On 29 May the battery was assigned to 35th Heavy Artillery Group (HAG) which was due to support VII Corps' Attack on the Gommecourt Salient in the forthcoming 'Big Push' (the Battle of the Somme).
Its main role was to use the high-angle fire of its howitzers to bombard German trenches and strongpoints facing 46th (North Midland) Division's attack frontage.
Firing from the south-west of the Gommecourt salient they could take the trench lines in enfilade.
The specific targets assigned to 93rd Siege Bty were the German support and reserve trenches from Gommecourt Road to a position known as the 'Little Z', the western edge of Gommecourt Wood, and Fortune, Form and Force trenches. (
The divisional commander requested that the German front trench should not be bombarded because he wanted it kept intact for use by his own troops.)
The howitzers joined in the bombardment on 25 June ('V' Day, four days before 'Z' day, the date set for the attack).
Ammunition for the modern howitzers like the 9.2-inch was in short supply, and had to be carefully rationed during the preliminary bombardment: The planned rate of fire was 50 rounds per gun on V to X days, then 70 rounds on Y day.
At all times during daylight, No 8 Squadron Royal Flying Corps had a BE2c observation aircraft in the air spotting fall of shot for 35th HAG's batteries.
Because of poor weather for observation, the attack was postponed for two days, and the additional days (Y1 and Y2) were used for further bombardment, although the lack of ammunition resulted in a reduced rate of fire.
There were also many 'duds' among the 9.2-inch shells, despite the care taken over fuzes at the insistence of the CO of 35th HAG.

A final bombardment began at 06.25 on Z Day (1 July), with 65 minutes of intense fire before H Hour at 07.30.
The 9.2-inch howitzers fired at a rate of nearly two rounds per minute for this period (120 rounds per gun).
At 07.28 the heavy howitzers lifted onto their pre-arranged targets in the German support and reserve lines as the infantry got out of their forward trenches and advanced towards Gommecourt behind a smoke screen.
The attack of 139th (Sherwood Foresters) Brigade on the left, south of The Z, was initially successful, the leading waves getting into the first German trench (albeit with heavy casualties) and some parties entering the second line.
But they were hit by enfilade fire from The Z, even though the RFC observers reported British troops in the Z and Little Z.
There was little that the battery could do to help: communication with its Forward Observation Officer (FOO) was broken for most of the day, and the 9.2s had few shells left.
They had been allocated 10 rounds per gun for the first pre-arranged lift, 15 for the second, and their last 25 rounds for the third and final lift.
After the initial phase of the attack, therefore, the intensity of the shelling the Germans received, and the direct support that the heavies could offer, was severely limited.
Fire from the Z positions and unsuppressed German artillery prevented 139th Brigade's follow-up waves and ammunition carrying parties from crossing No man's land.
139th Brigade's attack had been halted by 09.00 and the leading attack waves were destroyed or driven out of their small gains by the end of the day.
On 29 May the battery was assigned to 35th Heavy Artillery Group (HAG) which was due to support VII Corps' Attack on the Gommecourt Salient in the forthcoming 'Big Push' (the Battle of the Somme). Its main role was to use the high-angle fire of its howitzers to bombard German trenches and strongpoints facing 46th (North Midland) Division's attack frontage. Firing from the south-west of the Gommecourt salient they could take the trench lines in enfilade. The specific targets assigned to 93rd Siege Bty were the German support and reserve trenches from Gommecourt Road to a position known as the 'Little Z', the western edge of Gommecourt Wood, and Fortune, Form and Force trenches. (The divisional commander requested that the German front trench should not be bombarded because he wanted it kept intact for use by his own troops.) The howitzers joined in the bombardment on 25 June ('V' Day, four days before 'Z' day, the date set for the attack). Ammunition for the modern howitzers like the 9.2-inch was in short supply, and had to be carefully rationed during the preliminary bombardment: The planned rate of fire was 50 rounds per gun on V to X days, then 70 rounds on Y day. At all times during daylight, No 8 Squadron Royal Flying Corps had a BE2c observation aircraft in the air spotting fall of shot for 35th HAG's batteries. Because of poor weather for observation, the attack was postponed for two days, and the additional days (Y1 and Y2) were used for further bombardment, although the lack of ammunition resulted in a reduced rate of fire. There were also many 'duds' among the 9.2-inch shells, despite the care taken over fuzes at the insistence of the CO of 35th HAG.
A final bombardment began at 06.25 on Z Day (1 July), with 65 minutes of intense fire before H Hour at 07.30. The 9.2-inch howitzers fired at a rate of nearly two rounds per minute for this period (120 rounds per gun). At 07.28 the heavy howitzers lifted onto their pre-arranged targets in the German support and reserve lines as the infantry got out of their forward trenches and advanced towards Gommecourt behind a smoke screen. The attack of 139th (Sherwood Foresters) Brigade on the left, south of The Z, was initially successful, the leading waves getting into the first German trench (albeit with heavy casualties) and some parties entering the second line. But they were hit by enfilade fire from The Z, even though the RFC observers reported British troops in the Z and Little Z.
There was little that the battery could do to help: communication with its Forward Observation Officer (FOO) was broken for most of the day, and the 9.2s had few shells left. They had been allocated 10 rounds per gun for the first pre-arranged lift, 15 for the second, and their last 25 rounds for the third and final lift. After the initial phase of the attack, therefore, the intensity of the shelling the Germans received, and the direct support that the heavies could offer, was severely limited. Fire from the Z positions and unsuppressed German artillery prevented 139th Brigade's follow-up waves and ammunition carrying parties from crossing No man's land. 139th Brigade's attack had been halted by 09.00 and the leading attack waves were destroyed or driven out of their small gains by the end of the day.
93rd Siege Battery, Royal Garrison Artillery