BL 60 pounder gun

Infobox Weapon
name= BL 60 Pounder Gun


caption= A 60-pounder Mk I at full recoil. In action at Cape Helles during the Battle of Gallipoli, June 1915.
origin= UK
type= Heavy field gun
is_ranged=
is_artillery=yes
is_explosive=yes
is_UK=
service= 1905 - 1944
used_by= UK and Commonwealth
USA
wars=World War I, World War II
designer=Elswick Ordnance
design_date=1904
manufacturer=
unit_cost=
production_date=
number=1,756 (Mk. I)Clarke 2004]
variants=Mk I, Mk II
weight=
length=
part_length=Mk I 160 inch (4064 mm) bore
Mk II 185 inch (4699 mm) bore [Hogg & Thurston 1972, Pages 117 & 119]
width=
height=
diameter=
crew=10
cartridge=convert|60|lb|sigfig=4 shell, later convert|56|lb|sigfig=4
caliber= convert|5|in|mm|sigfig=4|sing=on
action=
rate=2 rounds/min
velocity=convert|2080|ft/s|m/s|sigfig=3 (Mk I)
convert|2130|ft/s|m/s|sigfig=3 (MK II)
max_range=convert|10300|yd|m|sigfig=3 (original 60 lb 2 c.r.h. shell), convert|12300|yd|m|sigfig=3 (modified 8 c.r.h. shell shape) (Mk. I);
convert|15500|yd|m|sigfig=3 (56 lb Mk 1D 10 c.r.h. shell, Mk. II gun)
range=
feed=
sights=
breech=
recoil=55 inches hydro-spring constant (carriage Mk I - III)
54 inches hydro-pneumatic variable (carriage Mk IV)
carriage= Wheeled, box trail
elevation=-5° - 21.5° (Mk I)
-4° - 35° (Mk. II)Hogg & Thurston pages 117, 119]
traverse=4° L & R [Mk II carriage was limited to 3° Left & Right traverse at elevations greater than 16.5°. Handbook of Artillery, US Ordnance Dept, May 1920, Page 192, 195]
filling=8 lb Lyddite [Treatise on Ammunition 10th Edition 1915 quotes 8 lb Lyddite. Hogg & Thurston 1972 quote 4 lb Lyddite and 6 lb Amatol, but 4 lb Lyddite is assumed to be a misprint as Amatol fillings tended to be much lighter than Lyddite] , later 6 lb AmatolThe British Ordnance BL 60-pounder was a medium 5 inch (127 mm) gun designed in 1904, replacing the obsolete QF 4.7 inch Gun. Mk II remained in service into World War II when it was superseded by the BL 5.5 inch Medium Gun.

History

Mk I gun on Mk I carriage

The original 1904 gun and carriage was designed for the gun to be moved rearwards on its carriage (i.e. the breech moved towards the end of the trail) when traveling. This was intended to equalise the weight born by the 2 gun carriage wheels and the 2 wheels of the limber towing the gun,Hogg & Thurston 1972, page 116] hence minimising the weight born by any single wheel. Mk I carriage had the usual field artillery wooden spoked wheels with iron tyres.

In February 1915, wartime manufacturing and maintenance requirements led to a simplification of the barrel construction, as gun Mk I* and Mk I**.

Mk I gun on Mk II carriage

Wartime manufacturing of the carriage was simplified in Mk II by removing the provision for moving the gun rearwards for traveling. This moved most of the weight when traveling away from the limber on to the carriage's own wheels - most weight was on the gun carriage wheels rather than the limber wheels. convert|5|ft|m|abbr=on diameter x convert|1|ft|m|abbr=on wide steel traction engine wheels replaced the wooden wheels to cope with the added weight. The tractor wheels added more weight to be towed, requiring the use of Holt tractors to replace horses.

Mk I gun on Mk III carriage

The increased weight with the traction engine wheels made manouvring difficult in typical mud conditions. The ability to move the gun back on its carriage for travelling was re-introduced in simplified form, by disconnecting the barrel from the recoil system and locking it on the trail in the recoiled position. Wooden spoked wheels were re-introduced. This became the Mk III carriage, or Mk II* for converted Mk II carriages.

