BL 8 inch Howitzer Mk 6 - 8

Infobox Weapon


caption=US-built version of Vickers BL 8-inch Howitzer Mk 6 outside the War Museum in Helsinki, Finland
name=BL 8 inch Howitzer Mk VI, VII, VIII
target=general
origin= UK
is_artillery=yes
is_UK=yes
is_ranged=yes
used_by=UK
AUS
FIN
USA
wars=World War I, World War II
designer=Vickers
design_date=
manufacturer=Vickers
Midvale Steel
prod_date=
type=Heavy howitzer
date=
service=1916 - 1943
caliber=convert|8|in|mm|sigfig=4|sing=on
part_length=convert|117.7|in|m|sigfig=4 Mk VI
convert|138.4|in|m|sigfig=4 Mk VII, VIII
carriage=wheeled, box trail
breech=Asbury interrupted screw
rate=
velocity=convert|1300|ft/s|m/s|sigfig=3 (Mk VI)
convert|1500|ft/s|m/s|sigfig=3 (Mk VII, VIII)
cartridge= HE convert|200|lb|kg|sigfig=4
ammo_wt= 90 kg
range=convert|10745|yd|m|sigfig=4 Mk VI
convert|12300|yd|m|sigfig=4 Mk VII, VIII
recoil=hydro-pneumatic recuperator, hydraulic buffer
weight= 3.4 tonnes
length=
crew=
number=678 (UK) [Clarke 2005, page 38]
elevation=-4° - 50° (Mk VI)
0° - 45° (Mk VII, VIII)
traverse=4° L & RThe BL 8-Inch Howitzer Marks 6, 7 and 8 were a family of British artillery pieces of the First and Second World Wars, built by Vickers in Britain and by Midvale Steel in USA.

Design and variants

8 inch was a common howitzer caliber during the First World War. The Mk 6, 7 and 8 were specifically designed as a howitzer and should not be confused with the stopgap early Marks 1 - 5 of 8-inch howitzer which used shortened and bored-out naval 6-inch gun barrels.

;Mk 6Requested in August 1915 and first delivered March 1916. It was effectively a scaled-up version of Vickers's successful 6 inch howitzer [Clarke 2005, page 38] and was 4-5 tonnes lighter than the current improvised 8 inch "howitzers". The barrel was 14.7 calibres (117.7 inches) in length, with a range of 10,745 yards (9,825 m).

;Mk 7Introduced July 1916. Mk 7 had a longer barrel (17.3 calibres, or 138.4 inches) and increased the range to 12,300 yards (11,250 m). The new barrels turned out to have short lives and suffered from cracked A tubes (the inner rifled layer of the built-up barrel).

;Mk 8Mk 8 incorporated various small improvements and a thicker and stronger barrel.

Combat use

World War I

Early problems of stability on very hard or soft ground became apparent with the Mk VI, leading to the recoil system not functioning correctly. A Commission went to France to investigate, and a special level "Vickers platform" was adopted, to which the wheels and trail were secured for accurate shooting. A major change in the line of shooting required the platform to be relaid. Setting-up and adjusting the platform was labour-intensive. [Clarke 2005, page 46] The US manual describes it :- [Handbook of artillery. United States. Army. Ordnance Dept, May 1920, Page 281]

"The platform consists of wooden beams which assemble to form a triangular platform. The spade must be removed and a special bracket fitted on the trail when using this platform. This bracket travels in a groove which gives a bearing for the bracket and also provides a means of traversing the piece 52° on the platform. The main objects in the use of the firing platform are : To provide a reliable support for the wheels and rear end of the trail, so as to prevent sinking or movement when firing on soft ground; to ensure the gun remaining on the target when firing; and to provide means for shifting the trail transversely through an angle of 52° (26° each side of center). By using the traversing gear on the carriage a total traverse of 30° on each side of the center is obtainable... The carriage wheels rest on steel plates on the wheel platform and are guided by curved-steel angles which prevent lateral movement of the gun off the target when in action. When the firing platform is used, the float plate, with spade attached, which is bolted to the underside of the trail, is removed and another float plate, having a thrust bracket attached, is bolted in its place".

