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BL 6-inch Mk VII naval gun#Coast defence gun

{{Short description|Naval and Heavy Field Gun}}

{{Use British English|date=January 2017}}

{{Use dmy dates|date=January 2023}}

{{Infobox weapon

| is_artillery = yes

| is_explosive = yes

| is_UK = yes

| is_ranged = yes

| image = HMCS-PRINCE-DAVID-Bgun.png

| image_size = 300

| caption = Aboard HMCS Prince David circa 1941

| name = BL 6-inch gun Mk VII

| origin = United Kingdom

| used_by =

| wars = {{indented plainlist|

}}

| prod_date =

| type = {{indented plainlist|

}}

| date =

| designer = Vickers

| design_date = 1899

| manufacturer =

| service = {{indented plainlist|

  • 1901–1972 (Fort Scratchley)
  • 1915–1918 (field use)
  • 1901–1959 (naval use)

}}

| caliber = {{convert|6|in|mm|abbr=on|0}}

| part_length = {{convert|269.5|in|m}} (44.9 cal)

| carriage =

| breech = Welin interrupted screw

| rate = 8 rpm{{efn|1=8 rounds per minute is the figure given by Vickers. Quoted in {{cite book |url=http://www.gwpda.org/naval/brassey/b1901o08.htm |title=Brassey's Naval Annual |year=1901 |page=453}}}}

| velocity = {{indented plainlist|

  • {{convert|2525|ft/s|m/s|abbr=on}} (light charge)
  • {{convert|2775|ft/s|m/s|abbr=on}} (heavy charge){{efn|1=2,525 ft/s firing a {{convert|100|lb|abbr=on}} projectile using {{convert|23|lb|abbr=on}} Cordite MD size-16 propellant; 2,775 ft/s using {{convert|28|lb|10|oz|kg}} Cordite MD size 26 was the standard naval loading in WWI. Twin mounts and unstrengthened P IV mounts were restricted to the light charge.{{harv|Treatise on Ammunition|1915}} The original loading was {{convert|20|lb|abbr=on}} of the more powerful cordite Mk I size 20, but Mk I caused greater wear.}}

}}

| cartridge_weight = Lyddite, HE, Shrapnel {{cvt|100|lb|kg}}{{efn|1=Shell weights given are filled and fuzed i.e. as fired. {{cvt|100|lb|kg}} was standard shell weight in WWI. Some earlier shells had slightly higher weights e.g. Mk IV common lyddite shell weighed {{convert|101|lb|kg|0}}.}}

| max_range = {{indented plainlist|

  • Field carriage Mk. II: {{convert|13700|yd|m|abbr=on}}{{efn|1={{harv|Clarke|2005|page=23}} quotes {{convert|13700|yd|abbr=on}} on the Mk II carriage; {{harv|Farndale|1986|page=130}} quotes {{convert|12000|yd|m|abbr=on}} – this is possibly on the Mk I carriage.}}
  • Naval: {{convert|14600|yd|m|abbr=on}} (light charge); {{convert|15800|yd|m|abbr=on}} (heavy charge){{cite web |first=Tony |last=DiGiulian |website=NavWeaps |url=http://www.navweaps.com/Weapons/WNBR_6-45_mk7.htm |title=British 6"/45 (15.2 cm) BL Mark VII 6"/45 (15.2 cm) BL Mark VIII 6"/45 (15.2 cm) BL Mark XXIV}}{{efn|1=All figures for {{convert|100|lb|abbr=on}} shell, which was standard in WWI.}}

}}

| recoil = {{cvt|16.5|in|mm|0}}

| weight = {{indented plainlist|

  • {{cvt|16875|lb|kg}} (gun & breech){{efn|1=7 tons, 10 cwt, 2 qtrs. 19 lbs with breech fitting, including shot guide.}}
  • 25 tons (gun on field carriage)

}}

| length = {{convert|279.2|in|m|2}}

| crew = 9

| number = 898

| variants = Mk VII, Mk VIIv, Mk VIII, Mk XXIV

| filling_weight = {{indented plainlist|

  • Lyddite: {{convert|13|lb|5|oz|kg|abbr=on}}
  • Amatol: {{convert|8|lb|14|oz|kg|abbr=on}}
  • Shrapnel: 874 balls @ 27/lb{{efn|1=Figures for WWI field gun.{{harv|Hogg|Thurston|1972|page=243}}}}

