The limbers, caissons, and gun carriages were all constructed of oak. Excavation of the piers and icebreakers was accomplished through the use of caissons. It had a solid masonry superstructure to support the weight of the loaded caissons. Embankments seal a basin where it is not sealed by caissons. Gammon Construction constructed the caissons for the bridge towers. They sit on concrete filled caissons, driven into the lake's bedrock. It lifted boats using a moveable hoist rather than caissons. The French admitted casualties of 1,839 soldiers, one cannon, and two caissons. The platform is rested on caissons, that are drilled underground. The towers rest on underwater caissons made of southern yellow pine. The caissons were manufactured in a shipyard in Williamsburg. The use of suction caissons/anchors has now become common practice worldwide. Each of the two caissons is wide, and can hold up to four canal boats. Both caissons contain interior spaces that were used by construction workers. The distance between the centres of the anchorage caissons is .