10 Largest Naval Guns Ever Mounted On Warships

Naval guns on warships evolved due to technological advancements and strategic requirements of the time. In the 15th and 16th centuries, early naval guns were simple cannons, used in close-range combat.

By the 19th century, the Industrial Revolution brought about ironclad warships and rifled barrels that enhanced accuracy and range which led to the development of powerful guns such as the 12-inch rifled guns on ironclads.

The early 20th century saw the rise of dreadnoughts, with ships such as HMS Dreadnought having massive, uniform-caliber guns which made earlier designs obsolete.

In this article, we will look at the 10 largest naval guns (by caliber), ever mounted on warships.

Some of these guns are a testament to maritime engineering and have left an everlasting mark on naval history.

1. 46 cm/45 Type 94 Naval Guns

These guns with the largest bore diameter were mounted on the Japanese Navy’s Second World battleships Yamato and Musashi.

The Kure Naval Arsenal built a total of 27 such guns, designed according to the prevailing Japanese naval strategy of ‘Kantai Kessen’ or the Decisive Battle Doctrine which suggested that Japan would emerge victorious in war by winning a single and decisive naval action.

These guns were the most powerful and no ship of the time could match them. However, they saw limited action.

Gun Specifications

• Caliber: 46 cm (18.1 inches)
• Barrel Length: 20.7 m
• Weight of Shells:
• Armor-Piercing Shells: Approximately 1,460 kg
• High-Explosive Shells: Around 1360 kg
• Maximum range: 42 km at an elevation of 45 degrees
• Rate of Fire: About 1.5 to 2 rounds per minute.
• Muzzle Velocity: 780 m/s.

Officially designated as Type 94 naval guns, they were developed in the 1930s to outrun potential adversaries.

Each Yamato-class ship had nine of these guns, in three triple turrets, two forward and one aft, serving as the main armament of Yamato-class battleships. When the turrets and guns were mounted, each weighed around 2510 tonnes, the same tonnage as an average-size destroyer of the time!

These could also fire special anti-aircraft shells, also called beehive shells.

2. The BL 18-inch Mk I naval gun

This was a breech-loading rifle used during the First World War by the Royal Navy and was the second-largest naval gun to be mounted on a warship. It was also the biggest and heaviest used by the British.

The guns were developed to equip the ‘large light cruiser’ HMS Furious and provide the Royal Navy with a powerful weapon to engage heavily armoured enemy ships at extreme ranges.

HMS Furious was fitted with two of these guns, one forward and one aft however the ship’s design proved not suitable for massive guns and due to blast effects and stability issues, the gun at the aft was removed and the ship was transformed into an aircraft carrier.

The guns were repurposed and mounted on Lord Clive-class warships, HMS General Wolfe and HMS Lord Clive.

Only three of these guns were built and due to their shortcomings, they were out of service by 1920 and were eventually scrapped.

Gun Specifications

• Caliber: 45.72 cm or 18 inches
• Barrel Length: Approximately 18.3 m
• Weight: 151 tons each
• Shell Weight: 1510 Kg
• Muzzle Velocity: 740 m/s
• Range: Maximum range of about 37 km at a 30-degree elevation

3. BL 16.25 inch naval gun

Also called the 110-ton gun or the 111-ton gun, this was one of the heaviest rifled muzzle-loading guns ever constructed.
It was developed in the late 19th century by W G Armstrong Whitworth & Co Ltd, it represented an era when naval artillery reached the upper limit of muzzle-loading technology before a shift to breech-loading systems.

Twelve such guns were built, however, shortcomings including droop and crackings were found in the earliest designs which meant no two guns were identical and were referred to by their serial numbers.