}}

}}

The BL 6-inch gun Mark VII (and the related Mk VIII){{efn|1=Mk VII = Mark 7, Mk VIII = Mark 8. Britain used Roman numerals to denote Marks (models) of ordnance until after World War II. Mark VIII's breech opened to the left and Mark VII's opened to the right, allowing for paired mounts. Guns mounted singly were all the right-opening Mark VII}} was a British naval gun dating from 1899, which was mounted on a heavy travelling carriage in 1915 for British Army service to become one of the main heavy field guns in the First World War, and also served as one of the main coast defence guns throughout the British Empire until the 1950s.

Background

The gun superseded the QF six-inch gun of the 1890s, a period during which the Royal Navy had evaluated QF technology (i.e. loading propellant charges in brass cartridge cases) for all classes of guns up to {{cvt|6|in|0}} to increase rates of fire. BL Mk VII returned to loading charges in silk bags after it was determined that with new single-action breech mechanisms a six-inch BL gun could be loaded, a vent tube inserted and fired as quickly as a QF six-inch gun. Cordite charges in silk bags stored for a BL gun were also considered to represent a considerable saving in weight and magazine space compared to the bulky brass QF cartridge cases.{{sfn|Treatise on Ammunition|1915|page=393}}

Naval gun

The gun was introduced on the {{sclass|Formidable|battleship|2}}s of 1898 (commissioned September 1901) and went on to equip many capital ships, cruisers, monitors, and smaller ships such as the {{sclass2|Insect|gunboat|2}} which served throughout World War II.

The Mk VIII in naval service was identical to the Mk VII, except that the breech opened to the left instead of to the right, for use as the left gun in twin turrets.

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In World War II the gun was used to arm British troop ships and armed merchant cruisers, including {{HMS|Rawalpindi}}, which briefly fought the German {{cvt|11|in}}-gunned battleships {{ship|German battleship|Scharnhorst||2}} and {{ship|German battleship|Gneisenau||2}} in November 1939, and {{HMS|Jervis Bay}}, which similarly sacrificed herself to save her convoy from the {{cvt|11|in}}-gunned cruiser {{ship|German cruiser|Admiral Scheer||2}} in November 1940.

HMS Kent Falklands damage IWM Q 045916.jpg|Casemate guns on {{HMS|Kent|1901|6}} showing shell damage from the Battle of the Falkland Islands

6 inch gun Laconia March 1942 AWM 028103.jpg|Gun drill on the troop ship {{RMS|Laconia|1921|6}} during World War II

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World War I field gun

The Mk VII gun was first used as a field gun in France in 1915. It was initially mounted on an improvised rectangular-frame field carriage designed by Admiral Percy Scott. The carriage was based on a design he had improvised for the 4.7-inch gun in the Second Boer War.{{sfn|Hogg|Thurston|1972|page=144}} It was a successful carriage, except that it limited the elevation and hence the range. A better carriage which allowed elevation to 22°, the MK II, was introduced early in 1916. This was followed by Mk III, V and VI carriages. The gun was operated by the Royal Garrison Artillery in batteries of four, as were all the larger field guns in World War I.

Following a successful deployment in the Battle of the Somme, the role of the gun was defined as counter-battery fire. They "were most effective for neutralising defences and for wire cutting with fuze 106 (a new fuze which reliably burst instantly above ground on even slight contact, instead of forming craters)". They were also effective for long-range fire against "targets in depth".{{harvnb|Farndale|1986|page=158}}, quoting {{cite book |publisher=War Office |title=Artillery Notes |volume=4 – Artillery in Offensive Operations |date=February 1917}} The Mk VII was superseded by the lighter and longer-range BL 6-inch gun Mk XIX which was introduced from October 1916, but the Mk VII remained in service to the end of World War I.

