15 Vulpeculae
This is an Am star with a stellar classification of A4 IIIm, matching an evolved A-type giant star. However, Gray & Garrison (1989) found a class of kA5hA7mA7 (IV–V), which matches a blend of subgiant and main sequence luminosity classes with the K-line (kA5) of an A5 star and the hydrogen (hA7) and metal (mA7) absorption lines of an A7 star. It is an Alpha2 Canum Venaticorum-type variable with magnitude ranging from 4.62 down to 4.67 over a period of 14 days. The star is radiating 60 times the Sun's luminosity from its photosphere at an effective temperature of 8,084 K.


15 Westferry Circus
15 Westferry Circus is a 16,250 m2 (174,900 sq ft) building located on the upper level of Westferry Circus, Canary Wharf. Construction began in November 1998. Its finish marked the completion of the Westferry Complex, the westernmost point of Canary Wharf.


15 Westferry Circus
The building was designed to fully incorporate the requirements of the tenant, Morgan Stanley Dean Witter, who also occupied the adjoining building. Their lease began in March 2000, the same month Citigroup leased 25 Canada Square.


15 Westferry Circus
Morgan Stanley Dean Witter sublet the building to Tube Lines. They share the building leading to the video wall, built for use in stock trading but used as a Recovery Silver Control for the London Underground in the aftermath of the 7 July 2005 London bombings. In 2013 Morgan Stanley vacated the building and it was taken over by London Underground, who had taken over Tube Lines. London Underground vacated the building in 2017.


15 Westferry Circus
15 Westferry Circus serves as the fifteen mile (24 km) marker in the London Marathon.


15 Westferry Circus
The ownership of this building was the subject of a protracted legal dispute in Ireland in 2012.


15 Westferry Circus
As of 2018, Morgan Stanley is once again occupying two floors of the building, with another floor sublet to a tenant.


15 William
15 William, formerly known as the William Beaver House, is a 47-story, 528-foot-tall (161 m) condominium apartment building at 15 William Street in the Financial District of Manhattan, New York City. It opened in 2008, at which time it was the only ground-up residential development in the Financial District.


15 William
15 William was designed by the New York firms Tsao & McKown, Ismael Leyva Architects, and SLCE Architects, with interiors and public spaces designed by SPAN Architecture and Allied Works Architecture. It was developed by SDS Investments, Sapir Organization, André Balazs Properties, and CIM Group.


15 William, Site
15 William is located in the Financial District of Manhattan, at the northwest corner of William Street and Beaver Street. The block on which the building is located is bounded by Broad Street to the west, Exchange Placeto the north, William Street to the east, and Beaver Street to the south. The site at William and Beaver Streets was historically taken up by the Corn Exchange Bank in the early 20th century, and later by a 20-story office building, although the lot was vacant by the 1990s.


15 William, Design
15 William, initially known as the William Beaver House, was designed by Tsao & McKown, Ismael Leyva Architects, and SLCE Architects. The interior was designed by SPAN Architecture and Allied Works Architecture. The building was jointly developed by SDS Procida Development Group and André Balazs. The building is 528 feet (161 m) high, with 47 floors, and includes 320 residential units and two commercial spaces. There are 370,815 square feet (34,449.8 m2) of space in 15 William.


15 William, Design, Facade
The building has a brick exterior with dark grey and gold brick panels between the windows. Shears, staggers, and other components of the building's facade were incorporated into the building’s design to give apartments the most light and views in a part of the city that is densely built. Its general appearance has earned it the nickname "The Post-It Note Building".


15 William, Design, Features
According to two of the project's principal architects, Calvin Tsao and Zack Mckown, the condominium was designed as a "vertically integrated village" and a "self-sufficient place to live."


15 William, Design, Features
The interiors have open living spaces and bathrooms with separate rain showers and oversized deep-soaking tubs. Bedrooms and bathrooms are en suite with louvered doors.


15 William, Design, Features
The property includes a fitness center with an outdoor terrace and herb garden, squash court, yoga studio, boxing gym, indoor saltwater swimming pool, outdoor saltwater jacuzzi, sauna, steam room, an indoor children’s playroom, and an outdoor children's playground designed by Jean-Gabriel Neukomm of SPAN Architecture that includes a slate-clad wall for children to use as a chalkboard. The building also has a covered dog-run, landscaped roof deck, rooftop lounge with catering kitchen and views of Manhattan and the New York Harbor, event space, movie theater, an outdoor basketball court, and a resident’s library. Residents additionally have the option of renting private storage bins in the basement.


15 William, Design, Features
The ground floor of the building includes retail space with a deli and a subterranean parking lot.


15 William, History
Plans were filed with the New York City Department of Buildings in 2004, and announced to the public in May 2006; sales were launched later that year. In 2007, the building's three penthouses were each sold for prices ranging between $4.7 to $5 million, the highest price per square foot ever paid in the Financial District at the time. Work was completed in 2008.


15 William, Reception
In September 2016, Interior Design ranked 15 William one of the "5 Enviable Residential Buildings in New York." The building was ranked one of the "Top 50 Luxury Condos & Co-ops in Manhattan" by Manhattan Scout. New York Family included 15 William on its list of the most family-friendly buildings in New York City. The AIA Guide to New York City called the building "daring amidst the financial district's monochromatic canyons." In 2015, 15 William was featured in a series of articles in Domino Magazine where designers redecorated several apartments throughout the building.


15 Year Killing Spree
15 Year Killing Spree is a box set by the American death metal band Cannibal Corpse. The cover art contains demons and skeletons placed in windows in a castle surrounded by a moat of blood. Observant Cannibal Corpse fans will notice that the cover art, drawn by the usual artist Vincent Locke draws from the themes and features characters from previous Cannibal Corpse albums.


15 Year Killing Spree
In addition to the three CDs and DVD which are listed below, this boxed set also contains a poster of the band. Two thousand of the posters that were shipped with the boxed set were autographed by the band. The boxed set also contains a booklet with history and commentary by the band members as well as pictures from the band's history.


15 Year Killing Spree
15 Year Killing Spree also contains a comic book depicting the story behind one of Cannibal Corpse's most famous songs "Unleashing The Bloodthirsty" from their album Bloodthirst.


15 Years After
15 Years After is a box set by the musical project Enigma. It was released by Virgin Germany on 9 December 2005. The box set contains 8 discs, 5 of them original studio albums created from 1990 to 2003, 2 DVDs and a bonus CD of Enigma's songs covered by Rollo Armstrong.


15 Years After
As the title suggests, the box set's release was to celebrate the 15 years since the release of Enigma's first single, "Sadeness (Part I)". The album cover was taken from Lady with an Ermine, a 1490 painting by Leonardo da Vinci. The box set packaging and photography was done by Dirk Rudolph while artwork direction and original designs were created by Johann Zambryski, a long-time designer of Enigma artworks.


15 Years After
Originally the box set was sold at €128 and this raised a stir with fans of the project, since the discs were not remastered unlike the compilation album Love Sensuality Devotion: The Greatest Hits but were instead fitted with Copy Control. The new single, "Hello and Welcome" (from the unreleased 6th album A Posteriori) and The Dusted Variations disc also received mixed responses from the fans, who questioned the release of the album.


15 Years After
Additionally, the music video for "Out from the Deep" which was dropped from the Remember the Future DVD without an apparent reason, was still absent in this re-release, and despite the box set being 12-inch vinyl-sized, there were little information about the history of the project within the booklet, apart from the credits and a press release inside.


15 Years After
Later on, the price of the box set dropped to €92.99 and on 30 November 2005, the producer and creator of Enigma, Michael Cretu personally visited the EMI factory in Uden, Netherlands to sign a thousand copies of the box set. The thousand signed copies had Cretu's initials ("MC") signed with a silver marker. While signed copies of Enigma's albums are extremely rare, the autographed version of the box set was still available for purchase at Amazon.de half a year after its release. Also within the box set was a code which enabled owners of the box set to download the music videos of "Voyageur" and "Boum-Boum" by typing it in a special section within Enigma's official website, but is no longer available.


15 Years On
15 Years On is the eleventh studio album by the Irish folk band The Dubliners. This album was created to celebrate the band's 15th anniversary from the day they started music together. The album was released on the Chyme label in 1977. The album features 24 tracks on two records (nine of which were previously unreleased). In spite of having only nine previously unreleased tracks, it is still regarded as an original album.


15 Years On, Special Track Features
The group's line-up consisted of Barney McKenna, Luke Kelly, John Sheahan and Jim McCann. (Ronnie Drew and Ciarán Bourke feature on a number of the previously available tracks).


15 Years On, Mislabelled Instrumental Tracks
The tune labelled "Salamanca" is a medley of "The Snow on the Hills" (O'Neill 569) and "The Salamanca Reel"(O'Neill 603), from O'Neill's Dance Music of Ireland.


15 Years On, Tour
The 15 Years On Tour was a tour of Europe and Australia throughout 1977 in support of the album.


15 Years and One Day
15 Years and One Day (Spanish: 15 años y un día) is a 2013 Spanish drama film directed by Gracia Querejeta. The film was selected as the Spanish entry for the Best Foreign Language Film at the 86th Academy Awards, but it was not nominated.


15 Years on Death Row
15 Years on Death Row is a double album compilation released in 2006 by CEO of Death Row Recordings, Suge Knight. The release features several notable Death Row artists such as Snoop Dogg, Dr. Dre, 2Pac, Nate Dogg, Daz Dillinger, and The Lady Of Rage. A music video DVD is included. The album includes "G'z Up, Hoes Down", a Track from Snoop Dogg's Doggystyle album that was removed for sample clearance issues.


15 Years on Death Row, Track listing, Music Videos
1. Dr. Dre – Dre Day2. Dr. Dre – Nuthin' but a "G" Thang3. Dr. Dre – Let Me Ride4. Dr. Dre – Lil' Ghetto Boy5. Dr. Dre & Ice Cube – Natural Born Killaz6. Snoop Dogg – Who Am I (What's My Name)? 7 . Snoop Dogg – Gin and Juice (Laid Back Mx)8. Snoop Dogg – Doggy Dogg World9. Snoop Dogg – Vapors10. Snoop Dogg – Murder Was The Case11. Snoop Dogg – Doggfather12. Snoop Dogg – Snoop's Upside Ya Head13. Warren G – Regulate14.


15 Years on Death Row, Track listing, Music Videos
The Lady of Rage – Afro Puffs15. 2Pac – How Do U Want It16. 2Pac – All About U17. 2Pac – California Love (Original Version)18. 2Pac – California Love (Remix Version)19. 2Pac – I Ain't Mad at Cha20. 2Pac – Hit 'Em Up21. 2Pac – Made Niggaz22. 2Pac – To Live & Die in L.A.23. 2Pac – Toss It Up24. 2Pac – Hail Mary


15 Years: A Retrospective
15 Years: A Retrospective is the tenth Sons of the San Joaquin album. It contains three previously unreleased songs. According to the liner notes, the previously released material was "digitally re-mixed and re-mastered."


15 Years: A Retrospective, Track listing
All tracks are written by Jack Hannah, except where noted.


15 and 290 theorems
In mathematics, the 15 theorem or Conway–Schneeberger Fifteen Theorem, proved by John H. Conway and W. A. Schneeberger in 1993, states that if a positive definite quadratic form with integer matrix represents all positive integers up to 15, then it represents all positive integers. The proof was complicated, and was never published. Manjul Bhargava found a much simpler proof which was published in 2000.


