To help future landings, the British would develop specialist armoured vehicles for engineers to perform tasks protected by armour. Because the tracks of most of the Churchill tanks were caught up in the shingle beach, the Allies began to study beach geology where they intended to land and adapting vehicles for them. The Allies changed their view that capturing a major port was necessary to establish a second front; the damage inflicted on a port to capture it and by the Germans firing demolition charges would make it useless afterwards. Prefabricated Mulberry harbours were to be built and towed to beaches during the invasion.