BL 8 inch Mk I – VII naval gun

Ordnance BL 8 inch gun Mks I - VII
Ordnance BL 8 inch gun Mks I - VII
	300px Mk VII on disappearing carriage at North Head, Devonport, New Zealand
Type	Naval gun; Coast defence gun
Place of origin	United Kingdom
Service history
In service	1884 - 190?
Used by	United Kingdom; Colonial navies of Australia; New Zealand; Singapore
Production history
Designer	Mk I, VI : RGF; Mk VII : EOC
Manufacturer	Mk I, III, IV : RGF; Mk III, IV, VI, VII EOC
Unit cost	£6,015
Variants	Mks III, IV, VI, VII, VIIA
Specifications
Weight	Mk III & VI : 14 tons; Mk IV : 15 tons; Mk VII : 12 tons; Mk VIIA : 13 tons barrel & breech
Barrel length	Mk III : Lua error in Module:Convert at line 1851: attempt to index local 'en_value' (a nil value).; Mk VII : Lua error in Module:Convert at line 1851: attempt to index local 'en_value' (a nil value).; Mk IV & VI : Lua error in Module:Convert at line 1851: attempt to index local 'en_value' (a nil value). bore
Shell	Mks III, IV, VI : Lua error in Module:Convert at line 1851: attempt to index local 'en_value' (a nil value).; Mk VII : Lua error in Module:Convert at line 1851: attempt to index local 'en_value' (a nil value).
Calibre	Lua error in Module:Convert at line 1851: attempt to index local 'en_value' (a nil value).
Muzzle velocity	Mk III : Lua error in Module:Convert at line 1851: attempt to index local 'en_value' (a nil value).; Mk IV & VI : Lua error in Module:Convert at line 1851: attempt to index local 'en_value' (a nil value).; Mk VII : Lua error in Module:Convert at line 1851: attempt to index local 'en_value' (a nil value).
Maximum firing range	8,000 yards (7,300 m)

The BL 8 inch guns Mark I to Mark VII^{[note 2]} were the first generations of British rifled breechloaders of medium-heavy calibre. They were initially designed for gunpowder propellants and were of both 25.5 and 30 calibres lengths.

History

Mks I and II were several early proof guns that did not enter British service and Mk V was not made. Limited numbers of 25.5 and 30 calibres guns were produced.

By 1885 the Royal Navy abandoned the 8-inch gun in favour of the 9.2 inch and later the 7.5 inch gun for cruisers, until 1923 when the restrictions of the Washington Naval Treaty led Britain to develop the Mk VIII 8-inch gun in order to arm heavy cruisers with the largest gun allowed by the Treaty.

In the interim Elswick Ordnance continued to develop 8-inch guns in 40 calibre and 45-calibre lengths for export, mainly to Japan.

Mark III

Mk III were low-powered 25-calibres guns mounted on :

HMS Bellerophon as re-gunned in 1885

Mark IV

Mk IV were 30-calibres guns mounted in :

Mersey-class cruisers of 1885

Mark VI

Mk VI were 30 calibres guns mounted in :

Indian monitors Abyssinia and Magdala as re-gunned in 1892

Mark VII

Mk VII were lighter 25-calibres low-powered guns firing a lighter 180-pound projectile used to equip Australian colonial navies and Australian and New Zealand coastal defences in response to expected Russian expansionism in the Pacific (The "Russian scares" of the 1880s).

Naval service

File:HMCS Gayundah bow view AWM 300016.jpg

As mounted in bow of Gayundah, 1903

Mk VII guns armed the following Australian colonial gun vessels :

Coast defence gun

File:BL 8 inch Disappearing Gun Fort Queenscliff VIC.JPG

At Fort Queenscliff, Victoria, Australia

Mk VII guns were installed on disappearing mountings in Australia and New Zealand as coast-defence guns during the "Russian scares" of the 1880s. In the event, no Russian invasion occurred and the guns were rarely if ever fired.

Four Mk VII coast defence guns were installed at Singapore in the 1880s-1890s : two atop Mount Serapong and two at Fort Tanjong Katong.^[8] Lua error in package.lua at line 80: module 'strict' not found.

