67th Siege Bty transferred to 42nd HAG in Fifth Army in the Ypres Salient on 19 May. It was then made up to six howitzers and was joined in June by the personnel of a section from newly-arrived 318th Siege Bty. This battery had been formed at Prees Heath Camp the previous December but the men had trained on 6-inch howitzers. (The other section of 318th reinforced 145th Siege Bty at the same time.) On 29 June the expanded battery switched to 99th HAG in Second Army as Second and Fifth Armies prepared for the forthcoming Third Ypres Offensive. Second Army's role was to provide flank support, but as the campaign bogged down it took over direction of the battle in September. The Battles of the Menin Road, Polygon Wood and Broodseinde were highly successful because of the weight of artillery brought to bear on German positions. But as the offensive continued with the Poelcappelle and First and Second Battles of Passchendaele, the tables were turned: British batteries were clearly observable from the Passchendaele Ridge and were subjected to CB fire, while their own guns sank into the mud and became difficult to aim and fire. 67th Siege Bty had been with 16th HAG from 29 September, then with 1st Canadian HAG from 24 October, supporting the Canadian Corps at Passchendaele to the end of the fighting.