15 and 290 theorems
Bhargava used the occasion of his receiving the 2005 SASTRA Ramanujan Prize to announce that he and Jonathan P. Hanke had cracked Conway's conjecture that a similar theorem holds for integral quadratic forms, with the constant 15 replaced by 290. The proof has since appeared in preprint form.


15 and 290 theorems, Details
Suppose Qij{\displaystyle Q_{ij}} is a symmetric matrix with real entries. For any vector x{\displaystyle x} with integer components, define


15 and 290 theorems, Details
This function is called a quadratic form. We say Q{\displaystyle Q} is positive definite if Q(x)>0{\displaystyle Q(x)>0} whenever x≠0{\displaystyle x\neq 0}. If Q(x){\displaystyle Q(x)} is always an integer, we call the function Q{\displaystyle Q} an integral quadratic form.


15 and 290 theorems, Details
We get an integral quadratic form whenever the matrix entries Qij{\displaystyle Q_{ij}} are integers; then Q{\displaystyle Q} is said to have integer matrix. However, Q{\displaystyle Q} will still be an integral quadratic form if the off-diagonal entries Qij{\displaystyle Q_{ij}} are integers divided by 2, while the diagonal entries are integers. For example, x2 + xy + y2 is integral but does not have integral matrix.


15 and 290 theorems, Details
A positive integral quadratic form taking all positive integers as values is called universal. The 15 theorem says that a quadratic form with integer matrix is universal if it takes the numbers from 1 to 15 as values. A more precise version says that, if a positive definite quadratic form with integral matrix takes the values 1, 2, 3, 5, 6, 7, 10, 14, 15 (sequence  in the OEIS), then it takes all positive integers as values. Moreover, for each of these 9 numbers, there is such a quadratic form taking all other 8 positive integers except for this number as values.


15 and 290 theorems, Details
is universal, because every positive integer can be written as a sum of 4 squares, by Lagrange's four-square theorem. By the 15 theorem, to verify this, it is sufficient to check that every positive integer up to 15 is a sum of 4 squares. (This does not give an alternative proof of Lagrange's theorem, because Lagrange's theorem is used in the proof of the 15 theorem.)


15 and 290 theorems, Details
is a positive definite quadratic form with integral matrix that takes as values all positive integers other than 15.


15 and 290 theorems, Details
The 290 theorem says a positive definite integral quadratic form is universal if it takes the numbers from 1 to 290 as values.


15 and 290 theorems, Details
A more precise version states that, if an integer valued integral quadratic form represents all the numbers 1, 2, 3, 5, 6, 7, 10, 13, 14, 15, 17, 19, 21, 22, 23, 26, 29, 30, 31, 34, 35, 37, 42, 58, 93, 110, 145, 203, 290 (sequence  in the OEIS), then it represents all positive integers, and for each of these 29 numbers, there is such a quadratic form representing all other 28 positive integers with the exception of this one number.


15 and 290 theorems, Details
Bhargava has found analogous criteria for a quadratic form with integral matrix to represent all primes (the set {2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 67, 73} (sequence  in the OEIS)) and for such a quadratic form to represent all positive odd integers (the set {1, 3, 5, 7, 11, 15, 33} (sequence  in the OEIS)).


15 and 290 theorems, Details
Expository accounts of these result have been written by Hahn and Moon (who provides proofs).


15 ans déjà...
15 ans déjà... is the 12th French studio album by Joe Dassin. It came out in 1978 on CBS Disques.


15 ans et demi
15 ans et demi (lit. '15 years and a half', also known as Daddy Cool) is a 2008 French comedy film by François Desagnat and Thomas Sorriaux, starring Daniel  Auteuil.


15 ans et demi, Critical reception
French reviewers considered the film a creditable French attempt at an American-style teen movie, derivative but entertaining on its own terms.


15 auténticos éxitos (Irma Serrano album)
15 auténticos éxitos (15 Authentic Hits) is a greatest hits album by Mexican singer Irma Serrano, released in 1984 by CBS Records International. It features Serrano's fifteen hit songs released from 1963 to 1967.


15 años de éxitos
15 Años De Éxitos is the first greatest hits album (sixteenth overall) from Mexican singer Alejandro Fernández this album contains 15 successful tracks from 8 of his previous albums (Piel De Niña, Que Seas Muy Feliz, Muy Dentro de Mi Corazón, Me Estoy Enamorando, Mi Verdad, Orígenes, Niña Amada Mía and A Corazón Abierto) in addition to the newly recorded track "El Lado Oscuro Del Amor" from the Mexican film "El Búfalo De La Noche". The CD/DVD edition brings in addition to the CD with the 16 tracks, a DVD with 6 videos of Alejandro Fernández.


15 chansons d'avant le déluge, suite et fin
15 chansons d'avant le déluge, suite et fin is a compilation by experimental French singer Brigitte Fontaine and French rock singer Jacques Higelin, released in 1976 on the Productions Jacques Canetti label.


15 chansons d'avant le déluge, suite et fin
It is an album of Boris Vian-penned songs recorded by Higelin and released on an EP in January 1966 and on an LP shared with Marie-José Casanova, also released in 1966. The nine Brigitte Fontaine songs come from her first album, 13 chansons décadentes et fantasmagoriques. Contrary to the first release co-billed to both artists, 1966's 12 chansons d'avant le déluge, none of the songs are duets. The Fontaine songs were only added to fill in because the Higelin songs were not enough to make an LP.


15 chansons d'avant le déluge, suite et fin, Track listing
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15 cm Autokanone M. 15/16
The 15 cm Autokanone M. 15/16 was a heavy field gun used by Austria-Hungary in World War I. Guns turned over to Italy as reparations after World War I were taken into Italian service as the Cannone da 152/37. Austrian and Czech guns were taken into Wehrmacht service after the Anschluss and the occupation of Czechoslovakia as the 15.2 cm K 15/16(t). Italian guns captured after the surrender of Italy in 1943 were known by the Wehrmacht as the 15.2 cm K 410(i). Due to their unique ammunition, the Germans did not use them that much, and generally served on coast-defense duties during World War II.


15 cm Autokanone M. 15/16, Design
The M. 15 was a thoroughly conventional design for its day with a box trail, iron wheels and a curved gunshield. It was notable as being the first Austro-Hungarian gun to be designed for motor transport, towed behind the M 17 'Goliath' artillery tractor, hence the Autokanone designation. For transport the barrel was generally detached from the recoil system and moved on its own trailer. The original M. 15 weapons had a maximum elevation of only 30°, but an elevation of 45° was demanded early in the gun's production run, mainly to engage high-altitude targets in the mountains. 27 M. 15 guns were completed before production switched to the improved M. 15/16 with greater elevation in the first half of 1917. A total of 44 barrels and 43 carriages were completed by the end of the war.


15 cm Autokanone M. 15/16, Design
It seems likely that surviving M. 15 guns were rebuilt after the war to M. 15/16 standards. During the Twenties, guns in Italian service were relined and given new wheels by Vickers-Terni. In June 1940 Italy had 29 Cannone da 152/37 in service. By the time of the Italian capitulation this number had declined to 17.


15 cm K (E)
The 15 cm Kanone in Eisenbahnlafette (gun on railroad mounting) (15 cm K (E)) was a type of German railroad gun used in the Second World War. They were used in the invasion of Belgium in 1940, but spent most of the war on coast-defense duties.


15 cm K (E), Design
This weapon was the first modern railroad gun to enter service with the Heer. The gun was mounted on a simple pivot mount on a ballrace on a well-base flatcar with four outriggers. In action the outriggers and their jacks would be dropped to stabilize the gun and absorb the firing recoil. In addition jacks locked the spring suspension, bore on the surface of the rails and screw clamps gripped the rails for more stability. The elderly 15 cm Schnelladekanone L/40 was used because it was available in some numbers.


15 cm K (E), Ammunition
The standard high-explosive shell was the 15 cm K Gr 18, a 43 kilograms (95 lb) nose-fuzed round containing 5.68 kilograms (12.5 lb) of TNT. An anti-concrete shell was also available, the 15 cm Gr 19 Be. It was a base-fuzed 43.5 kilograms (96 lb) shell with a TNT filler of 4.8 kilograms (11 lb), with a rounded sheet-steel ballistic cap.


15 cm K (E), Ammunition
A base propellant charge was combined with three increments to form three standard loadings, Small Load (Kleine Ladung) with a muzzle velocity of 600 metres per second (2,000 ft/s), Medium (Mittelere) with a muzzle velocity of 725 metres per second (2,380 ft/s) and Large (Grosse) with a muzzle velocity of 805 metres per second (2,640 ft/s).


15 cm K (E), Combat history
Two guns were damaged by premature detonations in their barrels on 20 May 1940 while bombarding Liège. They spent most of the war assigned to Artillery Battery (Artillerie-Batterie) 655 (E) in Belgium on coast-defense duties along the Channel coast.


15 cm K (E), Note
Sources are contradictory on the gun used and numbers produced of this weapon. The most recent source, François, has been generally been followed, not least because he cites serial numbers. Do not confuse this gun with those of Naval Artillery Battery (Marine-Artillerie-Batterie) "Gneisenau" that used a slightly more modern 15 cm SK L/45 gun with a gun shield.


15 cm Kanone 16
The 15 cm Kanone 16 (15 cm K 16) was a heavy field gun used by Germany in World War I and World War II. Guns turned over to Belgium as reparations after World War I were taken into Wehrmacht service after the conquest of Belgium as the 15 cm K 429(b). It generally served on coast-defense duties during World War II.


15 cm Kanone 16, Design
The K 16 was a thoroughly conventional design for its day with a box trail, steel wheels for motor transport and a curved gunshield. The axle was suspended on a traverse leaf spring. For transport the barrel was generally detached from the recoil system and moved on its own trailer. In 1941 a small number of K 16 barrels were placed on 21 cm Mrs 18 carriages to become the 15 cm K 16 in Mrs Laf.


15 cm Kanone 16, Ammunition
It fired 2 types of high-explosive shells, which differed only in which fuzes they could accept. It used a three part charge in its cartridge case. Charge 1 yielded a muzzle velocity of 555 metres per second (1,820 ft/s). Charge 2 replaced Charge 1 in the cartridge case and propelled the shell with a velocity of 696 metres per second (2,280 ft/s). Charge 3 was added to Charge 2 and raised the muzzle velocity to 757 metres per second (2,480 ft/s).


15 cm Kanone 18
The 15 cm Kanone 18 (15 cm K 18) was a German heavy gun used in the Second World War.


15 cm Kanone 18, Design and history
In 1933 Rheinmetall began development of a new artillery piece to fulfill a German Army requirement for a replacement of the aged 15 cm Kanone 16, with the first production units received in 1938. There was not much of an improvement over the older gun as it weighed two tons more than the K 16, but only had 2,290 metres (2,500 yd) more range. The army was happy with the range, but not with the carriage. There was a special transport carriage for just the gun when traveling long distances. Putting it on its turntable took even more time to assemble. The rate of fire was at best two rounds per minute.


15 cm Kanone 18, Design and history
Around a hundred were built between 1939 and 1943. It was not popular in service as it was regarded as too much gun for too little shell. This caused its production to be terminated in August 1943. Many were used in coastal installations.


15 cm Kanone 39
The 15 cm Kanone 39 (15 cm K 39) was a German heavy gun used in the Second World War. First deliveries began in 1940 to the Wehrmacht. In the Battle of France, only the independent Artillerie-Batterie 698 was equipped with the gun. For Operation Barbarossa, it served with the Artillerie-Abteilungen 680, 731, 740 and 800. A year later, for Fall Blau, they served with Artillerie-Abteilungen 511, 620, 680, 767 and 800.


