The passage into the harbour was not more than three-quarters of a mile across, and was defended on the north side by a battery of eight brass and twelve iron guns; and on the south by a platform of twenty brass and twenty iron guns, also a stone fort, with a breast-work and deep trench before it, mounting ten guns and manned by five hundred men. There was, from one side of the harbour to the other, a strong boom composed of ships-yards and top masts, fastened together with three-inch rope, and underneath with hawsers and cables. The top-chain at each end was moored to a seventy-gun ship; one the _Hope_, which had been taken from the English, and the other the _Bourbon_. Within the boom were moored five ships, of between sixty and seventy guns each, with their broadsides fronting the entrance of the passage, so as to command any ship that came near the boom, forts, and platform. The admirals removed their flags from the great ships into third-rates, the first- and second-rates being all too big to go in. Sir George Rooke went out of the _Royal Sovereign_ into the _Somerset_; Admiral Hopson out of the _Prince George_ into the _Torbay_; Admiral Fairbourne out of the _St. George_ into the _Essex_; and Admiral Graydon out of the _Triumph_ into the _Northumberland_. A detachment of fifteen English and ten Dutch men-of-war, with all their fire-ships, frigates, and bomb-vessels, was ordered to go upon the service. The Duke of Ormond, to facilitate this attack, landed two thousand five hundred men on the south side of the river, at a distance of about six miles from Vigo; and Lord Shannon, at the head of five hundred men, attacked the stone fort at the entrance of the harbour and made himself master of the platform of forty pieces of cannon. The French governor, M. Sozel, ordered the gates of the fort to be thrown open, resolving to force his way through the English troops. But though there was great bravery, there was but very little judgment in this action, for his order was no sooner obeyed than the grenadiers stormed the place, sword in hand, and forced the garrison, consisting of about three hundred and fifty Frenchmen and Spaniards, to surrender as prisoners of war.