The BL 13.5 inch naval gun Mk I ("67-ton gun") was Britain's first successful large breechloading

Rifled breech loader

A rifled breech loader is an artillery piece which, unlike the smooth-bore cannon and rifled muzzle loader which preceded it, has rifling in the barrel and is loaded from the breech at the rear of the gun....

 naval gun. Mks I - IV were all of 30 calibres length and of similar construction and performance.

Royal Navy service

The gun was designed to match the new large guns of the French Amiral Baudin

Amiral Baudin class battleship

The Amiral Baudin class was a type of ironclad battleships of the French Navy.-Design and history:They were built on a design similar to that of Amiral Duperré, enlarged and designed from the start to use steam propulsion only....

class battleships. Development and manufacture occurred very slowly. It was originally intended to equip the Admiral class battleship

Admiral class battleship

The British Royal Navy's pre-dreadnought Admiral class battleships of the 1880s followed the pattern of the Devastation class in having the main armament on centre-line mounts with the superstructure in between. This pattern was followed by most following British designs until in 1906...

s, begun in 1880, but delays led to Collingwood

HMS Collingwood (1882)

HMS Collingwood was an ironclad battleship of the Royal Navy. She was the first example of the Admiral-class and was named after Admiral Cuthbert Collingwood, Horatio Nelson's second-in-command in the British victory at the Battle of Trafalgar....

 being equipped with inferior 12 inch guns and Benbow

HMS Benbow (1885)

HMS Benbow was a Victorian era Admiral-class battleship of the British Royal Navy, named for Admiral John Benbow.With the exception of her armament she was a repeat of HMS Anson and HMS Camperdown. The contract for her construction was awarded to Thames Ironworks, and stipulated delivery within...

 with the subsequently unsuccessful 16.25 inch guns

BL 16.25 inch Mk I naval gun

The Elswick BL 16.25 inch naval gun was an early British superheavy breech-loading naval gun, commonly known as the 110-ton gun or 111-ton gun.-Service:...

.

The remaining Admiral class ships Anson

HMS Anson (1886)

HMS Anson was a pre-dreadnought battleship of the British Royal Navy, and was the last member of the Admiral-class to be laid down....

, Camperdown

HMS Camperdown (1885)

HMS Camperdown was an Admiral-class battleship of the Royal Navy, named after Adam Duncan, 1st Viscount Duncan of Camperdown.She was a full sister to , and was an improved version of the earlier and . In comparison to these earlier ships, she had an increased thickness of barbette armour, and a...

, Howe

HMS Howe (1885)

HMS Howe was an Admiral-class battleship of the Royal Navy, the last of the Admiral-class to be completed.Along with her sisters, , and , she was a progressive development of the design of . She carried a main armament of four guns, compared to the guns carried in the earlier ship...

 and Rodney

HMS Rodney (1884)

HMS Rodney was a battleship of the Victorian Royal Navy, a member of the Admiral class of warships designed by Nathaniel Barnaby.She was a development of the design of Collingwood, but carried 13.5 inch calibre main armament as against 12 inch in the earlier ship...

 were eventually completed in 1889 equipped with 4 13.5 inch guns each, in twin barbettes on the centreline at each end of the superstructure.

The guns also equipped the subsequent Trafalgar

Trafalgar class battleship

The two Trafalgar-class battleships of the British Royal Navy were late nineteenth century ironclad warships. Both were named after naval battles won by the British during the Napoleonic wars under the command of Admiral Nelson.-Design:...

 class laid down in 1886 and Royal Sovereign

Royal Sovereign class battleship

The Royal Sovereign class was a class of pre-dreadnought battleships of the British Royal Navy. The class comprised seven ships built to the same design: HMS Royal Sovereign, , HMS Ramilles, HMS Repulse, HMS Resolution, HMS Revenge, and HMS Royal Oak, and a half-sister built to a modified design: ....

 class battleships laid down in 1889.

Coast defence service

A single Mk III gun was mounted as a disappearing gun

Disappearing gun

A disappearing gun is a type of heavy artillery for which the gun carriage enabled the gun to rotate backwards and down into a pit protected by a wall or a bunker after it was fired...

 for coast defence at Penlee Battery

Penlee Battery

Penlee Battery is a nature reserve lying on the coastal headland of Penlee Point on the Rame Peninsula, in southeast Cornwall, United Kingdom....

, Plymouth.

Italian Service

Guns were also sold to Italy to arm the Re Umberto class battleships

Re Umberto class battleship

The Umberto Re class were a group of pre-dreadnought battleships built for the Italian Navy in the 1880s. All three ships of the class saw service during World War I in secondary roles.-Description:...

 Re Umberto

Italian battleship Re Umberto

Re Umberto was a pre-dreadnought battleship built for the Italian Navy in the 1880s. She was the lead ship of her class. She was laid down in 1884; work proceeded so slowly that she was not finished until 1893....

, Sicilia

Italian battleship Sicilia

Sicilia was a pre-dreadnought battleship built for the Italian Navy in the 1880s. She was the second ship of her class to be laid down, but was the last to be completed. Decommissioned before World War I she was used during the war as a depot ship at Taranto and then became a repair ship...

, and Sardegna

Italian battleship Sardegna

Sardegna was a pre-dreadnought battleship built for the Italian Navy in the 1880s. She was the third ship of her class laid down, but the second finished.-General characteristics:...

, laid down in 1884 and finally commissioned in 1893 and 1895.

External links

• Tony DiGiulian, British 13.5"/30 (34.3 cm) Marks I, II, III and IV
• Diagram showing gun on disappearing mounting, as mounted at Penlee Battery, Plymouth at Palmerston Forts Society website