The Johore Battery was a former British coastal artillery battery located in Changi on the easternmost side of mainland Singapore. It consisted of three large BL 15-inch Mk. I naval guns installed on land by the British government in the late 1930s to defend the approaching path to the east of the island to their large naval base located at Sembawang in the north (accessed via the Johor Straits ) from an attacking enemy naval force.
60-835: Five massive 15–inch naval guns were installed in Singapore by the British government before 1940, with three based in Changi to the east and two located in Buona Vista to the southwest. Collectively, the three naval guns in Changi formed the Johore Battery , named after the King of Johor, Sultan Ibrahim , who gave King George V of the UK a grand royal gift of £500,000 for his Silver Jubilee in 1935, of which £400,000 of
120-510: A 1 ⁄ 4 charge, to make up the full service charge. Howitzer cartridges, both BL and separate QF, contained a central core of cordite surrounded by several stacked ring-shaped bags of cordite. To obtain the appropriate "charge" for the required range and angle of elevation, the gunner discarded one or more rings before loading. See charge for how Ordnance QF 25-pounder charges varied in World War II. The case, usually brass, holding
180-403: A 15-inch gun was approximately 335 full charge firings using standard charges, after which it had to be re-lined. All shipboard mounts of the gun were in twin turrets. All mountings were designated Mk I, with an as-built maximum elevation of 20°, though some were subject to later modifications. HMS Hood, however, had its guns in a unique mounting, designated Mk II. Incorporating experience from
240-438: A Crossley pad with an interrupted thread screw block e.g. a Welin screw . The shell was loaded via the breech, followed by the propellant charge in a cloth bag. A single-use " vent sealing tube ", a type of primer not dissimilar in appearance to a blank rifle round, was inserted into the breech for firing the gun. While originally, the term "BL" contrasted with "ML", or " muzzleloader " guns, after muzzleloaders were discontinued,
300-420: A cartridge case containing a reduced charge, and an attached star shell. British explosive shells filled with Lyddite were initially designated "common lyddite" and beginning in 1896 were the first British generation of modern "high explosive" shells. Lyddite is picric acid fused at 280 °F (138 °C) and allowed to solidify, producing a much denser dark-yellow form which is not affected by moisture and
360-461: A cloth bag, usually silk. The "stick" nature of cordite gave the cartridges a degree of rigidity and hence they retained a tubular shape and could be handled and loaded as a solid unit even without a case. With BL, cordite is contained in one or more cloth bags joined together. The complete unit is termed a cartridge. The empty bag was termed an "empty cartridge". Heavy naval guns may require up to four separate cartridges to be loaded, each consisting of
420-477: A dummy 15-inch shell, placed upon a modern large lifting-lever; allowing visitors to have a feel of its 800kg weight by trying to hoist it up from the ground. The old, and still inaccessible, tunnels are marked out in a maze of above ground trails. A plaque detailing the history of the battery is present at the hut forming the entrance to the site. Admission to the site of the battery is free with opening hours 09:00 to 17:00 Monday to Friday. The compound also includes
480-403: A full service charge for his gun, and cartridge Z to fire a star shell. Cartridges were sometimes made up of fractions of charges e.g. a 6-inch (152 mm) gun cartridge may be made up of two half charges or one two-fifths and one three-fifths laced together. A gun normally fired all rounds using the full charge, and varied the range by elevating or depressing the barrel. A howitzer gunner's job
540-473: A new gun's development were bypassed, and it was ordered straight from the drawing board. Despite its hurried development process, the gun met all expectations and was a competitive battleship main armament throughout both World Wars. According to an American report produced after World War II, the British 15 inch Mk I was the most reliable and accurate battleship main armament of the war, though other guns and mountings had superior individual features. The barrel
