135th Siege Battery was a heavy howitzer unit of Britain's Royal Garrison Artillery (RGA) raised during World War I. 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 and training Once the fighting on the Western Front had bogged down into Trench warfare in 1914, there was an urgent need for siege artillery. 135th Siege Bty was formed at Tynemouth in Northumberland under Army Council Instruction 996 of 13 May 1916. The gunners were drawn from Nos 12 and 47 Companies, RGA, which manned coast artillery in the Tynemouth Garrison (66 from No 12 Co and 44 from No 47). Most of them were recent recruits under the Derby Scheme with just a few weeks' training. The first officers and warrant officers set up battery headquarters (BHQ) at the Temperance Hotel at Cullercoats. Ten non-commissioned officers (NCOs) arrived from the RGA's B Depot at Bexhill-on-Sea, together with the signal detachment of three NCOs and eight men from A Depot at Bexhill. Captain D.B.C. Sladen was appointed to command the battery.Army Council Instructions for May 1916.Frederick, pp 703–7.Frederick, pp. 581, 586, 647.Walters & Hurle Hobbs, pp. 17–9.

The battery left Cullercoats on 4 June to join R Siege Brigade (Training) at Horsham and after a month moved to Lydd to complete its training, first with B Bde, then with C Bde. On 29 July the battery began to move to Bristol to mobilise, where its guns were waiting. The battery was equipped with four 8-inch howitzers.Walters & Hurle Hobbs, pp. 19–22.Frederick, pp. 716–7. At this stage of the war the 8-inch howitzers in use (Marks I–V) were improvised from cut-down and bored-out barrels of 6-inch coast defence guns, with the recoil checked by enormous wooden wedges.Edmonds, 1916, Vol I, p. 301.Farndale, Western Front, pp. 130, 141.

Western Front

135th Siege Bty went out to Western Front in the summer of 1916, the advance party leaving on 11 August, and on 13 August the guns and the motor transport column of the Army Service Corps (ASC) – four Holt 75 caterpillar tractors, over 30 lorries, plus a car and assorted motorcycles – went to Avonmouth Docks to be shipped to France. The rest of the personnel embarked on the Golden Eagle at Folkestone Harbour on 19 August. After unloading the guns at Boulogne the battery entrained and joined the advance party at La Houssoye on 23 August, where it joined III Corps' Heavy Artillery on 23 August.Walters & Hurle Hobbs, pp. 22–3.'Allocation of Siege Batteries RGA', The National Archives (TNA), Kew, file WO 95/5494/4.

Somme While at La Houssoye the battery was visited by the official war photographer John Warwick Brooke, several of whose pictures of the battery are in the collection of the Imperial War Museum. On 29 August 135th Siege Bty was assigned to 27th Heavy Artillery Group (HAG). At that stage of the war a heavy artillery group (HAG) was a lieutenant-colonel's command controlling a fluctuating number of RGA heavy and siege batteries.Farndale, Annex E. The battery was temporarily split up and attached to experienced batteries for initiation into front-line service. Left Half Battery was attached to 19th Siege Bty (of 27th HAG) outside Mametz, Right Half Battery to 57th Siege Bty (of 30th HAG) with No 1 gun near Contalmaison with the forward section, and No 2 gun at Fricourt with the rear section. These batteries were supporting Fourth Army conducting the Somme Offensive; although the gun positions were rarely under fire, the forward observation officers (FOOs) and signallers were in Observation Posts (OPs) in the midst of fighting in High Wood and Delville Wood. After a month the battery was pulled out on 21 September, but immediately sent forward to new positions, with Right Half to 67th Siege Bty and Left Half to 47th Siege Bty, both close to Montauban in XV Corps' Heavy Artillery. From these positions the battery supported the attacks of September that cleared High Wood and Delville Wood, and captured Flers, Guillemont and Ginchy, and then Gueudecourt.Walters & Hurle Hobbs, pp. 24–5.'Headquarters Heavy Artillery Groups', TNA file WO 95/5494/1.Becke, Pt 4, pp. 99–109.Becke, Pt 4, pp. 223–88.