15 cm Kanone 39, Design and history
Designed by Krupp as a dual-purpose heavy field and coast defence gun in the late-1930s for Turkey. Only two had been delivered before the rest were appropriated by the Heer upon the outbreak of World War II. In the coast defense role, it was provided with an elaborate portable turntable. This had a central platform and twelve radial struts that connected to an outer ring. In action, the trails would be locked together and put on a small trolley that rode on the outer ring. Coarse aiming was by cranking the trolley back and forth while fine laying was done by traversing the gun on its mount, up to the 6° limit imposed by the closed trails.


15 cm Kanone 39, Design and history
For transport, it broke down into two loads, the barrel being removed and carried on its own wagon. A third wagon was necessary to carry the firing platform. It could fire the same ammunition as the 15 cm Kanone 18 as well as its own special ammunition designed to Turkish specifications.


15 cm Kanone M 80
The 15 cm Kanone M 80 was a siege gun used by Austria-Hungary during World War I. Designed to replace the M 61 series of siege guns the M 80 family of siege guns offered greater range and armor penetration than the older guns. The proven steel-bronze (92% copper bronze strengthened by autofrettage) was used for the barrel and the iron carriage lacked any system to absorb recoil other than the traditional recoil wedges placed underneath and behind the wheels of the carriage.


15 cm Kanone M 80
These wedges helped to absorb the recoil force and encouraged the wheels to run forward to bring the gun back into battery. Generally a wooden firing platform was constructed for these guns in action to provide a level and smooth surface. Shortly after these guns were adopted a hydraulic recoil cylinder was adapted to absorb the recoil forces. It was attached to the underside of the carriage and the firing platform. For transport the barrel was removed from the carriage by a crane and carried separately.


15 cm Kanone M 80
These siege guns were no longer useful against modern armored fortresses by the outbreak of World War I and many saw action in the field to fill the need for heavy artillery.


15 cm L/40 Feldkanone i.R.
The 15 cm Feldkanone L/40 in Räderlafette (40-caliber Field Gun on Wheeled Carriage) was a heavy field gun used by Germany in World War I. It was an ex-naval gun hastily adapted for land service by rigidly mounting it in a field carriage.


15 cm L/40 Feldkanone i.R., History
The Germans were desperate for long-range artillery by 1915 and were forced to adapt a number of ex-naval guns for Army use, details of which are often lacking. The 15-cm SK L/40 (SK = Schnelladekanone or quick loading cannon) was an obsolete gun that was used as the secondary armament by pre-dreadnought battleships. It seems that there were actually two versions of this gun, one with an L/40 and the other with an L/45 barrel and the layout of the recoil mechanism differs between the two. It is not known if the designation changed depending on the barrel. The gun could not traverse on the mount and had to be fixed on a firing platform that weighed 7,450 kilograms (16,420 lb) to give it 60° of traverse. For transport purposes, it was broken down into three loads; barrel, carriage and firing platform.


15 cm L/40 Feldkanone i.R., History
While details are unclear, it seems that this gun was also adapted for land use, complete with its armored gunhouse, as the 15 cm KiSL (Kanone in Schirmlafette). It was mounted on a central pivot, which was in turn mounted on a firing platform. It was transported by rail or by road to its firing location in one piece and then offloaded onto the firing platform by crane.


15 cm L/40 Feldkanone i.R., History
It retained the Navy's (Kaiserliche Marine) semi-fixed ammunition, where one bag of powder was loaded before the brass cartridge containing the rest of the propellant and the primer.


15 cm L/40 Feldkanone i.R., History
At the final stages of the World War I at least 6 guns were ceded to Bulgaria.


15 cm Lang staal L/24
The 15 cm Lang staal L/24 was a Dutch rifled breechloading steel siege gun made by Krupp.


15 cm Lang staal L/24, Context, The name 15 cm Lang staal L/24
The Dutch army had a rather efficient naming system for its artillery. The 15 cm Lang staal L/24 was at first known as '15 cm zwaar' in order to distinguish it from a planned '15 cm licht'. When many more breechloading guns appeared in the Dutch Army's inventory, it added an 'A' for Achterlader (breechloader) to distinguish these from the smoothbore or rifled muzzle loaders.


15 cm Lang staal L/24, Context, The name 15 cm Lang staal L/24
When steel and bronze guns of the same caliber appeared, it added the label staal (steel) to distinguish the 8 cm staal, 12 cm Lang staal and this gun as '15 cm Lang staal' from other guns. At first this gun was therefore simply known as '15 cm zwaar', later it became the '15 cm Lang staal'. However, within a few years, even longer guns of the same caliber appeared among the coastal artillery. Therefore, the Dutch army added the length in calibers (L/24) in order to keep these apart.


15 cm Lang staal L/24, Context, The name 15 cm Lang staal L/24
In fact they did this only for the long guns, and by replacing the label 'Lang' with the exact length in calibers. While all long guns of 15 cm and longer were made of steel, the label 'staal' was omitted for these guns, leading to the name 15 cm L/24. Still later, when the gun became part of the field army, there was a renewed preference for the name 15 cm Lang staal, to designate it as an old gun, but the designation 15 cm L/24 was also used. Hence the name 15 cm Lang staal L/24.


15 cm Lang staal L/24, Context, The failed 15 cm A. brons
In 1872 the Minister for War was busy modernizing the rifles of the infantry. For artillery he had a 24 cm gun in production. He expected that a 15 cm gun breechloading gun would be ready in 1872, and be tested before the end of the year, so production of 15 cm guns could start in early 1873. He planned to construct 25 15 cm guns in 1873. In total, 120 15 cm A. brons were thought to be required.


15 cm Lang staal L/24, Context, The failed 15 cm A. brons
Much later, in November 1880 the House of Representatives asked why 10 15 cm A. brons had disappeared from the army's inventory. The Minister of War answered that these were 10 15 cm breechloaders made (i.e. cast) from regular bronze in 1871 and 1872. Only one had been completed. The other 9 had not been rifled, nor been provided with a breech lock. Trials had ended after the decision to buy steel siege guns. The 15 cm A. brons's had then been designated to be melted down.


15 cm Lang staal L/24, Procurement, Procurement of 15 cm Lang staal L/24
By 1875 it was clear that in a direct artillery duel, the Dutch bronze guns would be at a severe disadvantage against the newest steel guns. Therefore, these bronze guns would have to be supplemented with a number of steel (staal) guns. For 1876, the plan for the siege artillery was to procure 40 15 cm Lang staal L/24 ('15 cm zwaar staal') guns at 22,570 guilders a piece all included, 20 12 cm Lang staal at 13,200 guilders a piece ditto, and 100 bronze 12 cm K.A. at 3,825 guilders a piece ditto. For trials of the foreseen guns, single steel guns of 15 cm, 12 cm, and 8.7 cm(!) were bought in 1875.


15 cm Lang staal L/24, Procurement, Procurement of 15 cm Lang staal L/24
In December 1875 the Minister of War declared that the inclusion of the 8,7 cm under the siege artillery was a mistake. Even while the procurement was urgent, no more than 40 15 cm zwaar staal guns, and 20 12 cm Lang staal siege guns to be ordered at Krupp were brought on the budget for 1876. It was sound practice to limit the first series, and it was not even clear whether Krupp could deliver more. The trials would serve to specify alterations which would make the guns fit with the rest of the Dutch equipment.


15 cm Lang staal L/24, Procurement, Procurement of 15 cm Lang staal L/24
In September 1876 trials with the 15 cm zwaar staal and 12 cm Lang staal were held at the Krupp trial grounds. The results were very positive. In light of the trials at the Krupp grounds, the Minister of War then decided to contract with Krupp. However, for the money that was voted on the 1876 budget, he bought less 15 cm zwaar staal guns and more 12 cm Lang staal guns. The House of Representatives was not amused, and wanted to know how many guns had been bought at Krupp for which price.


15 cm Lang staal L/24, Procurement, Procurement of 15 cm Lang staal L/24
In December 1876 the minister replied that the state had 20 15 cm zwaar staal guns and 60 12 cm Lang staal guns on order at Krupp. The 12 cm Lang staal gun would cost 15,310 mark, same price as before. For 1877 the Minister of War then asked money for 100 12 cm Lang staal, i.e. did not order anymore 15 cm Lang staal L/24.


15 cm Lang staal L/24, Procurement, Procurement of 15 cm Lang staal L/24
In November 1877 the Minister of War deemed 124 15 cm Lang staal still to be required for the first line of the new Dutch Water Line. 22 had already been bought on the budgets for 1876 and 1877. Therefore, the minister asked for money for 54 more guns on the 1878 budget. On the final budget for 1879, a new Minister of War only asked budget for the lighter 12 cm guns. On 1 January 1880 there were 75 15 cm Lang staal available in the Netherlands.


15 cm Lang staal L/24, Characteristics, Barrel
The barrel of the 15 cm Lang staal L/24 was made by Krupp. It was a built-up gun barrel. It was 3,6 m long and weighed 3,045 kg. The caliber was 149.1 mm at the muzzle. The powder chamber was 42.5 cm long, and had a diameter of 151.1 mm.


15 cm Lang staal L/24, Characteristics, Barrel
What makes the 15 cm Lang staal L/24 hard to discern from the 12 cm Lang staal, is that both had a caliber of 24.


15 cm Lang staal L/24, Characteristics, Carriage
The carriage of the 15 cm Lang staal L/24 was made of steel, and was also made by Krupp. For transport the barrel would be placed in a lower position on the carriage.


15 cm Lang staal L/24, Characteristics, Transport
The 15 cm Lang staal L/24 was envisioned as a siege gun, which would dismount enemy siege artillery.


15 cm Lang staal L/24, Capabilities
The first serious tests of the gun were done by Krupp in Dülmen in June 1875. With a charge of 6.2 kg of prismatic powder, and a projectile of 28.4 kg, the average velocity was 470.9 m/s at 50 meters from the muzzle with a pressure of 1,939 atm. With 6.2 kg of another kind of gunpowder it was 412.8 m/s and a pressure of 1,296 atm. A third type of powder gave a speed of 451 m/s and a pressure of 1,420 atm. The first kind of powder gave the highest velocity.


15 cm Lang staal L/24, Capabilities
In the subsequent Dutch trials, which started in April 1876 many kinds of gunpowder were tested. Most of it was coarse gunpowder of about 350 grains per kg. Krupp had determined that the gas pressure inside the gun should not exceed 2,200 atm, and that a suitable gunpowder should propel the projectile to at least 465 m/s at 50 m from the muzzle. That is, the speed of the 15 cm should be equal to that of the 12 cm, but it could withstand a higher pressure.


15 cm Lang staal L/24, Capabilities
The next round of Dutch tests was done with a new set of two guns, which had grooves inside the chamber, and of which the 15 cm gun fired a heavier 31.3 kg projectile. With a charge of 6.8 kg a velocity of 465.4 m/s was achieved at a pressure of 2,180 atm. With 6.9 kg this was 468.3 m/s, at a pressure of 2,070 atm. It led to establishing that the regular charge of the gun would be 6.8 kg.


15 cm Lang staal L/24, Capabilities
The trials were then invalidated by a change that was made to the guns as a result of trials in Germany. The change was that the angle of the grooves was changed from constant to progressive. After some tests, the commission noted very significant differences with regard to atmospheric pressure in July. In particular, it had the first 15 cm gun fired again, and with the same 6.8 kg charge as above, it now noted a speed of 474.5 m/s at a pressure of 2,410 atm. After many investigations, it was found that in warm weather there was a slight increase in velocity, and a much higher increase in gas pressure inside the guns.