600-599: A restaurant. . BL 15 inch Mk I naval gun The BL 15-inch Mark I succeeded the BL 13.5-inch Mk V naval gun . It was the first British 15-inch (380 mm) gun design and the most widely used and longest lasting of any British designs, and arguably the most successful heavy gun ever developed by the Royal Navy . It was deployed on capital ships from 1915 until 1959 and was a key Royal Navy gun in both World Wars. The BL 15-inch Mk I, designed by Vickers, Son, and Maxim in 1912,
660-457: A revolving weight of 855 tons. The Mk II mounts of HMS Hood had a revolving weight of 860 tons. The BL 15-inch Mark I gun proved its effectiveness at the Battle of Jutland in 1916, scoring hits out to 19,500 yards (17,800 m), a record for naval gunnery at that time. In World War II the gun was responsible for the longest range shell-hit ever scored by one battleship on another in combat. At
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#1732855304224720-552: A strong and a powerful navy by the later part of the 1930s and was expanding deeper and deeper into China), the Johore Battery is a large gun emplacement site consisting of a labyrinth of tunnels. These tunnels were used to store quantities of ammunition for the three 15-inch guns (most of which were of the armour-piercing (AP) type rather than the high-explosive (HE) type as these naval guns were intended to be employed against heavily armoured enemy warships). These naval guns were
780-402: A system by which multiple small metallic-cased charges were loaded and fired at the same time. Using multiple small fabric bags also allows the gunners to use a reduced charge if need be. The term "BLC" stood for "BL converted" and referred to a breech and breech mechanism modified from an early long-screw three- or four-motion to modern short-screw single-motion. An example is the conversion of
840-417: Is above the deck. This allows for a lower profile for a turret , meaning that the turrets need not be superfiring (i.e. they can be mounted on the same deck and not obstruct each other at high angles of elevation). The term BL, in its general sense, stood for breech loading , and contrasted with muzzle loading. The shell was loaded via the breech (i.e. the gunner's end of the barrel, which opened) followed by
900-562: Is assigned an effective full charge (EFC) value of "one*. Other round combinations are assigned lesser values derived from testing and experience. If a gun barrel is capable of firing three different round types: round A (EFC = 1); round B (EFC = 0.75); and round C (EFC = 0.25), and if 100 of each round type is fired, then the barrel is said to have fired (100×1.00) + (100×0.75) + (100×0.25) = 200 EFCs. If it had previously been determined from testing and experience that this type of barrel has an estimated wear life of 250 EFCs, this specific barrel
960-458: Is at about 80% of its useful life. Plans would be made to order a replacement barrel within the time an additional 50 EFCs were expected to be fired. However the actual decision to retire any specific barrel would be made on examination and measurement of actual wear rather than that predicted by the EFC count. In practice, a barrel might be replaced before reaching its EFC life, or the limits of wear. In
1020-443: Is easier to detonate than the liquid form. Its French equivalent was "melinite", Japanese equivalent was " shimose ". Common lyddite shells "detonated" and fragmented into small pieces in all directions, with no incendiary effect. For maximum destructive effect the explosion needed to be delayed until the shell had penetrated its target. Early shells had walls of the same thickness for the whole length, later shells had walls thicker at
1080-433: Is synonymous with " round ". For separate QF artillery, cartridge referred to the cartridge case, its primer, propellant charge, and the disposable lid and fastener of the case. In BL artillery terminology, cartridge referred to the propellant unit only – there was no case. British cartridges contained gunpowder until about 1892, and thereafter sticks of cordite bound together with an igniter pad, if necessary, in
1140-505: Is usually equivalent full charge) Gun barrels naturally experience internal wear when fired, caused by mechanical wear from the projectile moving along the barrel, and thermal and chemical wear from propellant gases. This wear can reduce muzzle velocity and hence range, affect accuracy, produce unstable projectile flight, and, eventually, cause the gun barrel to fail. Most guns are capable of firing different types of ammunition with varying charges, and not all of these combinations produce
1200-692: The Battle of Calabria on 9 July 1940, HMS Warspite gained a hit on the Italian battleship Giulio Cesare with her first salvo at 26,400 yards (24,100 m). In the Attack on Mers-el-Kébir , when the French fleet was largely neutralised following the fall of France to the Germans, the BL 15-inch Mark I gun (arming HMS Hood , HMS Valiant and HMS Resolution )
