The RML 12-inch 25-ton guns were large rifled muzzle-loading guns of mid-late 1800s used as primary armament on British ironclad turret battleships and coastal monitors, and also ashore for coast defence. They were the shorter and less powerful of the two 12-inch (305-mm) British RML guns, the other being the 35-ton gun.
Ordnance RML 12-inch 25-ton gun
A 12-inch (305 mm) 25-ton gun in an armoured turret aboard the ramHMS Hotspur. A shell is suspended near the muzzle ready for loading.
Rear view of a 12-inch (305 mm) 25-ton gun aboard the ramHMS Hotspur.
Mark Iedit
Four guns were first made in 1866 with a toughened mild steel tube surrounded by multiple wrought iron coils on the original Armstrong pattern.
Mark IIedit
While strong, the multiple coils were considered too expensive for construction in quantity. From 1867 guns were built on the simplified and hence cheaper "Fraser" system involving fewer but larger coils similar to the 10-inch (254-mm) Mk II gun. The guns were not considered a success, with the rifling twist of 1 in 100 increasing to 1 in 50 considered insufficient for accuracy, and guns were retubed in 11-inch (279-mm) calibre when their bores wore out.[4]
When the gun was first introduced projectiles had several rows of "studs" which engaged with the gun's rifling to impart spin. Some time after 1878, "attached gas-checks" were fitted to the bases of the studded shells, reducing wear on the guns and improving their range and accuracy. Subsequently, "automatic gas-checks" were developed which could rotate shells, allowing the deployment of a new range of studless ammunition. Thus, any particular gun potentially operated with a mix of studded and studless ammunition.
The gun's primary projectile was 600 to 608-pound (272- to 275-kilogram) "Palliser" armour-piercing shot, fired with a "Battering charge" of 85 pounds (38.5 kilograms) of "P" (gunpowder) or 67 pounds (30.4 kilograms) "R.L.G." (gunpowder) for maximum velocity and hence penetrating power. Shrapnel and Common (exploding) shells weighed 497 pounds (225.5 kilograms) and were fired with a "Full charge" of 55 pounds (25 kilograms) "P" or 50 pounds (22.7 kilograms) "R.L.G.".[5]
^Unit cost of £1,715 13 shillings 5 pence is quoted in "The British Navy" Volume II, 1882, by Sir Thomas Brassey. Page 38
^Treatise on Construction of Service Ordnance 1877, page 292
^MV of 1,300 feet/second firing 600-pound projectile with "Battering charge" of 85 pounds "P" (gunpowder) is quoted in "Treatise on Construction of Service Ordnance 1877", page 348. MV of 1,292 feet/second firing 608 lb 6 oz projectile with "Battering charge" of 85 pounds "P2" (gunpowder) is quoted in "Text Book of Gunnery 1887" Table XVI
^Treatise on Construction of Service Ordnance 1877, pages 92-94
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 Archived 2012-12-04 at archive.today
Sir Thomas Brassey, The British Navy, Volume II. London: Longmans, Green and Co. 1882
External linksedit
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December 15, 2023
inch, this, article, includes, list, general, references, lacks, sufficient, corresponding, inline, citations, please, help, improve, this, article, introducing, more, precise, citations, april, 2011, learn, when, remove, this, template, message, were, large, . This article includes a list of general references but it lacks sufficient corresponding inline citations Please help to improve this article by introducing more precise citations April 2011 Learn how and when to remove this template message The RML 12 inch 25 ton guns were large rifled muzzle loading guns of mid late 1800s used as primary armament on British ironclad turret battleships and coastal monitors and also ashore for coast defence They were the shorter and less powerful of the two 12 inch 305 mm British RML guns the other being