Gun Specifications

• Caliber: 16.25 inches (413 mm)
• Barrel Length: 12.4 m
• Weight of Common shells: 1,800 pounds (816 kg).
• Weight of Palliser armour-piercing shells: 1,700 pounds (771 kg)
• Powder Charge: Typically used 450 pounds (204 kg) of black powder
• Muzzle Velocity: 636 m/s
• Range: Maximum firing range of 11 km

They were mounted on the Italian Navy’s Caio Duilio-class ironclad warships, Caio Duilio
And Enrico Dandolo, among the era’s most heavily armed and armoured warships.

4. 41 cm/45 3rd Year Type naval gun

This breech-loading naval gun was designed during the First World War for the Imperial Japanese Navy and served as the main armament in the Nagato-class dreadnoughts which were completed after the war ended and also for coastal defence.

Around 40 of these guns were built and remained in service from 1920 to 1945.

It had a wire-wound build and an overall length of 18.84 m, weighing 102,000 kg. The Nagato-class dreadnoughts were the only ships which had this gun. Although there were plans to put this gun onto the Tosa-class, Kii-Class and Amagi-class ships, they were cancelled due to the Washington Naval Treaty of 1922.

The wreck of the Japanese ship Mutsu revealed two turrets and guns which were salvaged in the 1970s and are currently displayed in Japan.

Specifications

• Caliber: 41 cm (16.1 in)
• Shell weight: 1,020 kilograms
• Rate of fire: 1 round per 24 seconds
• Muzzle velocity: 780–790 meters per second
• Maximum firing range: 38.4 km

5. 16inch/50 caliber Mark 7 gun

This was the most advanced large-caliber naval artillery used by the United States Navy, comprising the main armament of the Iowa-class battleships, which were the last and most powerful battleships built by the U.S.

They remained in service from 1943-1992 and were used in the Second World War, Korean War, Vietnam War, Lebanese Civil War and Gulf War.

Specifications

• Caliber: 16 inches (406 mm)
• Gun weight: 121,519 kg) (including breech)
• Gun length: 816 in ( 20.7 m) (breech face to muzzle)
• Rifling length: 682.86 in ( 17.345 m)
• Chamber volume: 27,000 cu in (440,000 cm3)
• Rate of fire: 2 rounds per minute
• Range: 38.059 km
• Muzzle velocity: 820 m/s with 860 kg HC (High Capacity) shell and 760 m/s with 1,200 kg AP (Armor Piercing) shell

These guns had one of the longest ranges and could strike a target far beyond visual range. They were also highly accurate which is why they remained operational for a long time.

6. 16inch/45 caliber Mark 6 gun

This gun was designed in the 1930s by the United States Navy for its Treaty Battleships and introduced on North Carolina Battleships in 1941 and also onboard South Dakota Class. These ships had 9 guns in three 3-gun turrets.

They were in service from 1941-1956 mainly used for engaging enemy warships, shore bombardment, and general naval fire support.

Battleship USS Massachusetts (BB-59) had these guns as her primary armament and is said to have fired America’s first and last 16-inch shells in the Second World War, first on 8 November 1942 during the Naval Battle of Casablanca and the last on 9 August 1945 off Hamamatsu, Japan.

Specifications

• Caliber:16 inches (40.6 cm)
• Length: 18.69 m
• Shell weight: AP: 1,225 kg
• HC: 862 kg
• Recoil: 48-inch
• Rate of fire 2 rounds per minute
• Muzzle velocity: 701 m/s for A.P and 803m/s for HC
• Maximum firing range: 33,74 km with A.P

7. 16 Inch 45 Caliber Mark 1, 5 and 8 Guns

These guns were early variants of the United States Navy’s large-caliber guns and were mainly deployed on warships during the World Wars, such as USS Colorado, USS Maryland and USS West Virginia.

They remained in service from 1921 till 1947.

The Mark 1 variant was developed in the 1920s, as the U.S decided to manufacture more battleship armament after post-World War I naval treaties.

Mark 5 was a modified variant of Mark 1 and saw limited use often for coastal defence.

The Mark 8 variant was an evolved version of Mark 1 and Mark 5 designs. They also ended up as coastal artillery later.

