At 7:00 am on 8 September 1782 the bombardment commenced, concentrating mainly on the western parallel of the Spanish siege works. Supporting the heavy guns were the field artillery and other types of British guns. Within a few hours of intense bombardment the results became apparent and soon exceeded the garrison's expectations. The Mahon battery along with conjoining works were set on fire. The other batteries, San Carlos and San Martín, were heavily damaged and had to be partly dismantled by French and Spanish pioneers.