BL6inchGunMkVIIOnScottCarriage.jpg|Original Percy Scott field carriage

6inchMkVIIGunBeaumetz21April1917.jpeg|Firing near Beaumetz-lès-Loges, cutting wire for the Australian advance Second Battle of Bullecourt

Naval gun firing over Vimy Ridge.jpg|Night firing at Vimy Ridge

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Coast defence gun

The 6-inch Mk VII gun, together with the 9.2-inch Mk X gun, provided the main coast defence throughout the British Empire, from the early 1900s until the abolition of coast artillery in the 1950s. Many guns were specially built for army coast defence use, and following the decommissioning of many obsolete cruisers and battleships after World War I, their 6-inch Mk VII guns were also recycled for coast defence. During World War I, 103 of these guns were in service in coastal defences around the UK.{{sfn|Farndale|1988|page=404}} Some of these, together with others at ports around the wider British Empire, played an important defence role in World War II and remained in service until the 1950s.

A number of new similar guns with stronger barrels which allowed more powerful cordite charges to be used were manufactured for coast defence during World War II, and were designated 6-inch BL Mark XXIV.

File:Bastions C and D of the Keep at the Royal Naval Dockyard on Ireland Island, Bermuda with two 6-inch RBL Mk VII.jpg|Bastions C and D of the Keep at the Royal Naval Dockyard on Ireland Island, Bermuda, with 6-inch Mk VIIs

File:Mk VII gun Fort Nepean 1943.jpg|Mk VII with a concrete hood at Fort Nepean in 1943

File:BL 6-inch rifle, with two BL 9.2-inch rifles beyond, at St. David's Battery, Bermuda, 2011.jpg|One of two 6-inch Mk VIIs, and two 9.2-inch Mk Xs, at St. David's Battery, Bermuda, in 2011

File:BL6inchGunMkVIINewhavenFort1March2008.jpg|Mk VII gun on typical coast mounting at Newhaven Fort

File:Gun at Half Moon Battery Pendennis Castle.jpg|A Mk XXIV gun at Half Moon Battery Pendennis Castle.

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Notable actions

In the German raid on Scarborough, Hartlepool and Whitby on 16 December 1914, a notable action was fought by the Durham Royal Garrison Artillery of the Territorial Force at Heugh (two guns) and Lighthouse (one gun) batteries defending Hartlepool. They duelled with the German battlecruisers {{SMS|Seydlitz || 2}} and {{SMS|Moltke || 2}} ({{cvt|11|in}} guns) and {{SMS|Blücher || 2}} ({{cvt|8.2|in}}), firing 112 rounds and scoring seven hits. The battlecruisers fired a total of 1,150 rounds at the town and the batteries, causing 112 civilians and seven military killed.{{sfn|Farndale|1988|pages=368–369, 401}}

World War I ammunition

class="wikitable"