1260-417: The BL 15-pounder to BLC 15-pounder . Calibre radius head: the radius of a circle with the curve of the shell's nose on its circumference, expressed in terms of the shell's calibre. The longer and more pointed (and hence streamlined) the shell's nose, the higher the C.R.H. Typical C.R.H. for British shells leading up to World War I was two: e.g. the curve of the nose of a two C.R.H. 6-inch (152 mm) shell
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#17328553042241320-752: The Battle of Jutland , the Mk II mounting had a maximum elevation of 30°, thus increasing the maximum range. In the 1930s a modification of the Mk I mounting, designated the Mk I (N), was introduced for use in those capital ships that were completely reconstructed. The Mk I (N) mounting also increased the maximum elevation from 20° to 30°. Maximum range in shipboard mountings was 33,550 yards (30,680 m) (30° elevation). During World War II unreconstructed older battleships, with gun elevation limited to 20°, were supplied with supercharges to increase their maximum range to 29,930 yards (27,370 m) at 2,638 ft/s (804 m/s) using
1380-572: The Imperial War Museum in London. British ordnance terms#Wire-wound This article explains terms used for the British Armed Forces ' ordnance ( weapons ) and ammunition . The terms may have different meanings depending on its usage in another country's military. Between decks: applies to a naval gun mounting in which part of the rotating mass is below the deck, and part of it
1440-490: The Mk XVIIB or Mk XXII projectile, while HMS Vanguard could theoretically range to 37,870 yards (34,630 m) while using supercharges at a gun elevation of 30°. Coastal artillery mountings with higher elevations could reach 44,150 yards (40,370 m). The Mk I mounting had a revolving weight of 750 tons (1915) and 785 tons (1935). The Mk I (N) had a revolving weight of 815 tons; the Mk I (N) RP12 mounts of HMS Vanguard had
1500-566: The amount was used by the British government to fund the installation of the three large naval guns in Changi. In early 1942, the Johore Battery was employed in the Allied artillery bombardment of Johor Bahru , which at that time was under Japanese military occupation following the retreat of all Allied forces from British Malaya to Singapore. Built by the British government in 1939 for the naval defence of Singapore (in particular, to defend Singapore from an aggressive Imperial Japan , which had possessed
1560-432: The base and thinning towards the nose. This was found to give greater strength and provide more space for explosive. Later shells had 4 c.r. heads , more pointed and hence streamlined than earlier 2 c.r.h. designs. Proper detonation of a lyddite shell would show black to grey smoke, or white from the steam of a water detonation. Yellow smoke indicated simple explosion rather than detonation, and failure to reliably detonate
1620-455: The case of the 15-inch (381 mm) guns fitted to the World War I Marshal Ney-class monitors a gun was generally condemned when wear reached about 0.74 in (19 mm) at 1 in (25 mm) from the start of the rifling. However it was the usual practice to replace guns when their projected remaining life fell below the ship's normal full outfit of ammunition per gun, which ensured that
1680-622: The common shell's nose fuze. The ogival two C.R.H. solid pointed nose was considered suitable for attacking shipping but was not armour-piercing - the main function was still explosive. They were of cast or forged (three- and six-pounder) steel and contained a gunpowder bursting charge slightly smaller than that of a common shell, a tradeoff for the longer heavier nose. In British service common pointed shells were typically painted black, except 12-pounder shells specific for QF guns which were painted lead colour to distinguish them from 12-pounder shells usable with both BL and QF guns. A red ring behind
1740-428: The correct dimensions but progressively weakened the case. Charge was a concept or category label rather than a specific item. It can be described as "the standard amount of propellant specified to carry out a particular purpose": For practical purposes, specific cartridges were specified for use to obtain the required charge. A gunner dealt with cartridges and would know that he could load (e.g.) cartridge X or Y for
