BL 9.2 inch Railway Gun

Infobox Weapon
name= Ordnance BL 9.2 inch Gun on truck, railway


caption=Camouflaged Mk XIII gun in action
origin= UK
type=heavy gun
is_artillery=yes
is_ranged=yes
is_bladed=
is_explosive=yes
is_UK=yes
service=1915 - 1945
used_by=UK
wars=First World War
designer=
design_date=
manufacturer=Elswick Ordnance Company
unit_cost=
production_date=
number=
variants=
spec_label=
weight=
length=
part_length=
width=
height=
diameter=
crew=
cartridge=HE convert|380|lb|kg|sigfig=5
caliber=convert|9.2|in|mm|sigfig=4
action=
rate=
velocity=
range=Mk III & VI : convert|17000|yd|m|sigfig=4
Mk X : convert|21000|yd|m|sigfig=4
Mk XIII : convert|22600|yd|m|sigfig=4
feed=
sights=
breech=
recoil=inclined slide
carriage=
elevation=28° (Mk I mount); 40° (Mk IV mount)
traverse=10° L & R (Mk I mount); 360° (Mk III mount)
filling=Lyddite, Amatol
filling_weight=convert|40|lb|kg|sigfig=4
detonation=
yield=The Ordnance BL 9.2 inch gun on truck, railway mounted a variety of surplus 9.2 inch naval guns, together with the custom-designed Mk XIII railway gun, on various railway platforms to provide mobile long-range heavy artillery on the Western Front in World War I.

History

Early in 1915 a variety of surplus Mk III and Mk VI 9.2-inch naval and coast-defence guns were adapted by the Elswick Ordnance Company for mounting on railway trucks for use in France and Belgium. They were mounted on Vavasseur slides, which travelled backwards and upwards to absorb the recoil, on "well-based" trucks, where the base was level with the axles.

These early mountings allowed 10° of traverse left and right, and moved forward and backwards alonged curved sections of track for further traversing. They limited elevation to 28° and hence limited maximum range. In March 1916 a modification increased elevation to 35° [On 20th January 1916 Admiral Percy Scott visited the front and pointed out to General Rawlinson that by "putting a piece on top of the mounting" an increase in elevation to 35° and range to 17,000 yards could be achieved, and Rawlinson agreed it was urgent. It took the War Office bureaucracy until 28th March to approve the changes and forward the altered plans to Armstrongs. The episode is recounted in Admiral Scott's memoirs [http://www.archive.org/details/fiftyyearsinroya00scotuoft "Fifty Years in the Royal Navy"] published 1919, pages 322-323.] .

In June 1916 Elswick produced a more sophisticated turntable mounting with a loading platform, on a "straight-back" truck which mounted the gun much higher. This was lowered to the ground for firing, had outriggeres for stability, allowed 360° traverse and elevation to 30° [Clarke 2005, page 36] . The more modern Mk X gun was mounted on this design, together with 2 Mk X variants intended for Australian coast defence (Mk XT), 4 Vickers 45-calibre guns (Mk XIV) which were originally intended for a foreign order, and a specially developed 35-calibres railway gun (Mk XIII).

Mk XIII gun

The custom-designed 35-calibres Mk XIII gun had a heavier breech which allowed the trunnions to be closer to the breech and hence the breech did not depress as far when the barrel was elevated. On a new Mk IV mounting, Mk XIII guns could then be elevated to 40° and attain a range of 22,600 yards. [Hogg & Thurston 1972, page 168-173] . These remained in service until 1945, serving in the home defence of Britain in World War II.

Combat service

9.2-inch railway guns expended 45,000 rounds during World War I [Clarke 2005, page 36] . At the Armistice guns in service were : [Farndale 1986, Annex M]
First Army : 6 guns : Batteries 366 (2), 461 (2), 523 (2)
Second Army : 3 guns : Batteries 45 (2), 53 (1)
Third Army : 4 guns : Batteries 363 (2), 442 (2)
Fifth Army : 3 guns : Batteries 53 (1), 546 (2)

Mk XIII guns remained in service until 1945; all others were declared obsolete after World War I [Hogg & Thurston 1972, page 169] .

Notes

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.amazon.co.uk/dp/1870114000/ History of the Royal Regiment of Artillery. Western Front 1914-18. London: Royal Artillery Institution, 1986]
*I.V. Hogg & L.F. Thurston, British Artillery Weapons & Ammunition 1914 - 1918. London: Ian Allan, 1972

See also

*List of artillery#Railway artillery

urviving examples

External links

* [http://www.chakoten.dk/eng_jernb_art_wwi.html Om engelsk jernbaneartilleri under Første Verdenskrig]