The RML 40-pounder gun was a British rifled muzzle-loading siege and fortification gun designed in 1871. It was intended to supersede the RBL 40-pounder Armstrong gun after the British military reverted to rifled muzzle-loading artillery until a more satisfactory breech-loading system than that of the

Armstrong gun An Armstrong gun was a uniquely designed type of rifled breech-loading field and heavy gun designed by Sir William Armstrong and manufactured in England beginning in 1855 by the Elswick Ordnance Company and the Royal Arsenal at Woolwich. Such g ...

s was developed.

Description

The original Mk I short barrel of 18 calibres suffered from irregular velocity and hence accuracy, due to incomplete burning of the powder charge, hence only 20 were built. The Mark II of 1874 with barrel lengthened to 22 calibres solved this problem and became the definitive model. The gun consisted of a central toughened steel "A" tube surrounded by

wrought-iron Wrought iron is an iron alloy with a very low carbon content (less than 0.08%) in contrast to that of cast iron (2.1% to 4%). It is a semi-fused mass of iron with fibrous slag inclusions (up to 2% by weight), which give it a wood-like "grain" t ...

coils, with a trunnion ring and

cascabel Cascabel may refer to: * Cascabel (artillery), a subassembly of a muzzle-loading cannon * Cascabel chili, a small, round chili pepper * Cascabel, a Shuttle Loop roller coaster at Chapultepec Park in Mexico City * Spanish common name for ''Crotalu ...

. Rifling was the "Woolwich" pattern of three broad grooves, with a uniform twist of 1 turn in 35 calibres (i.e. in 166.25 inches).

Service use

Four 40-pounders were used during the defence of Kandahar, during the 2nd Anglo-Afghan War in 1880. Ten 40-pounder RML guns were landed in Egypt in 1882 as part of a

Royal Artillery The Royal Regiment of Artillery, commonly referred to as the Royal Artillery (RA) and colloquially known as "The Gunners", is one of two regiments that make up the artillery arm of the British Army. The Royal Regiment of Artillery comprises t ...

Siege train formed for the

Anglo-Egyptian War The British conquest of Egypt (1882), also known as Anglo-Egyptian War (), occurred in 1882 between Egyptian and Sudanese forces under Ahmed ‘Urabi and the United Kingdom. It ended a nationalist uprising against the Khedive Tewfik Pasha. It ...

, however none of them were deployed in action.Goodrich, Caspar F (Lt Cdr), Report of the British Naval and Military Operations in Egypt 1882, Navy Department, Washington, 1885, p.231 The guns were also deployed at Forts and Batteries around Great Britain to form part of the fixed defences. In some cases special overbank carriages were issued for this use. They remained in this role until 1902, by which time most had been dismounted and scrapped.

Notes and references

Bibliography

Treatise on the Construction and Manufacture of Ordnance in the British Service. War Office, UK, 1877

Text Book of Gunnery, 1887. LONDON : PRINTED FOR HIS MAJESTY'S STATIONERY OFFICE, BY HARRISON AND SONS, ST. MARTIN'S LANE

External links

Handbook for the 40-pr R.M.L. gun of 35 cwt. 1889
at State Library of Victoria
Handbook for the 40-pr R.M.L. gun of 35 cwt 1897
at State Library of Victoria

at Victorian Forts and Artillery website {{VictorianEraBritishWeapons Artillery of the United Kingdom 120 mm artillery