At the end of World War I on the Western Front Canada had 2 6-gun batteries, Australia 1, Britain 37. [Farndale 1986, Annex M Order of Battle France and Flanders 11th November 1918] British 8 inch howitzer batteries serving in other theatres at the Armistice were : UK 1 (6 guns), Macedonia 1 (4 guns), and 2 guns in Palestine [Farndale 1988, Annex 1]

World War II

By the start of World War II some Mk 8 were still in use and were used in France in May to June 1940. After the Fall of France, remaining guns were used for training only. The advent of the BL 7.2-Inch howitzer meant that remaining 8 inch barrels were relined to 7.2 inch. With no guns left they were not surprisingly declared obsolete by July 1943.

Use by United States

Versions of Mk 6 were manufactured in the United States by Midvale Steel and Ordnance Co, Nicetown, Pa. during World War I, initially supplied to Britain and then used to equip US forces when it entered the war.

A US Mk 8 1/2 version was also manufactured and adopted in US service from October 1918. [Hartwell "8-inch British Howitzer"] Quoting from the US Army manual of 1920 on artillery in US service :- [Handbook of Artillery, US Ordnance Dept, May 1920, page 261, 263, 268]

"The 8 inch howitzer materiel is called the "Vickers" model of 1917, of which there are in use two types, the Mark VI and Mark VII. The main differences between the Mark VI and Mark VII being that the former has a lower muzzle velocity and consequently a shorter range than the latter, also that the Mark VII has a barrel of the "wire wound" construction, whereas the Mark VI type is of the "built up" construction...

The Mark VII has lately been superseded by a Mark VIII 1/2, the difference between the two being that the powder chamber walls of the Mark VII proved to be too thin, while the Mark VIII 1/2 overcomes this defect by having thicker powder chamber walls...

... the average life of the 8-inch howitzer, Mark VI, [before the barrel needs relining] is 7,800 rounds, while that of the Mark VIII 1/2 is 3,000 rounds.

The Mark VI howitzer has a muzzle velocity of 1,300 feet per second and a maximum range of 10,760 yards and is of British design and both British and American manufacture. The Mark VII howitzer has a muzzle velocity of 1,525 feet per second and maximum range of 12,280 yards and is of British design and manufacture.

The Mark VIII 1/2 is an American modification of the British wire-wound Mark VIII howitzer to permit of a built up type of construction and is strictly of American manufacture. The Mark VIII 1/2 has the same muzzle velocity and range as the Mark VIII.

Due to the combination of British and American manufacture, there are several types of breech mechanism in service; the two main types are the T and the French percussion type...

The Mark VIII 1/2 howitzer is also of the built-up-construction type, but differs from the Mark VI howitzer in that it consists of two tubes, an inner and an outer, over which is shrunk the jacket. The jacket in this case supports the howitzer, without the use of guide rings. A breech ring is shrunk on over the jacket and carries a lug for connecting the gun to the recoil mechanism. A breech bushing similar to that of the Mark VI is fitted for the breech mechanism. The total length of this howitzer is about 12 1/2 feet [compared to Mk VI 10 1/2 feet] and its maximum range is approximately 12,360 yards. This howitzer is mounted on the Mark VII carriage".

The 58th Regiment Coast Artillery Corps (C.A.C.) was in action in France in the final days of World War I with the US-manufactured Mk 6, and 44th, 51st, and 59th Regiments were in action with British-manufactured versions. [Hartwell "History of United States Army Coast Artillery Corps During World War One"]

Use by Finland

During the Russo-Finnish Winter War Finland found itself in dire need of heavy artillery. Thirty-two "8 in Howitzer Mk 7 (Vickers Mk 6)" 8-inch howitzers were bought from the United States in 1939 but arrived too late to see action in the war. The howitzers were given the designation 203 H 17 (203 mm, Howitzer, 1917) and were first issued to three heavy artillery battalions (1st, 2nd and 3rd), which later were re-organised into six heavy artillery batteries (11th, 12th, 13th, 14th, 15th and 16th). The howitzer with its durable design was well liked by the Finnish army. Thirteen of these howitzers were lost in the battles during the summer of 1944, eight of these belonged to Heavy Artillery Battery 4 and were lost at Valkeasaari on 10 June, while the other five belonged to Heavy Artillery Battery 3, located northeast of Lake Ladoga. The howitzers were stored after the war and were stricken from the lists in the late 1960s. [Paulaharju, p. 148]

