The workers building the railroad had huge obstacles to overcome concerning the geographical aspect of the railroad. Getting through the Sierra would be the biggest challenge for the Central Pacific. The Central Pacific had to wait until the summer of the next year to begin their work on the summit of the Sierra. Engineers used a 4-sided approach to tunnel into the mountain and used the Sacramento, the abandoned train to carry debris and rock out. Workers used explosives to blast tunnels from inside to the outside of the mountain. The use of black powder to blast through the mountain was a very taxing task. Chemist James Howden showed up and brought Nitroglycerin which highly improved efficiency. A year after beginning the tunneling project,