135th Siege Bty had been subordinated to 14th HAG since 12 September, and on 29 September the sections began moving forward to prepare four new positions on the Longueval–High Wood road and reunite the battery. The gunners worked in mud and rain, and had to carry their ammunition down the last along the shell-damaged road. Eventually the exhausted gunners were helped by fatigue parties from the British West Indies Regiment. The gunners were accommodated in old German dugouts that were collapsing under shellfire and rain. The OPs, however, were behind the front line, only just in front of the battery. The battery's targets were usually over the Ligny-Thilloy sector and round the Butte de Warlencourt. It suffered its first few fatal casualties in early October. Fourth Army's offensive was now completely held up, and XV Corps was relieved by I ANZAC Corps, taking over the batteries in position. 135th Siege Bty was transferred to the command of 3rd HAG on 16 October. 3rd HAG's primary target was the troublesome 'Gird Trench' nd associated strongpoints, which had withstood many attacks in the Battle of the Transloy Ridges. The shelling of the German positions continued, with 135th Siege Bty putting down a particularly heavy bombardment on 13 November to support Fifth Army's attack further north (the Battle of the Ancre).Walters & Hurle Hobbs, pp. 25–8.3rd HAG War Diary September 1916–November 1917 TNA file WO 95/297/2.

Winter 1916–17 The Somme Offensive died down after the Ancre and 135th Siege Bty pulled its guns out on the night of 1/2 December. It exchanged with ASC ammunition column with 67th Siege Bty and then moved to Bonnay for rest. The BEF was taking over part of the line from the French, so 135th Siege Bty moved south to rejoin XV Corps in this new sector, transferring to 6th HAG on 11 December. Its new gun positions were in the valley below 'Saverake Wood;, SW of Combles, at least half a mile from any road, so the only way to get the guns in was to dismantle them at the railhead and send the pieces up on small light railway trucks. The battery had to construct a railway siding connecting to the Decauville Railway while the gunners lived in camouflaged tents in the snow, until some experienced miners in their ranks constructed deep dugouts in the underlying chalk. The first gun was registered on 21 December and all four were in position and ready for action on 25 December. Major Sladen was invalided to England on 18 December and was succeeded on 17 January 1917 by Acting-Maj C.P. Heath from 66th Siege Bty.Walters & Hurle Hobbs, pp. 28–32.

The battery's miners also constructed camouflaged OPs for the brigade, despite alternate frosts and thaws. From February the battery was engaged in shelling the enemy's 'Jupiter' trenches along the edge of St Pierre Vaast Wood, for which the OP was in the infantry's lines, at the end of a telephone line that frequently had to be repaired after being cut by enemy shellfire. The battery's bombardments continued daily until 4 March, when 8th Division of XV Corps carried out a surprise local attack on Bouchavesnes. The battery pushed its OPs forwards and attempted to shell a group of German batteries that were now in sight. Unfortunately, they were beyond the limited range of the Mk V 8-inch howitzers. On 13 March the battery was ordered to pull out, and on 16 March it was officially transferred to 32nd HAG.Walters & Hurle Hobbs, pp. 32–41.6th HAG War Diary March–December 1917, TNA file WO 95/299/3.

Arras 32nd HAG was with VI Corps in the Arras sector under Third Army, and the battery joined it on 21 March.Walters & Hurle Hobbs, pp. 42–3. Third Army was preparing for the forthcoming Arras Offensive, in which 135th Siege Bty's role was counter-battery (CB) fire. Positions had been selected for it in private gardens off the Place Vauban in the middle of Arras, only behind the front line. The flowerbeds had to be carefully protected as the guns were pulled in, because any changes would have been obvious to German air observers. The battery remained silent for several days while 3600 rounds of ammunition were stockpiled. The artillery plan for Arras was much more carefully worked out than previous operations. It began with systematic CB work to put the German artillery out of action, 135th Siege Bty's targets, beginning on 1 April being mainly in 'Battery Valley' (east and north-east of Tilloy ), in the valley of the River Scarpe, and behind 'Orange Hill'. Occasionally the battery also bombarded the villages of Feuchy, Fampoux and Athies. The main bombardment was planned to last for five days (V, W, X, Y and Z) beginning on 4 April. given the mass of guns firing, the area bombarded was divided into small zones without overlapping fire, to help the FOOs spot the fall of shot of their own guns. 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. 135th Siege Bty was badly shelled in the Place Vauban on V day, with the Battery Quartermaster-Sergeant mortally wounded and the Battery Sergeant-Major wounded and evacuated. On Z day 135th Siege Bty was manning the brigade OP, with the FOOs and signallers tasked with following the attacking infantry as closely as possible, jumping off from the same tunnels under Arras and laying out a telephone line as they advanced. The enemy's SOS barrage came down too late, and slackened off as their batteries were captured, the infantry sweeping forward against scattered resistance. VI Corps had captured Orange Hill and the Wancourt–Feuchy lines by the end of the day, an advance of .Becke, Pt 4, pp. 89–98.Becke, Pt 4, pp. 169–74.Falls, 1917, Vol I, pp. 182–5.Farndale, Western Front, pp. 164–71, Map 23.Walters & Hurle Hobbs, pp. 43–50.32nd Bde War Diary, April 1916–July 1916, TNA file WO 95/389/2.