Ordnance, 7.2in Howitzer Mk I-V

The 7.2in Howitzer Mk I-V was an improvised weapon that was originally produced in 1940 and based around relined First World War 8in Howitzers.

During the inter-war years the Royal Artillery’s main project was the new 25-pounder field gun, and as a result heavier artillery was largely neglected. As a result the Royal Artillery was still equipped with the First World War era BL 8in Howitzer at the start of the Second World War. This had been an excellent weapon for its time, but it had a maximum range of 11,245m, not long enough for the circumstances of 1940. Most of the Army’s stock of usable heavy artillery went to France with the BEF, and was lost during the retreat to Dunkirk. As a result new heavy guns were urgently required.

The quickest way to fill the gap was to modify the old 8in guns to increase their range. This was done by relining the gun barrels to reduce their calibre from 8in to 7.2in. A new range of slightly heavier shells was developed, which gave the modified weapon the required range. If a full charge was used the range increased to 15,454m, but the recoil forces were too much for the old carriage to cope with, and the howitzer had a tendency to move backwards, needed repositioning after each shot. If ramps were placed behind the wheels the impact of this was reduced, as the howitzer would roll back down the ramps into roughly the correct position, but this wasn’t an ideal situation.

The modified weapons used the same heavy box trail, which gave it a reasonable degree of elevation, as the gun could recoil into a large gap in the trail, but limited the range of traverse to only 8 degrees. The old traction engine wheels of the First World War era were replaced with new wheels with pneumatic balloon tires to allow the new weapon to be towed by motor transport. The recoil mechanism was carried below the barrel, which extended some way in front of it.

Despite the problems at maximum range, the 7.2in Howitzer proved to be an accurate weapon, with a very useful range. It entered combat towards the end of the North African campaign, where its performance led to calls for more of the same. The original Mk I was followed by three more (Mk.II to Mk.IV) which combined various types of 8in barrels with different versions of the box trail carriage.

Some of the barrels came from the United States, having originally been given to the US Army during the First World War. These barrels were followed by the excellent US M1 gun carriage, a much more modern carriage with a split trail, which had originally been developed for the US 155mm Gun, but then used on their own 8in Howitzer M1, a US development of the British original. A number of the modified 7.2in barrels were installed on the M1 Carriage, becoming the 7.2in Howitzer Mk V. However it soon became clear that the M1 Carriage could cope with a much more powerful gun. Only a handful of Mk Vs were produced before production moved onto the much improved 7.2in Howitzer Mk 6, which used a longer barrel and saw the range increase to 17,984m, without the recoil problems of the Mk I to IV. 

The Mk I to Mk V saw service in North Africa, Sicily, Italy, during the invasion of Normandy, and the campaign in north-western Europe. However by the end of 1944 very few of the older carriages remained in use, and the Mk 6 had become the standard version.


7.2in Howitzer Mk I-V


183mm (7.2in)

Barrel Length

4.343m (14ft 3in)

Weight for transport


Weight in action

10,387kg (22,900lb)


0 to 45 degrees


8 degrees

Shell Weight

91.6kg (202lb)

Muzzle Velocity

518m (1,700ft)/ second

Maximum Range

15,454m (16,900 yards)

Rate of Fire


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How to cite this article: Rickard, J (5 December 2018), Ordnance, 7.2in Howitzer Mk I-V , http://www.historyofwar.org/articles/weapons_ordnance_7_2in_howitzer_I_V.html

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