Series I with doorless bomb bays could carry bomb load in the bomb bay and up to in wing cells. Series II, V and VI could carry load on bomb bay and on wing cells and fuselage racks. Series III and IV had the original RAF bomb bays and racks and could carry only load on bomb bay and on wing cells. The bomb bays, bomb bay doors and bomb racks of various series were modified on major overhauls to host bigger bombs.,