div class=trans-pagebuttonPage 1button div class=trans-image amp-img class=trans-thumb alt=Page 1: AEROTRAIN - DULLES AIRPORT TRAIN SYSTEMtunneling methods were used to excavate these tunnels The first method called cut and cover was used to excavate approximately 7700 track src=https:reader034fdocumentsinreader034viewer20220420185e75f54bb6a81a325c31723ehtml5thumbnails1jpg width=142 height=106 layout=responsive amp-img divdivdiv class=trans-pagebuttonPage 2button div class=trans-image amp-img class=trans-thumb alt=Page 2: AEROTRAIN - DULLES AIRPORT TRAIN SYSTEMtunneling methods were used to excavate these tunnels The first method called cut and cover was used to excavate approximately 7700 track src=https:reader034fdocumentsinreader034viewer20220420185e75f54bb6a81a325c31723ehtml5thumbnails2jpg width=142 height=106 layout=responsive amp-img divdivdiv class=trans-pagebuttonPage 3button div class=trans-image amp-img class=trans-thumb alt=Page 3: AEROTRAIN - DULLES AIRPORT TRAIN SYSTEMtunneling methods were used to excavate these tunnels The first method called cut and cover was used to excavate approximately 7700 track src=https:reader034fdocumentsinreader034viewer20220420185e75f54bb6a81a325c31723ehtml5thumbnails3jpg width=142 height=106 layout=responsive amp-img divdivdiv class=trans-pagebuttonPage 4button div class=trans-image amp-img class=trans-thumb alt=Page 4: AEROTRAIN - DULLES AIRPORT TRAIN SYSTEMtunneling methods were used to excavate these tunnels The first method called cut and cover was used to excavate approximately 7700 track src=https:reader034fdocumentsinreader034viewer20220420185e75f54bb6a81a325c31723ehtml5thumbnails4jpg width=142 height=106 layout=responsive amp-img divdiv