15 cm Lang staal L/24, Capabilities
Later in the trials, the regular charge of the 15 cm Lang staal L/24 was established to be 6.0 kg black gunpowder. With that charge there was no danger of ignition of the explosive charge of the projectile itself. Initial velocity with the 6.0 kg black gunpowder charge was 428.8 m/s.


15 cm Lang staal L/24, Operations, Becomes part of the field artillery and is retired
In 1927 the fortification artillery regiment was disbanded. From its remains two regiments of Onbereden Artillerie (unmounted artillery) were formed. In times of war, the first regiment of dismounted artillery would form 6 artillery regiments. These were the 13th, 18th, 14th, and 19th artillery regiments armed with the 12 cm Lang staal, and the 20th and 21st Artillery Regiments armed with the 15 cm Lang staal L/24. On 1 April 1933 the first dismounted artillery regiment was disbanded. Training for the 15 cm Lang staal L/24 ceased, and the 20th and 21st artillery regiments were deleted from the war time organization. The 15 cm Lang staal L/24 guns were then put in storage.


15 cm Lang staal L/24, Operations, World War II
During the mobilization for World War II the 15 cm Lang staal L/24 was brought out of storage. Three new artillery artillery regiments of only one company (Artillerie Afdeling) were founded. These were the units: 24 AA, 25 AA and 26 AA. Each had three batteries of 4 15 cm Lang staal L/24, but no traction. 25 AA was actively engaged in the fight near Moerdijk. Four of its 12 guns permanently broke down due to mechanical defects. For multiple reasons, the fire of the guns was almost completely ineffective. 26 AA was in Numansdorp. When the enemy did not appear before its guns, it had to move. After the orders were given, and horses were collected etc. two days had passed, and the army had surrendered.


15 cm Luftminenwerfer M 15 M. E.
The 15 cm Luftminenwerfer M 15 M. E. (Pneumatic Trench Mortar Maschinenfabrik Esslingen) was a medium mortar used by Austria-Hungary in World War I. It was developed by the German firm Maschinenfabrik Esslingen in response to a German requirement. Its initial testing was observed by an Austro-Hungarian representative and his positive report convinced them to order a batch of five for comparative testing. It was evaluated on 21 September 1915 and it produced the right impression. Nonetheless four weapons were sent off for combat trials at the end of October 1915, which were presumably favorable.


15 cm Luftminenwerfer M 15 M. E.
The barrel was mounted on a central pivot attached to a base plate, apparently with 360° of traverse. A single cylinder of compressed air was good for twelve shots.


15 cm Luftminenwerfer M 15 M. E.
The Model II incorporated minor improvements suggested by both the Austrians and German pioneer troops and was evaluated at the end of 1915. It was deemed satisfactory and another hundred were ordered. However, they were soon made obsolete by the better performance of the 12 cm Luftminenwerfer M 16 and shelved before the production run was finished.


15 cm Mörser M 80
The 15 cm Mörser M 80 was a heavy howitzer used by Austria-Hungary in World War I. It had a bronze barrel and was intended for siege work, although it had carriages suitable for both field and siege duties. The siege carriage was a steel sledge-type and was equipped with a hydraulic braking device to help absorb the recoil forces. Two wheels could be attached to the front of the carriage and a limber attached to the rear for transport. The field carriage relied on chock blocks and a rope brake device to absorb the gun's recoil.


15 cm Mörser M1881
The 15 cm Festungs und Belagerungs Mörser M1881 or (15 cm Fortress and Siege Mortar M1881) in English was a heavy mortar designed by Krupp that armed several European countries before and during World War I.


15 cm Mörser M1881, Background
During the second half of the 1800s, several military conflicts changed the balance of power in Europe and set off an arms race leading up to World War I. A company that profited from this arms race was the Friedrich Krupp Company of Essen Germany and several European countries were armed with Krupp artillery. Some customers like Belgium, Italy, Romania, and Russia imported and built Krupp designs under license while others like the Ottoman Empire and Bulgaria lacking industrial capacity imported Krupp weapons.


15 cm Mörser M1881, Design
The majority of military planners before World War I were wedded to the concept of fighting an offensive war of rapid maneuver that before mechanization meant a focus on cavalry and light horse artillery firing shrapnel shells at formations of troops in the open. This focus on quick firing light horse artillery meant that the use of mortars declined before World War I. However, Krupp continued to produce a range of siege mortars including 7.5 cm, 8.7 cm, 10.6 cm, 12 cm, 15 cm, 21 cm, and 24 cm mortars for their customers.


15 cm Mörser M1881, Design
The 15 cm M1881 was a heavy mortar that was designed to provide high-angle indirect fire for siege operations. It could be used to either attack or defend fortified areas. In defense, the mortar was used to provide high-angle fire to destroy enemy communications, supply, and attack trenches dug by an attacker during siege operations or it could be used by an attacker to destroy gun turrets, casemates, pillboxes, supply dumps, and command posts.


15 cm Mörser M1881, Design
The 15 cm M1881 was a breech-loaded rifled mortar with an early form of horizontal sliding block breech that used separate loading propellant charges and projectiles. There were two types of mount one was a static fortress mount that had a round metal base that bolted to a concrete slab or a mobile siege mount that bolted to a rectangular wooden platform.


15 cm Mörser M1881, Design
The upper part of both mounts was a wedge-shaped cradle constructed of riveted metal plates that held a trunnioned barrel. The U-shaped cradle allowed for high angles of elevation and was adjusted by a hand wheel on the side of the cradle that connected to a crescent-shaped elevation mechanism. Traverse was adjusted by a wooden pole that fit into a hole in the rear of the base and was levered into position. For transport, a pair of wheels were attached to an axle on the carriage and the rear was attached to a caisson with a seat for the crew. Or a set of poles could be attached to the base and towed by the crew.


15 cm Mörser M1881, Users
The 15 cm M1881 was used during the Balkan Wars and World War I by the Ottoman Empire. A number armed Ottoman forts in the Balkans and a few were captured during the Balkan Wars. It is unknown if Serbia, Bulgaria, Greece, or Montenegro continued to use the mortars they captured? It may have also seen action during the Italo-Turkish War of the same period. The 15 cm M1881 was also used by the Swiss and the Italians used them during World War I.


15 cm Mörser M1881, Gallery
An Italian 15 cm mortar captured by Austro-Hungarian forces during World War I.


15 cm Mörser M1881, Gallery
A 15 cm mortar attached to a caisson for transport.


15 cm Mörser M1881, Gallery
A similar 21 cm mortar at the Royal Military Museum, Brussels.


15 cm Nebelwerfer 41
The 15 cm Nebelwerfer 41 (15 cm NbW 41) was a German multiple rocket launcher used in the Second World War. It served with units of the Nebeltruppen, German Chemical Corps units that had the responsibility for poison gas and smoke weapons that were also used to deliver high-explosives during the war. The name Nebelwerfer is best translated as "smoke mortar".


15 cm Nebelwerfer 41
Allied troops nicknamed it Screaming Mimi and Moaning Minnie due to its distinctive sound.


15 cm Nebelwerfer 41, Development
Rocket development had begun during the 1920s and reached fruition in the late-1930s. These offered the opportunity for the Nebeltruppen to deliver large quantities of poison gas or smoke simultaneously. The first weapon to be delivered to the troops was the 15 cm Nebelwerfer 41 in 1940, after the Battle of France, a purpose-designed rocket with gas, smoke, and high-explosive warheads. It was fired from a six-tube launcher mounted on a towed carriage adapted from that used by the 3.7 cm PaK 36 to a range of 6,900 metres (7,500 yds), later also mounted on a halftrack as Panzerwerfer 42. Almost five and a half million 15 cm rockets and six thousand launchers were manufactured over the course of the war.


15 cm Nebelwerfer 41, Ammunition
Like virtually all German rocket designs, 15 cm Wurfgranate 41 projectiles were spin-stabilized to increase accuracy. However, one unusual feature was that the rocket motor was in the front, the exhaust venturis being about two-thirds down the body from the nose, with the intent to optimize the blast and fragmentation effect of the rocket as the warhead would still be above the ground when it detonated. This proved to greatly complicate manufacture without much improvement and it was not copied on later rocket designs.


15 cm Nebelwerfer 41, Ammunition
The motor consisted of seven sticks of solid-fuel propellant and the exhaust ring had twenty-six venturis that were drilled at a 14° angle to impart spin. There were high-explosive, smoke and chemical warfare rockets available. The chemical warfare rockets were stockpiled but are said to have not been used operationally. Field Rocket Equipment of the German Army 1939-45 lists Phosgene Gas and Mustard Gas as the two primary chemical agents but it does not describe how the rockets were identified with color coded rings. German and Japanese Solid-Fuel Rocket Weapons describes the color coding for the rockets but only gives cryptic codes like M/HA for the type of chemical agent it was filled with.


15 cm Nebelwerfer 41, Photo gallery
Nebelwerfer 41 rocket launcher on display at the Rock Island Arsenal museum, viewed from the front.


15 cm Nebelwerfer 41, Photo gallery
Wgr. 41 projectile for the 15 cm Nbw 41 on display at the Steven F. Udvar-Hazy Center.


15 cm Ring Kanone C/72
The 15 cm Ring Kanone C/72 was a fortress and siege gun developed after the Franco-Prussian War and used by Germany and Portugal before and during World War I.


15 cm Ring Kanone C/72, History
After the Franco-Prussian War, the Army began to study replacements for its cast bronze 15 cm Kanone C/61 and steel 15 cm Kanone C/64 breech loaded cannons. Although Prussian artillery had outclassed their French rivals during the war the breech mechanism the C/64 used was weak and there was a tendency for barrels to burst due to premature detonation of shells. In 1872 a new gun which retained the same 149.1 mm (5.87 in) caliber as the previous gun was designed and placed in production. The new gun designated the 15 cm Ring Kanone C/72 was assigned to fortress and siege artillery battalions of the Army. Each artillery battery consisted of four guns with four batteries per battalion.


15 cm Ring Kanone C/72, Design
The C/72 was a typical built-up gun constructed of steel with a central rifled tube, reinforcing layers of hoops, and trunnions. The C/72 featured a new breech which although similar to the breech of the C/64 had a semi-circular face which allowed the gun to avoid the stress fractures which caused catastrophic failures in its square blocked predecessor. This type of breech was known as a cylindro-prismatic breech which was a predecessor of Krupp's horizontal sliding-block and the gun used separate-loading, bagged charges and projectiles.


15 cm Ring Kanone C/72, Design
The C/72 was fairly conventional for its time and most nations had similar guns such as its Russian cousin the 6-inch siege gun M1877 or the Italian Cannone da 149/23. Like many of its contemporaries, the C/72 had a tall and narrow box trail carriage built from bolted iron plates with two wooden 12-spoke wheels. The carriages were tall because the guns were designed to sit behind a parapet with the barrel overhanging the front in the fortress artillery role or behind a trench or berm in the siege role.


15 cm Ring Kanone C/72, Design
Like its contemporaries, the C/72's carriage did not have a recoil mechanism or a gun shield. However, when used in a fortress the guns could be connected to an external recoil mechanism which connected to a steel eye on a concrete firing platform and a hook on the carriage between the wheels. For siege gun use a wooden firing platform could be assembled ahead of time and the guns could attach to the same type of recoil mechanism.


