During the First World War, the Polytechnic manufactured munitions and gas masks for the war effort and ran courses for the army. After the War, the National Certificate system was taken up, engineering courses were offered to women in the 1920s and printing classes were dropped and run at Morley College. J W Bispham was elected the new Principal in 1922 when C T Millis retired and a rebuilding scheme was undertaken including a new facade for the Borough Road building. Class numbers increased to 8,682 students by 1927 and on 20 February 1930 the Duke of York officially opened the Polytechnic's new buildings. In 1933, Dr D H Ingall took over as Principal and a sports ground at Turney Road Dulwich was obtained for the Polytechnic. In 1933, farriery was dropped as it was too difficult to bring horses into the building.