and the Brooklyn Rapid Transit Company (BRT) was to operate on Lexington Avenue. The IRT submitted an offer for what became its portion of the Dual Contracts on February 27, 1912. Soon after the IRT submitted its offer for the Dual Contracts, construction was halted on Section 6. The contracts were formalized in early 1913, specifying new lines or expansions to be built by the IRT and the BRT. Steinway Tunnel The Dual Contracts involved opening the Steinway Tunnel as part of the new Flushing subway line. The route, traveling under 41st and 42nd Streets in Manhattan, was to go from Times Square through the tunnel over to Long Island City and from there continue toward Flushing. The tunnel, with trolley loops on both the Manhattan and Queens sides, had sat unused since 1907, when test runs had been performed in the then-nearly-complete tunnel. The Manhattan trolley loop was near the Grand Central station. The Flushing Line platform was the first Dual Contracts improvement to be completed at Grand Central, opening on June 22, 1915. On August 31, 1916, a passageway connecting the Flushing Line platform with the rest of the subway station was opened with an inspection tour; it was opened to the public in the following days. The new passageway connected the station's eastern mezzanine with the Flushing Line platform via ramp and a pair of elevators. This was part of a ramp that the Public Service Commission had hoped to use to connect the Steinway Tunnel to the 42nd Street Line. "H" system Also as part of the Dual Contracts, the construction of the Lexington Avenue Line, in conjunction with the construction of the Broadway–Seventh Avenue Line, would change the operations of the IRT system. Instead of having trains go via Park Avenue, turning onto 42nd Street, before finally turning onto Broadway, there would be two trunk lines connected by the 42nd Street Shuttle. The system would be changed from looking like a "Z" system to an "H"-shaped system. One trunk would run via the new Lexington Avenue Line down Park Avenue, and the other trunk would run via the new Seventh Avenue Line up Broadway. It was predicted that the subway extension would lead to the growth of the Upper East Side and the Bronx. To reduce the transfer between the eastern end of the original line's station and the new Lexington Avenue Line station, a