V-3 cannon

Infobox Weapon
name= Hochdruckpumpe
(high-pressure-pump)

cite book |last=Thompson|first=Peter|authorlink=
title=The V-3 Pump Gun|year=1999|publisher=ISO Publications|location=London|pages=]


caption=
origin= Nazi Germany
type= artillery
is_ranged=yes
is_bladed=
is_explosive=
is_artillery=yes
is_vehicle=
is_missile=
is_UK=
service= 1944 - 1945
used_by= Nazi Germany
wars= World War II
designer=
design_date=
manufacturer= Krupp

cite book |last=Henshall|first=Philip|title=Hitler’s Rocket Sites|year=1985|publisher=St Martin's Press|location=New York|isbn= |pages=p61|quote=]
unit_cost=
production_date=
number=
variants=
weight=
length= 130 metrescite web|last=|first=|url=http://www.theotherside.co.uk/tm-heritage/visit/visit-2caps-mimoyec-v3.htm|title=Fortress de Mimoyecques|work=|accessdate=2007-12-24|publisher=theotherside.co.uk (bottom of page)]
part_length=
width=
height=
diameter=
crew=
cartridge= 140 kg
caliber= 150 mm
action=
rate= 300 shells per hour (projected)
velocity= 1500 m/s
range=
max_range= 165 km
feed=
sights=
breech=
recoil=
carriage=
elevation=
traverse=

The V-3 (Vergeltungswaffe 3), also known as the "Hochdruckpumpe" ("High Pressure Pump", HDP for short) and "Fleissiges Lieschen" ("Busy Lizzie"),cite web|last=|first=|url=http://www.nat-military-museum.lu/pageshtml/museumspecial.php|title=The V3 weapon system (HDP), «High pressure pump» or «Centipede»|work=Current museum specials & news|accessdate=2007-12-24|publisher= (bottom of page)] was a German World War II supergun working on the multi-charge principle whereby secondary charges are detonated to add velocity to a projectile.

The weapon was planned to be used to bombard London from two large bunkers in the Pas-de-Calais region of northern France, which were rendered unusable by Allied bombing raids before completion. Two similar guns were used to bombard the city of Luxemburg from December 1944 to February 1945.

Description of V-3

The gun used multiple propelling charges placed along the barrel's length and timed to fire as soon as the projectile passed them by, to provide an additional boost. Due to their higher suitability and ease of use, solid-fuel rocket boosters were used instead of explosive charges. These were arranged in symmetrical pairs along the length of the barrel, angled to project their thrust against the base of the projectile after it passed. This layout spawned the German codename "Tausendfüßler" ("millipede"). Unlike conventional rifled weapons of the day, the smooth-bore gun fired a fin-stablized shell, dependent upon aerodynamic (rather than gyroscopic) forces to prevent tumbling and consequent high drag. [cite web | last = | first = | authorlink = | coauthors = | title = V-3 | work = | publisher = [http://www.astronautix.com/ Astronautix.com] | date = | url = http://www.astronautix.com/lvs/v3.htm | format = | doi = | accessdate = 2008-06-11]

Development

In 1943, German engineer August Cönders, of Röchling Stahlwerk AG, proposed an electrically-detonated multi-charge weapon. Thanks to the success of one of Cönders' other projects, the "Röchling Shell", major figures in the Nazi establishment took notice of him, most importantly Albert Speer, the Minister of Munitions.cite book | last = Wood | first = Paul | authorlink = | coauthors = Roger Ford | title = Germany's Secret Weapons in World War II | publisher = Zenith Imprint | year = 2000 | location = | pages = pp. 117 - 119 | url = | doi = | id = | isbn = 0760308470]

Cönders was ordered to produce a prototype of the "Hochdruckpumpe" ("high-pressure-pump")

cite book |last=Thompson|first=Peter|authorlink= |title=The V-3 Pump Gun|year=1999|publisher=ISO Publications|location=London|pages=] and duly constructed one in 20 mm calibre which proved satisfactory. At this point Adolf Hitler, who had been following the project with interest, took a hand. He decided that a battery of 50 full size guns would be sited in northern France and used to bombard London.

