15 cm MRK L/40

15 cm MRK L/40 15 cm Kanone L40 C89 in Mittel-Pivot-Schiffs-Lafette 1890 91124---0018.jpg 300px A 15 cm MRK L/40 C/89 in 1890 German Empire yes yes yes Norway (In a test) Krupp 1889 Krupp 1890 2+ 5,300 kgAlmanach 1892 64 5,960 mm (L/40)Almanach 1892 64 149.1 mmAlmanach 1892 64 Pattern C/80: 685 m/s (light grenade) 610 m/s (heavy grenade)Almanach 1892 65 The 15 cm Mantel Ring Kanone L/40 or 15 cm Kanone L/40 was basically a rare, slightly longer version of the 15 cm MRK L/35. It was a long rifled breech loader built-up gun with a Krupp cylindroprismatic sliding breech. Shortly after its introduction, Krupp introduced quick-firing guns of 15 cm caliber, making the 15 cm MRK L/40 practically obsolete. Development The 15 cm MRK L/35 15 cm MRK L/35 thumb|The gun on a photo bearing the year 1888 In March 1882, the first 15 cm Mantel Ring Kanone L/35 was tested in Meppen alongside the new 30.5 cm MRK L/35. It had two conspicuous characteristics: its great length and the great length (L/4) of the projectiles that it fired. The effect of the increased length of the gun was almost obvious, i.e. the velocity of the projectile increased. The effect of the longer and therefore heavier projectiles was less obvious. The total energy with which the longer projectiles left the barrel was about the same as that of the shorter projectiles. However, the longer projectiles of the same caliber were slowed down by drag only a little more than the shorter ones. Which meant that at realistic combat distances, both projectiles had lost a lot of their velocity, but the longer projectile retained the punch of its weight.Schwarz 1882 389 The 15 cm MRK L/40 Not much was published about the development of the 15 cm MRK L/40. It showed up in a table about the Krupp Pattern 1886 (C/86) guns. This showed data about guns from 10.5 to 40 cm caliber with lengths of L/35 and L/40. By this table, the 15 cm L/40 would have a weight of 7,600 kg and use a charge of 28.5 kg.Almanach 1890 62 The fact that this table gave a uniform velocity of 640 m/s for all calibers from 10.5 to 40 cm, shows that this was a design, not a summary of guns that had actually been built and tested. Some years later, tables about the Krupp guns of the C/87 and C/89 pattern were published. These also contained a 15 cm MRK L/40, but suffer from the same defect: they were calculations, not data about guns that had been built. This is again shown by the uniform velocity of the guns.Almanach 1892 64 Because it is known that at least one C/89 model was built, the characteristics section is based on the C/89 pattern. From 15 July 1889 till 1 March 1890, Krupp tested the recently invented smokeless powder, a new more effective type of propellant. During these extensive tests, about 20 guns were used. There was no mention of a 15 cm L/40.Schiessversuche 1890 367 From two photographs bearing the years 1888 and 1890, we know that at least two 15 cm MRK L/40 were built. The photo of a 15 cm L/40 gun bearing the year 1888 does not give much more information than that it was a 15 cm L/40 gun on a centre pivot naval carriage. It could be a gun constructed to the C/86 or C/87 pattern.Almanach 1892 64 The problem is that it is not clear what the years printed on official Krupp gun photographs mean. These years could refer to the year that the photo was made, but they could also refer to the year that the gun was designed. The only thing that is sure, is that the image cannot depict the C/89 version of the gun. The other photo of a 15 cm L/40 gun bears the caption '15 cm gun L/40 C/89 on centre pivot naval carriage' and the year 1890. It therefore shows a 15 cm MRK L/40 gun constructed according to the 1889 pattern. The C/89 data is used in the characteristics section. So far, we know only about a single 15 cm MRK L/40 leaving the Krupp premises. This