The side spans, between each suspension tower and each side's suspension anchorages, are long. At the time of construction, engineers had not yet discovered the aerodynamics of bridge construction, and bridge designs were not tested in wind tunnels. It was coincidental that the open truss structure supporting the deck is, by its nature, subject to fewer aerodynamic problems. This is because John Roebling designed the Brooklyn Bridge's truss system to be six to eight times as strong as he thought it needed to be. However, due to a supplier's fraudulent substitution of inferior-quality cable in the initial construction, the bridge was reappraised at the time as being only four times as strong as necessary.