15 cm Ring Kanone C/72, Design
A set of wooden ramps were also placed behind the wheels and when the gun fired the wheels rolled up the ramp and was returned to position by gravity. There was also no traverse so the gun had to be levered into position to aim. A drawback of this system was the gun had to be re-aimed each time which lowered the rate of fire. For transport, the gun was broken down into two loads 4,560 kg (10,050 lb) and 2,780 kg (6,130 lb) for towing by horse teams or artillery tractors.


15 cm Ring Kanone C/72, World War I
The majority of military planners before the First World War were wedded to the concept of fighting an offensive war of rapid maneuver which in a time before mechanization meant a focus on cavalry and light horse artillery firing shrapnel shells. Since the C/72 was heavier and wasn't designed with field use in mind it was employed as a fortress gun.


15 cm Ring Kanone C/72, World War I
Although the majority of combatants had heavy field artillery prior to the outbreak of the First World War, none had adequate numbers of heavy guns in service, nor had they foreseen the growing importance of heavy artillery once the Western Front stagnated and trench warfare set in. The theorists hadn't foreseen that trenches, barbed wire, and machine guns had robbed them of the mobility they had been counting on and like in the Franco-Prussian and Russo-Turkish war the need for high-angle heavy artillery reasserted itself.


15 cm Ring Kanone C/72, World War I
Since aircraft of the period were not yet capable of carrying large diameter bombs the burden of delivering heavy firepower fell on the artillery. The combatants scrambled to find anything that could fire a heavy shell and that meant emptying the fortresses and scouring the depots for guns held in reserve. It also meant converting coastal artillery and naval guns to siege guns by either giving them simple field carriages or mounting the larger pieces on rail carriages.


15 cm Ring Kanone C/72, World War I
A combination of factors led the Germans to issue C/72's to their frontline troops:


15 cm Ring Kanone C/72, World War I
Although new guns with superior performance were introduced the C/72's remained in service until the end of the war due to the number in service and a lack of replacements. However, their poor range eventually became a handicap.


15 cm Ring Kanone C/72, World War I
In 1886, Portugal bought several C/72 artillery pieces and they were still in use by the time the Great War began. They were initially deployed in forts around the city of Lisbon, but during the war they were moved to batteries elsewhere, like in neighboring city of Setúbal and the islands of Azores and Madeira, for coastal defensive duties.


15 cm Ring Kanone C/92
The 15 cm Ring Kanone C/92 was a fortress and siege gun developed in the 1880s that saw service in the Italo-Turkish War, Balkan Wars, and World War I.


15 cm Ring Kanone C/92, History
During the Franco-Prussian War, the breech-loaded Prussian cannons easily outclassed their muzzle-loaded French rivals. After the war, the Prussian Army replaced its 15 cm C/61 and C/64 cannons with the new 15 cm Ring Kanone C/72. The French also rearmed and their new breech-loaded Canon de 155 L mle 1877 had nearly twice the range of the C/72. During the 1880s Krupp began designing a replacement for the C/72 which would retain the same 149.1 mm (5.87 in) caliber as the C/72 and would feature a barrel 30 calibers in length rather than the 23 calibers of its predecessor.


15 cm Ring Kanone C/92, History
The new gun was designated the 15 cm Ring Kanone C/92 and could have been introduced as early as 1889 but the development of smokeless powder and new high-explosive shells necessitated design changes and the new guns weren't introduced until 1892. C/92's were assigned to fortress and siege artillery battalions of the Imperial German Army. Each artillery battery consisted of four guns with four batteries per battalion.


15 cm Ring Kanone C/92, Design
The C/92 was a typical built-up gun constructed of steel with a central rifled tube, reinforcing layers of hoops, and trunnions. The guns used a predecessor of Krupp's horizontal sliding-block breech known as a cylindro-prismatic breech and it fired separate-loading, bagged charges and projectiles.


15 cm Ring Kanone C/92, Design
The C/92 was fairly conventional for its time and most nations had similar guns such as the Russian 6-inch siege gun M1904. Like many of its contemporaries, the C/92 had a tall and narrow box trail carriage built from bolted iron plates with two wooden 12-spoke wheels. The carriages were tall because the guns were designed to sit behind a parapet with the barrel overhanging the front in the fortress artillery role or behind a trench or berm in the siege role. Like its contemporaries, the C/92's carriage did not have a recoil mechanism or a gun shield.


15 cm Ring Kanone C/92, Design
However, when used in a fortress the guns could be connected to an external recoil mechanism which connected to a steel eye on a concrete firing platform and a hook on the carriage between the wheels. For siege gun use a wooden firing platform could be assembled ahead of time and the guns could attach to the same type of recoil mechanism. A set of wooden ramps were also placed behind the wheels and when the gun fired the wheels rolled up the ramp and was returned to position by gravity.


15 cm Ring Kanone C/92, Design
There was also no traverse so the gun had to be levered into position to aim. A drawback of this system was the gun had to be re-aimed each time which lowered the rate of fire. To facilitate towing on soft ground and lessen recoil the wheels were often fitted with Bonagente grousers patented by the Italian major Crispino Bonagente. These consisted of twelve rectangular plates connected with elastic links and are visible in many photographs of World War I artillery from all of the combatants. For transport, the gun was broken down into two loads 5,035 kg (11,100 lb) and 3,860 kg (8,510 lb) for towing by horse teams or artillery tractors.


15 cm Ring Kanone C/92, Balkan Wars
C/92's were used by both the Bulgarians and Ottoman forces during the Balkan Wars. It's also possible that Albania, the Kingdom of Greece, the Kingdom of Montenegro, the Kingdom of Romania, and the Kingdom of Serbia may have either bought C/92's or captured them from Ottoman forces. It is also likely they were used by Ottoman forces during the Italo-Turkish War.


15 cm Ring Kanone C/92, World War I
The majority of military planners before the First World War were wedded to the concept of fighting an offensive war of rapid maneuver which in a time before mechanization meant a focus on cavalry and light horse artillery firing shrapnel shells. Since the C/92 was heavier and wasn't designed with field use in mind it was employed as a fortress gun.


15 cm Ring Kanone C/92, World War I
Although the majority of combatants had heavy field artillery prior to the outbreak of the First World War, none had adequate numbers of heavy guns in service, nor had they foreseen the growing importance of heavy artillery once the Western Front stagnated and trench warfare set in. The theorists hadn't foreseen that trenches, barbed wire, and machine guns had robbed them of the mobility they had been counting on and like in the Franco-Prussian and Russo-Turkish war the need for high-angle heavy artillery reasserted itself.


15 cm Ring Kanone C/92, World War I
Since aircraft of the period were not yet capable of carrying large diameter bombs the burden of delivering heavy firepower fell on the artillery. The combatants scrambled to find anything that could fire a heavy shell and that meant emptying the fortresses and scouring the depots for guns held in reserve. It also meant converting coastal artillery and naval guns to siege guns by either giving them simple field carriages or mounting the larger pieces on rail carriages.


15 cm Ring Kanone C/92, World War I
A combination of factors led the Germans to issue C/92's to their frontline troops:


15 cm Ring Kanone C/92, World War I
The C/92 could be considered a dubious upgrade from the C/72 because at the time of their introduction they were virtually obsolescent due to the invention of hydro-pneumatic recoil mechanisms and the introduction of separate loading quick fire ammunition. Also despite having a barrel 7 calibers longer and using smokeless propellant the improvement in range was only 3.2 km (2 mi). Although new guns with superior performance were introduced the C/92's remained in service until the end of the war due to the number in service, a shortage of heavy artillery and a lack of replacements.


15 cm Ring Kanone C/92, Ammunition
The C/92 fired a variety of separate-loading, 10.7 kg (23 lb 9 oz) bagged charges and projectiles.


15 cm Ring Kanone L/30
The 15 cm Ring Kanone L/30 was a naval gun and coastal artillery piece that was used by the German Navy before the First World War that was converted to a siege gun for the German Army during the First World War when the ships that carried it were decommissioned.


15 cm Ring Kanone L/30, History
The majority of military planners before the First World War were wedded to the concept of fighting an offensive war of rapid maneuver which in a time before mechanization meant a focus on cavalry and light horse artillery firing shrapnel shells. Although the majority of combatants had heavy field artillery prior to the outbreak of the First World War, none had adequate numbers of heavy guns in service, nor had they foreseen the growing importance of heavy artillery once the Western Front stagnated and trench warfare set in.


15 cm Ring Kanone L/30, History
The theorists hadn't foreseen that trenches, barbed wire, and machine guns had robbed them of the mobility they had been counting on and like in the Franco-Prussian War and Russo-Turkish War the need for high-angle heavy artillery reasserted itself. Since aircraft of the period were not yet capable of carrying large diameter bombs the burden of delivering heavy firepower fell on the artillery. The combatants scrambled to find anything that could fire a heavy shell and that meant emptying the fortresses and scouring the depots for guns held in reserve. It also meant converting coastal artillery and surplus naval guns to siege guns by either giving them simple field carriages or mounting the larger pieces on rail carriages.


15 cm Ring Kanone L/30, Design
The 15 cm Ring Kanone L/30 was a typical built-up gun constructed of steel with a central rifled tube, reinforcing layers of hoops, and trunnions. This type of breech was known as a cylindro-prismatic breech which was a predecessor of Krupp's horizontal sliding-block and the gun used separate-loading, bagged charges and projectiles.


15 cm Ring Kanone L/30, Design
The 15 cm Ring Kanone L/30 was fairly conventional for its time and most combatants during the First World War had similar conversions of naval guns such as the British BL 6-inch Mk VII or the French Canon de 155 L modele 1916. The barrels were mounted on simple two-wheeled steel box trail carriages which did not have a recoil mechanism or a gun shield. The carriages were tall and there was an opening behind the breech to allow high angles of elevation.


15 cm Ring Kanone L/30, Design
To facilitate towing on soft ground the wheels were often fitted with Bonagente grousers patented by the Italian major Crispino Bonagente. These consisted of rectangular plates connected with elastic links and are visible in many photographs of World War I artillery from all of the combatants. A set of wooden ramps were placed behind the wheels and when the gun fired the wheels rolled up the ramp and the gun was returned to position by gravity. A drawback of this system was the gun had to be re-aimed each time which lowered the rate of fire.


15 cm Ring Kanone L/30, Photo Gallery
The same gun being towed away by a MK IV tank.


15 cm SK "Nathan"
The 15 cm SK L/45 "Nathan" or, more formally, the 15 cm SK L/45 in Mittelpivot-Lafette (SK - Schnelladekanone (quick loading gun)) 45 caliber on a central-pivot mount was a German railroad gun used in World War I.


15 cm SK "Nathan", Design and history
The Germans were desperate for long-range artillery in the early part of World War I and resorted to mounting naval guns on wheeled carriages as well as rail cars. The wheeled carriages were less than successful due to their great weight, but the rail-mounted guns rather more so. All of the naval guns received nicknames and were crewed by sailors. The 15 cm guns were called "Nathan", "Nathan Ernst" and "Nathan Emil" although the reason for three different names isn't known for certain.


15 cm SK "Nathan", Design and history
Quite probably they were used to differentiate between models of the 15 cm gun as both the C/13 and the C/16 guns are known to have been used. The latter guns were originally intended for the canceled  Cöln-class cruisers then under construction while the former were spare guns for dreadnoughts and older light cruisers.


15 cm SK "Nathan", Design and history
At any rate the 15 cm guns were mounted in a well-base flatcar with two four-wheel bogies. No outriggers were fitted so the recoil energy from shots fired perpendicular to the railroad track could rock the flatcar significantly even with it chained to the ground. They were fitted with front and side gunshields, although, oddly enough, no overhead armor was fitted. They first saw service in 1918 and appear to have been mainly used for coastal defense duties.