1800-421: The entire magazine could be safely fired in action. This was the term for a gun together with its gun carriage , i.e. the complete set of equipment needed to be able to fire the gun, as the gun could only be fired when mounted on its correct carriage. The carriage could be a wheeled carriage, a static siege carriage or include both a traversing mounting and railway wagon in the case of a railway gun. For example,
1860-403: The explosive shell designation. Common lyddite shells in British service were painted yellow, with a red ring behind the nose to indicate the shell had been filled. For shellite, a successor of lyddite, see HE below. Common pointed shells, or CP were a type of common shell used in naval service from the 1890s to the 1910s which had a solid nose and a percussion fuze in the base rather than
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1920-399: The general sense, but in the formal nomenclature it separated 6-inch (152 mm) guns with breeches designed for charges in brass cartridge cases for quick-firing QF from those designed for cloth bag charges for breech-loaders BL . Shells designed for one type were not necessarily suitable for use in the other type; for instance, a BL shell relied upon the tight fit of its driving band in
1980-404: The gun bore to prevent it slipping back when the gun was elevated, but a QF shell could rely upon the cartridge case, either fixed or separate, to prevent it slipping back. This presented difficulties for BL guns at high angles. A special cartridge was developed for BL 9.2-inch (234 mm) guns on HA mountings, with provision for a wooden ( beech ) stick to be inserted through the centre to prevent
2040-519: The interior of shells had to be varnished, the exterior had to be painted with leadless paint and the fuze-hole had to be made of a leadless alloy. Fuzes containing any lead could not be used with it. When World War I began Britain was replacing lyddite with modern "high explosive" (HE) such as TNT. After World War I the term "common lyddite" was dropped, and remaining stocks of lyddite-filled shells were referred to as HE (high explosive) shell filled lyddite. Hence "common" faded from use, replaced by "HE" as
2100-456: The largest to be installed on land outside of Britain itself during World War II. They were all destroyed before the official surrender of the British Army on 15 February 1942 to the conquering Imperial Japanese military and the related tunnels (for the storage of the ammunition for the guns and gun-crew quarters) were sealed up and almost forgotten after the war in 1945. In 1948 one of the guns
2160-520: The last battleship to be built for the Royal Navy , completed in 1946. Warships armed with the BL 15-inch Mark I gun: 186 guns were manufactured between 1912 and 1918. They were removed from ships, refurbished, and rotated back into other ships over their lifetime. Two guns, one formerly from HMS Ramillies (left gun) and the other originally mounted in HMS ; Resolution , but later moved to HMS Roberts (right gun), are mounted outside
2220-430: The late 1890s, but some stocks remained as late as 1914. In British service common shells were typically painted black with red bands behind the noses to indicate the shells were filled. Central pivot: was applied to a naval gun mounting that rotates around a central pivot that could be bolted to the deck without any structural alterations being required. The abbreviation cwt stands for hundredweight , which, despite
2280-611: The name, is equal to 112 pounds (51 kg), and signifies the weight of the gun barrel and breech. It is sometimes included in the name of a gun to differentiate it from other guns of the same calibre or weight of shot. For example, the QF 12-pounder 18 cwt naval gun is a different (and heavier) weapon than the QF 12-pounder 8-cwt Mk I naval gun , though they both fire shells of the same approximate weight (12 pounds (5.4 kg)). The director-control tower (DCT in British usage or "director" in US usage)
2340-550: The nose indicated the shell was filled. By World War II they were superseded in Royal Navy service by common pointed capped (CPC) and semi-armour piercing ( SAP ), filled with TNT. "Common shell" is a designation for early 19th century British explosive shells filled with "low explosives" such as "P mixture" (gunpowder) and usually had the fuzes located in the nose. Common shells on bursting (they did not "detonate") tended to break into relatively large fragments which continued along
2400-405: The propellant charge, and the breech mechanism was closed to seal the chamber. Breech loading, in its formal British ordnance sense, served to identify the gun as the type of rifled breechloading gun for which the powder charge was loaded in a silk or cloth bag and the breech mechanism was responsible for "obturation" i.e. sealing the chamber to prevent escape of the propellant gases. The term BL
