The gun originated from a desire for a longer 12 in (30 cm) gun than the existing RML 12-inch 35-ton gun. Experiments in 1874 with both 12 in (30 cm) and 12.5 in (32 cm) versions 3 ft (91 cm) longer than the existing 12 in (30 cm) gun showed the 12.5 in (32 cm) calibre was more suitable, and further experiments showed a projectile of 800 lb (360 kg) could be fired with a charge of 130 lb (59 kg) of P2 gunpowder without undue strain. The same construction as in the existing 12 in (30 cm) 35-ton gun was used : a mild steel "A" tube toughened in oil, surrounded by wrought iron "B" tube, triple coil in front of the trunnion, coiled breech-piece and breech coil. This was approved in January 1875.[4]
The gun was rifled on the "Woolwich" pattern of a small number of broad shallow rounded grooves, with 9 grooves increasing from 0 to 1 turn in 35 calibres ( i.e. 1 turn in 437.5 in (1,111 cm)).
Mark II had an enlarged powder chamber and attained higher muzzle velocity and slightly longer range.
This gun was the final development of large British rifled muzzle-loading guns before it switched to breechloaders beginning in 1880. It was succeeded in its class on new battleships by the BL 12 in (30 cm) Mk II gun.
Naval serviceedit
Guns were mounted on HMS Dreadnought commissioned in 1879, HMS Agamemnon commissioned in 1883, and HMS Ajax commissioned in 1885, the last British warships completed with muzzle-loading guns.
Ammunitionedit
When the gun was first introduced projectiles had several rows of "studs" which engaged with the gun's rifling to impart spin. Sometime 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.
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RML 12.5in Studded Shell, located at Hurst Castle, UK
RML 12.5in Studded Shrapnel Shell Mk I with Attached Gas-Check Mk I
RML 12.5in Studded Palliser Shell Mk III with Attached Gas-Check Mk II
RML 12.5in Studded Common Shell Mk I with Attached Gas-Check Mk II
RML 12.5in Studded Shrapnel Shell Mk I with Attached Gas-check Mk II
RML 12.5in Case Shot Mk III
RML 12.5in Studless Palliser Shell Mk I with Automatic Gas-Check
RML 12.5in Studless Common Shell Mk I with Automatic Gas-Check
RML 12.5in Studless Shrapnel Shell Mk I with Automatic Gas-check
Images 3–9 show the range of ammunition for the RML 12.5-inch gun in 1885.[5] By this time the gun no longer fired studded ammunition without gas-checks. Instead there were two sets of ammunition available, namely: older studded ammunition with attached gas-checks Mk II, and newer studless ammunition with automatic gas-checks. Case ammunition neither was studded nor required gas-checks. Also by this time, attached gas-checks Mk I as shown in image 2 had been superseded by attached gas-checks Mk II.
Gun number 87 and 95, dated 1878. Now in the ditch at Fort Cunningham, Bermuda
Notes and referencesedit
^Treatise on Construction of Service Ordnance 1877, page 292
^1,425 feet/second firing 800-pound projectile with "Battering charge" of 130 pounds "P2" (gunpowder). Treatise on Construction of Service Ordnance 1877, page 347.
^Muzzle velocity of 1,575 feet/second firing an 809lb 6oz projectile with a charge of 210 pounds Prism2 black powder, is quoted for Mark II gun in "Text Book of Gunnery 1887" Table XVI.
^Treatise on Construction of Service Ordnance 1877, pages 286-287
^Handbook for RML 12.5-inch gun (1885) pp. 32-33; Plates XI-XIV
Bibliographyedit
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
Sectretary of State for War (1885). Handbook for the R.M.L. 12.5-inch 38-ton Gun, Marks I and II. London: Her Majesty's Stationery Office.
External linksedit
Wikimedia Commons has media related to RML 12.5 inch 38 ton naval gun.
