Jump to content

BL 9.2-inch howitzer: Difference between revisions

From Wikipedia, the free encyclopedia
Content deleted Content added
refine cat, copyedit, and or AWB general fixes using AWB
Combat use: added video
Line 56: Line 56:


==Combat use==
==Combat use==
[[File:9.2inchhowitzerfiringWWI.ogv|thumb|left|300px|<center>Newsreel footage of Mk I howitzer firing in World War I</center>]]
[[Image:9.2inchHowitzerTransportWagons.jpg|thumb|left|<center>Transport (L-R) of barrel, bed, cradle & body</center>]]
[[Image:9.2inchHowitzerTransportWagons.jpg|thumb|left|<center>Transport (L-R) of barrel, bed, cradle & body</center>]]
[[Image:9.2inchHowitzerCorbieMay1918.jpeg|thumb|left|<center>2 Mk Is in support of Australians, Corbie, May 1918. Note earth box in front</center>]]
[[Image:9.2inchHowitzerCorbieMay1918.jpeg|thumb|left|<center>2 Mk Is in support of Australians, Corbie, May 1918. Note earth box in front</center>]]
Line 65: Line 66:


The gun was used to demolish deep fortifications and enemy batteries. GHQ considered howitzers "par excellence the counter-battery weapon for destructive purposes, owing to the advantages it possesses over the gun in accuracy and its ability to deliver its shell at very steep angles of descent". But the same document estimated that even for the 9.2 a minimum 60 rounds "will be required to effect the complete destruction of a single well-protected gun pit".<ref>Counter-Battery Work, page 16</ref>
The gun was used to demolish deep fortifications and enemy batteries. GHQ considered howitzers "par excellence the counter-battery weapon for destructive purposes, owing to the advantages it possesses over the gun in accuracy and its ability to deliver its shell at very steep angles of descent". But the same document estimated that even for the 9.2 a minimum 60 rounds "will be required to effect the complete destruction of a single well-protected gun pit".<ref>Counter-Battery Work, page 16</ref>
<br style="clear:left;" ><!--don't delete this, it forces next heading to nicely follow below the Images-->


==US service==
==US service==

Revision as of 13:26, 28 November 2009

BL 9.2 inch Howitzer
Australian gunners of 55th Siege Artillery Battery about to load their 9.2 inches (234 mm) howitzer, Western Front, circa. July 1916.
TypeHeavy siege howitzer
Place of origin United Kingdom
Service history
In service1914 - 1945
Used byUK and Commonwealth
 United States
WarsWorld War I, World War II
Production history
DesignerMk I : Coventry Ordnance Works
Mk II : Vickers
Designed1913
No. built512
VariantsMk I, Mk II
Specifications
Barrel lengthBore 121.5 inches (3.086 m) (Mk I)
159.16 inches (4.043 m) (Mk II)[1]

ShellHE 290 pounds (131.54 kg)
Caliber9.2-inch (233.7 mm)
Recoilhydropneumatic, variable 23-40 inches (MK I); 20-44 inches (MK II)
Carriagesiege carriage
Elevation15° - 55° (Mk I)
15° - 50° (Mk II)[1]
Traverse30° L & R
Muzzle velocity1,187 feet per second (362 m/s) (Mk I)
1,600 feet per second (488 m/s) (Mk II)[2]
Maximum firing range10,060 yards (9,199 m) (Mk. I); 13,935 yards (12,740 m) (Mk. II)[1]

The Ordnance BL 9.2 inch howitzer was a heavy siege weapon, among the largest British artillery pieces in World War I.

History

The prototype "Mother" at the Imperial War Museum, London

The origins of a British heavy "siege" howitzer broken down into multiple wheeled loads for transport perhaps lie in the Skoda 9.45-inch howitzer that Britain had bought from Austria in 1900 for trials. Britain decided to develop its own heavy weapon instead, but retained the Skoda transport technique, with the 9.2-inch prototype resulting in 1913.[3]

The weapon incorporated a sophisticated variable recoil mechanism. Full recoil (40 inch Mk I, 44 inch Mk II[4]) was allowed at lower elevation, hence absorbing most of the horizontal (i.e. backward) force. A shorter recoil (23 inch Mk I, 20 inch Mk II[5]) was allowed at high elevation where the ground itself could absorb much of the vertical (i.e. downward) recoil force. This prevented the breech from approaching the carriage base.

Gunners of 56th Heavy Regiment with Mk II, May 1940

The weapon was undergoing trials as World War I began, and the prototype, "Mother", was in action in France on October 31 1914. This was soon followed by the production Mk. I.