2460-410: The propellant charge. Used with small arms and QF artillery ammunition. The QF cases in 1915 could be cleaned and then reloaded up to a maximum of six firings with Cordite charges, with the record detailing the "life of the case" marked on the base. The limitation on the number of firings was due to the case expanding on firing, having to be "rectified" by turning metal off the lower part, which restored
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2520-399: The same firing damage per round fired. The concept of ‘effective full charge’ provides a means of estimating the remaining life of a gun barrel taking into account the varying charges that can be fired from it before it becomes so worn as to be unusable, or no longer safe. To illustrate, the round (i.e. the combination of projectile and propelling charge) that produces the most firing damage
2580-447: The shell slipping back on elevation. Although fixed ammunition allows for a rapid rate of fire in small to medium guns, BL is a better choice for heavy calibre guns; propellant was loaded in a number of small fabric bags, because a single bag holding the full charge would be far too big and bulky for the handlers to lift. Using fabric allows for the charge to be broken into small, easily handled units, while it would be difficult to design
2640-557: The shell's trajectory rather than laterally. They had some incendiary effect. In the late 19th century "double common shells" were developed, lengthened so as to approach twice the standard shell weight, to carry more powder and hence increase explosive effect. They suffered from instability in flight and low velocity and were not widely used. As at 1914, common shells 6 inches (152 mm) and larger were of cast steel, smaller shells were of forged steel for service, and cast iron for practice. They were replaced by "common lyddite" shells by
2700-468: The standard 25-pound (11 kg) shell came ready-loaded with a red bag at the bottom containing the basic charge (charge one), together with white and blue bags laid lengthwise, as in a conventional gun charge, to make up the full service charge (charge three). The blue and white bags could be removed to provide progressively reduced charges (charge two and charge one). From 1944 one or two 4-ounce (110 g) "intermediate charge increments" could be added to
2760-469: The standard charge (replacing the blue bag) for high-angle fire and to provide greater control over angle of shell descent. For small arms or fixed QF ammunition, where the charge could not be varied by the gunner, the term charge was used to identify the Cordite propellant within the cartridge case, and the round as a whole was referred to as a full or reduced charge. E.g. an 18-pounder star round consisted of
2820-485: The term breech-loaders BL has applied exclusively to the type of breechloader introduced from 1880 onwards, using an interrupted-screw breeches. Early British Elswick breechloaders in the 1880s used a steel "cup" obturation method. This was quickly superseded in guns designed by the Royal Gun Factory by the French de Bange method, the basic principle of which is still in use today. In British service this became
2880-432: The term came to distinguish between traditional, non- obturating guns with fabric propellant bags and separately loaded shells , and quick-firing QF guns which used self-sealing brass cartridge cases, and which usually had the propellant and projectile fixed together as a unit for faster handling and loading. For instance, Britain before World War I had both QF and BL 6-inch (152 mm) guns. Both were "breech loading" in
2940-655: Was 42 calibres long (i.e., length of bore was 15 in x 42 = 630 in) and was referred to as "15 inch/42". Overall length of gun: 650.4 inches, Weight of gun, excluding breech mechanism: 97 tons 3cwt. Weight of breech mechanism: 2 tons 17cwt. Rifling: polygroove, 76 grooves, uniform right-hand twist of one turn in 30 calibres. This wire-wound gun fired at a muzzle velocity of 2,450 ft/s (750 m/s) (4 crh shell), 2,640 ft/s (6 crh shell) with supercharge. Weight of shell: 1,920 lbs (4 AP crh shell), 1,938 lbs (6 crh AP shell – 1937). Weight of charge: 428 lbs cordite, 490 lbs cordite for supercharge. The firing life of
3000-439: Was a feature of naval ships. It was a trainable turret incorporating the gun-laying sights and often a rangefinder . From here the gunnery officer could select targets and take the range, bearing and rates of change. This data would be provided to the transmitting station (TS), where a firing solution would be calculated and passed on to the gun turrets as the correct degree of training and elevation. (Note: The British Army term
