Each boat was anchored at stem and stern with loose cables.
Strong timbers, with cross rafters, were placed upon the boats, upon which heavy frame-work the planked pathway was laid down.

A thick parapet of closely-fitting beams was erected along both the outer edges of the whole fabric.

Thus a continuous and well-fortified bridge, two thousand four hundred feet in length, was stretched at last from shore to shore.
Each of the thirty-two boats on which the central portion of the structure reposed, was a small fortress provided with two heavy pieces of artillery, pointing, the one up, the other down the stream, and manned by thirty-two soldiers and four sailors, defended by a breastwork formed of gabions of great thickness.
The forts of Saint Philip and St.Mary, at either end of the bridge, had each ten great guns, and both were filled with soldiers.

In front of each fort, moreover, was stationed a fleet of twenty armed vessels, carrying heavy pieces of artillery; ten anchored at the angle towards Antwerp, and as many looking down the river.

One hundred and seventy great guns, including the armaments of the boats under the bridge of the armada and the forts, protected the whole structure, pointing up and down the stream.
But, besides these batteries, an additional precaution had been taken.