is the Norwegian 15 cm MRK L/40 described below. It was described as an M88 model built in 1891, which makes it difficult to link it to either of the photos.Information 1892 89 Characteristics The barrel The barrel of the 15 cm MRK L/40 C/87 was 5,960 mm long. The length of bore was 5,540 mm. The barrel weighed 5,300 kg.Almanach 1892 64 The barrel of the 15 cm MRK L/40 C/89 was to be of the same dimensions, but to weigh 5,650 kg, or 350 kg more.Almanach 1892 66 The carriage The front or centre pivot carriage of the C/87 gun weighed 5,700 kg.Almanach 1892 64 For the C/89, this was to be 6,000 kg.Almanach 1892 66 Projectiles The 15 cm MRK L/40 C/87 could fire the old short grenades and the new longer (L/4) grenades. It used a charge of 19 kg of gunpowder. With that, the old 2.8 caliber long steel grenade was propelled to 685 m/s. The heavy 3.5 caliber long steel grenade got a velocity of 610 m/s.Almanach 1892 65 The 15 cm MRK L/40 C/89 would use a charge of 22 kg. This would give the old L/2.8 steel grenade a velocity of 720 m/s. The heavy L/3.5 grenade would attain a velocity of 630 m/s.Almanach 1892 67 Use Norway The Norwegian navy's gunboat Viking 1891 6 was meant to be armed with two 15 cm MRK L/40.Barnes 1892 253 One of these was a C/88 gun made in 1891. During trials in Horten the barrel burst on 18 September 1891, killing one man and severely wounding an officer.Information 1892 89 Previously, this particular gun had been test-fired by Krupp. With the projectiles of 112.2 lb kg on and charges of 58.3 lb kg on and 41.8 lb kg on of a very slow burning gunpowder. This gave velocities of 2070 ft m on and 1893 ft m on m/s.Information 1892 89 During these trials, pressures between 2,600 and 2,690 Atm were measured.Springen 1891 719 During the trials in Horten, the Norwegians used the prismatic gunpowder P.P. C/82. This gunpowder was used in the smaller charges for the previous 15 cm models. At first 14 rounds were fired with a reduced charge of 26.4 lb kg on, developing 11.8 tons of pressure. Then a fifteenth round was fired with a charge of 52.8 lb kg on.Information 1892 89 This caused the gun to burst at the breech block. During this fatal shot, a pressure of 7,400 Atm was measured and velocity was 637 m/s.Springen 1891 719 Notes 2 References 1890 Almanach für die K. und K. Kriegsmarine II. Theil Artillerie der verschiedenen Flotten Redaction der Mittheilungen aus dem Gebiete des Seewesens, Pola https://books.google.com/books?id=LrdtGk_RcHEC 35-65 Almanach 1890 1892 Almanach für die K. und K. Kriegsmarine II. Theil Artillerie der verschiedenen Flotten Redaction der Mittheilungen aus dem Gebiete des Seewesens, Pola https://books.google.com/books?id=xA5KrIcBDQYC 33-78 Almanach 1892 Barnes F.K. 1892 The Naval Annual Tables and plans of British and Foreign Armoured and Unarmoured Ships Griffin & Co. Portsmouth https://books.google.com/books?id=4_s_AAAAYAAJ 1892 General Information Series: Information from Abroad Notes on Ordnance Office of Naval Intelligence 81–159 https://books.google.com/books?id=MRZIAQAAIAAJ Information 1892 Schwarz Jos. 1882 Mittheilungen aus dem Gebiete des Seewesens Schiessversuche der Fr. Krupp'schen Gusstahlfabrik im März 1882 K.K. Hydrographischen Amte, Marine-Bibliothek, Pola 389–397 https://books.google.com/books?id=fkYrAwK2egcC 1890 Mittheilungen aus dem Gebeite des Seewesens Krupp'sch Schiessversuche mit rauchlosem Pulver K.u.K. Hydrographischen Amte, Pola 367–370 https://books.google.com/books?id=R-c5AQAAMAAJ Schiessversuche 1890 1891 Mitteilungen aus dem Gebiete des Seewesens Springen einer Krupp'schen 15 cm Kanone L/40 K. u K. Hydrographischen Amte, Pola https://books.google.com/books?id=o182AQAAMAAJ 719 Springen 1891 Category:Naval guns of Germany Category:World War I naval weapons Category:Military equipment introduced in the 1880s Category:Krupp naval guns