During the interwar period, the 18-pounder was developed into the early versions of the Ordnance QF 25-pounder, which would form the basis of the British artillery forces during and after the Second World War in much the same fashion as the 18-pounder had during the First.

[10] At the same time, the British Cabinet ordered Field Marshal Lord Roberts, the Commander-in-Chief in South Africa, to send home artillery brigade and battery commanders "selected for their eminence and experience" to form an Equipment Committee.

This used the Armstrong gun, Vickers' recoil system, and Royal Ordnance Factory's sighting and elevating gear and ammunition carrying.

The rocking bar and telescope were retained for direct fire, as was the range scale on the right in spite of a clinometer being part of the Dial Sight mount.

[16] Unusually for a 20th-century British gun, the 18-pounder retained two-man laying throughout its life, elevation (in yards) was set on a range scale on the righthand side of the cradle.

The narrow single-pole trail design of the Carriages Mk I and II were suited to towing by teams of horses, but constrained downward motion of the breech, and thus limited the gun's range to 6525 yards in normal use.

The gun's relatively low muzzle velocity, and the unsatisfactory ballistic characteristics of its shrapnel shell at high angles, made it a marginal performer in such a role.

[19] However, by sleeving the barrel down to 3 inches (76 mm) and mating the 18-pounder cartridge with the 13-pounder's shell, the successful QF 13-pounder 9 cwt anti-aircraft gun was produced with the necessary high muzzle velocity.

In action, the wagon was placed close beside the gun; its steel body provided an extended shield to protect the detachments against small arms fire.

On 28 June 1922, Michael Collins effectively started the Irish Civil War by using two 18-pounder field guns, previously owned by the British Army, to bombard the Four Courts in Dublin.

Initially, this was by fitting heavy wooden wheels with solid rubber tyres, the carriages becoming Mks IIITR, IVR and VR.

Introduction of a new streamlined shell, Mk 1C, with a 4/7.5 crh increased maximum range to 11,100 yards with Mks III, IV and V carriages.

modelo 1922 (105/22) at partially Vickers-owned Sociedad Española de Construcción Naval plant; those howitzers were used by both sides of the Spanish Civil War.

By the end of September 1914, all reserve guns (25% above the establishment entitlements as decided by the Mowat Committee in 1901) had been delivered to France, although new production orders had been placed on the outbreak of war.

They were used for wire cutting and most importantly in the creeping barrage, where they prevented defenders from manning their trench parapets during a British assault.

In this respect, they were perhaps the key element in the British artillery doctrine of neutralizing defenders during an assault instead of trying to destroy the enemy in their defences before an attack.

This made the role of the Observing Officer crucial for 18-pounder batteries engaging targets as they could no longer rely on direct line of sight.

But its relatively flat high velocity trajectory meant that it could not reach an enemy sheltering out of the direct line of sight, in dips in the ground, on reverse slopes (such as the Quadrilateral east of Ginchy on the Somme) or in deep trenches or cellars.

for creeping barrages, due partly to shrapnel directing its force forward hence being safer for those following, especially if it fell short.

[51] British regular army field gunners were already proficient in accurately timed low shrapnel bursts in 1914, as demonstrated in the early battles, but few remained by early 1917 and many gunners were relatively new recruits and inexperienced; HE had only been in use with 18-pounders for two years, so this note perhaps reflects a desire to stick with a proven method for which they could still draw on a nucleus of experts.

[52] At the opening of the Battle of Arras on 9 April 1917, the order was for 18-pounders to fire 50% HE and 50% shrapnel in the creeping barrage ahead of the advancing infantry, with one gun for every 20 yards of front.

[53] For the Third Battle of Ypres in July 1917, the plan was for wire cutting to be done by mortars and howitzers, "to conceal the strength of the field guns".

[56] The barrage was generally successful; but as the weather deteriorated, tracks turned to mud and shell holes filled with water, it became nearly impossible for guns to advance in support of the infantry as planned.

However, the effectiveness of the German fire plan on 21 March caused many casualties amongst the gunners, and in too many cases batteries were unable to withdraw before being overrun.

Nevertheless, on 4 April, the Germans made their final attempt to break the British line having advanced to the area of Villers Bretonneux held by 14th (Light) and 18th (Eastern) Divisions, reinforced by the 16th (Irish) and 39th divisional artilleries although batteries were understrength through losses.

Brigadier-General Edward Harding-Newman, CRA of 14th (Light) Division issued the following order "This attack must and can be stopped by artillery fire.

The 18-pounder Mk IV, with its box trail which allowed it to fire in a high trajectory, had begun its evolution into the more versatile 25-pounder gun-howitzer.

During the war against Japan (from December 1941), the 18-pdr was used in the Malayan campaign (by a number of British field regiments) and, to a lesser degree, the Battle of Hong Kong (by 965 Beach Defence Battery).

The 18-pounder played an important role throughout the Irish Civil War, being instrumental in the fighting in Munster alongside the Rolls-Royce Armoured Car.

The fuze was designed to function as close as 50 yards from the muzzle if required, in order to eliminate the need for case shot.