15 cm SK "Nathan", Design and history
It fired naval Spgr. L/5 (Haube) HE shells weighing 44 kilograms (97 lb) with 5 kilograms (11 lb) of explosive filler. It used the German naval system of ammunition where the base charge was held in a metallic cartridge case and supplemented by another charge in a silk bag which was rammed first.


15 cm SK "Nathan", Design and history
The same gun was used for coast defense duties in concrete emplacements after World War I as the 15 cm SK L/45.


15 cm SK C/25
The 15 cm SK C/25 was a German medium-caliber naval gun used during the Second World War. It served as the primary armament for the K- and  Leipzig-class cruiser. No surplus weapons of this type appear to have been used as coast-defense guns.


15 cm SK C/25, Description
This gun was the most powerful of the Kriegsmarine's 15 centimetres (5.9 in) guns and was designed with a loose barrel, jacket and breech-piece with a vertical sliding breech block.


15 cm SK C/25, Description, Mount
The Drh. LC/25 triple-gun mount was the only mount used for this gun in the Kriegsmarine. The mount weighed between 136.91–147.15 tonnes (134.75–144.83 long tons; 150.92–162.21 short tons), depending on its armor thickness; the Nürnberg's mounts had between 20–80 mm (0.79–3.15 in) of armor while the other ships had 20–30 mm (0.79–1.18 in). Each mount was designed for full 360° of traverse, but was limited to much less than that by the ship's superstructure. The electrically powered hydraulic pumps had a maximum elevating speed of 8° per second, while train was a maximum of 6-8° per second. The maximum firing cycle was 7.5 seconds, or 8 rounds per minute, despite being hand-loaded and rammed. Ammunition was supplied by three hoists, one between the left and center guns and the other two between center and right guns at the rear of the mount.


15 cm SK C/25, Description, Ammunition
The SK C/25 had a number of different shells available.


15 cm SK C/28
The 15 cm SK C/28 was a German medium-caliber naval gun used during the Second World War. It served as the secondary armament for the  Bismarck class and  Scharnhorst-class battleships,  Deutschland-class cruisers and the  Graf Zeppelin-class aircraft carriers. A number of surplus weapons were used as coast-defense guns and eight were adapted to use Army carriages and used as heavy field guns as the 15 cm Schiffskanone C/28 in Mörserlafette


15 cm SK C/28, Description
This gun was designed as a smaller and lighter version of the 15 cm SK C/25 guns used as the main armament of the  Königsberg- and  Leipzig-class cruisers. It shared the earlier gun's design with a loose barrel, jacket and breech-piece with a vertical sliding breech block.


15 cm SK C/28, Description, Naval mountings
The Drh. LC/34 twin-gun mount was the most common mount for the gun in the Kriegsmarine. It was used as the secondary armament of the  Bismarck-class and  Scharnhorst-class battleships and was planned to equip the proposed H-class battleships. The mount weighed between 114–120 tonnes (112–118 long tons; 126–132 short tons), depending on its armor thickness; the Scharnhorst's mounts had between 14–3 cm (5.5–1.2 in) of armor while the Bismarck's had 10–2 cm (3.94–0.79 in). Maximum elevation was 40°, giving a range of 23,000 metres (25,000 yd) and maximum depression was -10°, while maximum elevating speed was 8° per second.


15 cm SK C/28, Description, Naval mountings
Each mount was designed for full 360° of traverse, but was limited to much less than that by the ship's superstructure. Speed in train was a maximum of 9° per second. The fastest firing cycle was 7.5 seconds, or 8 rounds per minute. Ammunition was supplied by twin hoists between the guns, at the rear of the mount. The M-class cruiser was intended to use a lighter version of this mount with thinner armor that only weighed approximately 102 tonnes (100 long tons; 112 short tons). This may have designated as the Drh. LC/40, but development ceased when the ships were canceled in 1939.


15 cm SK C/28, Description, Naval mountings
Scharnhorst and Gneisenau also carried four single MPL C/35 mounts that weighed 26.71 tonnes (26.29 long tons; 29.44 short tons) with armor between 6–2 cm (2.36–0.79 in) thick. Each mount could depress -10° and elevate to 35°; this gave a maximum range of 22,000 metres (24,000 yd). The MPL C/28 mount used in the  Deutschland-class cruisers was virtually identical to the newer mount except its gun shield was smaller so it weighed only 24.83 tonnes (24.44 long tons; 27.37 short tons).


15 cm SK C/28, Description, Naval mountings
The  Graf Zeppelin-class aircraft carriers were going to carry eight twin-gun Dopp MPL C/36 casemate mountings. These weighed 47.6 tonnes (46.8 long tons; 52.5 short tons) and had an armored shield  30 millimetres (1.2 in) thick. The mount elevated at a speed of 6° per second and trained at a rate of 8° per second.


15 cm SK C/28, Description, Coast defense mountings
The Küsten-Marinepivotlafette (Küst. MPL C/36) was a highly successful mobile coast defense mount fitted with a gun shield. The gun traversed on a six-legged firing platform that allowed 360° of traverse. It could depress -7° and elevate to a maximum of 47° 30', which gave it a range of 23,500 metres (25,700 yd). The gun on its carriage weighed 19,761 kilograms (43,566 lb). It was towed via two two-axle trailers, one at each end. For travel the four lateral legs of the platform folded vertically. It entered service in 1940.


15 cm SK C/28, Description, Army mount
Production of carriages for the 21 cm Mörser 18 and the 17 cm Kanone 18 in Mörserlafette exceeded the available number of barrels in 1941 and eight SK C/28 barrels were adapted for use on the carriages as the 15 cm Schiffskanone C/28 in Mörserlafette. They were converted to Heer-standard percussion firing. Most guns were replaced by 17-centimetre (6.7 in) barrels as they became available, but one battery retained them through the beginning of the Battle of Kursk in July 1943.


15 cm SK C/28, Description, Ammunition
The SK C/28 used several different shells depending on its target. The 15 cm Sprgr L/4.6 KZ m Hb weighed 45.5 kg (100 lb) and had a muzzle velocity of 785 m/s (2,580 ft/s). It was a nose-fused HE shell with ballistic cap with two copper driving band and a lead ring behind them to act as a decoppering device by scraping away any copper residue from the driving band. The 15 cm Sprgr L/4.5 Bd Z m. Hb was a base-fused shell with a ballistic cap and weighed 44.8 kg (99 lb).


15 cm SK C/28, Description, Ammunition
It was roughly equivalent to the British "Common Pointed" and also used a lead decoppering ring. The armor-piercing 15 cm Pzgr L/3.8 m Hb shell had a ballistic cap and weighed 45.3 kg (100 lb). All shells used 14.1 kg (31 lb) of propellant in an artificial silk bag, housed in a brass cartridge case. An illumination shell was also available, although details are unknown.


15 cm SK C/28, History
Surplus naval mountings were used to reinforce German coast defenses from Norway to the French Atlantic coast. These included guns from incomplete or disarmed ships like the aircraft carrier Graf Zeppelin or the battleship Gneisenau. For example, three or four of the Graf Zeppelin's Dopp MPL C/36 mounts equipped both batteries of Naval Artillery Battalion (Marine-Artillerie-Abteilung) 517 at Cap Romanov near Petsamo, Finland while two of the Gneisenau's Drh. LC/34 mounts were emplaced on the west coast of Denmark at Esbjerg where they equipped Batterie Gneisenau of Naval Artillery Battalion 518. All told, a total of 111 SK C/28 guns were employed on coast defense duties in a variety of mounts, 28 in Norway, 12 in Denmark, 24 in the German Bight, 8 in the Netherlands, and 39 in Belgium and the Atlantic coast of France.


15 cm SK C/28, History
Surviving guns in Norway and Denmark were used throughout the Cold War by both countries.


15 cm SK L/35
The 15 cm Schnelladekanone Länge 35, abbreviated as 15 cm SK L/35, was a German naval gun developed in the years before World War I that armed a variety of warships from different nations. The navies of Austria-Hungary, China, Denmark, Japan, The Netherlands, The Ottoman Empire, Romania and Spain all used this gun.


15 cm SK L/35, History
In 1880 Krupp designed the 15 cm SK L/35 and started production in 1883 to arm protected cruisers, turret ships and coastal defense ships then under construction. It was also used to rearmed a number of earlier iron clad warships. Originally designed to use one piece ammunition 1.33 m (4 ft 4 in) long and weighing 68 kg (150 lb) the gun was redesigned to use two part quick loading cased charges and projectiles due to complaints about the size and weight of the ammunition. By breaking the ammunition down into two pieces the rate of fire was improved and crew workload was eased.


15 cm SK L/35, Land use
In addition to its naval artillery role the 15 cm SK L/35 was also used as coastal artillery in either armored gun turrets or on garrison mounts. The garrison mount consisted of a rectangular steel firing platform which sat on a concrete slab behind a parapet with a pivot at the front and two wheels at the rear to give a limited amount of traverse. The recoil system consisted of a U shaped gun cradle which held the trunnioned barrel and a slightly inclined firing platform with a hydro-gravity recoil system. When the gun fired the hydraulic buffers under the front slowed the recoil of the cradle which slid up a set of inclined rails on the firing platform and then returned the gun to position by the combined action of the buffers and gravity.


15 cm SK L/35, Ammunition
Ammunition was of separate quick loading type with a cased charge and projectile. The charge for AP and Common shells weighed 8 kg (18 lb). The charges for Shrapnel were 3.7–5.2 kg (8.2–11.5 lb).


15 cm SK L/35, Photo Gallery
The breech block of a 15 cm SK L/35 at the Khabarovsk Krai Local Museum.


15 cm SK L/40 naval gun
The 15 cm SK L/40 was a German naval gun that was used as secondary armament on pre-dreadnought battleships, protected cruisers and armored cruisers of the Imperial German Navy in World War I. It was also used as a coast-defence gun during World Wars I and II.


15 cm SK L/40 naval gun, Construction
The 15 cm SK L/40 gun was constructed of A tube, two layers of hoops and used a Krupp horizontal sliding-wedge breech block. It used separate loading metallic cased propellant charges and projectiles. Unlike other large naval guns of the time which used separate loading bagged charges and projectiles, this gun used charges inside of a brass cartridge case to provide obturation. The guns were often mounted in single casemates or single turrets amidships. In addition to guns produced for the Imperial German Navy comparable export models were produced for the Royal Netherlands Navy and produced under license by Škoda for the Austro-Hungarian Navy.


15 cm SK L/40 naval gun, Naval Use
Ship classes that carried the 15 cm SK L/40 include:


15 cm SK L/40 naval gun, Ammunition
Ammunition was of separate loading quick fire type. The projectiles were 39–46.5 cm (1–2 ft) long with a cartridge case and  bagged charge which weighed 10 kg (22 lb).


15 cm SK L/45
The 15 cm SK L/45 was a German naval gun used in World War I and World War II.


15 cm SK L/45, Naval service
The 15 cm SK L/45 was a widely used naval gun on many classes of World War I Dreadnoughts and Cruisers in both casemates and turrets. It was constructed of an A tube and two layers of hoops with a Krupp horizontal sliding-wedge breech block. During World War I a few pre-war cruisers that were armed with 10.5 cm guns were rearmed with these weapons. In World War II the 15 cm SK L/45 was widely used as Coastal artillery and as primary armament on German Auxiliary Cruisers.