Cönders had constructed a full-calibre gun at the Hillersleben proving ground near Magdeburg but by the end of 1943 had encountered severe problems both in putting the gun's basic principle into operation and in producing a feasible design for the shells it was to fire. Even when everything worked, the muzzle velocity was just over convert|1000|m/s|ft/s which was nowhere near what had been promised. Nonetheless plans were progressed to build a single full-size gun with a convert|150|m|ft barrel at Misdroy on the Baltic island of Wolin, near Peenemünde, while construction at the Mimoyecques site in France (which had already been attacked by the USAAF and the RAF) went ahead. By March 1944, with no good news coming out of Misdroy, the "Heereswaffenamt" (Weapon Procurement Office) took control of the project and Cönders became one of the engineers working on the three chief problems: projectile design, obturation, and ignition of the secondary charges.

Six different companies including Krupp and Skoda produced satisfactory designs for projectiles. Obturation problems were solved by placing a sealing piston behind the projectile and the initial propellant charge, which in turn prevented the flash from the charge from getting ahead of the projectile and solved the problem of controlling the detonation of the secondary charges. By the end of May 1944 there were four designs for the 150 mm finned projectile, one manufactured by Fasterstoff (designed by Füstenberg), and three others by Röchling (Cönders), Bochumer (Verein-Haack), and Witkowitz (Athem).

Trials were held at Misdroy from May 20-24 1944 with ranges of up to convert|55|mi|km being attained.^p218 On July 4, 1944 the Misdroy gun was test fired with 8 rounds (one of the 6-foot-long shells travelled convert|93|km|mi) before it burst,^p245 effectively putting an end to the project.

Mimoyecques site

Following Hitler's decision that HDP guns be sited in northern France to bombard London, the task of finding a suitable site for the HDP batteries was given to Major Bock of Festung Pioneer-Stab 27, the fortification regiment of LVII Corps, Fifteenth Army, at the time based in the Dieppe area. A study in early 1943 concluded that a hill with a rock core would be most suitable, as the gun tubes could be placed in drifts (inclined tunnels) and support equipment and supplies located in adjacent tunnels.

A suitable site was selected at a limestone hill about convert|5|km|mi north of the Hidrequent quarries, near Mimoyecques in the Pas-de-Calais region of northern France behind Cap Gris Nez, very close to the French end of the present day Channel tunnel, where V-1 and V-2 launch sites were already under construction. The site was convert|8|km|mi from the sea and convert|165|km|mi from London.cite web | last = | first = | authorlink = | coauthors = | title = BASE V-3 UNE BASE POUR BOMBARDER LONDRES | work = Les Canons De L'apocalypse | publisher = | date = | url = http://html2.free.fr/canons/basev3.htm | format = | doi = | accessdate = 2008-06-11] Codenamed "Wiese" (meadow) and "Bauvorhaben 711" (Construction Project 711), Organisation Todt began construction in September 1943 with the building of railway lines to support the work, and began to excavate the gun shafts in October.cite book | last = Zaloga | first = Steven J. | authorlink = Steven Zaloga | coauthors = Hugh Johnson, Chris Taylor | title = German V-Weapon Sites 1943-45 | publisher = Osprey Publishing | year = 2008 | location = | pages = | url = | doi = | id = | isbn = 1846032474] The initial layout comprised two parallel facilities approximately convert|1000|m|ft apart, each with five drifts which were to hold a stacked cluster of five HDP gun tubes, for a total of 50 guns. Both facilities were served by an underground railway tunnel and underground ammunition storage galleries.

