1/1st West Riding Bty transferred to 28th HAG on 8 August 1917, with which it remained (apart from short attachments) until the end of the war. In August 1917, 28th HAG was supporting Fifth Army in the dreadful Third Ypres Offensive, moving to Second Army when that took over part of the line on 16 September for the artillery-led battles of the Menin Road Ridge, Polygon Wood, Broodseinde and Poelcappelle before the offensive bogged down in the two Battles of Passchendaele. 1/1st West Riding Battery was withdrawn for rest and refitting on 8 November. 28th Brigade reverted to Fourth Army during the winter of 1917–18.