armed warships – followed by destroyers, frigates, and corvettes. Size and displacement, once defining factors, now vary significantly even within the same class. Advances in technology have enabled these classes to adopt overlapping roles, such as anti-air warfare (AAW), anti-surface warfare (ASuW), and anti-submarine warfare (ASW).
A few decades ago, warship categories were distinct. In NATO, cruisers (9,000+ tons) were multi-role ships for extended missions or task force command. Destroyers (5,000-8,000 tons) escorted carriers and served as offensive platforms. Frigates (2,500-4,500 tons) focused on anti-submarine warfare (ASW) and patrolling, while corvettes (below 2,500 tons) handled coastal defense. The Soviet Navy, unlike NATO, emphasized specialized roles. Cruisers, though capable of AAW and ASW, primarily carried long-range anti-ship missiles to counter U.S. carrier groups. Their destroyers, frigates, and corvettes also undertook specific tasks, reflecting differing naval doctrines.
In contemporary era, with advancement in technology, weapon and sensor systems have become modular in design, lighter in weight, and compact in size. Therefore, instead of developing warship for specialized role, multi-mission warships have become standard. Additionally, even small ships can now carry highly capable weapon systems which were previously beyond their physical capacity.
Modern cruisers usually have full-displacement in excess of 10,000 tons each. The US Navy with Ticonderoga class cruisers and Russian Navy with Kirov class battlecruisers and Slava class cruisers are the only navies that continue to operate these formidable vessels. These cruisers are heavily armed with weapons and sensor suite and can perform various duties ranging from command & control to saturated missile attack. Cruisers mission profile covers all three dimensions of naval warfare, i.e., ASuW, ASW, and AAW. However, with advancement in technology, the role of cruiser is gradually being taken-over by destroyers. Currently no new cruiser class is in development anywhere in world.
Modern destroyers are among the most versatile warships, equipped with ASuW, ASW, and AAW systems and are indispensable in fleet operations, where they serve as protectors and strike platforms. When gauged from displacement perspective, destroyers range from 6000 tons at lower end to 10,000 tons at higher end. As discussed above, heavy destroyers have essentially turned cruisers out of fashion. China’s Type-55 class, Japan’s Maya class, South Korea’s Sejong-The Great, and United States Arleigh Burke Flight-III class are amongst the largest and heaviest surface combatants with displacement in excess of 10,000 tons each. But navies operating these warships still label them as destroyers. Other naval powers also operate destroyers as their top-tier surface combatant. Standard destroyers, weighing below 9000 include: Royal Navy Daring class destroyers and its derivatives operational with European navies, Australian Navy Hobart class, Indian Navy Kolkata class, and China’s Type-52 C/D class destroyers. These destroyers, although sufficiently equipped with modern systems, carry lesser missiles than the heavier counterparts.
At the lower end, destroyers’ distinction began to overlap with that of frigates. Modern frigates have displacement in range of 3000-7000 tons, putting those in-between destroyers and corvettes. When compared with destroyers, frigates are relatively small, carry comparatively less weapon load-out, but are more cost-effective and can also operate in blue waters. During Cold War, frigates were primarily designed for ASW missions. But many modern frigates are now fully equipped multi-mission capabilities. Germany’s Baden Wurttemberg class, Italy’s Bergamini class, Spain’s Álvaro de Bazán class, Russia’s Gorshkov class, and India’s Shivalik class are the examples of frigates that have displacement of more than 5500 tons. These heavy frigates are destroyers in disguise. China’s Type-54A class, Russia’s Grigorovich class, South Korea’s Daegu class, Turkey’s Istanbul class, and Australia’s Anzac class fall in 3000-4000 tons displacement frigates category.
Corvettes are compact and less heavily armed than frigates. Their reduced size limits their ability to operate in blue waters, but they are well-suited for littoral operations. Modern corvettes can be designed for specialized role, or they can even host multi-mission capabilities. For example, Pakistan Navy’s Babur class, Qatar’s Doha class, Israel’s Sa’ar-6 class and Russia’s Gremyashchiy class corvettes are multi-mission vessels. Meanwhile China’s Type-56A and India’s Kamorta class are primarily ASW warships. The varying alteration of corvettes indicates that these vessels are designed to meet specific requirement of naval forces, and beside traditional patrolling duties, these compact vessels can act as credible war-fighting assets.
The evolution of warships reflects the dynamic nature of naval warfare. Understanding this evolution highlights the technological advancements shaping naval forces. The unique capabilities of each warship type remain indispensable to modern navies. Together, they form a cohesive and formidable force, capable of addressing a wide range of threats in an increasingly complex maritime environment.
