The Armstrong Breech Loading 12 pounder 8 cwt, later known as RBL 12 pounder 8 cwt, was an early modern 3-inch rifled breech-loading

field gun A field gun is a field artillery piece. Originally the term referred to smaller guns that could accompany a field army on the march, that when in combat could be moved about the battlefield in response to changing circumstances (field artillery ...

of 1859.

Design

The gun incorporated some advanced features for its day. It was one of the first breech-loaders: shell and gunpowder propellant were loaded through the gunner's end of the barrel, rather than through the muzzle as in previous guns, allowing a higher rate of fire. The shells were coated with lead, which engaged spiral grooves cut inside the barrel ("rifling") and caused the shell to spin rapidly in flight and hence imparted far greater accuracy and range than previous guns. The lead coating effectively sealed the gap between shell and barrel and eliminated the wastage of propellant gases, previously known as "

windage In aerodynamics, firearms ballistics, and automobiles, windage is the effects of some fluid, usually air (e.g., wind) and sometimes liquids, such as oil. Aerodynamics Windage is a force created on an object by friction when there is relative m ...

", and hence only half the amount of gunpowder propellant as previous was required. The barrel was of

wrought iron Wrought iron is an iron alloy with a very low carbon content (less than 0.05%) in contrast to that of cast iron (2.1% to 4.5%), or 0.25 for low carbon "mild" steel. Wrought iron is manufactured by heating and melting high carbon cast iron in an ...

, "built up" of a tube with additional layers heated and then shrunk over it as they cooled. The result was a "pre-stressed" barrel: the interior of the barrel was under compression from the layers shrunk over it, so that the heat and pressure of firing did not stretch it. Hence the barrel was smaller and lighter than previous guns.

United Kingdom service

The gun was the British army's first rifled breechloading field gun, superseding the SBML 9 pounder 13 cwt of 1801. The gun as originally adopted had a barrel 84 inches long, with a bore of 73.375 inches. The Royal Navy adopted a version with a 72-inch barrel, with a bore of 61.375 inches, by simply cutting 12 inches off the end, and from 1863 the shorter length was incorporated into a common version for both land and sea use. The new technology involved required higher standards of gun maintenance and gunner training than the British army was prepared to provide and as a result the gun had a reputation in service for unreliability. In 1871 Britain reverted to muzzle-loading guns, such as the RML 9 pounder 8 cwt, which were cheaper and fired much cheaper ammunition.

Colony of Victoria service

The Colony of Victoria (today the

State of Victoria Victoria, commonly abbreviated as Vic, is a state in southeastern Australia. It is the second-smallest state (after Tasmania), with a land area of ; the second-most-populated state (after New South Wales), with a population of over 7 million; ...

, in Australia), sold 6 Armstrong 12-pounders to New Zealand for use in the

Māori Māori or Maori can refer to: Relating to the Māori people * Māori people of New Zealand, or members of that group * Māori language, the language of the Māori people of New Zealand * Māori culture * Cook Islanders, the Māori people of the Co ...

wars, for a sum of 3,592 pounds 1s 8d with equipment and ammunition. They travelled from

Melbourne Melbourne ( , ; Boonwurrung language, Boonwurrung/ or ) is the List of Australian capital cities, capital and List of cities in Australia by population, most populous city of the States and territories of Australia, Australian state of Victori ...

on 7 November 1863 on the troopship ''Himalaya'', and arrived in

Auckland Auckland ( ; ) is a large metropolitan city in the North Island of New Zealand. It has an urban population of about It is located in the greater Auckland Region, the area governed by Auckland Council, which includes outlying rural areas and ...

on 11 November 1863. The Victorian Government purchased 6 more guns in 1864 to equip its horse artillery; one of these is restored and displayed at the

Australian War Memorial The Australian War Memorial (AWM) is a national war memorial, war museum, museum and archive dedicated to all Australians who died as a result of war, including peacekeeping duties. The AWM is located in Campbell, Australian Capital Territory, C ...

Canberra Canberra ( ; ) is the capital city of Australia. Founded following the Federation of Australia, federation of the colonies of Australia as the seat of government for the new nation, it is Australia's list of cities in Australia, largest in ...

.Australian War Memorial. http://cas.awm.gov.au/ search for REL30087. Accessed 30 August 2008 A second restored piece is displayed at the Sunbury War Memorial and another is at the Deniliquin RSL.

New Zealand Wars

"C" Battery, 4th Brigade Royal Artillery, with six guns, served in

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

under Captain H.A. Mercer, in March 1861 in the final stages of the

First Taranaki War The First Taranaki War (also known as the North Taranaki War) was an armed conflict over land ownership and sovereignty that took place between Māori people, Māori and the Colony of New Zealand in the Taranaki region of New Zealand's North Is ...

. Captain Mercer again led this battery in the Second Taranaki War until he died leading an unsuccessful attack on a Maori redoubt at Rangiriri in November 1863. In January 1864 "I" battery, equipped with the "new pattern" of 24-calibres, arrived in New Zealand with another six guns. The guns from Victoria were employed from January 1864 onwards to reinforce "C" and "I" batteries. At the end of the war these guns apparently remained in New Zealand where they were used to equip the militia.

Ammunition

Surviving examples

* Australian War Memorial, Canberra
Te Awamutu Museum

Te Awamutu Te Awamutu is a town in the Waikato, Waikato region in the North Island of New Zealand. It is the council seat of the Waipā District and serves as a service town for the farming communities which surround it. Te Awamutu is located some south ...

, New Zealand * Royal Artillery Museum,

Woolwich Woolwich () is a town in South London, southeast London, England, within the Royal Borough of Greenwich. The district's location on the River Thames led to its status as an important naval, military and industrial area; a role that was mainta ...

London London is the Capital city, capital and List of urban areas in the United Kingdom, largest city of both England and the United Kingdom, with a population of in . London metropolitan area, Its wider metropolitan area is the largest in Wester ...

* Fort Henry National Historic Site, Kingston Ontario, Canada * Uruguayan Army Military Museum, Montevideo-Uruguay.

Notes and references

Bibliography

Treatise on the construction and manufacture of ordnance in the British service. War Office, UK, 1877

Text Book of Gunnery, 1902. LONDON: PRINTED FOR HIS MAJESTY'S STATIONERY OFFICE, BY HARRISON AND SONS, ST. MARTIN'S LANE
* W.L. Ruffell

* W.L. Ruffell

* Major Darrell D. Hall

* Alexander Lyman Holley, ttps://archive.org/details/treatiseonordnan00hollrich "A treatise on Ordnance and Armor" published by D Van Nostrand, New York, 1865

External links

{{DEFAULTSORT:RBL 12-pounder 8 cwt 76 mm artillery Artillery of the United Kingdom Field artillery Victorian-era weapons of the United Kingdom