3060-453: Was a problem with lyddite, especially in its earlier usage. To improve the detonation "exploders" with a small quantity of picric powder or even of TNT (in smaller diameter shells, such as in 3-pounder and 12-pounder guns) was loaded between the fuze and the main lyddite filling or in a thin tube running through most of the shell's length. Lyddite presented a major safety problem because it reacted dangerously with metal bases. This required that
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#17328553042243120-409: Was an enlarged version of the successful BL 13.5-inch Mk V naval gun . It was specifically intended to arm the new Queen Elizabeth -class battleships as part of the British response to the new generation of Dreadnought battleships Germany was building, during the naval arms race leading up to World War I. Due to the urgency of the times, the normally slow and cautious prototype and testing stages of
3180-630: Was demolished and returned to England as scrap. In 1950 the Royal Army Ordnance Corps began an exercise to remove live gun shells that were buried at Changi during the British evacuation in 1942. The location remained unknown until the Singapore Prisons Service discovered them by chance in April 1991. The former site of the Johore battery now includes a replica of the large naval gun and
3240-400: Was designed so that one or more rings could be quickly removed and discarded before loading, hence providing progressively smaller charges. E.g. if the gunner on a QF 4.5-inch howitzer was ordered to load charge four, he would know he had to remove the top ring from the cartridge, leaving four rings; for charge three he would remove two rings. Discarded rings were burned after the action. This
3300-410: Was equivalent to the curve of a circle with a radius of 12 inches (300 mm). Shells of four C.R.H. were soon developed in World War I, identified by an A following the shell mark number, B for six, and so on. For modern streamlined shells post-World War I, two numbers were necessary to more correctly denote a shell's C.R.H. characteristics. For instance, the World War I 6-inch 26 cwt howitzer shell
3360-528: Was first used to refer to the Armstrong breechloaders , introduced in 1859. Following the discontinuation of Armstrong breechloaders and the period of British rifled muzzle-loaders RML , British breechloaders were re-introduced in 1880. At this point the term rifled breech-loaders RBL was retrospectively introduced to refer to the Armstrong breechloaders, which had a totally different breech mechanism, and since then
3420-411: Was more complicated because the range table would specify different "charges", or fractions of the full service charge, for different ranges and angles of shell descent. The standard cartridge for his gun, which as a whole made up the full service charge, would consist of a central "mushroom" cordite core and several smaller cordite rings in bags stacked around the core like doughnuts, all tied together. It
3480-472: Was responsible for the destruction by a magazine explosion of the old battleship Bretagne , and the disabling and beaching (deliberate running aground in shallow water) of the old battleship Provence and the new battleship Dunkerque . Dunkerque' s main 225mm armour belt was twice penetrated by 15-inch shells, which destroyed its fighting and steaming abilities. These guns were used on several classes of battleships from 1914 until HMS Vanguard ,
3540-512: Was the standard procedure for howitzers up to and including World War II. In World War II a different system was introduced for varying charges for the QF 25 pounder gun-howitzer , which used separate-loading QF ammunition. A separate 2.7-pound (1.2 kg) "super charge" cartridge was available for firing the 20-pound (9.1 kg) high-velocity anti-tank AP shot, and an additional 4.5-ounce (130 g) "super charge increment" could be added to that for even higher velocity. The cartridge for firing
3600-515: Was two C.R.H., and the World War II Mk 2D shell was referred to as "5/10 C.R.H.". "Cartridge" in British ammunition terminology typically refers to the physical object containing the propellant that a gunner loads. For small arms and fixed QF artillery ammunition, e.g., the .303 or 18-pounder respectively, this denoted the complete round, that is, the cartridge case, percussion cap or primer, propellant charge and projectile. In this use it
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