15 cm SK L/45, Naval service
Ship classes that carried the 15 cm SK L/45 include:


15 cm SK L/45, Ammunition
Ammunition was of separate loading quick fire type. The projectiles were 61 cm (2 ft) long with a single bagged charge which weighed 13–14 kg (29–31 lb).


15 cm SK L/45, Coast Defense Gun
The same gun was used for coast defense duties in concrete emplacements after World War I. One example was 3./Marine-Artillerie Abteilung 604 ("3rd Battery of Naval Artillery Battalion 604") in Jersey. They show it using 44 kilograms (97 lb) shells with a range of 18,000 metres (20,000 yd)


15 cm SK L/45, Railroad Gun
It was also used as a railroad gun during World War I.


15 cm Schiffskanone C/28 in Mörserlafette
The 15 cm Schiffskanone C/28 in Mörserlafette (SK C/28 in Mrs Laf) was a German heavy gun used in the Second World War.


15 cm Schiffskanone C/28 in Mörserlafette, Development
Production of carriages for the 21 cm Mörser 18 and the 17 cm Kanone 18 in Mörserlafette exceeded available barrels in 1941 and eight naval 15 cm SK C/28 coast defense gun barrels were adapted for use on the carriages. They were converted to Heer-standard percussion firing (see the articles of those guns for details on the design of the carriage).


15 cm Schiffskanone C/28 in Mörserlafette, Operational use
For Operation Barbarossa (the invasion of the Soviet Union), it equipped Artillerie-Abteilung 625. Most guns were replaced by 17 cm barrels as they became available. However, for Case Blue (the German summer offensive in southern Russia), one battery of Artillery Battalion (Artillerie-Abteilung) 767 was still equipped with them. That same battery retained them through the beginning of the Battle of Kursk in July 1943.


15 cm Schiffskanone C/28 in Mörserlafette, Ammunition
The 15 cm SK C/28 in Mrs Laf could not be converted to use the Heer's standard 15 cm ammunition and had to use naval ammunition. These included the 15 cm Sprgr L/4.6 KZ m. Hb., the 15cm Sprgr L/4.5 BdZ m. Hb. and the 15 cm Pzgr L/3.8 m. Hb. The former was a nose-fuzed 45.5 kilograms (100 lb) HE shell with a ballistic cap. The second was a base-fuzed 44.8 kilograms (99 lb) HE shell, also with a ballistic cap. The last-named was a standard 45.3 kilograms (100 lb) armor-piercing shell. Only one 14.1 kilograms (31 lb) bag of propellant was used in a separate-loading cartridge case.


15 cm TbtsK C/36 naval gun
The 15 cm TbtsK C/36 was a German medium-caliber naval gun deployed on Type 1936A (Mob) destroyers during the Second World War. It was designed because the Oberkommando der Marine (German Naval High Command) thought that the 12.7 cm (5.0 in) guns of the Type 1936 and 1936A destroyers would potentially be inferior to those of possible enemies. The guns caused serious issues when actually placed upon ships however, as they added significant weight high up on the ships. To deal with this increase in weight, the destroyers had one gun removed, sometimes with a twin gun being used in order to keep five guns.


15 cm TbtsK C/36 naval gun, Design history
In 1932, the Reichsmarine (Weimar Republican Navy) approved a new program for 1,500 tonnes (1,500 long tons; 1,700 short tons) destroyers. Design work for the project began immediately, at the Vulcan Shipyard in Stettin, and at the F Schichau yard in Elbing. These were to have main guns of a 12.7-centimetre (5.0 in) caliber, in order to match or exceed the firepower of other countries destroyers, which usually had a caliber of between 12 cm (4.7 in) and 13 cm (5.1 in).


15 cm TbtsK C/36 naval gun, Design history
The 15 cm TbtsK C/36 was originally designed to be used on torpedo boats, but studies into its possible usage on destroyers, and of rearming the Type 1934 and 1934A destroyers with it began after the commissioning of the two classes, in 1936. The Oberkommando der Marine (Naval High Command) thought that the 12.7 cm (5.0 in) guns of the Type 1936 and 1936A destroyers may be inferior to that of some potential enemies, and thus ordered that the new Type 1936 destroyers should have 15 cm (5.9 in) guns.


15 cm TbtsK C/36 naval gun, Design history
In order to test the 15 cm guns, the German destroyer Z8 Bruno Heinemann had her 12.7 cm SK C/34 guns replaced by five 15 cm TbtsK C/36 guns, in single mountings, in 1938. It was quickly discovered that not only did the guns themselves cause problems, but also that the mountings were far too heavy. The new weight placed so high up on the ship seriously damaged stability, and in heavy seas only two of the five guns could be worked. In an attempt to remedy the problem, one of the 15 cm guns was removed, but this did not fix the problem. Z8 Bruno Heinemann quickly had her old 12.7 cm guns reinstalled.


15 cm TbtsK C/36 naval gun, Gun characteristics
The 15 cm TbtsK C/36 naval gun had an actual caliber of exactly 14.91 cm (5.87 in), a weight of 7,200 kilograms (15,900 lb), an overall length of 7.165 metres (23.51 ft), a bore length of 6.815 m (22.36 ft), a chamber volume of 212 cubic centimetres (12.9 cu in), a rifling length of 558.7 cm (220.0 in). It had 44 grooves, which were all 1.75 millimetres (0.069 in) by 6.14 mm (0.242 in) in size.


15 cm TbtsK C/36 naval gun, Gun characteristics
It shot a projectile which weighed 45.3 kg (100 lb), which was propelled by 13.5 kg (30 lb) of RPC/38, with a muzzle velocity of 875 metres per second (2,870 ft/s). The gun had a working pressure of 3,000 kilograms per square centimetre (43,000 psi), and had a service life of about 1,600 rounds fired. The gun had a maximum range of 23.55 kilometres (14.63 mi) at 47° of elevation.


15 cm TbtsK C/36 naval gun, Gun characteristics, Gun mechanics
The 15 cm TbtsK C/36 naval gun was semi-automatic, and had a horizontal sliding breech, which needed to be manually opened to load the first shot. The first shot was loaded using a breech level, which was on the right hand side of the breech ring. The barrel was somewhat loose, but anchored to the breech end with a breech nut. The gun had an electromagnetic trigger circuit, which was backed up by a mechanical system in case of emergency. The gun was placed on a TbtsL C/36 mount.


15 cm TbtsK C/36 naval gun, Gun characteristics, Gun mechanics
This mount was placed upon a cylindrical pillar, which was affixed to the base by fourteen bolts. The mount's vertical shaft bearing was in the centre of the pillar, and was topped by the toothed training ring. The mount itself was made out of a splinter-proof shield, training and elevation mechanisms, buffer-stops, the gunners' seats, gun sights, triggers, remote control mechanisms and the electric gun motors.


15 cm TbtsK C/36 naval gun, Gun characteristics, Gun mechanics
In 1943, tests were done on adding a muzzle heater to the barrel of the 15 cm TbtsK C/36 gun, in order to prevent the barrel from icing up in freezing temperatures, but this was abandoned when it was found that it both would consume too much electricity, and put too much strain on the mount's elevating gear. The gun cradle was made of a hollow tube, two hydraulic buffers which could absorb a recoil force of up to 58,000 kg (128,000 lb), and a pneumatic recuperator.


15 cm TbtsK C/36 naval gun, Gun characteristics, Controls
The 15 cm TbtsK C/36 naval gun's training and elevation mechanisms were powered either manually or by electric motors, which were controlled by hydraulic handles. The left side gunner controlled the training and elevating mechanisms. When power training was on, the movement of the gun could be controlled simply by the hand-wheels, in an arc of up to 150°. In order to revert to manual controls, all the handles had to be disengaged. In an emergency, the right side gunner could take control of the training and elevation of the gun.


15 cm TbtsK C/36 naval gun, Gun characteristics, Controls
The gun had two trigger systems, one electromagnetic, the other mechanical. Both gunners had a foot pedal for the mechanical system, which could also be fired directly by attaching a lanyard to the trigger level, if needed. Both gunners had a trigger switch on their right hand-wheel, which controlled the electromagnetic circuit, which could also be fired remotely from the conning tower, if needed. Both gunners had linked stereoscopic sights, which could magnify between 5x and 10x zoom. The right gunner was responsible for making corrections for elevation, which were supplied by two sets of compensating gears.


15 cm TbtsK C/36 naval gun, Gun characteristics, Controls
The first gear, also called the "Regler" gear, gave corrections based upon what type of ammunition was in use, and the second compensated for barrel wear. Firing information was transmitted to the gun via wire, from the fire-direction centre. Both gunners had a receiver, and their settings would be transmitted to the fire-direction centre, which also had an intercom link to the guns.


15 cm TbtsK C/36 naval gun, Gun houses, C/36 single turret
The C/36 gun house had a total weight of 18,800 kg (41,400 lb): 7,200 kg (15,900 lb) from the barrel and breech, 1,730 kg (3,810 lb) from the cradle and recuperating gear (only 1,500 kg (3,300 lb) after 1942 modifications), 3,885 kg (8,565 lb) from the mount, 4,153 kg (9,156 lb) from the gun shield, 650 kg (1,430 lb) from the gun sights, and 580 kg (1,280 lb) from the electronic wires and equipment. The gun house could have up to an extra 330 kg (730 lb) in auxiliary equipment.


15 cm TbtsK C/36 naval gun, Gun houses, C/36 single turret
Of the five single turrets, the first, 'A', could be trained from 30° to 0° to 330°. The second, 'B', could be trained from 40° to 0° to 320°. The third, 'C', could be trained from 20° to 0° to 340°. The fourth, 'D', could be trained from 27° to 0° to 333°. The fifth, 'E', could be trained from 42° to 0° to 318°. All of the turrets could be depressed to up to –10°, or elevated to up to 30°.


15 cm TbtsK C/36 naval gun, Gun houses, C/36 single turret
The C/36 gun house was encased by a splinter-proof shield, which covered the front, sides, and top of the gun, but not the rear. The gun house's armor was 10 mm (0.39 in) thick in the front, and 6 mm (0.24 in) thick on the sides and roof. The front side contained two closable flaps for sighting ports, one to the right and one to the left of the central gun port. The foot of the shield contained four inspection flaps, two at the front, and one on both the right and left side.


15 cm TbtsK C/36 naval gun, Gun houses, C/36 single turret
These flaps allowed for the power-training equipment to be serviced easily. The mount was supplied from the ship's main supply, at 220-electronvolt (35 aJ) direct current. This current powered the trigger circuit solenoid, the 1 kilowatt (1.3 hp) permanent and 3 kW (4.0 hp) peak output training and elevating motors, and the moveable auxiliary lighting of the mount. The lights for the gun sights, the control positions, the breech, and the firing warning system (flashing blue and red lights, alongside a buzzer), were all powered by a 4 eV (0.64 aJ) transformer.


15 cm TbtsK C/36 naval gun, Gun houses, DrhL C/38 twin turret
The DrhL C/38 turret was originally designed for the three O class battlecruisers and cruisers, but after these were cancelled, it was decided to use them to arm the Type 1936A destroyers. It was thought that one twin turret might raise the number of effective guns back to five, without causing the same weight problems that led to the reduction down to four. Two 15 cm TbtsK C/36 guns were thus fit into the DrhL C/38 twin turret.


