 The tunnel boring machine was originally expected to arrive six to eight months after construction began , but the utility relocation and excavation required to create its " launch box " delayed its deployment until May 2010 . On May 14 , 2010 , MTA 's contractors completed the TBM installation and turned it on at the Second Avenue Subway launch box at 96th Street and boring southward to connecting shafts built at 86th and 72nd Streets . 
