The 122nd Siege Battery was a heavy howitzer unit of Britain's Royal Garrison Artillery (RGA) raised during the First World War. It saw active service on the Western Front at the Somme and Arras, against the German spring offensive, and in the final Allied Hundred Days Offensive.
Mobilisation
On the outbreak of war in August 1914, units of the part-time Territorial Force (TF) were invited to volunteer for Overseas Service and the majority of the Sussex Royal Garrison Artillery did so. This unit had mobilised as part of No 10 Coastal Fire Command, responsible for the defence of Newhaven. By October 1914, the campaign on the Western Front was bogging down into Trench warfare and there was an urgent need for batteries of siege artillery to be sent to France. The WO decided that the TF coastal gunners were well enough trained to take over many of the duties in the coastal defences, releasing Regular RGA gunners for service in the field. Soon the TF RGA companies that had volunteered for overseas service were also supplying trained gunners to RGA units serving overseas and providing cadres to form complete new units.
A cadre of 3 officers and 78 other ranks (ORs) of the Sussex RGA was assigned to 122nd Siege Battery, RGA, when it was formed at Dover on 22 March 1916. The battery was equipped with four modern 6-inch 26 cwt howitzers and had an ammunition column of Army Service Corps lorries attached to it, including four FWD Model B gun tractors. The battery went out to the Western Front on 18 July 1916
Service
The battery went to Beaufort near Arras where on 23 July it joined 8th Heavy Artillery Group (HAG) supporting Third Army. Two days later it began firing to register targets such as Ficheux Mill, the villages of Beaurains and Ransart, the Slag Heap (a nest of machine gunners), a railway bridge and enemy batteries. The Arras sector was relatively quiet during the summer with the emphasis being on the Battle of the Somme further south, but deliberate shoots were carried out with aircraft or balloon observation when weather permitted. On 3 September the battery engaged enemy anti-aircraft batteries to support an attack by the Royal Flying Corps on enemy balloons.
Somme
In mid-September 8th HAG was ordered to move south with its batteries to Bayencourt to join VII Corps. From 14 September the batteries were engaged in counter-battery (CB) tasks supporting the adjacent Reserve Army attacking on the Somme, particularly the attack on Miraumont on 28 September. On 16 October 122nd Siege Bty transferred to 25th HAG with II Corps in Reserve Army with which it continued CB work and joined in bombardments for the continuing Battle of the Ancre Heights. Reserve Army (renamed Fifth Army) kept attacking during November (the Battle of the Ancre) before the Somme offensive died out.
Arras
In January 1917 122nd Siege Bty moved back to Third Army, intended to join 26th HAG with VI Corps, but actually joined 47th HAG (9 January) and immediately moved to 48th HAG (13 January). The battery was placed 'out of action' on 14 January and from then until 31 January the personnel were employed on ammunition fatigues, etc., then from 1 to 13 February they were engaged in training, overhauling the guns, etc.. By now the battery was commanded by W.F.H. Grinsted, who had been a lieutenant in No 1 Co Sussex RGA on the outbreak of war, promoted to captain on 4 November 1914, and seconded for duty with the Regular RGA from 28 April 1916. He was now an Acting Major.
122nd Siege Bty joined 78th HAG at Anzin-Saint-Aubin on 14 February and moved its guns into position north west of Arras two days later. Third Army was carrying out the artillery preparation for the Battle of Arras, with 78th HAG supporting XVII Corps. The main bombardment was planned to last for five days (V, W, X, Y and Z) beginning on 4 April. On 4 April one of 122nd Siege Bty's howitzers suffered a premature explosion of a shell in the barrel, destroying the gun, killing one gunner and wounding five others. The zone bombarded was divided into small zones without overlapping fire, to help the forward observation officers (FOOs) spot the fall of shot of their own guns. The 6-inch howitzers concentrated on the German second and third defence systems, destroying trenches and strongpoints and cutting barbed wire. Fire on targets was maintained at an even rate in daylight, with pauses for air reconnaissance. Harassing fire (HF) tasks were carried out at night. However, visibility was poor on some of the days, so an additional day (Q) was inserted on 7 April and Z day for the attack (the First Battle of the Scarpe) became 9 April.