 Group Two , under the command of Captain Burn , would land at the old entrance to the St Nazaire basin . Their objectives were to destroy the anti @-@ aircraft positions in the area and the German headquarters , to blow up the locks and bridges at the old entrance into the basin and then to guard against a counter @-@ attack from the submarine base . Group Three was under the command of Major William ' Bill ' Copland , who was also the Commandos ' second in command . They were to secure the immediate area around Campbeltown , destroy the dock 's water @-@ pumping and gate @-@ opening machinery and the nearby underground fuel tanks . All three groups were subdivided into assault , demolition and protection teams . The assault teams would clear the way for the other two . The demolition teams carrying the explosive charges only had <unk> for self @-@ defence ; the protection teams , armed with Thompson <unk> guns , were to defend them while they completed their tasks . 