15 cm TbtsK C/36 naval gun, Gun houses, DrhL C/38 twin turret
Despite extensive melding and other modifications, the new twin turret still weighed almost twice that of the C/36 turret, making it roughly weight equal with simply adding back the fifth C/36 gun. Additionally, there were problems integrating the new DrhL C/38 turret into the existing fire control systems. There were some plans to mount two of these turrets onto new destroyers, but they were never put into place. The DrhL C/38 turret was used on the German destroyers: Z23, Z24, Z25, Z29, Z31, Z32, Z33, Z34, Z37, Z38, Z39, Z40, Z41, and Z42.


15 cm TbtsK C/36 naval gun, Gun houses, DrhL C/38 twin turret
The C/38 turret was elevated by a Pittler-Thoma hydraulic gear, which was powered by electric motors, and training was done by electric motors. Manual training could also be used in emergencies. The internal design of the C/38 turret was almost identical to that of the C/36, and their guns and equipment were entirely identical. Both guns had an Ardelt electric ammunition hoist, and a ten-round ready use supply was placed at the rear of the turret, allowing the gunners to fire at short notice, without having to wait for the hoists. These ready use charges were kept in airtight aluminum containers, which were themselves locked in galvanized steel boxes, in order to keep them dry.


15 cm TbtsK C/36 naval gun, Gun houses, DrhL C/38 twin turret
The C/38 had a total weight of 60.4 t (59.4 long tons; 66.6 short tons): 7,200 kg from the barrel and breech, 4,300 kg (9,500 lb) from the cradle and recuperator, 22,250 kg (49,050 lb) from the mount, 13,750 kg (30,310 lb) from the turret shield, 650 kg (1,430 lb) from the sights, and 2,400 kg (5,300 lb) from the electronic wiring and mechanisms. The turret had an armor thickness of 30 mm (1.2 in) on the front, 20 mm (0.79 in) on the sides, 20 mm on the roof, and 15 mm (0.59 in) on the rear.


15 cm TbtsK C/36 naval gun, Gun houses, DrhL C/38 twin turret
The turret had a barbette diameter of 3.2 m (10 ft), a turret diameter of 2.8 m (9 ft 2 in), and a recoil distance of 44 cm (17 in). The distance between the twin guns was 1.07 m (3 ft 6 in). The gun could be elevated at up to 8°/s, and trained at the same speed. The turret had a maximum depression of –10°, and a maximum elevation of 65°.


15 cm TbtsK C/36 naval gun, Gun houses, DrhL C/38 twin turret
Of the turrets: 'A', which was the sole Drhl C/38 twin turret, could be trained from 30° to 0° to 330°. 'B' could be trained from 42° to 0° to 318°. 'C' could be trained from 27° to 0° to 333°. 'D' could be trained from 20° to 0° to 340°.


15 cm TbtsK C/36 naval gun, Static gun batteries
The C/36 gun was installed in a number of static gun batteries for coastal defence. In Normandy, the Longues-sur-Mer battery had four steel-reinforced concrete casemates each with a C/36 naval gun. The guns were controlled by a ranging post in front of the battery.


15 cm hrubá houfnice vz. 25
The 15 cm hrubá houfnice vz. 25 (Heavy howitzer model 25) was a Czech heavy howitzer used in the Second World War. It was taken into Wehrmacht service as the 15 cm sFH 25(t). Slovakia had 126 in inventory.


15 cm hrubá houfnice vz. 25, Design & History
Intended to replace the various Austro-Hungarian heavy howitzer that the Czechs had inherited, they began a program to develop a new howitzer shortly after achieving independence in 1919. It didn't reflect many of the lessons of World War I as it retained a box trail and wooden wheels suitable only for horse traction. Its carriage broke down into two loads for transport. It fired a 42 kilograms (93 lb) shell.


15 cm sFH 02
The 15 cm schwere Feldhaubitze 1902 was a German heavy field howitzer cannon introduced in 1903 and served in World War I.


15 cm sFH 02, Design and history
It was the first artillery piece to use a modern recoil system in the German Army. Some 416 were in service at the beginning of the World War I. Its mobility, which allowed it to be deployed as medium artillery, and fairly heavy shell gave the German army a firepower advantage in the early battles in Belgium and France in 1914 as the French and British armies lacked an equivalent. France had a Canon de 65 M with a recoil system, but used it only as a mountain howitzer.


15 cm sFH 02, Design and history
The remains of a German sFH 02 howitzer located in Kei Mouth, South Africa. It was captured from German forces in South West Africa during World War I. Like other such German weapons of the time, it was cast with the markings R II Ultima Ratio Regum ("last argument of kings").


15 cm sFH 02, Design and history
Another sFH 02 howitzer, this one confiscated by the US after World War I and now located in Sierra Madre Memorial Park.


15 cm sFH 13
The 15 cm schwere Feldhaubitze 13 (15 cm sFH 13), was a heavy field howitzer used by Germany in World War I and the beginning of World War II.


15 cm sFH 13, History
The gun was a development of the previous standard howitzer, the 15 cm sFH 02. Improvements included a longer barrel resulting in better range and a gun shield to protect the crew. Variants were: the original "kurz" (L/14 – 14 calibre short barrel version), the lg. sFH13 with a longer barrel; with minor modifications to simplify wartime manufacture of the lg. sFH weapons. Initially there were serious issues of weak recoil spring mechanisms that would break, and gun barrel explosions. The problems were solved with the upgrades.


15 cm sFH 13, History
A sub variant of the sFH 13 was the lg. 15 cm sFH 13/02 which combined the long barrel with the carriage of the earlier sFH 02 when those guns became obsolete. The sFH 13/02 gun shield wasn't hinged at the top and it only used a hydro-spring recoil system. Approximately 1,000 conversions were completed and their performance was the same with only a 40 kg difference in weight.


15 cm sFH 13, History
The British referred to these guns and their shells as "five point nines" or "five-nines" as the internal diameter of the barrel was 5.9 inches (150 mm). The ability of these guns to deliver mobile heavy firepower close to the frontline gave the Germans a major firepower advantage on the Western Front early in World War I, as the French and British lacked an equivalent. It was not until late 1915 that the British began to deploy their own 6 inch 26 cwt howitzer.


15 cm sFH 13, History
About 3,500 of these guns were produced from 1913 to 1918. They continued to serve in the Reichswehr and then the Wehrmacht in the interwar period as the standard heavy howitzer until the introduction of 15 cm sFH 18 in the 1930s. They were then shifted to reserve and training units, as well as to coastal artillery. Guns turned over to Belgium and the Netherlands as reparations after World War I were taken into Wehrmacht service after the conquest of the Low Countries as the 15 cm sFH 409(b) and 15 cm sFH 406(h) respectively.


15 cm sFH 13, History
In the course of World War II about 94 of these howitzers were mounted on Lorraine 37L tractors to create self-propelled guns, designated 15 cm sFH13/1 (Sf) auf Geschuetzwagen Lorraine Schlepper (f).


15 cm sFH 18
The 15 cm schwere Feldhaubitze 18 or sFH 18 (German: "heavy field howitzer, model 18"), nicknamed Immergrün ("Evergreen"), was the basic German division-level heavy howitzer of 149mm during the Second World War, serving alongside the smaller but more numerous 10.5 cm leFH 18. Its mobility and firing range and the effectiveness of its 44 kilogram shell made it the most important weapon of all German infantry divisions. A total of 6,756 examples were produced.


15 cm sFH 18
It replaced the earlier, First World War-era design of the 15 cm sFH 13, which was judged by the Krupp-Rheinmetall designer team of the sFH 18 as completely inadequate. The sFH 18 was twice as heavy as its predecessor, had a muzzle velocity increase of forty percent, a maximum firing range 4.5 kilometers greater, and a new split-trail gun carriage that increased the firing traverse twelvefold. The secret development from 1926–1930 allowed German industry to deliver a trouble-free design at the beginning of German re-armament in 1933. It was the first artillery weapon equipped with rocket-assisted ammunition to increase range. The sFH 18 was also used in the self-propelled artillery piece schwere Panzerhaubitze 18/1 (more commonly known as Hummel).


15 cm sFH 18
The sFH 18 was one of Germany's three main 15 cm calibre weapons, the others being the 15 cm Kanone 18, a corps-level heavy gun, and the 15 cm sIG 33, a short-barreled infantry gun.


15 cm sFH 18, Design and development
Development work on the sFH 18 began in 1926 and the gun was ready for production by 1933. The model year was an attempt at camouflage. The gun originated with a contest between Rheinmetall and Krupp, both of whom entered several designs that were all considered unsatisfactory for one reason or another. In the end the army decided the solution was to combine the best features of both designs, using the Rheinmetall gun on a Krupp carriage.


15 cm sFH 18, Design and development
The carriage was a relatively standard split-trail design with box legs. Spades were carried on the sides of the legs that could be mounted onto the ends for added stability. The carriage also saw use on the 10 cm schwere Kanone 18 gun. As the howitzer was designed for horse towing, it used an unsprung axle and hard rubber tires. A two-wheel bogie was introduced to allow it to be towed, but the lack of suspension made it unsuitable for towing at high speed.


15 cm sFH 18, Design and development
The gun was officially introduced into service on 23 May 1935, and by the outbreak of war the Wehrmacht had about 1,353 of these guns in service. Production continued throughout the war, reaching a peak of 2,295 guns in 1944. In 1944, the howitzer cost 40,400 RM, 9 months and 5,500 man-hours to make.


15 cm sFH 18, Design and development, Variants
Several other versions of the basic 15 cm were produced:


15 cm sFH 18, Combat record
The first field combat for the 15 cm sFH 18 was with the Chinese National Revolutionary Army in the Second Sino-Japanese War. The Chinese were desperately short on artillery guns and other heavy weapons, but the few 15 cm sFH 18 units the Chinese did have hopelessly outclassed their Japanese counterparts which were mainly the Type 38 15 cm howitzer and Type 4 15 cm howitzer, forcing the Japanese to introduce the Type 96 15 cm Howitzer. Some earlier pieces (about 24) of sFH18 in China were designed specially with a 32/L barrel, known as sFH18 32/L; the maximum range was increased to 15 km.


15 cm sFH 18, Combat record
Against the Soviet Union, the sFH 18 lacked the range of the Red Army 152 mm ML-20 gun-howitzer, its maximum range of 17.3 kilometres (18,900 yd) allowed it to fire counter-battery against the sFH 18 with a   4 kilometres (4,400 yd) advantage. This led to numerous efforts to introduce new guns with even better performance than the ML-20, while various experiments were also carried out on the sFH 18 to improve its range.


15 cm sFH 18, Combat record
These led to the 15 cm sFH 18M version with a removable barrel liner and a muzzle brake that allowed a larger "special 7" or 8 charge to be used. The 18M increased range to 15,100 metres (16,500 yd), but it was found that the liners suffered increased wear and the recoil system could not handle the increased loads in spite of the brake. This led to the introduction of the 15 cm R. Gr. 19 FES ammunition, which used a rocket-assisted round that could reach 18,200 metres (19,900 yd) and give it some level of parity with the ML-20.


15 cm sFH 18, Combat record
Several countries continued fielding the sFH 18 after the war in large numbers including Czechoslovakia, Portugal and many South American and Central American countries. Finland bought 48 sFH 18 howitzers from Germany in 1940 and designated them 150 H/40. These guns were modernized in 1988 as the 152 H 88, and they were used by the Finnish Army until 2007.


15 cm sFH 36
The 15 cm schwere Feldhaubitze 36 or sFH 36 (German: "heavy field howitzer, model 36"), was a shortened lightweight version of the earlier 15 cm schwere Feldhaubitze 18 that was produced in limited numbers from 1938-1942 and used during World War II.