QF 13-pounder 6 cwt AA gun

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QF 13 pounder 6 cwt anti-aircraft gun
13Pdr6cwtAAgunThornycroftLorry1916.jpg
On Mk II mounting on Thornycroft Type J lorry, Armentieres March 1916
Type Anti-aircraft gun
Place of origin United Kingdom
Service history
In service 1915 - 1918[1]
Used by British Empire
Wars World War I
Specifications
Barrel length Bore: 5 feet 9 inches (1.753 m);
Total: 6 feet 1 inch (1.854 m)[2]

Shell 12.5 pounds (5.67 kg) Shrapnel; later HE
Calibre 3-inch (76.2 mm)
Recoil hydro-spring, constant, 25 inches (635 mm)[2]
Carriage high-angle mounting on lorry
Elevation 0° - 70°[2]
Traverse 360°
Maximum firing range 17,000 ft (5,200 m)[2]

The Ordnance QF 13 pounder Mk III anti-aircraft gun, also known as 13 pounder 6 cwt, was an early British improvisation in World War I to adapt the 13 pounder field gun to anti-aircraft use. 6 cwt referred to the weight of barrel and breech (6 x 112 lb = 672 lb) to differentiate it from other "13 pounder" guns.

History[edit]

On Mk I mount, on a Daimler Mk 3 lorry

This was a standard QF 13 pounder field gun barrel and breech with the addition of a retaining catch to the breech to retain the round when loading at high angles.[3]

It was first approved in October 1914 and was issued on Mk I high angle mounting, usually mounted on a motor lorry. The Mk I mounting had an additional recuperator housing mounted directly above the normal recuperator to facilitate gun runout at high angles.[3] Hence the appearance was of a gun barrel with 2 slightly shorter tubes of similar diameter above it.

Mk II mount improved the usability, added deflection gear and the recoil system was improved so that the additional recuperator became unnecessary and was removed.[3] On the Mk II mount the gun has the appearance of a standard 13 pounder.

The mount design was unusual in having both gunlayers on the left side.[1]

Following World War I the guns were returned to service as standard 13 pounder field guns.

Combat use[edit]

The gun's performance was "ballistically poor"[1] and it was only marginally effective against aircraft. It was relegated to minor war theatres and the 13 pounder 9 cwt and 3 inch 20 cwt guns took over the major anti-aircraft role.

At the end of World War I there were only 20 of the guns in service worldwide, with 12 in Egypt and Palestine, 4 in Mesopotamia, 2 in Greece (Salonika front) and 2 on the Western Front.[4]

Performance[edit]

The following table[5] compares the gun's performance with the other British World War I anti-aircraft guns:-

Gun m/v ft/s Shell (lb) Time to 5,000 ft (1,500 m) at 25° (seconds) Time to 10,000 ft (3,000 m) at 40° (seconds) Time to 15,000 ft (4,600 m) at 55° (seconds) Max. height (ft)[6]
QF 13 pounder Mk III 1600 12.5 ? ? ? 17,000
QF 13 pounder 9 cwt 1990[7] 12.5 10.1 15.5 22.1 19,000
QF 12 pdr 12 cwt 2200 12.5 9.1 14.1 19.1 20,000
QF 3 inch 20 cwt 1914 2500 12.5 8.3 12.6 16.3 23,500
QF 3 inch 20 cwt 1916 2000 16 9.2 13.7 18.8 22,000[8]
QF 4 inch Mk V WWI 2350 31 (3 c.r.h.) 4.4?? 9.6 12.3 28,750
QF 4 inch Mk V WWII[9] 2350 31 (4.38/6 c.r.h.) ? ? ? 31,000

See also[edit]

Surviving examples[edit]

Notes and references[edit]

  1. ^ a b c Routledge 1994, page 6
  2. ^ a b c d Hogg & Thurston 1972, page 61
  3. ^ a b c Hogg & Thurston 1972, page 60
  4. ^ Routledge 1994, page 27
  5. ^ Routledge 1994, Page 9
  6. ^ Hogg & Thurston 1972, Page 234-235
  7. ^ Routledge 1994, page 9 quotes muzzle velocity 1,990 feet per second (607 m/s). Hogg & Thurston 1972, page 65 quote 2150 ft/second
  8. ^ Routledge 1994, Page 13
  9. ^ World War II details from Tony DiGiulian's website

Bibliography[edit]

  • I.V. Hogg & L.F. Thurston, British Artillery Weapons & Ammunition 1914-1918. London:Ian Allan, 1972. ISBN 978-0-7110-0381-1
  • Brigadier NW Routledge, History of the Royal Regiment of Artillery. Anti-Aircraft Artillery, 1914-55. London: Brassey's, 1994. ISBN 1-85753-099-3

External links[edit]