Queens College and Kissena Boulevard with a later extension to Springfield Boulevard A new Archer Avenue subway line for eastern Queens, running to 188th Street in Hollis A Second Avenue Subway line, with multiple connections to the 63rd Street line This proposal, with some modifications, received approval from the Board of Estimate on September 21, 1968. Construction Plans for the 63rd Street Line were approved by the New York City Board of Estimate on June 3, 1969. Groundbreaking ceremonies for the line took place on November 24, 1969, at Vernon Boulevard and 21st Street in Queensbridge Park, Long Island City. Workers tunneled westward from Queens, as well as in both directions under Roosevelt Island. Four prefabricated sections of the 63rd Street Tunnel were constructed at Port Deposit, Maryland, then towed to New York and sunk under the East River. The first of the tunnel segments was delivered in May 1971 and was lowered into place on August 29, 1971; the last section was lowered on March 14, 1972. The double-deck, tunnel under the East River was "holed through" on October 10, 1972, with the separate sections of tunnels being connected. One section of the line that ran through Central Park was controversial because it called for of cut-and-cover tunneling, which would require digging an open trench through Central Park. In May 1970, Manhattan Community Board 8 held a meeting so constituents could voice concerns about the project's impact. The next month, Mayor John Lindsay told city engineers to write a report that studied ways to reduce the project's impact. The results of the report, released in January 1971, called for using tunnel boring machines underneath Central Park to reduce disruption. In February 1971, the NYCTA published advertisements in newspapers, seeking construction bids for the tunnels under Central Park. After the advertisements had run for three days, the NYCTA withdrew them after community and conservation groups objected. Later that month, the NYCTA finally agreed to halve the width of the proposed -wide cut, which resulted in a proportionate decrease in the area of affected parkland. The NYCTA also agreed to reduce disruption to the Heckscher Playground, located above the proposed subway tunnel's path, by cutting construction time from three years to two years and by constructing a temporary playground nearby. In March, the NYCTA again sought construction bids. The sections that connected to the existing Broadway and Sixth Avenue Lines were