BL 7.2-inch howitzer

BL 7.2-inch howitzer
7.2-inch howitzer of 51st Heavy Regiment, Royal Artillery, France, 2 September 1944. Cannon crew em-placing recoil ramps in rear and setting wheel brakes. Front ramps prevent howitzer from rolling past position fired from.
Type	Howitzer
Place of origin	United Kingdom
Specifications
Weight	Mk I–IV 22,000 lb (10,000 kg) Mk 6 38,580 lb (17,500 kg)
Length	Mk I–IV 24 ft 4 in (7.42 m) Mk 6 34 ft (10 m)
Barrel length	Mk I–IV 22.4 calibres / 14 ft 3 in (4.34 m) Mk 6 33.1 calibres / 20 ft 8 in (6.30 m)
Width	Mk I–IV 9 ft (2.7 m) Mk 6 8 ft (2.4 m)
Height	Mk I–IV 4 ft 3 in (1.30 m) Mk 6 8 ft 3 in (2.51 m)
Crew	Mk I–IV 10 Mk 6 12
Shell	HE
Shell weight	202 pounds (92 kg)
Calibre	7.2 inches (182.9 mm)
Breech	Welin screw & Asbury mech
Carriage	Mk I–IV Box trail Mk 6 Split trail
Elevation	Mk I–IV 0° to 45° Mk 6 -1° to 63°
Traverse	Mk I–IV 4° Left & Right Mk 6 30° Left & Right
Rate of fire	1/3 rpm
Muzzle velocity	Mk I–IV 1,697 ft/s (517 m/s) Mk 6 1,925 ft/s (587 m/s)
Maximum firing range	Mk I–V 16,900 yd (15,500 m) Mk 6 19,667 yd (17,984 m)

The BL 7.2-inch howitzer Mks I–V and Mk 6, were a series of heavy artillery pieces used by the British Army throughout World War II.

History

In 1940 the British Army concluded that the only available heavy artillery, the World War I era BL 8-inch howitzer, had insufficient range for the conditions of WWII. As a stopgap the decision was made to re-line the existing barrels to a smaller calibre and develop a new range of ammunition to achieve the desired ranges.

Development

Marks I–IV

The 8 inch barrels were re-lined to 7.2 inches (180 mm) and the old carriages were retained although the original steel rimmed wheels were replaced with new pneumatic balloon-tyre wheels, as was consistent with the motorisation of the British Army. The new four-charge ammunition provided a useful increase in range to 16,900 yd (15,500 m), although when fired at full charge the recoil was fearsome, causing the weapon to rear violently and jump backwards. To help counter this, two wedge shaped ramps were placed behind the wheels but it remained a risky proposition as the gun would sometimes still jump over them. Marks I–IV differed only in the original 8-inch barrel used and the type of conversion, some barrels and carriages were also supplied from US WWI stocks.

Mark V

In 1944 several 7.2-inch barrels were placed in the US Carriage M1 used by the 155 mm Long Tom already in use by the British Army, becoming the BL 7.2-inch howitzer Mk V. Few Mk Vs were produced and it was never issued to batteries, as it was apparent that the Carriage M1 was capable of accepting greater recoil forces.

Mark 6

The BL 7.2-inch howitzer Mk 6 (there was a shift from Roman numerals) retained the Carriage M1 of the Mk V but had a new built 7.2 inch barrel 6 ft 5 in (1.96 m) longer than previous marks and a fifth charge was added to the ammunition. The longer barrel and extra charge provided a range increase to 19,667 yd (17,984 m), the new carriage also provided a far more stable platform, greatly increasing accuracy, the Mk 6 finished the war with an enviable reputation.

Use

The original marks performed well, the first 7.2-inch howitzers were issued to batteries from mid-1942 and used in action in North Africa and later following the Normandy landings. In Burma they were provided as a pool of two guns per corps and used by Regiments as required. By the end of 1944, most of the earlier marks had been replaced by the Mk 6.

The usual gun tractor for the 7.2-inch howitzer in the early war years was the Scammell Pioneer, although this was never available in sufficient numbers. From late 1943 the Pioneer was supplemented by the Albion CX22S.^[1]

The BL 7.2-inch howitzer formed parts of "Heavy" regiments of Army Group Royal Artillery (AGRA) units, providing heavy fire support for British and Commonwealth troops. The Mk 6 remained in British Army service until the early 1960s.

Operators

See: "7.2-Inch Howitzer". British Artillery in World War 2.^[2]

7.2 in howitzer Mk 6 at Rhine crossing 1945

 Newfoundland

• 57 (later 166) (Newfoundland) Field Artillery Regiment
• 59 (Newfoundland) Heavy Regiment

 United Kingdom

• Royal Artillery
  • 1 Heavy Regiment
  • 32 Heavy Regiment
  • 51 (Lowland) Heavy Regiment
  • 52 (Bedfordshire Yeomanry) Heavy Regiment
  • 53 Heavy Regiment
  • 54 Heavy Regiment
  • 55 Heavy Regiment
  • 56 Heavy Regiment
  • 58 Heavy Regiment
  • 60 Heavy Regiment
  • 61 Heavy Regiment
  • 75 Heavy Regiment
  • 171 Heavy Regiment
  • 8th (Belfast) Heavy Anti-Aircraft Regiment – section only; in Burma campaign^[3]
  • 52nd (London) Heavy Anti-Aircraft Regiment – section only; in Burma campaign^[3]
  • 56th (Cornwall) Heavy Anti-Aircraft Regiment – section only; in Burma campaign^[3]
  • 67th (York and Lancaster Regiment) Heavy Anti-Aircraft Regiment – section only; in Burma campaign^[3]

See also

• List of artillery
• 8 inch Howitzer M1 US equivalent, sharing the Carriage M1
• 203 mm howitzer M1931 (B-4) approximate Soviet equivalent

References

1. Pat Ware: A complete dictionary of military vehicles, Anness Publishing, 2012, p101.
2. "7.2-Inch Howitzer". British Artillery in World War 2. 17 Nov 2007. Retrieved 20 February 2011.
3. Brig N.W. Routledge, History of the Royal Regiment of Artillery: Anti-Aircraft Artillery 1914–55, London: Royal Artillery Institution/Brassey's, 1994, ISBN 978-1870114004, p. 244.