Four engineers responded: Edward Serrell, Samuel Keefer, Charles Ellet, Jr., and John Augustus Roebling. All submitted designs for a suspension bridge. At the time of the bidding, Ellet and Roebling were acknowledged as masters of suspension bridge building in America. Roebling submitted two designs, a conservative single-deck suspension bridge and a double-decked version, both with meticulous calculations and drawings. Instead of relying solely on submissions, Charles Ellet, Jr. took a proactive approach. When he got wind of the project in 1845, he wrote to Charles B. Stuart, chief engineer of the Great Western Railway, boldly proclaiming that he could build a bridge for any likely purpose across the Niagara. After the charters had been obtained, Ellet helped Stuart to sell the bridge companies' stock and offered to buy US$30,000 worth of stock himself. His efforts earned him the $190,000 bridge contract on November 9, 1847.