Ammunition

BL 8 inch common shell Mk I diagram.jpg

210 pound Mk I common shell

Surviving examples

Mk VII at North Head, Devonport, New Zealand
Mk VII at summit of Mount Victoria, Auckland, New Zealand
An unrestored Mk VII disappearing gun at Fort Jervois, Ripapa Island, New Zealand
Mk VII at Fort Siloso, Sentosa Island, Singapore See also Photograph at Flickr
Mk VII at Royal Artillery Museum, Woolwich, London
A Mk VII gun from 1885 on hydro-pneumatic mounting at Fort Queenscliff, VIC, Australia

Notes

↑ Different types of shell had different weights : figures are for the gun's heaviest shell. Hence for the Mk VII gun the Victorian Navy Manual of 1895 quotes Common 168 lb, Segment 177 lb, Palliser, Case & Shrapnel 180 lb
↑ Mark I to Mark VII = Mark 1 to Mark 7. Britain used Roman numerals to denote marks (models) of ordnance until after World War II. Hence these were the first 7 models of BL 8-inch naval gun.

References

↑ Unit price for 10 Mk VII guns on Hydro-Pneumatic carriages, with 50 rounds per gun, delivered in London, as purchased by New Zealand in 1885. 1885 New Zealand Harbour defences (Table showing amount required for) Laid on the Table by the Hon. Mr Ballance, with the Leave of the House.
↑ ^2.0 ^2.1 ^2.2 Text Book of Gunnery 1902, Table XII Page 336
↑ Mk III : 1953 ft/sec firing 210-pound projectile using 104 lb Prismatic Brown powder or 28 lb 12 oz cordite Mk I size 20. Text Book of Gunnery 1902.
↑ Mks IV & VI : 2150 ft/sec firing 210-pound projectile using 118 lb Prismatic brown powder or 32 lb 10 oz cordite Mk I size 20. Text Book of Gunnery 1902.
↑ Mk VII : 2,000 ft/sec firing a 180 lb projectile, with 90 lb black prism powder (gunpowder); or 22 lb cordite MK I propellant size 20. Text Book of Gunnery, 1902
↑ Mk VII : Victorian Navy Manuals 1887 and 1895 quote 100 lb Black powder for "battering charge" and 90 lb for regular charge. Muzzle Velocity of 2027 ft/sec is quoted with 180 lb projectile and 90 lb charge in the Victorian Navy Manual of 1895
↑ 12000 yards is quoted for Mk VII gun in the Victorian Navy Manual of 1895
↑ Fort Siloso. The Gun Museum. 8-inch BL gun

Bibliography

External links

Instructions for 8 inch Rifled Breech Loading Armstrong Gun and Hydro-Pneumatic Disappearing Carriage Describes Mk VII gun. From Australian National Archives
Instructions for 8 inch Rifled Breech Loading Armstrong Gun and Naval Carriage and Slide Describes Mk VII gun. From Australian National Archives

[3] Different types of shell had different weights : figures are for the gun's heaviest shell. Hence for the Mk VII gun the Victorian Navy Manual of 1895 quotes Common 168 lb, Segment 177 lb, Palliser, Case & Shrapnel 180 lb

[9] Mark I to Mark VII = Mark 1 to Mark 7. Britain used Roman numerals to denote marks (models) of ordnance until after World War II. Hence these were the first 7 models of BL 8-inch naval gun.

[1] Unit price for 10 Mk VII guns on Hydro-Pneumatic carriages, with 50 rounds per gun, delivered in London, as purchased by New Zealand in 1885. 1885 New Zealand Harbour defences (Table showing amount required for) Laid on the Table by the Hon. Mr Ballance, with the Leave of the House.

[Gunnery1902-2] 2.0 ^2.1 ^2.2 Text Book of Gunnery 1902, Table XII Page 336

[4] Mk III : 1953 ft/sec firing 210-pound projectile using 104 lb Prismatic Brown powder or 28 lb 12 oz cordite Mk I size 20. Text Book of Gunnery 1902.

[5] Mks IV & VI : 2150 ft/sec firing 210-pound projectile using 118 lb Prismatic brown powder or 32 lb 10 oz cordite Mk I size 20. Text Book of Gunnery 1902.

