Stone then made additional changes to the design. In a Howe truss bridge, the vertical posts connect the upper and lower chords (main parallels) in the truss. The deck on which the train travels usually hangs from these posts; the greater the live load, the greater the tension on the posts. The bracing reacts in compression, counteracting the tension. Amasa Stone inverted this design so that only the upper chord (now at the bottom of the bridge) provided tension. Where diagonal braces did not receive the extra compression from a live load, inverted Howe truss bridges had a tendency to buckle where the vertical posts were attached to the deck with cast iron angle blocks. Stone's other major change involved the end panels. In the traditional Howe truss bridge, the end panel on each side of each end of the bridge has three vertical posts and three diagonal braces. Only five Howe truss bridges ever built by 1863 had just one vertical post and two diagonal braces in the end panels. These were known as "Single Howe" bridges. Amasa Stone used the "Single Howe" design for the end panels at Ashtabula. Thus, the bridge's entire structure relied on just 12 beams and posts (three at each end).