Trench warfare
Trench warfare occurred when a revolution in firepower was not matched by similar advances in mobility, resulting in a grueling form of warfare in which the defender held the advantage. On the Western Front in 1914–1918, both sides constructed elaborate trench, underground, and dugout systems opposing each other along a front, protected from assault by barbed wire, mines, camouflaged trapping pits, and other obstacles. The area between opposing trench lines (known as "no man's land") was fully exposed to artillery fire from both sides. Attacks, even if successful, often sustained severe casualties.
92nd Brigade (United Kingdom)
The brigade was first introduced to trench warfare on 21 March by groups being attached to the 36th (Ulster) Division in the line. On 28 March the 10th and 11th Bns relieved Ulster battalions in front of Beaumont-Hamel and Y Ravine, with 12th and 13th Bns in support. Although this was a quiet sector of the line, the battalions suffered their first casualties during this short tour, mainly from German "Minenwerfer"s (trench mortars). Shortly afterwards 31st Division formed its own light trench mortar batteries (TMBs), with the Hull Pals contributing men to 92/1 and 92/2 TMBs for 92 Bde. 10th Battalion also provided working parties to assist the 252nd Tunnelling Company, Royal Engineers, digging the Hawthorn Ridge mine that was to be exploded to launch the forthcoming Battle of the Somme. Over the next weeks the battalions took their turns in the routine of trench holding, working parties, patrolling and trench raiding, with a constant drain on manpower from shelling and snipers.