'Action: Capture of Switch Trench, South east of High Wood, 15th September 1916, and following days. I cannot speak too highly of this sappers work as a linesman. He was on duty at the headquarters of the 2nd Auckland and 2nd Otago Battalions during the fighting on the above dates. Though he had numerous difficulties to contend with and working under constant shell fire, he managed to put through not only our own Brigade work but also several messages for the 1st and 3rd Brigades. When the Brigade again went into the front line Sapper Pinkham again carried out his difficult duties with the greatest success, and with an utter disregard for his personal safety. The devotion to duty of the Signal Staff is beyond all praise.'
Source: London Gazette
Date: 9 December 1916

'For conspicuous gallantry and devotion to duty in an attack. All the forward signal party were casualties except himself, but he went forward alone and, finding the battalion commanders together, at once laid out a line to them, working with great coolness on an open slope swept with machine gun fire. He then brought in his officer, who was wounded, and continued the maintenance of the line. He showed the greatest gallantry in the execution of his duty on this and many other occasions.'
Source: London Gazette
Date: 4 March 1918