first work was to build of track from an existing line in the Arkansas flood plains to bring materials in place for construction. When this track was complete, 60 cars of timber waited for delivery. This material was used in building barges used for construction and moving materials into place. The first three months of construction were used to build 15 barges, and a total of 21 barges were needed to complete construction. The next phase of the project involved building massive willow mats. These mats were constructed on the river. When completed, they measured 200 feet x 300 feet. They were floated to the location of the piers (held in place by barges) and sunk to the bottom of the river with rip-rap and stone. The purpose of the willow mats was to reduce scouring, keeping the river bed in place as the pneumatic caissons were dug into the river bed. The Harahan Bridge was to be located north of the Frisco Bridge. Use of pneumatic caissons had been used on the Frisco and other major bridges; this did not eliminate the dangers involved. The Harahan pneumatic caissons were constructed on shore out of wood. The walls were thick, with heavy caulking and tar to make them airtight. The caisson was 40 feet wide x 90 feet long x 60 feet tall. In reality, it was a large wooden box, open at the bottom. The chamber at the bottom of the caisson had a 7-foot ceiling for the sandhogs to work. Digging the river bottoms to sink the caissons into the river bed was difficult and dangerous work. All the material inside the walls of the caisson had to be removed to the surface. The caisson was built with excavation shafts for removing dirt and clay. The pressure was increased to match the water pressure, keeping the river water out of the work area. When the pressure was high enough, the excavation shafts were opened and air pressure would remove the light weight river bottom in a "blow off." This eased the process greatly and saved a tremendous amount of time and effort for the sand hogs. It did, however, make a spectacular sight as a fountain of river bottom erupted from the caisson, it also left quite a mess on the top of it and any barges nearby. As the caissons were being sunk into the riverbed, the