Specifications

• Caliber:16 inches (406 mm)
• Length 61 ft 4 in (18.69 m)
• AP Mark 3: 960 kg armor-piercing (Mark 1 gun)
• AP Mark 5: 1,020 kg AP (Mark 5 and 8 guns)
• Rate of fire 1.5 rounds per minute
• Muzzle velocity
• AP Mark 3: 790 m/s
• AP Mark 5: 770 m/s Full Charge
• Maximum firing range
• AP Mark 3: 31.36 km ) at 30° elevation
• AP Mark 5: 32 km at 30° elevation

8. BL-15 Inch Mark 1 naval gun

This naval gun design was the most widely used and long-lasting of any British designs, and it was also the most successful heavy gun developed by the Royal Navy. Around 186 of these guns were built, remaining in service from 1915 to 1959.

The gun was designed by Vickers, Son and Maxim in 1912 and was built to arm the Queen Elizabeth class battleships in response to Germany which was building Dreadnought battleships in the naval arms race leading to the First World War.

Apart from Queen-Elizabeth-class battleships, these guns were mounted on Revenge-class battleships, Renown-class, the mighty HMS Hood, HMS Vanguard, Courageous-class etc.

Specifications

• Caliber: 15-inch (381.0 mm)
• Length: 650.4 inches (16.52 m)
• Shell weight: 879 kg
• Rate of fire: 2 rounds per minute
• Muzzle velocity: 750–800 m/s
• Maximum firing range: 30.68 km

9. 38 cm SK C/34 naval gun

This naval gun was developed by Germany in the 1930s which intended it for the Bismarck-class battleships. It was also planned for O-class battlecruisers and remained in service from 1940 to 1945.

These guns used four different types of shells. 16 guns were used for Tirpitz and Bismarck and 6 were intended for O-class battlecruisers. 6 mountings with 12 guns were sold to the Soviet Union who wanted to use them on two Kronshtadt-class battlecruisers but they were never delivered. Also, the remaining guns were used in coastal defence.

Its long barrel and high muzzle velocity gave it a high penetration power. The gun was excellent at long range, especially when used with advanced German fire-control systems.

Specifications

• Caliber : 15 inches
• Length: 19.63 m
• Rate of fire: 2.5 rounds per minute
• Muzzle velocity: 820 m/s
• Maximum firing range: 36.5 km with 800 kg shell at 30° elevation

10. Cannone da 381/50 Ansaldo M1934

This naval gun was designed and constructed for the Royal Italian Navy in the 1930s. It was the main armament of Italy’s Littorio class battleships and each ship carried 9 guns mounted in three triple turrets with a 35-degree elevation.

These guns were used during the Battle of Calabria (1940), where the Littorio-class battleships engaged the Royal Navy.

40 of these were produced of which 9 went down with the Roma battleship when it was sunk in 1943. 18 guns were scrapped in 1948 and the fate of the remaining ones is unclear.

It is said that a few were seized by Nazi Germany and others were scrapped after the World War ended in accordance with Article 51 of the Peace Treaty of 1947.

Specifications

• Caliber : 15 inches
• Length: 20.72 metres
• Shell weight
• AP: 885 kg
• HE: 774 kg
• Muzzle velocity: 850–870 m/s
• Maximum firing range: 42 km

Conclusion

The largest naval guns shaped naval warfare in the first half of the 20th century. During the World War era, when sea power was a decisive factor in battles, naval guns influenced military strategies and even the design of warships.

These guns evolved over time, becoming more powerful and expanding their range and accuracy to target their enemies. However, with missile technology many became obsolete. Today, many of these guns can be seen in museums, reminding us of the times when these mighty pieces of naval artillery ruled the high seas.

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About Author

Zahra is an alumna of Miranda House, University of Delhi. She is an avid writer, possessing immaculate research and editing skills. Author of several academic papers, she has also worked as a freelance writer, producing many technical, creative and marketing pieces. A true aesthete at heart, she loves books a little more than anything else.

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