RBL 40 pounder Armstrong gun
|Ordnance RBL 40 pounder gun|
Diagram from 'Treatise on Service Ordnance' (HMSO), 1877
|Place of origin||United Kingdom|
|In service||1860s - 1900?|
|Used by|| United Kingdom
|Wars||New Zealand Land Wars
Bombardment of Kagoshima
|Designer||W.G. Armstrong Co.|
|Manufacturer||W.G. Armstrong Co.
Royal Gun Factory
|Produced||1859 - 1863|
|Weight||32 cwt (3,584 pounds (1,626 kg)), later 35 cwt (3,920 pounds (1,780 kg)) gun & breech|
|Barrel length||106.3 inches (2.700 m) bore & chamber|
|Shell||40 pounds 2 ounces (18.20 kg)|
|Calibre||4.75-inch (120.6 mm)|
|Breech||Armstrong screw with vertical sliding vent-piece (block)|
|Muzzle velocity||1,180 feet per second (360 m/s)|
The Armstrong RBL 40 pounder gun was introduced into use in 1860 for service on both land and sea. It used William Armstrong's new and innovative breechloading mechanism. It remained in use until 1902 when replaced by more modern Breech Loading (BL) guns.
The Armstrong "screw" breech had already proved successful in the RBL 12 pounder 8 cwt field gun, and the British Government requested it be implemented for heavier guns despite Armstrong's protests that the mechanism was unsuited to heavy guns. Guns were produced at both the Royal Gun Factory in Woolwich, and the Elswick Ordnance Company.
Like other early Armstrong guns they were rifled on a polygroove system, firing a variety of lead coated projectiles.
The first version weighed 32 cwt, followed by the 35 cwt version which introduced a longer and stronger breech-piece. A 32 cwt variant having a horizontal sliding wedge breech instead of the Armstrong screw with vertical vent-piece was introduced in 1864 as an attempt to address the perceived weaknesses of the screw-breech design. It was withdrawn from service by 1877.
From 1880 a small number of 35 cwt guns had their trunnion rings rotated to the left to allow the vent-piece to open horizontally to the right, being known as "side-closing" guns. They differed from the wedge guns in that the vent piece was still locked in place by tightening the screw behind it.
|“||The 40-pounder we found answer exceedingly well, for coming out of the place [Kagoshima] we planted common shell, with pillar fuze, wherever we wished, at a range of 3,800 yards. Three steel vent-pieces broke, but another placed them immediately and no harm was done. These guns work very easily, are very true, and the drill is very simple.||”|
|— Reported in The Times, 25 April 1864.|
A number of different carriages for guns employed for Land Service were available. A wooden siege carriage with wheels and attached limbers, enabled the guns to be drawn by teams of heavy horses.
For guns mounted in fortifications they could be mounted on two different types of carriage. The first was an iron traversing carriage, enabling the gun to be traversed right and left, with recoil being absorbed with a carriage being mounted on a slide. Others were mounted on high "siege travelling carriages" for use as semi-mobile guns in forts, firing over parapets.
A number were used by many British Volunteer Artillery Batteries to whom they were issued after 1889. Most remained in use in this role until 1902. A number were used for some years afterwards as saluting guns.
An RBL 40-pounder Armstrong breechloader appears to be present in a photograph by John Burke (photographer) from the Second Anglo-Afghan War (November 1878 - September 1880). The war began when Great Britain, fearful of what it saw as growing Russian influence in Afghanistan, invaded the country from British India. The first phase of the war ended in May 1879 with the Treaty of Gandamak, which permitted the Afghans to maintain internal sovereignty but forced them to cede control over their foreign policy to the British. Fighting resumed in September 1879, after an anti-British uprising in Kabul, and finally concluded in September 1880 with the decisive Battle of Kandahar.
Colony of Victoria service
The Australian colony of Victoria received six 35 cwt guns in August 1865. They were used as mobile coast fortification guns with one gun being fitted to the colonial sloop Victoria during 1866 & 1867. Later four of the guns were used as field guns at Hastings. Three of these guns are known to survive.
Colony of Tasmania service
As a result of the Jervois-Scratchley reports of 1877 into the defence of Australian colonies following the withdrawal of British troops, the Launceston Volunteer Artillery Corps in Tasmania acquired 2 guns on late-model iron carriages with iron wheels, which they continued to operate until at least 1902.
- A gun made by Royal Gun Factory in 1865 at Elizabeth Castle, Jersey
- Restored gun No. 272 at Hastings-Western Port Historical Society Museum, Victoria, Australia
- Restored Gun No. 271 at Fort Queenscliff, Victoria, Australia
- Unrestored Gun No. 268 in Como Park, South Yarra, Victoria
- A gun at Fort Henry, Canada
- A 40-pounder side closing gun made by Elswick Ordnance Company at Royal Armouries, Fort Nelson, Portsmouth
- Fort St Catherine, Bermuda
- On board HMS Warrior, Portsmouth, UK
Notes and references
- 1013 were in service in 1877 : 819 35cwt & 194 32cwt. Quoted in Treatise on Manufacture of Ordnance 1877, page 150. Holley 1865, page 13 quotes 641 as at 1863 : 535 manufactured by Elswick Ordnance and 106 by the Royal Gun Factory. From the Report of the Select Committee on Ordnance, 1863.
- Text Book of Gunnery, 1887
- 1180 ft/sec firing 40 lb 2 oz projectile with 5 lb RLG2 (gunpowder). Text Book of Gunnery 1887, Table XVI page 313
- Ruffell, The Armstrong Gun Part 5: British revert to Muzzle Loading
- Treatise on Manufacture of Service Ordnance, 1877
- Treatise on Manufacture of Service Ordnance, 1877. pages 89, 153
- The Times, 25th April 1864 : 25 April 1864 THE ARMSTRONG GUNS IN JAPAN http://www.pdavis.nl/Japan.php
- Elephant and Mule Battery ("Dignity & Impudence") WDL11496.png caption, Library of Congress
- Friends of the Cerberus Website : slideshow http://www.cerberus.com.au/reenactors/40_pounder_slideshow.html
- David Spethman, "The Garrison Guns of Australia" page 49. 2008, published by Ron H Mortensen, Inala, Qld. ISBN 978-0-9775990-8-0
- 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
- Text Book of Gunnery, 1902. LONDON : PRINTED FOR HIS MAJESTY'S STATIONERY OFFICE, BY HARRISON AND SONS, ST. MARTIN'S LANE
- Alexander Lyman Holley, "A treatise on Ordnance and Armor" published by D Van Nostrand, New York, 1865
|Wikimedia Commons has media related to RBL 40 pounder Armstrong gun.|
- Diagram of RBL 40-pdr on siege traveling carriage at Victorian Forts and Artillery website
- RBL 40-pdr on Platform, Medium No. 4 at Victorian Forts and Artillery website
- 40-pounder use in New Zealand Land Wars at New Zealand Electronic Text Centre
- W.L. Ruffell, Armstrong RBL 40-pr
- W.L. Ruffell, "The Armstrong Gun Part 4: Other Armstrong Equipments in New Zealand" - use ashore in New Zealand Land Wars
- Diagram showing gun on block trail carriage