Operators

*AUS - 6 pieces, 54th Siege Artillery Battery, Royal Australian Artillery
*FIN - 32 artillery pieces, known as 203 H 17
*FRA
*flag|South Africa|1928
*UK - Royal Garrison Artillery (amalgamated in 1924 into Royal Artillery
*USA (see [http://freepages.military.rootsweb.com/~cacunithistories/58tharty.htm History Of The Fifty-Eighth Artillery C.A.C.] )

Photo gallery

ee also

*21 cm Mörser 16
*List of artillery#Towed howitzers and field guns

References

;Published references
*Dale Clarke, [http://www.ospreypublishing.com/title_detail.php/title=S7883 British Artillery 1914-1919. Heavy Artillery. Osprey Publishing, Oxford UK, 2005]
*General Sir Martin Farndale, [http://www.naval-military-press.com/FMPro?-db=nmp%5fproducts.fp5&-format=nmpweb%2fdetail.htm&-lay=cgi&-sortfield=date&Co=NMP&search=History%20of%20the%20Royal%20Regiment%20of%20Artillery.%20Western%20Front%201914-18&-max=20&-recid=35933&-token.0=3668698&-find= History of the Royal Regiment of Artillery. Western Front 1914-18. London: Royal Artillery Institution, 1986]
*General Sir Martin Farndale, [http://www.amazon.co.uk/dp/1870114051 History of the Royal Regiment of Artillery : Forgotten Fronts and the Home Base 1914-18. London:The Royal Artillery Institution, 1988]
* [http://www.archive.org/details/handbookofartill00unitrich Handbook of artillery : including mobile, anti-aircraft and trench matériel (1920). United States. Army. Ordnance Dept, May 1920]
*cite book
last =Paulaharju
first = Jyri
authorlink =
title = Itsenäisen Suomen kenttätykit 1918-1995
publisher = Sotamuseo
series = Sotamuseon julkaisuja 1/1996
year = 1996
doi =
isbn = 951-25-0811-7
*British National Archives MUN5/373/9227

;Internet references
* [http://www.unsw.adfa.edu.au/~rmallett/Artillery.html Ross Mallett, AIF 1914-1918 Artillery]
* [http://www.landships.freeservers.com/new_pages/8inch_howitzer_info.htm 8 inch Howitzer Mk VI-VIII at Landships]
*Joe Hartwell, [http://freepages.military.rootsweb.com/~cacunithistories/defeating_the_hun.htm Defeating the Hun. History of United States Army Coast Artillery Corps During World War One.]
*Joe Hartwell, [http://freepages.military.rootsweb.com/~cacunithistories/8inch%20howitzer.html "8-inch British Howitzer" US-built versions]
* [http://freepages.military.rootsweb.com/~cacunithistories/58tharty.htm History Of The Fifty-Eighth Artillery C.A.C.]
* [http://www.jaegerplatoon.net/ARTILLERY7.htm Finnish Army 1918-1945. 203 mm H/17 Howitzer]
* [http://www.chakoten.dk/eng_8in_hb.html Om den engelske 8-tommers haubits 1915-1940 (Danish)]

Other Photographs

*Bill Maloney, [http://www.williammaloney.com/Aviation/CanadianWarMuseum/Artillery/pages/03WWICannon.htm Photograph of example in WWI camouflage paint at Canadian War Museum]

urviving examples

* [http://www.mpkk.fi/en/museum National Defence College Military Museum, Helsinki Finland]
*Artillery Museum, Hämeenlinna, Finland
*Mk VIII at [http://collections.civilization.ca/public/pages/cmccpublic/emupublic/Display.php?irn=1050739&QueryPage=%2Fpublic%2Fpages%2Fcmccpublic%2Femupublic%2FQuery.php&lang=0 Canadian War Museum, Ottawa, Canada]