the 35 ton gun Ordnance RML 12 inch 25 ton gunA 12 inch 305 mm 25 ton gun in an armoured turret aboard the ram HMS Hotspur A shell is suspended near the muzzle ready for loading TypeNaval gunCoast defence gunService historyUsed byRoyal NavyProduction historyDesigned1864 1866ManufacturerRoyal ArsenalUnit cost 1 716 1 Produced1866 187 VariantsMk I Mk IISpecificationsMassMk I 23 5 long tons 23 900 kg Mk II 25 long tons 25 000 kg Barrel length145 inches 3 7 m bore chamber 2 Shell600 to 608 4 pounds 272 2 to 276 0 kg Palliser 497 pounds 225 4 kg Common amp Shrapnel Calibre12 inch 304 8 mm Muzzle velocity1 300 feet per second 400 m s 3 Contents 1 Design 1 1 Mark I 1 2 Mark II 2 Naval service 3 Ammunition 4 See also 5 Surviving examples 6 Notes and references 7 Bibliography 8 External linksDesign edit nbsp Mk I amp II gun construction nbsp Rear view of a 12 inch 305 mm 25 ton gun aboard the ram HMS Hotspur Mark I edit Four guns were first made in 1866 with a toughened mild steel tube surrounded by multiple wrought iron coils on the original Armstrong pattern Mark II edit While strong the multiple coils were considered too expensive for construction in quantity From 1867 guns were built on the simplified and hence cheaper Fraser system involving fewer but larger coils similar to the 10 inch 254 mm Mk II gun The guns were not considered a success with the rifling twist of 1 in 100 increasing to 1 in 50 considered insufficient for accuracy and guns were retubed in 11 inch 279 mm calibre when their bores wore out 4 Naval service editGuns were mounted on HMS Captain 1869 4 HMS Monarch 1868 4 HMS Hotspur 1870 2 HMS Glatton 1871 2 HMS Belleisle 1876 4 HMS Orion 1879 4Ammunition editWhen the gun was first introduced projectiles had several rows of studs which engaged with the gun s rifling to impart spin Some time after 1878 attached gas checks were fitted to the bases of the studded shells reducing wear on the guns and improving their range and accuracy Subsequently automatic gas checks were developed which could rotate shells allowing the deployment of a new range of studless ammunition Thus any particular gun potentially operated with a mix of studded and studless ammunition The gun s primary projectile was 600 to 608 pound 272 to 275 kilogram Palliser armour piercing shot fired with a Battering charge of 85 pounds 38 5 kilograms of P gunpowder or 67 pounds 30 4 kilograms R L G gunpowder for maximum velocity and hence penetrating power Shrapnel and Common exploding shells weighed 497 pounds 225 5 kilograms and were fired with a Full charge of 55 pounds 25 kilograms P or 50 pounds 22 7 kilograms R L G 5 nbsp Palliser shotSee also editList of naval gunsSurviving examples editat Drake s Island Plymouth UKNotes and references edit Unit cost of 1 715 13 shillings 5 pence is quoted in The British Navy Volume II 1882 by Sir Thomas Brassey Page 38 Treatise on Construction of Service Ordnance 1877 page 292 MV of 1 300 feet second firing 600 pound projectile with Battering charge of 85 pounds P gunpowder is quoted in Treatise on Construction of Service Ordnance 1877 page 348 MV of 1 292 feet second firing 608 lb 6 oz projectile with Battering charge of 85 pounds P2 gunpowder is quoted in Text Book of Gunnery 1887 Table XVI Treatise on Construction of Service Ordnance 1877 pages 92 94 Treatise on Ammunition 1877 pages 191 194 220Bibliography editTreatise on Ammunition War Office UK 1877 permanent dead link 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 Archived 2012 12 04 at archive today Sir Thomas Brassey The British Navy Volume II London Longmans Green and Co 1882External links edit nbsp Wikimedia Commons has media related to RML 12 inch 25 ton gun Retrieved from https en wikipedia org w index php title RML 12 inch 25 ton gun amp oldid 1175616074, wikipedia, wiki, book, books, library,
