The New York City Tunnel Authority announced in March 1940 that it would start construction within forty days. Preliminary construction and land acquisition for the Brooklyn approach was already underway. The Army had already approved the tunnel, but due to a minor change in the plan, had to hold another hearing, and the Army was expected to uphold the permit. In May, La Guardia signed a preliminary contract to start construction. Moses stated that he wanted to complete the tunnel, a crucial link in the Circumferential Parkway System, as soon as possible. The RFC granted the city $57 million for the tunnel project later that month. Ole Singstad, the chief engineer of the New York City Tunnel Authority, was commissioned to design the tunnel. As a cost-saving measure, the Tunnel Authority briefly considered constructing the Brooklyn–Battery Tunnel by digging a trench under the East River and then covering it up.