BL 8-inch howitzer Mk VI – VIII

The BL 8-inch howitzer Marks VI, VII and VIII (6, 7 and 8)[3] were a series of British artillery siege howitzers on mobile carriages of a new design introduced in World War I. They were designed by Vickers in Britain and produced by all four British artillery manufacturers, but mainly by Armstrong, and one American company. They were the equivalents of the German 21 cm Morser 16 and in British service were used similarly to the BL 9.2-inch howitzer, but were quicker to manufacture, and more mobile. They delivered a 200 lb shell to 12,300 yards. They had limited service in the British Army in World War II before being converted to the new 7.2-inch calibre. They also equipped a small number of Australian and Canadian batteries in World War I and by the US Army in that war. They were used in small numbers by other European armies.

BL 8-inch howitzer Mk VI – VIII
Class Vehicle
Type Towed Artillery
Manufacturer Armstrong Whitworth
Origin United Kingdom - UK (Great Britain)
Country Name Origin Year
United Kingdom - UK (Great Britain) 1916
Country Name Operational Year Retirement Year
Australia View
Canada View
Finland View
Russia (USSR) View
United Kingdom - UK (Great Britain) 1916 1943 View
United States of America View
ManufacturerName Production From Production To Quantity
Armstrong Whitworth View
Vickers Limited View
William Beardmore and Company View
Midvale Steel View
Beyer, Peacock and Company View
Hadfields Limited View

8 inch was a calibre adopted in the First World War by the British Army. The Marks VI, VII and VIII (6, 7 and 8) were a new design and not related to the stopgap early Marks 1 - 5 of 8-inch howitzer, which used shortened and bored-out naval 6-inch gun barrels.

Mark VI

The Vickers design, very similar to their 6-inch howitzer, was approved in August 1915 and first substantial order placed in March 1916 for 50 howitzers, with 30 more in the autumn. It was 4-5 tonnes lighter than the improvised 8-inch "howitzers" Mks I - V. The Mk VI barrel was of built-up construction and was 14.7 calibres (117.7 inches) long, with a range of 10,745 yards (9,825 m).

Mark VII

Introduced July 1916. Mk VII had a longer barrel (17.3 calibres, or 138.4 inches) of wire-wound construction 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 VIII incorporated various small improvements and a thicker and stronger barrel.

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. The US manual describes it :-

"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 two 6-gun batteries, Australia 1, Britain 37. 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.

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 declared obsolete by July 1943.

Type Heavy howitzer
Place of origin United Kingdom
Service history
In service 1916–1943
Used by United Kingdom
Russian Empire
Wars World War I, World War II
Production history
Designer Vickers
Designed 1915
Manufacturer Vickers
Midvale Steel,
major assemblies by Hadfieldand Beyer Peacock.
Number built 711 equivalent complete equipments(UK contracts).
Weight 8.74 tonnes
Barrel length Mk VI: 9 feet 9 inches (2.972 m)
Mk VII & VIII: 11 feet 6 inches (3.505 m)
Shell HE 200 lb (91 kg)
Calibre 8-inch (203.2 mm)
Breech Welin interrupted screw with Asbury mechanism
Recoil Hydro-pneumatic recuperator, hydraulic buffer
Carriage Wheeled, box trail
Elevation Mk VI: -4° to 50°
Mk VII & VIII: 0° to 45°
Traverse 4° L & R
Muzzle velocity Mk VI: 1,300 ft/s (400 m/s)
Mk VII & VIII: 1,500 ft/s (460 m/s)
Effective firing range Mk VI: 10,745 yd (9,825 m)
Mk VII & VIII: 12,300 yd (11,200 m)

End notes