Aerial reconnaissance photographs taken on 18 September 1943 of "Marquise-Mimoyecques" (as the site was called in Allied documents) showed suspicious activity that had not appeared on earlier images taken on 2 September. The Central Interpretation Unit (CIU) issued a report on its interpretation of the Marquise-Mimoyecques site on 25 September 1943 and the site was attacked on 5 November 1943 as part of Operation Crossbow, resulting in light damage and 10 killed and 32 wounded.

A detailed study of the site was conducted on 13 November 1943, which concluded that it was a new type of site and the only one of its type so far discovered. The report described at length the railway facilities under development as well as eight strange structures which were identified as the covers for rocket launch tubes. These were in fact the covers for the HDP gun shafts.

Although the bombing of the site had little effect, Allied air attacks on communication networks and industrial centres had slowed down German economic activityFact|date=June 2008, forcing them to revise their plans to enable substantial savings of concrete on all sites under construction. It was therefore decided to scale back the project by stopping work on the western site before any shafts had been created and concentrate instead on the eastern site.

The eastern complex consisted of five drifts angled at 50 degrees reaching convert|105|m|ft below the hilltop. The five drifts exited the hilltop through a concrete slab convert|30|m|ft wide and convert|5.5|m|ft thick. Large steel plates protected the five openings and each drift had a special armoured door. Extensive tunnels and elevator shafts supported the guns, and had the site become operational about 1,000 troops from Artillerie Abteilung 705 and supporting units would have been deployed at Mimoyecques. Artillerie Abteilung 705 had been organised in January 1944 under Oberstleutnant Georg Borttscheller to operate the Wiese gun complex.

The plans were to have the first battery of five gun tubes ready for March 1944, and the full complex of 25 gun tubes by 1 October 1944. However, following a failure at the Misdroy proving ground in April 1944 after only 25 rounds had been fired, the project was further cut back, from five drifts to three even though work had begun on some of the other drifts. The site was finally put out of commission on 6 July 1944, when bombers of RAF Bomber Command's 617 Squadron attacked using convert|5400|kg|lb "Tallboy" deep-penetration bombs.

One Tallboy directly impacted the concrete slab on top of the complex, collapsing Drift IV, and three other Tallboys penetrated the tunnel system below creating extensive damage. Some effort was made to clean up the debris, but by late July it was obvious that the damage was too severe to justify continuing construction since the RAF could well conduct further Tallboy raids. Plans were made to reconstruct the gun battery at the Rixtent B81 liquid oxygen facility but this never occurred. The Allies were, however, unaware that work had ceased at Mimoyecques, and further missions were flown against the site. A mission was flown on 6 August 1944, as part of Operation Aphrodite, using drone B-17s laden with explosives, but none of the targets were hit. A further mission was flown on 12 August which again resulted in failure, and the death of Joseph P. Kennedy, Jr..

Never formally abandoned, the Mimoyecques site was overrun by the Canadian 3rd Infantry Division on 5 September 1944.

Allied attacks on Mimoyecques site

Luxembourg bombardment

The project eventually came under the control of the SS and SS General Hans Kammler ordered the project to be ready for action in late 1944. Assisted by Walter Dornberger, a battery of two shorter guns approx. convert|50|m|ft long with 12 sidechambers were constructed and placed in the hands of the army artillery unit Artillerie Abteilung 705 under the command of Captain Patzig. These were sited in a wooded ravine of the Ruwer River at Lampaden about convert|13|km|mi southeast of Trier in Germany.cite web | last = | first = | authorlink = | coauthors = | title = The V3 weapon system (HDP), « High pressure pump » or « Centipede » | work = | publisher = National Museum of Military History | date = | url = http://www.nat-military-museum.lu/pageshtml/museumspecial.php | format = | doi = | accessdate = 2008-06-01]

The two guns were aimed west, resting on 13 steel support structures on solid wooden bases on a 34 degree slope. The city of Luxembourg (which had been liberated in September 1944) was at a range of about convert|43|km|mi and was designated Target No. 305. Between the two gun tubes concrete blockhouses were constructed as well as ten smaller bunkers to hold projectiles and propellant charges.