Mk II gun on Mk IV carriage

The Mk. II gun introduced from 1918 had a longer barrel, new box trail carriage giving increased elevation, hydro-pneumatic recoil system below the barrel, single-motion Asbury breech. It arrived too late to see service in WWI and was effectively a new weapon. The gun was one of two types that could be carried by the Gun Carrier Mark I.

Combat use

World War I

The 60-pounder Mk. I were formed into "Heavy Batteries" in the First World War operated by the Royal Garrison Artillery and used mainly for counter-battery fire (i.e. suppressing or destroying the enemy's artillery). When World War I began a single 4-gun battery was attached to each infantry division of the BEF [Farndale 1986, page 355] as available - initial numbers restricted it to the Regular divisions 1 - 6, others were equipped with the obsolescent QF 4.7 inch Gun. From early 1915, 60 pounder batteries moved from Division to Army control [Farndale 1986, page 85] . As more 60 pounders became available the 4.7 inch guns were retired.

It is useful to note that writers such as General Farndale occasionally refer to 60 pounders as "medium" guns [Farndale 1988, page 5] , but in World War I they were officially referred to as heavy guns.

From 30th June 1916 the War Office adopted Major General Birch's recommendations to increase heavy battery sizes to 6 guns [Farndale 1986, page 356] , as more guns with better concentration of firepower were required on the Western Front, while minimising the administrative overhead of more batteries [Farndale 1986, page 362] . Batteries in the other minor theatres appear to have mostly retained a 4-gun structure.

In World War I the Mk I gun could fire the early 60 lb (27.3 kg) 2 c.r.h. shell 10,300 yd (9.4 km), and the later more streamlined 8 c.r.h. shell to convert|12300|yd. Weighing 4.4 tonnes, the 60-pounder required a team of 8 horses to tow it, with a maximum of 12 possible in difficult conditions. Mechanical towing by Holt Tractors and later motor lorries took over from horses towards the end of World War I.

At the end of World War I total batteries in service were : UK - nil, BEF (Western Front) - 74, Italy - 3, Macedonia - 11, Palestine - 7, Mesopotamia - 4. In addition Canada had 2 batteries on the Western Front, the only imperial forces using them.

World War II

In World War II the 60-pounder Mk II could fire a 56-pound 10 c.r.h. shell to 15,500 yards. It remained in use by the British Army until 1944, though its last combat action was in the Western Desert. It was superseded during WWII by the BL 5.5 inch Medium Gun.

US Service

USA acquired some 60 pounders, presumably for evaluation, reported in its May 1920 Handbook of Artillery :- [Handbook of Artillery, US Ordnance Dept, May 1920, page 189]

"The United States procured a number of batteries of 5-inch 60 pounder guns with the necessary accompanying vehicles from Great Britain. The materiel is of British design and manufacture throughout, and the units ceded to the United States include the Gun, Mark I, mounted on a carriage, Mark II; the gun carriage limber, Mark II, the ammunition wagon, Mark II; and the ammunition wagon limber, Mark II".

The accompanying photograph in the manual depicts a Mk I gun on Mk II carriage with traction-engine wheels typical of the Mk II carriage, and the accompanying diagram depicts the gun in the forward traveling position (i.e. with weight over the gun carriage) typical of the Mk II carriage mounting.

World War I Ammunition

Photographs

* [http://members.tripod.com/~nigelef/60pdrsheet.htm Photograph of Mk. 2 gun on carriage Mk 4R with solid rubber tyres, at Nigel Evans website - scroll to bottom of page for link to photo (external link)]

Image Gallery

Notes

References

*Dale Clarke, [http://www.ospreypublishing.com/title_detail.php/title=S6887 British Artillery 1914-1919. Field Army Artillery. Osprey Publishing, Oxford UK, 2004]
* [http://members.tripod.com/~nigelef/60pdrsheet.htm Nigel F Evans, Ordnance B.L. 60 pr Gun Mks 2 & 2* on Carriage 60 pr Mk 4P]
*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]
*I.V. Hogg & L.F. Thurston, British Artillery Weapons & Ammunition 1914-1918. London: Ian Allan, 1972
* [http://www.archive.org/details/handbookofartill00unitrich Handbook of artillery : including mobile, anti-aircraft and trench matériel (1920). United States. Army. Ordnance Dept, May 1920]

urviving examples

* [http://london.iwm.org.uk Imperial War Museum, London]