In January 1941, he was appointed Director of the Medical Research Council Physiological Laboratory at the Armoured Fighting Vehicle School at Lulworth, England.

Dr. Solandt joined the Canadian Army in February 1944 with the rank of Colonel and continued as Director of the Army Operational Research Group until 1945 when he was appointed Director of the Operational Research Division, South-East Asia Command, and scientific advisor to Lord Louis Mountbatten, then Commander-in-Chief S.E.A.C.

Returning to England in June 1945, he was soon appointed to the War Office as a member of the joint Military Mission sent to Japan to evaluate the effects of the atomic bomb.

His Chairman position was at the same level as the Canadian Military Chiefs of Staff, and the Deputy Minister of National Defence.

In retirement, Solandt was active as a company director and consultant, specializing in agricultural research in a number of developing countries (e.g., Peru, Kenya and Bangladesh).