| File:BL6inchGunCartridgeMkIII23lb.jpg

| File:6inchMkIVLydditeShell.jpg

| File:BL6inchMkVIILydditeShell.jpg

| File:6inchLydditeMkXIIAQNTShellDiagram.jpg

| File:BL6inchShrapnelShellMkIXDiagram.jpg

| File:BL 6-inch HE Gun Shell Mk XVI Diagram.jpg

{{center|Mk III {{convert|23|lb|abbr=on}} Cordite MD Cartridge}}

| {{center|Mk IV Common lyddite shell}}

| {{center|Mk VIIA Common lyddite naval shell}}

| {{center|MK XIIA QNT Common lyddite naval shell with night tracer}}

| {{center|Mk IX Shrapnel shell}}

| {{center|Mk XVI HE shell}}

Surviving examples

File:6-inch Mk VII gun at Royal Artillery Museum Flickr 6185561735.jpg

File:Bateria Outão 01.JPG

  • At the Royal Artillery Museum Woolwich, London.
  • A coast defence gun at [http://www.newhavenfort.org.uk/ Newhaven Fort, Sussex, UK]
  • A gun mounted on the 1904 coast defence emplacement at New Tavern Fort, Gravesend, UK
  • 2 coast defence Mk 7 guns at Fort Dunree, Lough Swilly, in County Donegal, Ireland
  • St. David's Battery, St. David's Head, St. David's Island, Bermuda. Two Mk VII RBLs, built by Vickers, on central pivot Mk II mounts.
  • Fort Scratchley, Newcastle, New South Wales, Australia. 2 guns dating from 1911. Decommissioned in 1965 and placed in a nearby park. Moved back to their original mounts in 1978 after the Fort became a museum. Both were restored in 1992 by the Fort Scratchley Historical Society and are capable of being fired on special occasions for ceremonial and saluting purposes.
  • Fort St. Catherine's, St. George's Island, Bermuda 6-inch BL gun Mk VII, built by Vickers, on central pivot Mk II mount.
  • Warwick Camp, Warwick, Bermuda. Two Mk. VII, built by Vickers, on central pivot Mk II mounts. (This is an active military base, and the battery is not accessible by the public. The barrels have reportedly been removed, recently, for remounting on the bastions of the Keep, at the Royal Naval Dockyard, on Ireland Island, which houses the Bermuda Maritime Museum.
  • Royal Naval Dockyard, Ireland Island, Bermuda. Two Mk VII (L/1029 and RGF) on central pivot Mk II, at Bastions C and D of the Keep (fortress) which houses the Bermuda Maritime Museum (there is also one BL 6-inch gun Mk II and one BL 6-inch gun Mk IV, at Bastion E).{{cite web |url=http://www.bmm.bm/map.htm#A |website=Bermuda Maritime Museum |title=Virtual site map |archive-url=https://web.archive.org/web/20070203020447/http://www.bmm.bm/map.htm |archive-date=2007-02-03}}{{cite book |title=American Seacoast Defenses: A Reference Guide |chapter=Other Surviving North American Seacoast Artillery Weapons |chapter-url=http://cdsg.org/wp-content/uploads/pdfs/CDSG/CDSG%20WEBSITE%20UPDATES/CDSG%20Downloads/survive14.pdf |date=February 2014 |author=C.L. Kimbell |author2=R.D. Zink |author3=T.C. McGovern |page=242 |access-date=2018-06-22}}
  • A gun on field carriage at [https://web.archive.org/web/20070313122211/http://www.frontmuseum.fi/en.html The Front Museum, Lappohja, Finland]
  • [https://www.flickr.com/photos/ewan_osullivan/2391720005 Fort Ogilvie, Point Pleasant Park], Halifax, Nova Scotia
  • [https://www.flickr.com/photos/9977224@N06/1504348797 VSM gun No. 1553 dated 1901] at Princess Royal Fortress, Albany, Western Australia. Obtained from Bermuda during restoration of the site in the 1980s.
  • Barrel 1489 which fired the first Australian shot of WWI, and 1317 which fired the first Australian shot of WWII at Fort Nepean, Victoria
  • [https://www.flickr.com/photos/9977224@N06/1489970720 Mk VII gun dated 1902] at Ile aux Aigrettes, Mauritius
  • [https://web.archive.org/web/20080907104000/http://www.southpacificphotography.com/photos.cfm/PhotoId/316/momi-gun-coral-coast.html] Momi, Vuda, Batteries, Viti Levu, Fiji Islands. One of the barrels is #1266 from 1900
  • Fort Mitchell, Spike Island, Ireland, 2 Mk VII Guns in casemates on central pivot Mk II mounts in good condition and in the process of being restored to full working condition.
  • Lonehort Fort, Bere Island, County Cork, Ireland- Two 6-inch BL guns are extant- Breech blocks are missing and the guns themselves somewhat rusty, but otherwise appear to be in good condition. The fort was open to the public on 14 and 15 March 2014 for an underground art experience titled "Nest", which took place in the shell rooms below the guns. The shell rooms and hoists are also in good condition.
  • Coastal Artillery Battery at Outão, Portugal on the mouth of Sado river, protecting Setubal harbour with 3 guns decommissioned in 1998
  • Two guns dated 1900 and 1902 from {{HMS|Lancaster|1902|6}} at Canopus Hill near Stanley Airport, the Falkland Islands, they were refurbished in 2003.{{cite web |url=http://www.stanley-services.co.fk/news/15/35/Stanley-Services-Refurbish-Naval-6inch-Guns/ |title=Stanley Services Refurbish Naval 6inch Guns |publisher=Stanley Service Ltd. |location=Stanley, Falkland Islands |access-date=15 October 2017 |archive-date=16 October 2017 |archive-url=https://web.archive.org/web/20171016101907/http://www.stanley-services.co.fk/news/15/35/Stanley-Services-Refurbish-Naval-6inch-Guns/ }}
  • Three Mk VII (dating 1904, 1914 and 1918) of the Ostenburg battery at the Royal Naval Dockyard, Trincomalee.{{cite web |title=The defence of Trincomalee and the 6 inch battery at Hood's Tower |url=https://www.victorianforts.co.uk/gall/trincomalee.htm |website=victorianforts.co.uk |access-date=22 November 2020}}
  • Three Mk VII of the Modara battery at the Rock House Army Camp.
  • Two Mk VII at Banana, on the Atlantic coast of the Democratic Republic of the Congo. They are out of use since 1960.
  • One Mk VII taken from Singapore and moved to Tinian as part of a battery of three such weapons, now sits outside the Tinian International airport. This gun fired on the battleship {{USS|Colorado|BB-45|6}} and destroyer {{USS|Norman Scott||6}}, on 24 July 1944, causing extensive casualties and damage to both vessels. This surviving weapon bears two distinct gouges on its barrel from American return fire that knocked it out, but is otherwise intact.

