Main Line in Jamaica began in January 1976, and were part of a line sections starting at Archer Avenue near 159th Street and ending about south of South Road near the Atlantic Branch, passing underneath the center of the York College campus. The two tunnels were built by MacLean, Grove and Company for $4.35 million, while the entire segment, Section 5, cost $24,810,955. This section was constructed using the tunneling shield method. The LIRR Main Line structure was heavily reinforced with metal beams and cables to prevent movement, which could have forced a temporary shutdown of the busy line. A continuous monitoring system was put into place and direct communication was maintained with LIRR personnel at track level. This section is below street level and below the LIRR tracks, and was deemed by the MTA's chief engineer to be the most costly and difficult portion of this section of the line. The average width of the two tunnels was . The driving of the two tunnels was expected to begin in September 1975. The first tunnel, the eastern one, was expected to be completed by late February early March 1976. On May 23, 1976, MTA Chairman David Yunich announced that the construction of the two tunnels under the Long Island Rail Road in Jamaica were completed. Work on the entire section was expected to be completed by September 1976. South of these tunnel segments, the line would have been extended south several hundred yards, going up a ramp, and onto the Atlantic Branch's right-of-way at an embankment at Liberty Avenue. Work on this section was expected to begin in the late 1980s, and would have used the Atlantic Branch to Springfield Boulevard, diverting trains to the Montauk Branch. In the interim, the agency planned to use the tracks for train storage. On March 17, 1976, construction began on a -long section of Route 133 underneath the LIRR tracks and the Van Wyck Expressway. The first tunnel between the Jamaica Avenue Elevated and the Archer Avenue subway was holed through in October 1977. The second tunnel connection holing through of the Archer Avenue subway tunnels occurred on December 14, 1977. On October 26, 1979, the groundbreaking for Section 2, which stretched from 144th Street to 147th Place, took place. This section was awarded to Slattery Associate Incorporated and Agrett Enterprise Corporation for $45,251,350, and was constructed using cut-and-cover. This section was