Mk I's range was relatively limited. On 24 June 1916 the MGRA (Major-General, Royal Artillery), the senior Artillery commander in France, Major General Birch, requested among other artillery improvements an increase in range to 15,000 yards "even if an increase of the weight of the equipment is entailed".[6] This resulted in Mk. II in December 1916 with heavier maximum propellant charge and longer barrel which increased the range to 13,935 yards.

Some went to France early in World War II but their main use was as British coastal defences.

Combat use

Newsreel footage of Mk I howitzer firing in World War I
Transport (L-R) of barrel, bed, cradle & body
2 Mk Is in support of Australians, Corbie, May 1918. Note earth box in front

It was transported in 3 separate loads - body and cradle, bed, barrel - towed either by heavy horses or a Holt tractor. A "holdfast" had to be buried to provide a secure platform, the weapon assembled on top, and a box containing 9 tons of earth further anchored the holdfast in front, to counteract the tendency of the carriage front to lift on firing.

The barrel had to be depressed 3° for loading, as can be seen in the photograph of Australian 55th Siege battery.

One disadvantage of the dismantling system was an inability to fire directly from the travelling carriage the way the 8-inch (203 mm) howitzer could. In addition the time required to bring the weapon into action was increased. However the stability of the siege mounting made it "the most accurate of heavy howitzers".[7]

The gun was used to demolish deep fortifications and enemy batteries. GHQ considered howitzers "par excellence the counter-battery weapon for destructive purposes, owing to the advantages it possesses over the gun in accuracy and its ability to deliver its shell at very steep angles of descent". But the same document estimated that even for the 9.2 a minimum 60 rounds "will be required to effect the complete destruction of a single well-protected gun pit".[8]

US service

Bethlehem Steel was already manufacturing 9.2-inch howitzers for Britain, prior to the US entry into World War I in April 1917. The order was expected to be completed by July 1917, as British manufacturing capacity rapidly increased and in fact became capable of export. The US government ordered 100 from Bethlehem and 132 from Britain to equip the US army building up in France. Sevellon Brown states that in fact Bethlehem could not meet the US order but that 40 were delivered from Britain by the end of the war.[9]

The US Ordnance manual of 1920 describes its current stock of Model of 1917 (Vickers Mk I) and Model of 1918 (Vickers Mk II) as being built both in Britain and USA.[10] The US-built guns may have been British orders to Bethlehem which were redirected to the US army.

Average barrel life of Mk I was estimated from combat experience at 8,300 rounds, while the life of the higher-velocity Mk II barrel was estimated at 3,500 rounds.[11]

Brown describes the US acquisition of the 9.2 as based mainly on the need at the time to utilize immediately-available manufacturing capacities, and that acquisition of a howitzer based on the French Schneider 240 mm Howitzer for its super-heavy artillery was the main US goal.[9] This view is supported by the 1920 US Ordnance manual which describes the 240 mm howitzer as far superior to the 9.2.[12]

In his memoir, Adolf Hitler: My Part in His Downfall, Spike Milligan describes training to fire 9.2's during the early part of World War II. This included the crews shouting 'bang' in unison as they had no shells to practice with. Eventually they were replaced with BL 7.2 inch Howitzers.[13]

See also

Surviving examples

At the Australian War Memorial, Canberra

Notes

  1. ^ a b c Hogg & Thurston 1972, page 161, 162
  2. ^ Hogg & Thurston 1972, page 161, 162 quote 1,600 feet per second (488 m/s) for Mk II in WWI British service. US Army manual May 1920 quotes 1,500 feet per second (457 m/s) Mk II, page 295, 303.
  3. ^ Clarke 2005, page 33
  4. ^ Hogg & Thurston 1972 pages 161-162 for WWI British service; US Army Handbook 1920 Page 295 for US service.
  5. ^ Hogg & Thurston 1972 quote recoil at maximum elevation as 23 inches and 20 inches for Mk I and Mk II respectively in WWI British service; the US Army Handbook of 1920 quotes recoil of 19 inches for both at maximum elevation.
  6. ^ Major General Birch (over General Haig's signature), to War Office, 24 June 1916. Letter Quoted in full in Farndale 1986 Annex E, Appendix 1.
  7. ^ Farndale 1986, page 139
  8. ^ Counter-Battery Work, page 16
  9. ^ a b Brown 1920, Page 68-69
  10. ^ Handbook of artillery, United States. Army. Ordnance Dept, May 1920. Page 288
  11. ^ Handbook of artillery, United States. Army. Ordnance Dept, May 1920, page 286
  12. ^ Handbook of artillery, United States. Army. Ordnance Dept, May 1920. Page 300
  13. ^ Milligan, Spike (1971). Adolf Hitler: My Part in His Downfall. Michael Joseph. pp. 36, 81.

References