See also

= Weapons of comparable role, performance and era =

Notes

{{notelist}}

References

{{reflist}}

Bibliography

  • {{cite book |title=Handbook for The 6-Inch Breech Loading Mark XII Gun |year=1917 |publisher=Admiralty, Gunnery Branch, G. 21117/17 |url=https://archive.org/details/HandbookForThe6-inchBreechLoadingMarkXiiGun1917.G.2111717.pdf}}
  • {{cite book |ref={{harvid|Treatise on Ammunition|1915}} |url=http://bulletpicker.com/pdf/Treatise%20on%20Ammunition,%201915.pdf |title=Treatise on Ammunition |edition=10th |publisher=War Office |year=1915}}
  • {{cite book |first=Dale |last=Clarke |url=http://www.ospreypublishing.com/title_detail.php/title=S7883 |title=British Artillery 1914–1919. Heavy Artillery. |publisher=Osprey Publishing |location=Oxford UK |year=2005 |isbn=978-1-84176-788-8 |access-date=26 September 2007 |archive-url=https://web.archive.org/web/20061021183226/http://www.ospreypublishing.com/title_detail.php/title=S7883 |archive-date=21 October 2006 }}
  • {{cite book |first=Martin |last=Farndale |author-link=Martin Farndale |title=History of the Royal Regiment of Artillery. Western Front, 1914–18 |location=London |publisher=Royal Artillery Institution |year=1986 |isbn=978-1-870114-00-4}}
  • {{cite book |first=Martin |last=Farndale |author-link=Martin Farndale |title=History of the Royal Regiment of Artillery. The Forgotten Fronts and the Home Base, 1914–18 |location=London |publisher=Royal Artillery Institution |year=1988 |isbn=978-1-870114-05-9}}
  • {{cite book |author-link=Ian V. Hogg |first1=I.V. |last1=Hogg |name-list-style=amp |first2=L.F. |last2=Thurston |title=British Artillery Weapons & Ammunition 1914–1918 |location=London |publisher=Ian Allan |year=1972 |isbn=978-0-7110-0381-1}}

External links

{{Commons category|BL 6 inch Mk VII naval gun}}

  • {{cite book |url=http://handle.slv.vic.gov.au/10381/107941 |title=Handbook for the 6-inch B. L. guns, marks VII and VIIv (land service) |year=1911 |location=London |publisher=His Majesty's Stationery Office |via=State Library of Victoria}}
  • {{cite journal |first=Terry |last=Gander |url=http://www.fsgfort.com/uploads/pdfs/Public/British%20Coastal%20Artillery%20P.pdf |archive-url=https://web.archive.org/web/20140414084352/http://www.fsgfort.com/uploads/pdfs/Public/British%20Coastal%20Artillery%20P.pdf |archive-date=2014-04-14 |title=Twentieth Century British Coast Defence Guns |journal=Fortlet |volume=2 |year=2011}}
  • {{cite book |first=Percy |last=Scott |author-link=Percy Scott |url=https://archive.org/details/fiftyyearsinroya00scotuoft |title=Fifty Years in the Royal Navy |location=London |publisher=John Murray |year=1919 |via=The Internet Archive}}

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Category:World War I artillery of the United Kingdom

Category:World War I guns

Category:Naval guns of the United Kingdom

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Category:Vickers naval guns

Category:Coastal artillery