Handbook for the R.M.L. 12.5-inch 38-ton gun, marks I and II : casemate, dwarf, and small port mountings (land service). Great Britain. War Office. London : H.M.S.O. 1885 at State Library of Victoria
Handbook for the 12.5-inch 38-ton R.M.L. gun, marks I and II, casemate, dwarf, and small part mountings land service 1888, 1893, 1899, 1904 at State Library of Victoria
Diagram of gun on small port 6-foot recoil carriage at Victorian Forts and Artillery website
Diagram of gun on Casemate Platform, 6 feet recoil Mark III at Victorian Forts and Artillery website
Diagram of gun on Dwarf 'C' Pivot Mark III at Victorian Forts and Artillery website
December 18, 2023
inch, inch, guns, were, large, rifled, muzzle, loading, guns, designed, british, battleships, were, also, employed, coast, defence, ordnance, fort, nelson, portsmouth, uktypenaval, guncoast, defence, gunplace, originunited, kingdomservice, historyin, service18. The RML 12 5 inch guns were large rifled muzzle loading guns designed for British battleships and were also employed for coast defence Ordnance RML 12 5 inch 38 ton gunGun at Fort Nelson Portsmouth UKTypeNaval gunCoast defence gunPlace of originUnited KingdomService historyIn service1875 1905Used byRoyal NavyProduction historyDesignerRoyal Gun FactoryDesigned1874ManufacturerRoyal ArsenalVariantsMk I Mk IISpecificationsBarrel length198 inches 5 0 m bore 1 Shell800 to 809 pounds 362 9 to 367 0 kg Palliser Common ShrapnelCalibre12 5 inch 317 5 mm Muzzle velocityMk I 1 425 feet per second 434 m s 2 Mk II 1 575 feet per second 480 m s 3 Maximum firing rangeMk I 6 000 yards 5 500 m Mk II 6 500 yards 5 900 m Contents 1 Design 2 Naval service 3 Ammunition 4 See also 5 Surviving examples 6 Notes and references 7 Bibliography 8 External linksDesign edit nbsp Mark I gun barrel constructionThe gun originated from a desire for a longer 12 in 30 cm gun than the existing RML 12 inch 35 ton gun Experiments in 1874 with both 12 in 30 cm and 12 5 in 32 cm versions 3 ft 91 cm longer than the existing 12 in 30 cm gun showed the 12 5 in 32 cm calibre was more suitable and further experiments showed a projectile of 800 lb 360 kg could be fired with a charge of 130 lb 59 kg of P2 gunpowder without undue strain The same construction as in the existing 12 in 30 cm 35 ton gun was used a mild steel A tube toughened in oil surrounded by wrought iron B tube triple coil in front of the trunnion coiled breech piece and breech coil This was approved in January 1875 4 The gun was rifled on the Woolwich pattern of a small number of broad shallow rounded grooves with 9 grooves increasing from 0 to 1 turn in 35 calibres i e 1 turn in 437 5 in 1 111 cm Mark II had an enlarged powder chamber and attained higher muzzle velocity and slightly longer range This gun was the final development of large British rifled muzzle loading guns before it switched to breechloaders beginning in 1880 It was succeeded in its class on new battleships by the BL 12 in 30 cm Mk II gun Naval service editGuns were mounted on HMS Dreadnought commissioned in 1879 HMS Agamemnon commissioned in 1883 and HMS Ajax commissioned in 1885 the last British warships completed with muzzle loading guns Ammunition editWhen the gun was first introduced projectiles had several rows of studs which engaged with the gun s rifling to impart spin Sometime 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 nbsp 1 nbsp 2 nbsp 3 nbsp 4 nbsp 5 nbsp 6 nbsp 7 nbsp 8 nbsp 9RML 12 5in Studded Shell located at Hurst Castle UK RML 12 5in Studded Shrapnel Shell Mk I with Attached Gas Check Mk I RML 12 5in Studded Palliser Shell Mk III with Attached Gas Check Mk II RML 12 5in Studded Common Shell Mk I with Attached Gas Check Mk II RML 12 5in Studded Shrapnel Shell Mk I with Attached Gas check Mk II RML 12 5in Case Shot Mk III RML 12 5in Studless Palliser Shell Mk I with Automatic Gas Check RML 12 5in Studless Common Shell Mk I with Automatic Gas Check RML 12 5in Studless Shrapnel Shell Mk I with Automatic Gas checkImages 3 9 show the range of ammunition for the RML 12 5 inch gun in 1885 5 By this time the gun no longer fired studded ammunition without gas checks Instead there were two sets of ammunition available namely older studded ammunition with attached gas checks Mk II and newer studless ammunition with automatic gas checks Case ammunition neither was studded nor required gas checks Also by this time attached gas checks Mk I as shown in image 2 had been superseded by attached gas checks Mk II See also editList of naval gunsSurviving examples editTwo at Hurst Castle UK originally at Cliff End Battery At Fort Nelson Portsmouth UK originally at Cliff End Battery Outside Fort Albert Isle of Wight No 22 of 1876 outside Calbourne Mill Isle of Wight originally at Cliff End Battery An unpreserved gun at Fort Delimara Malta Gun on replica carriage at Harding s Battery Gibraltar Gun number 87 and 95 dated 1878 Now in the ditch at Fort Cunningham BermudaNotes and references edit Treatise on Construction of Service Ordnance 1877 page 292 1 425 feet second firing 800 pound projectile with Battering charge of 130 pounds P2 gunpowder Treatise on Construction of Service Ordnance 1877 page 347 Muzzle velocity of 1 575 feet second firing an 809lb 6oz projectile with a charge of 210 pounds Prism2 black powder is quoted for Mark II gun in Text Book of Gunnery 1887 Table XVI Treatise on Construction of Service Ordnance 1877 pages 286 287 Handbook for RML 12 5 inch gun 1885 pp 32 33 Plates XI XIVBibliography editTreatise 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 Sectretary of State for War 1885 Handbook for the R M L 12 5 inch 38 ton Gun Marks I and II London Her Majesty s Stationery Office External links edit nbsp Wikimedia Commons has media related to RML 12 5 inch 38 ton naval gun Handbook for the R M L 12 5 inch 38 ton gun marks I and II casemate dwarf and small port mountings land service Great Britain War Office London H M S O 1885 at State Library of Victoria Handbook for the 12 5 inch 38 ton R M L gun marks I and II casemate dwarf and small part mountings land service 1888 1893 1899 1904 at State Library of Victoria Diagram of gun on small port 6 foot recoil carriage at Victorian Forts and Artillery website Diagram of gun on Casemate Platform 6 feet recoil Mark III at Victorian Forts and Artillery website Diagram of gun on Dwarf C Pivot Mark III at Victorian Forts and Artillery website Retrieved from https en wikipedia org w index php title RML 12 5 inch 38 ton gun amp oldid 1187162416, wikipedia, wiki, book, books, library,