[6] Mk VII : 2,000 ft/sec firing a 180 lb projectile, with 90 lb black prism powder (gunpowder); or 22 lb cordite MK I propellant size 20. Text Book of Gunnery, 1902

[7] Mk VII : Victorian Navy Manuals 1887 and 1895 quote 100 lb Black powder for "battering charge" and 90 lb for regular charge. Muzzle Velocity of 2027 ft/sec is quoted with 180 lb projectile and 90 lb charge in the Victorian Navy Manual of 1895

[8] 12000 yards is quoted for Mk VII gun in the Victorian Navy Manual of 1895

[10] Fort Siloso. The Gun Museum. 8-inch BL gun

[1]

[2]

[note 1]

[3]

[4]

[5]

[6]

[7]

[note 2]

[8]

v t e British Empire naval weapons of the Victorian era
Smoothbore muzzle-loading cannons	18-pounder 24-pounder 32-pounder 55 cwt 32-pounder gun 68-pounder Somerset cannon
Smoothbore muzzle-loading shell guns	8-inch 10-inch 86 cwt
Mortars	10-inch Blomefield 13-inch Blomefield
Howitzers	12-pounder Millar 24-pounder Millar
Rifled breechloaders (Armstrong)	RBL 9 pounder RBL 20-pounder RBL 40-pounder RBL 7-inch 110-pounder
Rifled muzzle-loaders (Lancaster)	68-pounder Lancaster gun
Rifled muzzle-loaders (converted)	RML 64-pounder 71 cwt
Rifled muzzle-loaders (Woolwich)	RML 9-pounder 8 cwt RML 64-pounder 64 cwt RML 7-inch RML 8-inch RML 9-inch RML 10-inch RML 11-inch RML 12-inch 25-ton RML 12-inch 35-ton RML 12.5-inch RML 16-inch
Breech-loaders (new pattern)	BL 4-inch BL 5-inch BL 6-inch 80-pounder BL 6-inch Mk II – VI BL 8-inch BL 9.2-inch Mk I – VII BL 9.2-inch Mk VIII BL 10-inch BL 12-inch Mk I – VII BL 12-inch Mk VIII BL 13.5-inch BL 16.25-inch
Quick-firing guns	QF 3-pounder Hotchkiss QF 6-pounder Hotchkiss QF 6-pounder Nordenfelt QF 12-pounder 12 cwt Mk I QF 4-inch QF 4.7-inch QF 6-inch
Light weapons	Gatling gun Gardner gun Nordenfelt gun 1-inch Nordenfelt gun
Torpedoes	Whitehead torpedo

BL 8 inch Mk I – VII naval gun

Contents

History

Mark III

Mark IV

Mark VI

Mark VII

Naval service

Coast defence gun

Ammunition

Surviving examples

See also

Notes

References

Bibliography

External links

Navigation menu

Personal tools

Namespaces

Variants

Views

More

Search

Navigation

Tools

Ordnance BL 8 inch gun Mks I - VII
300px Mk VII on disappearing carriage at North Head, Devonport, New Zealand
Type	Naval gun Coast defence gun
Place of origin	United Kingdom
Service history
In service	1884 - 190?
Used by	United Kingdom Colonial navies of Australia New Zealand Singapore
Production history
Designer	Mk I, VI : RGF Mk VII : EOC
Manufacturer	Mk I, III, IV : RGF Mk III, IV, VI, VII EOC
Unit cost	£6,015^[1]
Variants	Mks III, IV, VI, VII, VIIA
Specifications
Weight	Mk III & VI : 14 tons Mk IV : 15 tons Mk VII : 12 tons Mk VIIA : 13 tons barrel & breech^[2]
Barrel length	Mk III : Lua error in Module:Convert at line 1851: attempt to index local 'en_value' (a nil value). Mk VII : Lua error in Module:Convert at line 1851: attempt to index local 'en_value' (a nil value). Mk IV & VI : Lua error in Module:Convert at line 1851: attempt to index local 'en_value' (a nil value). bore^[2]

Shell	Mks III, IV, VI : Lua error in Module:Convert at line 1851: attempt to index local 'en_value' (a nil value). Mk VII : Lua error in Module:Convert at line 1851: attempt to index local 'en_value' (a nil value).^{[note 1]}
Calibre	Lua error in Module:Convert at line 1851: attempt to index local 'en_value' (a nil value).
Muzzle velocity	Mk III : Lua error in Module:Convert at line 1851: attempt to index local 'en_value' (a nil value).^[3] Mk IV & VI : Lua error in Module:Convert at line 1851: attempt to index local 'en_value' (a nil value).^[4] Mk VII : Lua error in Module:Convert at line 1851: attempt to index local 'en_value' (a nil value).^[5]^[6]
Maximum firing range	8,000 yards (7,300 m)^[2]^[7]