The assembly and mounting of the Lampaden guns coincided with the final preparations for the Battle of the Bulge. However, the supply of ammunition became problematical due to the state of the German railway network. As time had become critical, it was decided to use a convert|150|mm|in finned projectile with a discarding sabot, weighing convert|95|kg|lb and carrying a convert|7|kg|lb - convert|9|kg|lb explosive charge. The propellant comprised a convert|5|kg|lb main charge and 24 subsidiary charges for a total of convert|73|kg|lb.

By the time the Ardennes offensive began on 20 December 1944, Kammler received orders from OB West (German Army Command in the West) to begin firing at the end of the month and on 30 December 1944 the first gun tube was ready for action. Two warm up rounds were initially fired, followed by 5 high explosive shells which were fired in sequence, attended by Kammler. The muzzle velocity was approximately convert|935|m/s|ft/s.

The second gun tube was brought into operation on 11 January 1945 and in total some 183 rounds were fired until 22 February 1945, with 44 confirmed hits in the urban area. The guns were not particularly effective; of the 142 rounds that impacted Luxembourg, total casualties were 10 dead and 35 wounded. Firing ceased on 22 February, when US Army units had advanced to within convert|3|km|mi of the Lampaden site.

Final fate

A second battery of guns began to be deployed in January 1945 at Bühl, aimed at Belfort in support of the Operation Nordwind offensive. One gun was erected before the failure of the Nordwind offensive put the site at risk, and the equipment was removed before firing could begin.

There were other proposals to deploy batteries to bombard Antwerp and other cities but these were not implemented due to the poor state of the German railway network and a lack of ammunition. All four HDP guns were eventually abandoned at the Röchling works in Wetzlar and Artillerie Abteilung 705 was re-equipped with conventional artillery. [cite book | last = Zaloga | first = Steven J. | authorlink = Steven Zaloga | coauthors = Hugh Johnson, Chris Taylor | title = German V-Weapon Sites 1943-45 | publisher = Osprey Publishing | year = 2008 | location = | pages = | url = | doi = | id = | isbn = 1846032474] The disassembled gun tubes, spare parts, and remaining ammunition were later captured by the US Army and shipped to the United States where they were tested and evaluated at the Aberdeen Proving Ground, Maryland, where they were finally scrapped in 1948.

V-3 Museum

The Mimoyecques museum allows visitors to view the galleries (in various stages of construction and bombing damage), remains of the guns, a small scale V-3 replica, and examples of machinery, rail systems and tools employed. The site also contains memorials to the slave-laborers who were employed by the Nazis to construct it,cite web|last=|first=|url=http://translate.google.com/translate?hl=en&sl=fr&u=http://www.basev3-mimoyecques.com/&sa=X&oi=translate&resnum=1&ct=result&prev=/search%3Fq%3Dbasev3-mimoyecques%26hl%3Den|title=Forteresse de Mimoyecques|work=|accessdate=2007-12-24|publisher=basev3-mimoyecques.com NOTE: The length of the V-3 cannon at Mimoyecques surpassed the Schwerer Gustav (Dora) 800 mm super-cannon, the Mörser Karl (Gerät 040) 600 mm tracked siege mortar, and the "Leopold" and "Robert" 320 mm railway cannons.] alongside memorials to the airmen lost in action during the destruction of the base.

The Misdroy site also has a museum.cite web|last=|first=|url=http://translate.google.com/translate?hl=en&sl=pl&u=http://www.infoturystyka.net.pl/bunkierv3/&sa=X&oi=translate&resnum=1&ct=result&prev=/search%3Fq%3Dbunkierv3%26hl%3Den |format=html |title=bunkierv3|work=|accessdate=2008-06-09|publisher=infoturystyka.net.pl]

Notes

References

* [http://www.lostplaces.de/cms/content/view/94/33/ V3-Stellung bei Hermeskeil-Lampaden (V3 position at Hermeskeil-Lampaden)] - German language site